Arctic Sea Ice : Forum

Cryosphere => Permafrost => Topic started by: kassy on January 16, 2019, 02:42:56 PM

Title: Permafrost general science thread
Post by: kassy on January 16, 2019, 02:42:56 PM
I decided to make a new thread for general science on permafrost because the other threads are about either methane or snow cover or really specific issues.


*

The pace at which the world's permafrost soils are warming

As the new global comparative study conducted by the international permafrost network GTN-P shows, in all regions with permafrost soils the temperature of the frozen ground at a depth of more than 10 metres rose by an average of 0.3 degrees Celsius between 2007 and 2016 - in the Arctic and Antarctic, as well as the high mountain ranges of Europe and Central Asia. The effect was most pronounced in Siberia, where the temperature of the frozen soil rose by nearly 1 degree Celsius. The pioneering study has just been released in the online journal Nature Communications.

...

The complete dataset encompasses 154 boreholes, 123 of which allow conclusions to be drawn for an entire decade, while the remainder can be used to refine calculations on annual deviation. The results show that, in the ten years from 2007 to 2016, the temperature of the permafrost soil rose at 71 of the 123 measuring sites; in five of the boreholes, the permafrost was already thawing. In contrast, the soil temperature sank at 12 boreholes, e.g. at individual sites in eastern Canada, southern Eurasia and on the Antarctic Peninsula; at 40 boreholes, the temperature remained virtually unchanged.

...

The researchers observed the most dramatic warming in the Arctic: "There, in regions with more than 90 percent permafrost content, the soil temperature rose by an average of 0.30 degrees Celsius within ten years," reports first author Dr Boris Biskaborn, a member of the research group Polar Terrestrial Environmental Systems at the Potsdam facilities of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research. In northeast and northwest Siberia, the temperature increase at some boreholes was 0.90 degrees Celsius or even higher. For the sake of comparison: the air temperature in the respective regions rose by an average of 0.61 degrees Celsius in the same period.

Farther south, in Arctic regions with less than 90 percent permafrost, the frozen ground only warmed by 0.2 degrees Celsius on average. "In these regions there is more and more snowfall, which insulates the permafrost in two ways, following the igloo principle: in winter the snow protects the soil from extreme cold, which on average produces a warming effect. In spring it reflects the sunlight, and prevents the soil from being exposed to too much warmth, at least until the snow has completely melted away," Biskaborn explains.

Significant warming can also be seen in the permafrost regions of the high mountain ranges, and in the Antarctic. The temperature of the permanently frozen soils in the Alps, in the Himalayas and in the mountain ranges of the Nordic countries rose by an average of 0.19 degrees Celsius. In the shallow boreholes in the Antarctic, the researchers measured a rise of 0.37 degrees.

for full details:
https://www.eurekalert.org/pub_releases/2019-01/awih-tpa011519.php
Title: Re: Permafrost general science thread
Post by: Bernard on January 16, 2019, 11:35:54 PM
I just read the quoted article at phys.org
https://phys.org/news/2019-01-pace-world-permafrost-soils.html
One thing I was wondering is if similar studies are conducted in other places than permafrost. We have measures of sea water temperatures at different depths, but the global warming should also be measured in mean temperatures of underground, at depths where the temperature is stable year-round (about 10-20m if what I read is correct), whether this underground is frozen or not.
This is a bit off-topic, please point me to an existing thread if any.

Meanwhile, I created one such topic
https://forum.arctic-sea-ice.net/index.php/topic,2548.0.html
Title: Re: Permafrost general science thread
Post by: wdmn on April 16, 2019, 02:09:13 AM
Warming Arctic permafrost releasing large amounts of potent greenhouse gas

Quote
A recent study shows that nitrous oxide emissions from thawing Alaskan permafrost are about twelve times higher than previously assumed. About one fourth of the Northern Hemisphere is covered in permafrost, which is thawing at an increasing rate. As temperatures increase, the peat releases more and more greenhouse gases. And, even though researchers are monitoring carbon dioxide and methane, no one seems to be watching the most potent greenhouse gas: nitrous oxide.

https://www.sciencedaily.com/releases/2019/04/190415090848.htm
Title: Re: Permafrost general science thread
Post by: DaveHitz on April 16, 2019, 02:43:27 AM
Quote
A recent study shows that nitrous oxide emissions from thawing Alaskan permafrost are about twelve times higher than previously assumed.

This is clearly no laughing matter...
Title: Re: Permafrost general science thread
Post by: gerontocrat on April 23, 2019, 03:06:30 PM
A new study says the release of methane and carbon dioxide from thawing permafrost will accelerate global warming and add up to $70tn (£54tn) to the climate bill. Tried to find the article and failed. See summary from the guardian way down below or go to ...https://www.theguardian.com/environment/2019/apr/23/melting-permafrost-in-arctic-will-have-70tn-climate-impact-study

But I did find instead
https://www.nature.com/articles/s41467-018-08.240-4 that shows worrying increases in the temperature of permafrost all over the Arctic

Permafrost is warming at a global scale
Quote
Abstract
Permafrost warming has the potential to amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007–2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39 ± 0.15 °C. .....
Introduction
Carbon release resulting from permafrost degradation will potentially impact the Earth’s climate system because large amounts of carbon previously locked in frozen organic matter will decompose into carbon dioxide and methane. This process is expected to augment global warming by 0.13–0.27 °C by 2100 and by up to 0.42 °C by 2300. Despite this, permafrost change is not yet adequately represented in most of the Earth System Models14 that are used for the IPCC projections for decision makers. One major reason for this was the absence of a standardized global data set of permafrost temperature observations for model validation.
________________________________________________

Melting permafrost in Arctic will have $70tn climate impact - study
Study shows how destabilised natural systems will worsen man-made problem

Quote
Jonathan Watts Global environment editor

The release of methane and carbon dioxide from thawing permafrost will accelerate global warming and add up to $70tn (£54tn) to the world’s climate bill, according to the most advanced study yet of the economic consequences of a melting Arctic.

If nations fail to improve on their current Paris agreement commitments, this feedback mechanism combined with a loss of heat-deflecting white ice will cause a near 5% amplification of global warming and its associated costs, says the paper, which was published on Tuesday in Nature Communications.

The authors say their study is the first to calculate the economic impact of permafrost melt and reduced albedo – a measure of how much light that hits a surface is reflected without being absorbed – based on the most advanced computer models of what is likely to happen in the Arctic as temperatures rise. It shows how destabilised natural systems will worsen the problem caused by man-made emissions, making it more difficult and expensive to solve.

They assessed stocks of CO2 and methane trapped in the permafrost by using samples taken from a depth of three metres at multiple points across the Arctic. These were run through the world’s most advanced climate simulation software in the US and at the UK Met Office to predict how much gas will be released at different levels of warming. Even with supercomputers, the number crunching took weeks because the vast geography and complex climate interactions of the Arctic throw up multiple variables. The researchers then applied previous economic impact models to assess the likely costs.

Permafrost melt is the main concern. Greenhouse gases, which have been frozen below the soil for centuries, have already begun to escape at the current level of 1 degrees Celsius of global heating. So far the impact is small. Ten gigatonnes of CO2 have been released from the ice but this source of emissions will grow rapidly once temperatures rise beyond 1.5C.

On the current trajectory of at least 3C of warming by the end of the century, melting permafrost is expected to discharge 280 gigatonnes of carbon dioxide and 3 gigatonnes of methane, which has a climate effect that is 10 to 20 times stronger than CO2.

This would increase the global cost of destruction, adaptation and emissions reduction by $70tn between now and 2300. This is 10 times higher than the projected benefits from a melting Arctic, such as easier navigation for ships and access to minerals, says the paper.
Title: Re: Permafrost general science thread
Post by: Sleepy on April 23, 2019, 03:26:42 PM
^--> https://www.nature.com/articles/s41467-019-09863-x (https://www.nature.com/articles/s41467-019-09863-x)
Title: Re: Permafrost general science thread
Post by: gerontocrat on April 23, 2019, 04:34:14 PM
^--> https://www.nature.com/articles/s41467-019-09863-x (https://www.nature.com/articles/s41467-019-09863-x)
Thanks, Sleepy.
Title: Re: Permafrost general science thread
Post by: vox_mundi on May 03, 2019, 05:25:08 AM
Permafrost is Thawing in the Arctic So Fast Scientists are Losing Their Equipment   
https://www.cbc.ca/amp/1.5119767
https://phys.org/news/2019-04-rapid-permafrost-unrecognized-threat-landscape.html

Permafrost in some areas of the Canadian Arctic is thawing so fast that it's gulping up the equipment left there to study it.

"The ground thaws and swallows it," said Merritt Turetsky, a University of Guelph biologist whose new research warns the rapid thaw could dramatically increase the amounts of greenhouse gases released from ancient plants and animals frozen within the tundra.

Quote
...  "We've put cameras in the ground, we've put temperature equipment in the ground, and it gets flooded. It often happens so fast we can't get out there and rescue it.

"We've lost dozens of field sites. We were collecting data on a forest and all of a sudden it's a lake."

(https://media.nature.com/w800/magazine-assets/d41586-019-01313-4/d41586-019-01313-4_16683720.jpg)

Nearly one-fifth of Arctic permafrost is now vulnerable to rapid warming, Turetsky's paper suggests. Plenty of it is in Canada, such as in the lowlands south of Hudson Bay.

Soil analysis found those quickly thawing areas also contain the most carbon. Nearly 80 per cent of them hold at least 70 kilograms of carbon per cubic metre.

That suggests permafrost is likely to release up to 50 per cent more greenhouse gases than climate scientists have believed. As well, much of it will be released as methane, which is about 30 per cent more efficient at trapping heat than carbon dioxide.


Open Access: Merritt R. Turetsky et al. Permafrost collapse is accelerating carbon release (https://www.nature.com/articles/d41586-019-01313-4), Nature (2019)
Title: Re: Permafrost general science thread
Post by: vox_mundi on May 23, 2019, 01:59:44 PM
Widespread Permafrost Degradation Seen In High Arctic Terrain
https://phys.org/news/2019-05-widespread-permafrost-degradation-high-arctic.html

A McGill-led study published recently in Environmental Research Letters presents close to 30 years of aerial surveys and extensive ground mapping of the Eureka Sound Lowlands area of Ellesmere and Axel Heiberg Islands located at approximately 80 °N. The research focuses on a particular landform (known as a retrogressive thaw slump) that develops as the ice within the permafrost melts and the land slips down in a horseshoe-shaped feature. The presence of these landforms is well documented in the low Arctic.

... "Our study suggests that the warming climate in the high Arctic, and more specifically the increases in summer air temperatures that we have seen in recent years, are initiating widespread changes in the landscape," says Melissa Ward Jones, the study's lead author and a Ph.D. candidate in McGill's Department of Geography.

(https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/2019/widespreadpe.jpg)

The research team noted that:

- There has been a widespread development of retrogressive thaw slumps in high Arctic polar deserts over a short period, particularly during the unusually warm summers of 2011, 2012 and 2015;

- That the absence of vegetation and layers of organic soil in these polar deserts make permafrost in the area particularly vulnerable to increases in summer air temperatures;

- Despite its relatively short duration, the thaw season (which lasts for just 3-6 weeks a year) initially drives the development of slumps and their later expansion in size, as their headwall retreats; and

- Over a period of a few years after the initiation of slumps, study results suggest various factors related to terrain (e.g. slope) become more important than air temperature in maintaining active slumps


Open Access: Melissa K Ward Jones et al, Rapid initialization of retrogressive thaw slumps in the Canadian high Arctic and their response to climate and terrain factors (https://iopscience.iop.org/article/10.1088/1748-9326/ab12fd), Environmental Research Letters (2019)
Title: Re: Permafrost general science thread
Post by: Juan C. García on May 26, 2019, 06:24:11 AM
I haven’t followed the heat on land too much, but it seems that it is going to be pretty bad this year.
Title: Re: Permafrost general science thread
Post by: Shared Humanity on May 26, 2019, 04:05:33 PM
Going to start hanging out here as I feel permafrost is neglected when it comes to discussing the cryosphere.
Title: Re: Permafrost general science thread
Post by: Rod on June 11, 2019, 05:12:54 AM
I am sorry I can't post links from Twitter from my phone.  There might be a way but I can't figure out how.

That said, go check out Zack's link to this paper if you are interested in permafrost. They say "Observed maximum thaw depths at our sites are already exceeding those projected to occur by 2090 under RCP 4.5."

 Seems pretty important.  I would be interested in hearing you thoughts on the research.
Title: Re: Permafrost general science thread
Post by: kassy on June 11, 2019, 06:58:22 AM
Thanks!

This is a clickable version of the link:
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL082187

Another hint that we are underestimating the damage we are doing...i am pretty sure that the anomalously warm summers will be the new normal.

Title: Re: Permafrost general science thread
Post by: Viggy on June 11, 2019, 07:26:57 AM
Glad this thread was started! I've long felt that the effects of permafrost collapse and and the rate at which it can happen have been grossly underestimated. This just came across my news feed today -

Arctic death spiral speeds up sixfold, driving coastal permafrost collapse
https://thinkprogress.org/arctic-death-spiral-coastal-permafrost-collapse-23d650acea99/ (https://thinkprogress.org/arctic-death-spiral-coastal-permafrost-collapse-23d650acea99/)

Quote
They found that during a 40-day period in the summer of 2017, the coast had retreated a remarkable 47 feet — with daily rates of collapse sometimes exceeding 3 feet.

Think about how insane that rate of loss is!
Title: Re: Permafrost general science thread
Post by: kassy on June 12, 2019, 03:13:46 PM
Carbon dioxide sources from Alaska driven by increasing early winter respiration from Arctic tundra

We find that tundra ecosystems were a net source of CO2 to the atmosphere annually, with especially high rates of respiration during early winter (October through December). Long-term records at Barrow, AK, suggest that CO2 emission rates from North Slope tundra have increased during the October through December period by 73% ± 11% since 1975, and are correlated with rising summer temperatures. Together, these results imply increasing early winter respiration and net annual emission of CO2 in Alaska, in response to climate warming.

https://www.pnas.org/content/114/21/5361

Linked in the article above. The data is from 2012 to 2014 but I thought I would add it here just to show how bad our baseline is.
Title: Re: Permafrost general science thread
Post by: Rod on June 15, 2019, 12:24:11 AM
If you are feeling down because of methane and CO2 releases from melting permafrost, maybe a little laughing gas will cheer you up?  :-\

No laughing matter

https://news.harvard.edu/gazette/story/2019/06/harvard-chemist-permafrost-n2o-levels-12-times-higher-than-expected/

Title: Re: Permafrost general science thread
Post by: kassy on June 15, 2019, 05:30:10 PM
Thanks Rod.

Good article, not so good news. A couple of snippits copied below:

a paper published this month in the journal Atmospheric Chemistry and Physics shows that nitrous oxide emissions from thawing Alaskan permafrost are about 12 times higher than previously assumed. Since N2O traps heat nearly 300 times more efficiently than carbon dioxide does, this revelation could mean that the Arctic — and the global climate — are in more danger than we thought.

“The assumption is that these permafrost soils are so cold there wouldn’t be much microbial activity,” Wilkerson said. “Until 2009 there was no indication by any study whatsoever that emissions could actually be quite large in permafrost regions.”

the paper:
https://www.atmos-chem-phys.net/19/4257/2019/

Title: Re: Permafrost general science thread
Post by: Tom_Mazanec on June 15, 2019, 08:37:39 PM
Permafrost melting 70 years early:
https://weather.com/science/environment/news/2019-06-14-permafrost-melting-sooner
and https://www.independent.co.uk/news/world/americas/climate-change-breakdown-arctic-frost-thawing-canada-environment-a8959056.html?utm_source=reddit.com
and https://www.theguardian.com/environment/2019/jun/18/arctic-permafrost-canada-science-climate-crisis and
https://www.reuters.com/article/us-climate-change-permafrost/scientists-amazed-as-canadian-permafrost-thaws-70-years-early-idUSKCN1TJ1XN?utm_source=reddit.com

EDIT: AGW thawing the landscape glue:
https://www.cbc.ca/news/canada/north/the-national-permafrost-thaw-inuvik-tuktoyaktuk-1.5179842
The permafrost nightmare:
https://www.counterpunch.org/2019/06/10/the-permafrost-nightmare-turns-more-real/

EDIT 2:
Still more on 70 years early:
https://www.truthdig.com/articles/the-earth-may-have-already-passed-a-critical-tipping-point/
Title: Re: Permafrost general science thread
Post by: kassy on June 19, 2019, 02:04:58 PM
Short quote from the first of the three links above:

Quote
A new study published this week in the journal Geophysical Research Letters revealed that unusually warm summers in the Canadian High Arctic between 2003 and 2016 resulted in permafrost melt up to 240% higher than previous years.
Louise Farquharson, a researcher at the Permafrost Laboratory at the University of Alaska Fairbanks and the study's lead author, told weather.com the three areas of melting permafrost studied in remote northern Canada are believed to have been frozen for thousands of years.
“This change is unprecedented on this kind of time scale,” Farquharson said.
She noted that while scientists had predicted the permafrost wouldn't melt for another 70 years, those forecasts didn't take into account the unusually warm summers that have happened in recent years.
Title: Re: Permafrost general science thread
Post by: Ken Feldman on June 25, 2019, 09:56:48 PM
This study was published in 2016, it indicates that "observed short‐term temperature sensitivity from the Arctic will have little impact on the global atmospheric CH4 budget in the long term if future trajectories evolve with the same temperature sensitivity".

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL069292 (https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL069292)

Quote
No significant increase in long‐term CH4 emissions on North Slope of Alaska despite significant increase in air temperature

Colm Sweeney, Edward Dlugokencky, Charles E. Miller, Steven Wofsy, Anna Karion, Steve Dinardo

Abstract
 

Continuous measurements of atmospheric methane (CH4) mole fractions measured by NOAA's Global Greenhouse Gas Reference Network in Barrow, AK (BRW), show strong enhancements above background values when winds come from the land sector from July to December from 1986 to 2015, indicating that emissions from arctic tundra continue through autumn and into early winter. Twenty‐nine years of measurements show little change in seasonal mean land sector CH4 enhancements, despite an increase in annual mean temperatures of 1.2 ± 0.8°C/decade (2σ). The record does reveal small increases in CH4 enhancements in November and December after 2010 due to increased late‐season emissions. The lack of significant long‐term trends suggests that more complex biogeochemical processes are counteracting the observed short‐term (monthly) temperature sensitivity of 5.0 ± 3.6 ppb CH4/°C. Our results suggest that even the observed short‐term temperature sensitivity from the Arctic will have little impact on the global atmospheric CH4 budget in the long term if future trajectories evolve with the same temperature sensitivity.
Title: Re: Permafrost general science thread
Post by: Ken Feldman on June 25, 2019, 10:01:26 PM
The following paper, published in 2019, indicates that changes to wetlands will have more of an impact on the global methane concentrations than the thawing permafrost.

https://www.mdpi.com/2073-4433/10/4/187/htm (https://www.mdpi.com/2073-4433/10/4/187/htm)

Quote
Anthropogenic and Natural Factors Affecting Trends in Atmospheric Methane in Barrow, Alaska

Christopher Lawrence 1 and Huiting Mao 2,*
1 Atmospheric Sciences Research Center, State University of New York University at Albany, Albany, NY 12203, USA
2 Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA
* Author to whom correspondence should be addressed.

Received: 5 February 2019 / Accepted: 29 March 2019 / Published: 5 April 2019

Abstract: This study examined the long-term trends in Arctic ambient methane (CH4) mixing ratios over 1986–2014 and investigated their potential causes. Significant correlations between carbon monoxide (CO) and CH4 in Barrow, Alaska (r = −0.59, p = 0.007) and Alert, Canada (r = −0.62, p = 0.004) with the strongest correlations occurring in April (r = −0.81, p = 0.000, and r = −0.80, p = 0.000) suggest local to global anthropogenic contributions to ambient CH4 during the cold months. Backward trajectories indicate a significant influence (27% of total trajectories) of local emissions from the Prudhoe Bay Oil Field on ambient CH4 in Barrow in winter, and this influence was dominated by other factors in summer. The mean CH4 wetland emission flux in Barrow over 1986–2014 was estimated to be 0.008 ± 0.002 µg m−2 s−1 while in Tiksi, Russia it was 0.010 µg m−2 s−1 over 2012–2016, which is comparable to the lower end of measurements in the literature. Note that in Barrow, there was a decrease in wetland flux from 0.0083 ± 0.002 µg m−2 s−1 over 1986–1998 to 0.0077 ± 0.002 µg m−2 s−1 from 1999–2006 followed by an increase to 0.0081 ± 0.002 µg m−2 s−1 over 2007–2014. Although the difference between the three values is not statistically significant due to small sample size, it is indicative of possible warm season wetland emissions contributing to the zero-growth period. Strong support for this hypothesis is that these changes are consistent with a concurrent drop in summertime temperature possibly causing a decrease in wetland emissions over 1998–2006 based on the statistically significant correlations between temperature and CH4 during August through November (r ~ 0.36–0.56, p = ≤0.05). In a warming climate, permafrost thawing can increase CH4 wetland emissions and also decrease wetlands making it a complex problem, and, hence, further study is needed to better understand the mechanisms driving long-term trends in Arctic CH4.

Quote
. Summary

This study investigated factors affecting Arctic atmospheric CH4 in Barrow, Alaska along with comparison sites in Alert, Canada, Summit, Greenland, and Tiksi, Russia. During the winter, Barrow and Alert see a significant correlation between CO and CH4 concentrations, indicative of anthropogenic influences. Cluster Analysis of backward trajectories during the winter suggested transport of CH4 from the Eurasian Continent and significant contribution from the Prudhoe Bay Oil Field. The amplitude of the annual cycle of CH4 has decreased over time due to increasing summertime annual minimums indicating increasing wetland emissions of CH4. Wetland fluxes between May and July in Barrow and Tiksi were estimated to be 0.005 µg m−2 s−1 and 0.006 µg m−2 s−1, respectively, while fluxes between June and July were 0.011 µg m−2s−1 and 0.014 µg m−2s−1. These fluxes are near the lower end of the range of ones from in situ field measurement studies. Wetland emission fluxes were estimated to be 0.0083 µg m−2s−1 before, 0.0077 µg m−2s−1 during, and 0.0081 µg m−2s−1 after the CH4 growth rate plateau (1998–2006). Although the difference between these three periods is not statistically significant, it indicates that reduced wetland emissions in the Arctic linked to cooler temperature may have played a role in the CH4 plateau during 1998–2006. This hypothesis was supported by a correlation (r = 0.37–0.56, p = 0.05–0.00) between temperature and CH4 over August–November. As the planet continues to warm, global wetlands, including Arctic wetlands, are likely to play a growing role in increasing CH4 concentrations. It has been estimated that global wetland CH4 emissions could increase by 33–60% [55] or as high as 80–110% [56] by the year 2100. However, with the potential decrease of Arctic wetlands due to permafrost loss, CH4 emissions may decrease in the Arctic long term [33]. The complexity of how Arctic wetland emissions of CH4 would respond to a warming climate warrants further study.
Title: Re: Permafrost general science thread
Post by: longwalks1 on June 26, 2019, 03:48:45 PM
Although the paper above does not have many authors, it does appear close to the multi-authoured similar paper

No significant increase in long-term CH 4 emissions on North
Slope of Alaska despite significant increase in air temperature
Colm Sweeney 1,2 , Edward Dlugokencky 2 , Charles E. Miller 3 , Steven Wofsy 4 , Anna Karion 1,2,5 ,
Steve Dinardo 3 , Rachel Y.-W. Chang 6 , John B. Miller 2 , Lori Bruhwiler 2 , Andrew M. Crotwell 1,2 ,
Tim Newberger 1,2 , Kathryn McKain 1,2 , Robert S. Stone 7 , Sonja E. Wolter 1,2 , Patricia E. Lang 2 , and
Pieter Tans 2

 Geophys. Res. Lett., 43, doi:10.1002/2016GL069292.

I have not gone back to the original posts about this paper in the forum.       What struck me in the 2016 paper and is repeated here is the wide variability on numbers due to wind direction, especially from the drilling sites (Prudhoe Bay).

The 2016 study concluded with the need for more sampling sites  and more study, 2019, more study. 

However CARVE is no longer with us and much funding for study in Alaska has been carved out of the budget. 
Title: Re: Permafrost general science thread
Post by: kassy on June 26, 2019, 03:53:56 PM
Just a reminder there is an arctic methane thread so it's probably best to put the CH4 stuff there.
https://forum.arctic-sea-ice.net/index.php/topic,12.0.html

Title: Re: Permafrost general science thread
Post by: Stephan on June 30, 2019, 01:09:04 PM
Please find a new video by the "JUST HAVE A THINK" series on permafrost (focus on ESS shelf)
https://www.youtube.com/watch?v=osmzTSYRJJE
Title: Re: Permafrost general science thread
Post by: kassy on June 30, 2019, 05:13:48 PM
That one should go in the methane thread linked above since it is exactly on topic there.
Title: Re: Permafrost general science thread
Post by: vox_mundi on July 03, 2019, 04:58:09 PM
Scientists Find Thawing Permafrost Releasing Carbon at Higher Rates than Previously Thought   
https://phys.org/news/2019-07-scientists-carbon-permafrost-atmosphere-higher.html

... "This study was novel because we used new methods to directly track the soil carbon losses, and they were much higher than we previously thought," Schuur said. "This suggests that not only is carbon being lost through greenhouse gases directly to the atmosphere but also dissolved in waters that flow through the soil and likely carried carbon into streams, leaves and rivers."   

... According to the study, 5 to 15 percent of the soil carbon held in the permafrost could be released into the atmosphere by the end of the century, using the original scenario. The modeling exercise the research team used to compare agreed with the observations but suggests that the loss rate could be twofold or more higher. (I.e. >10-30%)

César Plaza et al. Direct observation of permafrost degradation and rapid soil carbon loss in tundra (https://www.nature.com/articles/s41561-019-0387-6), Nature Geoscience (2019)
Title: Re: Permafrost general science thread
Post by: b_lumenkraft on July 03, 2019, 05:03:31 PM
Ugh!

In Germany we have that saying "Die Einschläge kommen näher", translates to 'the woofs are coming closer'.
Title: Re: Permafrost general science thread
Post by: vox_mundi on July 03, 2019, 05:35:09 PM
'Die Einschläge' Indeed! 

30% of 1.5 trillion tons (of C) doesn't leave much for us humans to muck around with.
Title: Re: Permafrost general science thread
Post by: jai mitchell on July 03, 2019, 05:56:21 PM
This 500 GtC is in addition to the carbon emitted under RCP 8.5 emissions scenario.
Title: Re: Permafrost general science thread
Post by: wdmn on July 03, 2019, 06:03:29 PM
This 500 GtC is in addition to the carbon emitted under RCP 8.5 emissions scenario.

And according to pricing recently referred to by James Hansen, 500GtC would cost about 200-400 trillion dollars to remove from the atmosphere.
Title: Re: Permafrost general science thread
Post by: vox_mundi on July 08, 2019, 10:52:57 PM
Rising Tundra Temperatures Create Worrying Changes in Microbial Communities
https://phys.org/news/2019-07-tundra-temperatures-microbial.html

Rising temperatures in the tundra of the Earth's northern latitudes could affect microbial communities in ways likely to increase their production of greenhouse gases methane and carbon dioxide, a new study of experimentally warmed Alaskan soil suggests.

"We saw that microbial communities respond quite rapidly—within four or five years—to even modest levels of warming," said Kostas T. Konstantinidis, the paper's corresponding author and a professor in the School of Civil and Environmental Engineering and the School of Biological Sciences at the Georgia Institute of Technology.

"Microbial species and their genes involved in carbon dioxide and methane release increased their abundance in response to the warming treatment. We were surprised to see such a response to even mild warming."

Eric R. Johnston el al., "Responses of tundra soil microbial communities to half a decade of experimental warming at two critical depths," (https://www.pnas.org/content/early/2019/07/02/1901307116) PNAS (2019).
Title: Re: Permafrost general science thread
Post by: Tom_Mazanec on July 16, 2019, 03:31:06 PM
Still more on the 70 years earlier than expected:
https://www.theguardian.com/environment/2019/jun/18/arctic-permafrost-canada-science-climate-crisis?CMP=share_btn_tw
Title: Re: Permafrost general science thread
Post by: Rod on July 29, 2019, 05:25:09 AM
“More thawing weather . . . this summer than any in the past century.”  I’m not sure, but that sounds bad. 🤔
Title: Re: Permafrost general science thread
Post by: morganism on July 29, 2019, 09:30:55 AM
Pluto’s ocean is capped and insulated by gas hydrates

"Clathrate hydrates act as a thermal insulator, preventing the ocean from completely freezing while keeping the ice shell cold and immobile. The most likely clathrate guest gas is methane, derived from precursor bodies and/or cracking of organic materials in the hot rocky core. Nitrogen molecules initially contained and/or produced later in the core would probably not be trapped as clathrate hydrates, instead supplying the nitrogen-rich surface and atmosphere. The formation of a thin clathrate hydrate layer cap to a subsurface ocean may be an important generic mechanism to maintain long-lived subsurface oceans in relatively large but minimally heated icy satellites and Kuiper belt objects.

https://www.nature.com/articles/s41561-019-0369-8
Title: Re: Permafrost general science thread
Post by: kassy on July 29, 2019, 05:52:58 PM
Could you move that last one into this subforums methane thread? Thx.

https://forum.arctic-sea-ice.net/index.php/topic,12.0.html
Title: Re: Permafrost general science thread
Post by: vox_mundi on August 01, 2019, 05:22:23 PM
Researchers Calculate Soil Freezing Depth from Satellite Data
https://phys.org/news/2019-08-soil-depth-satellite.html

A team of researchers from the Space Research Institute of the Russian Academy of Sciences (RAS), the Institute for Water and Environmental Problems of the Siberian Branch of RAS, and the Moscow Institute of Physics and Technology (MIPT) has proposed a way to determine soil freezing depth based on satellite microwave radiometry. The findings were published in Studying the Earth From Space, a Russian-language journal of RAS.

... "This method has many advantages: gathering data from large areas independently from solar lighting and atmospheric conditions, a high frequency of observation in the high latitudes, sensitivity to subterranean processes, and relative cheapness," said Associate Professor Vasiliy Tikhonov from the space physics department at MIPT, who is also a senior researcher at the Space Research Institute of RAS. "We tested the method's reliability on the Kulunda Plain, a vast steppe in the southeast of Russia's West Siberian Plain. To this end, we compared satellite microwave radiometry data with the actual soil parameters and climate indicators measured on location at weather stations."

(https://lh4.googleusercontent.com/H2CcqOYqA9c_1sM8CdjUFVGjP1-P2zAIqsybAc3hTU3QcCf_rIIRc6wghAxT8WlU53ZhLIU5x-c2e7cyDM_YDTAgEB541uhsU2yuY2AqZx_TYGaE9NMAJNJUCEwY3tigViblexO8)
Figure 1. Frozen soil layer thickness, as measured and calculated using the model. The digits 1 through 4 indicate four studied areas on the Kulunda Plain in Altai Krai, Russia. The black symbols correspond to directly measured values, and the red triangles stand for calculated values.

... It turned out that identical sets of satellite data may correspond to different soil freezing depths. The additional factors at play are soil moisture, salinity, and composition, which can all affect the soil's capacity for microwave emission. The researchers also found that one-time radiometric observations do not produce reliable results, because radio waves may reflect at the interface between the frozen and unfrozen soil.

The team accounted for these findings in their calculations, proposing a method that determines soil freezing depth with a high accuracy based on the data from the Soil Moisture and Ocean Salinity (SMOS) satellite. To remotely determine soil freezing depth, the researchers employed daily series of thermal emission measurements, along with their own emission model that incorporates soil characteristics. The time period considered in the study began with the date of freezing, defined as a spike in thermal radiation picked up by the satellite. It ended with the first thaw day, when the amount of thermal radiation dropped sharply.


Open Access: D. A. Boyarskii et al. On evaluation of depth of soil freezing based on SMOS satellite data (https://journals.eco-vector.com/0205-9614/article/view/12723), Исследования Земли из Космоса (2019)

-------------------------

SMOS detects freezing soil as winter takes grip
https://phys.org/news/2011-12-smos-soil-winter.html
Title: Re: Permafrost general science thread
Post by: gerontocrat on August 23, 2019, 02:10:47 PM
A really good introduction to what is happening to the 9 million square miles (23.3 million km2) of the Arctic that is storing 1,600 billion tons of carbon.

https://www.nationalgeographic.com/environment/2019/08/arctic-permafrost-is-thawing-it-could-speed-up-climate-change-feature/

Arctic permafrost is thawing fast. That affects us all.
As the frozen ground warms much faster than expected, it’s reshaping the landscape—and releasing carbon gases that fuel global warming.

Quote
Now new discoveries suggest that the carbon will escape faster as the planet warms. From the unexpected speed of Arctic warming and the troubling ways that meltwater moves through polar landscapes, researchers now suspect that for every one degree Celsius rise in Earth’s average temperature, permafrost may release the equivalent of four to six years’ worth of coal, oil, and natural gas emissions—double to triple what scientists thought a few years ago. Within a few decades, if we don’t curb fossil fuel use, permafrost could be as big a source of greenhouse gases as China, the world’s largest emitter, is today.

We aren’t accounting for that. The UN’s Intergovernmental Panel on Climate Change has only recently started incorporating permafrost into its projections. It still underestimates just how wide Pandora’s freezer could swing open—and how much havoc that could unleash.

Permafrost’s potential to warm the planet is dwarfed by our own. But if we hope to limit warming to two degrees Celsius, as 195 nations agreed to during the 2015 Paris talks, new research suggests we may have to cut emissions eight years sooner than IPCC models project, just to account for the thawing that will be going on.
Title: Re: Permafrost general science thread
Post by: kassy on August 23, 2019, 02:57:06 PM
new discoveries suggest that the carbon will escape faster as the planet warms.

This is so obvious that it is almost surprising we are not accounting for that...almost.  ::)
Title: Re: Permafrost general science thread
Post by: kassy on October 18, 2019, 02:35:53 PM
Ok following is not really science although thet did add up stuff so there is that...

Russia’s Thawing Permafrost May Cost Economy $2.3 Billion a Year

...

The issue may get much worse. By 2050, warming may affect about a fifth of structures and infrastructure across the permafrost area, costing some $84 billion, according to research published in February by scientists including Dmitry Streletskiy, a professor at George Washington University. That would be equal to about 7.5% of Russia’s gross domestic product. More than half of residential real estate, worth about $53 billion, might be also damaged.

For details see:
https://www.bnnbloomberg.ca/russia-s-thawing-permafrost-may-cost-economy-2-3-billion-a-year-1.1333465

One more quote:
As well as driving piles deeper, it (a gas company) is using technology to help keep the ground frozen

In Siberia...   :(

Title: Re: Permafrost general science thread
Post by: kassy on October 21, 2019, 02:48:18 PM
Permafrost Thaws Rapidly as Arctic River Flooding Increases

...

Zheng et al. [2019] developed a heat-exchange model to investigate how changes in river flow affect permafrost within floodplains, and applied their model to the Kuparuk River, Alaska, where mean annual flow has increased by 35% since the 1970s and snowmelt floods now arrive earlier. Their results indicate that the changes to inundation extent and timing of river discharge cause floodplain permafrost to thaw more rapidly, as heat is transferred from the warmer floodwater down into the cooler subsurface. The model shows that the earlier arrival of spring flooding impacts permafrost warming more than a prolonged warm season would.

...

https://eos.org/editor-highlights/permafrost-thaws-rapidly-as-arctic-river-flooding-increases

Zheng, L., Overeem, I., Wang, K., & Clow, G. D. [2019]. Changing Arctic river dynamics cause localized permafrost thaw. Journal of Geophysical Research: Earth Surface, 124. https://doi.org/10.1029/2019JF005060
Title: Re: Permafrost general science thread
Post by: sark on October 22, 2019, 06:18:47 AM
Large loss of CO2 in winter observed across the northern permafrost region

"Here we synthesize regional in situ observations of CO2 flux from Arctic and boreal soils to assess current and future winter carbon losses from the northern permafrost domain. We estimate a contemporary loss of 1,662 TgC per year from the permafrost region during the winter season (October–April). This loss is greater than the average growing season carbon uptake for this region estimated from process models (−1,032 TgC per year). Extending model predictions to warmer conditions up to 2100 indicates that winter CO2 emissions will increase 17% under a moderate mitigation scenario—Representative Concentration Pathway 4.5—and 41% under business-as-usual emissions scenario"

Susan M. Natali, Jennifer D. Watts, […]Donatella Zona
Nature Climate Change (2019)

https://www.nature.com/articles/s41558-019-0592-8
Title: Re: Permafrost general science thread
Post by: Wherestheice on October 22, 2019, 06:43:02 AM
More evidence that the permafrost deniers are wrong.
Title: Re: Permafrost general science thread
Post by: Jontenoy on October 22, 2019, 02:41:15 PM
I attach a chart showing atmosphere methane levels (release from the permafrost)  in Barrow. It shows the level of methane in the atmosphere over a few years and is noteworthy that the  concentration is highest in winter. I would have thought more methane release in Summer.
Can some of the Methane Gurus enlighten me ?
Title: Re: Permafrost general science thread
Post by: blumenkraft on October 22, 2019, 04:54:16 PM
Can some of the Methane Gurus enlighten me ?

Not an expert.

I can recommend the Copernicus methane projection though. My guess is that most of the methane measured in Barrow comes from industry in China/Europe.

https://atmosphere.copernicus.eu/charts/cams/methane-forecasts?facets=undefined&time=2019102000,3,2019102003&projection=classical_arctic&layer_name=composition_ch4_totalcolumn
Title: Re: Permafrost general science thread
Post by: vox_mundi on October 22, 2019, 05:21:37 PM
https://phys.org/news/2015-12-methane-emissions-arctic-cold-season.html

https://www.pnas.org/content/113/1/40
Open Access

From 2015: The amount of methane gas escaping from the ground during the long cold period in the Arctic each year and entering Earth's atmosphere is likely much higher than estimated by current climate change models, concludes a major new study led by San Diego State University.

... "Virtually all the climate models assume there's no or very little emission of methane when the ground is frozen," Oechel said. "That assumption is incorrect."

The water trapped in the soil doesn't freeze completely even below zero degrees Celsius, he explained. The top layer of the ground, known as the active layer, thaws in the summer and refreezes in the winter, and it experiences a kind of sandwiching effect as it freezes. When temperatures are right around zero degrees Celsius—the so-called 'zero curtain'—the top and bottom of the active layer begin to freeze, while the middle remains insulated. Microorganisms in this unfrozen middle layer continue to break down organic matter and emit methane many months into the Arctic's cold period each year

(https://www.pnas.org/content/pnas/113/1/40/F1.large.jpg?width=800&height=600&carousel=1)

... the research team found that a major portion of methane emissions during the cold season were observed when temperatures hovered near the zero curtain.

Surprisingly, the researchers also found that during the cold season, the relative methane emissions were higher at the drier, upland tundra sites than at wetland sites, contradicting yet another longstanding assumption about Arctic methane emissions. Upland tundra was previously assumed to be a negligible contributor of methane, Zona said.

The freezing of the surface inhibits methane oxidation, resulting in significant net methane emissions during the fall and winter," she said. "Plants act like chimneys facilitating the methane's escape through the frozen layer to the atmosphere."
Title: Re: Permafrost general science thread
Post by: SteveMDFP on October 22, 2019, 10:19:05 PM
I attach a chart showing atmosphere methane levels (release from the permafrost)  in Barrow. It shows the level of methane in the atmosphere over a few years and is noteworthy that the  concentration is highest in winter. I would have thought more methane release in Summer.
Can some of the Methane Gurus enlighten me ?

Not a guru, but from my recollection, sunlight facilitates natural breakdown of methane (via hydroxyl radicals).  Absent sun means less breakdown.  I don't believe methane *emissions* go down in winter at all.

Clearly, we need more radicals.
 ;)
Title: Re: Permafrost general science thread
Post by: longwalks1 on October 23, 2019, 06:10:17 AM

http://www.pnas.org/content/113/1/40.abstract?sid=36140e33-589e-4e88-b08c-78fe9db33d7b
https://sci-hub.tw/10.1073/pnas.1516017113

https://forum.arctic-sea-ice.net/index.php/topic,12.msg86640.html#msg86640

I need to re-read 

As has been gently pointed out to me in the past, possibly better in a methane thread

I am swamped taking care of 180 + combined age parents and work/ overtime/  If anyone tracks down any more of subsequent research by these individuals I would be grateful.
Title: Re: Permafrost general science thread
Post by: kassy on October 26, 2019, 09:57:18 AM
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0889.2011.00527.x?deniedAccessCustomisedMessage=&userIsAuthenticated=false

By 2200, the PCF strength in terms of cumulative permafrost carbon flux to the atmosphere is 190 ± 64 Gt C. This estimate may be low because it does not account for amplified surface warming due to the PCF itself and excludes some discontinuous permafrost regions where SiBCASA did not simulate permafrost. We predict that the PCF will change the arctic from a carbon sink to a source after the mid‐2020s and is strong enough to cancel 42–88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible and accounting for the PCF will require larger reductions in fossil fuel emissions to reach a target atmospheric CO2 concentration.

Hattip Jay.
Bolding mine.

This flip should be prevented and thus our collective time frame for action is wrong.
Title: Re: Permafrost general science thread
Post by: Ken Feldman on October 28, 2019, 11:30:46 PM
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0889.2011.00527.x?deniedAccessCustomisedMessage=&userIsAuthenticated=false

By 2200, the PCF strength in terms of cumulative permafrost carbon flux to the atmosphere is 190 ± 64 Gt C. This estimate may be low because it does not account for amplified surface warming due to the PCF itself and excludes some discontinuous permafrost regions where SiBCASA did not simulate permafrost. We predict that the PCF will change the arctic from a carbon sink to a source after the mid‐2020s and is strong enough to cancel 42–88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible and accounting for the PCF will require larger reductions in fossil fuel emissions to reach a target atmospheric CO2 concentration.

Hattip Jay.
Bolding mine.

This flip should be prevented and thus our collective time frame for action is wrong.

That study came out in 2011 and was considered in the IPCC 2019 SROCC.

https://report.ipcc.ch/srocc/pdf/SROCC_FinalDraft_Chapter3.pdf (https://report.ipcc.ch/srocc/pdf/SROCC_FinalDraft_Chapter3.pdf)

Quote
The permafrost soil carbon pool is climate sensitive and an order of magnitude larger than carbon stored in plant biomass (Schuur et al., 2018b) (very high confidence). Initial estimates were converging on a range of cumulative emissions from soils to the atmosphere by 2100, but recent studies have actually widened that range somewhat (Figure 3.11) (medium confidence). Expert assessment and laboratory soil incubation studies suggest that substantial quantities of C (tens to hundreds Pg C) could potentially be transferred from the permafrost carbon pool into the atmosphere under RCP8.5 (Schuur et al., 2013; Schädel et al., 2014). Global dynamical models supported these findings, showing potential carbon release from the permafrost zone ranging from 37 to 174 Pg C by 2100 under high emission climate warming trajectories, with an average across models of 92 ± 17 Pg C (mean ± SE) (Zhuang et al., 2006; Koven et al., 2011; Schaefer et al., 2011; MacDougall et al., 2012; Burke et al., 2013; Schaphoff et al., 2013; Schneider von Deimling et al., 2015). This range is generally consistent with several newer data-driven modelling approaches that estimated that soil carbon releases by 2100 (for RCP8.5) will be 57 Pg C (Koven et al., 2015) and 87 Pg C (Schneider von Deimling et al., 2015), as well as an updated estimate of 102 Pg C from one of the previous models (MacDougall and Knutti, 2016). However, the latest model runs performed with either structural enhancements to better represent permafrost carbon dynamics (Burke et al., 2017a), or common environmental input data (McGuire et al., 2016) show similar soil carbon losses, but also indicate the potential for stimulated plant growth (nutrients, temperature/growing season length, CO2 fertilization) to offset some (Kleinen and Brovkin, 2018) or all of these losses, at least during this century, by sequestering new carbon into plant biomass and increasing carbon inputs into the surface soil (McGuire et al., 2018). These future carbon emission levels would be a significant fraction of those projected from fossil fuels with implications for allowable carbon budgets that are consistent with limiting global warming, but will also depend on how vegetation responds (high confidence). Furthermore, there is high confidence that climate scenarios that involve mitigation (e.g. RCP4.5) will help to dampen the response of carbon emissions from the Arctic and boreal regions.
Title: Re: Permafrost general science thread
Post by: vox_mundi on October 30, 2019, 01:15:40 PM
Abrupt Shifts in Arctic Climate Projected
https://phys.org/news/2019-10-abrupt-shifts-arctic-climate.html

Researchers from McGill University project that as the permafrost continues to degrade, the climate in various regions of the Arctic could potentially change abruptly, in the relatively near future. Their research, which was published today in Nature Climate Change, also suggests that as the permafrost degrades, the severity of wildfires will double from one year to the next and remain at the new and higher rate for regions in the Northwestern Territories and the Yukon.

"As we started analyzing more closely climate model simulations for the Arctic region, we noticed abrupt changes in soil moisture, as well as abrupt increases in intense rainfalls with a probable increase in lightning and wildfires too."

Prior research in the field has tended to project a gradual degradation of the permafrost, with few direct effects on climate. Typically, researchers will model climate changes by looking backwards and forwards in 20-30 year blocks, making it easier to miss the abrupt changes that are taking place. The McGill researchers analyzed the effects of changes in the permafrost on a completely different level.

... "We used climate model data spanning the 1970-2100 period to understand probable changes in the Arctic climate and permafrost. What we came away with, was a picture of alarming changes to climate driven by permafrost degradation."

B. Teufel, et.al. Abrupt changes across the Arctic permafrost region endanger northern development (https://www.nature.com/articles/s41558-019-0614-6), Nature Climate Change 2019
Title: Re: Permafrost general science thread
Post by: kassy on November 11, 2019, 01:58:17 AM
Arctic Shifts To a Carbon Source Due to Winter Soil Emissions
https://eurekalert.org/pub_releases/2019-11/nsfc-ast110819.php

A NASA-funded study suggests winter carbon emissions in the Arctic may be adding more carbon into the atmosphere each year than is taken up by Arctic vegetation, marking a stark reversal for a region that has captured and stored carbon for tens of thousands of years.

The study, published Oct. 21 in Nature Climate Change, warns that winter carbon dioxide loss from the world's permafrost regions could increase by 41% over the next century if human-caused greenhouse gas emissions continue at their current pace. Carbon emitted from thawing permafrost has not been included in the majority of models used to predict future climates.

"These findings indicate that winter carbon dioxide loss may already be offsetting growing season carbon uptake, and these losses will increase as the climate continues to warm," said Woods Hole Research Center Arctic Program Director Sue Natali, lead author of the study. "Studies focused on individual sites have seen this transition, but until now we haven't had a clear accounting of the winter carbon balance throughout the entire Arctic region."

Researchers estimate a yearly loss of 1.7 billion metric tons of carbon from the permafrost region during the winter season from 2003 to 2017 compared to the estimated average of 1 billion metric tons of carbon taken up during the growing season. ... "The warmer it gets, the more carbon will be released into the atmosphere from the permafrost region, which will add to further warming," ... . If fossil fuel use is modestly reduced over the next century, winter carbon dioxide emissions would increase 17% compared with current emissions. Under a scenario where fossil fuel use continues to increase at current rates through the middle of the century, winter carbon dioxide emissions from permafrost would rise by 41%.

Reposted here because it is a rather significant find about permafrost.

Abstract:
https://www.nature.com/articles/s41558-019-0592-8

Stuff that was bolded not long ago.

We predict that the PCF will change the arctic from a carbon sink to a source after the mid‐2020s


Well that failed.

Furthermore, there is high confidence that climate scenarios that involve mitigation (e.g. RCP4.5) will help to dampen the response of carbon emissions from the Arctic and boreal regions.


What really helps if you force the world onto that path. Or something even better.

Basically there is only one important scenario, the one we call the world.

We should go zero quicker and more coordinated and employ a bunch of cheap sensible carbon capture techniques ASAP which is ofc not going to happen.

The earlier 2020 date triggered me because one of the goals always was to prevent things like this from happening and now it is already here.

Eyeballing Mauna Loa CO2 anything over 370 is bad. So that is an interesting challenge.
Title: Re: Permafrost general science thread
Post by: bluesky on November 11, 2019, 10:37:43 AM

Geophysical Research Letters

Research Letter  Open Access

Rapid CO2 Release From Eroding Permafrost in Seawater
G. Tanski  D. Wagner  C. Knoblauch  M. Fritz T. Sachs  H. Lantuit
First published: 15 October 2019
https://doi.org/10.1029/2019GL084303
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Abstract
Permafrost is thawing extensively due to climate warming. When permafrost thaws, previously frozen organic carbon (OC) is converted into carbon dioxide (CO2) or methane, leading to further warming. This process is included in models as gradual deepening of the seasonal non‐frozen layer. Yet, models neglect abrupt OC mobilization along rapidly eroding Arctic coastlines. We mimicked erosion in an experiment by incubating permafrost with seawater for an average Arctic open‐water season. We found that CO2 production from permafrost OC is as efficient in seawater as without. For each gram (dry weight) of eroding permafrost, up to 4.3 ± 1.0 mg CO2 will be released and 6.2 ± 1.2% of initial OC mineralized at 4 °C. Our results indicate that potentially large amounts of CO2 are produced along eroding permafrost coastlines, onshore and within nearshore waters. We conclude that coastal erosion could play an important role in carbon cycling and the climate system

Rapid CO2 Release From Eroding Permafrost in Seawater
G. Tanski  D. Wagner  C. Knoblauch  M. Fritz T. Sachs  H. Lantuit
First published: 15 October 2019
https://doi.org/10.1029/2019GL084303
Title: Re: Permafrost general science thread
Post by: kassy on November 12, 2019, 02:09:47 PM
Thanks!

From the PLS:
A slow and continuous thaw is currently used in models to project future greenhouse gas release from permafrost. Yet along the rapidly eroding coastlines of the Arctic Ocean, which make up 34% of the Earth's coastlines, whole stretches of the coast simply collapse, sink or slide into the ocean, including the previously frozen organic carbon.

Bolded: i would never have guessed it was that much.
Title: Re: Permafrost general science thread
Post by: kassy on November 15, 2019, 01:22:09 PM
Shrubbier tundra likely accelerates permafrost thawing, study finds
Social Sharing

Areas with dwarf birch saw faster snow melt and deeper ground thawing

...

While their impact varies, a paper recently published in the journal, Arctic Science, found areas with birch shrubs had longer snow-free periods, in turn accelerating the thawing of the ground below.

"We discovered that the date at which the snow melts is a key driver in how deep the ground will thaw in the summer," said Evan Wilcox, a geography PhD candidate at Wilfrid Laurier University and the paper's lead author.

"Areas where the shrubs protrude through [the snow], the snow melts on average a week earlier," he said. Taller shrubs paired with warmer air temperatures will likely result in more permafrost thawing, he said.

for details see:
https://www.cbc.ca/news/canada/north/arctic-tundra-permafrost-thaw-shrub-1.5359354

and

Tundra shrub expansion may amplify permafrost thaw by advancing snowmelt timing

https://www.nrcresearchpress.com/doi/10.1139/as-2018-0028#.Xc6YDVdKjct
Title: Re: Permafrost general science thread
Post by: gerontocrat on December 11, 2019, 08:58:09 PM
The essay linked below is in the NOAA 2019 Arctic Report Card https://arctic.noaa.gov/Report-Card/Report-Card-2019
Basically, winter CO2 emissions grossly underestimated and more than CO2 capture in the Summer by 0.6 petagrams of CARBON per annum.

To us simple people it is 0.6 x 3.67 = 2.2 GT of CO2 - a significant amount meaning a carbon sink is a actually a carbon emitter.

Extracts.....
https://arctic.noaa.gov/Report-Card/Report-Card-2019/ArtMID/7916/ArticleID/844/Permafrost-and-the-Global-Carbon-Cycle
Permafrost and the Global Carbon Cycle

Quote
Highlights
- Northern permafrost region soils contain 1,460-1,600 billion metric tons of organic carbon, about twice as much as currently contained in the atmosphere.
- This pool of organic carbon is climate-sensitive. Warming conditions promote microbial conversion of permafrost carbon into the greenhouse gases carbon dioxide and methane that are released to the atmosphere in an accelerating feedback to climate warming.
- New regional and winter season measurements of ecosystem carbon dioxide flux independently indicate that permafrost region ecosystems are releasing net carbon (potentially 0.3 to 0.6 Pg C per year) to the atmosphere.
- These observations signify that the feedback to accelerating climate change may already be underway.

Introduction
The Arctic continues to warm at a rate that is currently twice as fast as the global average (see essay Surface Air Temperature). Warming is causing perennially-frozen ground (permafrost) to thaw, with permafrost in many locations currently reaching record high temperatures (Biskaborn et al. 2019). Organic carbon contained in soils of the permafrost region represent a climate-sensitive carbon reservoir that is affected by warming air and ground temperatures and permafrost thaw....

The northern permafrost region holds almost twice as much carbon as is currently in the atmosphere. Additional net releases of carbon dioxide (CO2) and methane (CH4) to the atmosphere as a result of warming and faster microbial decomposition of permafrost carbon have the potential to accelerate climate warming. ....

Permafrost carbon pools: How much permafrost carbon is available to release into the atmosphere?
The new, best mean estimate of the amount of organic carbon stored in the northern permafrost region is 1,460-1,600 petagrams (Pg; 1 Pg = 1 billion metric tons) (Hugelius et al. 2014; Schuur et al. 2015). Of this inventory, 65-70% (1,035 ± 150 Pg) of the carbon is within the surface layer (0-3 m depth) (Fig. 1). Soils in the top 3 m of the rest of Earth's biomes (excluding Arctic and boreal biomes) contain 2,050 Pg of organic carbon (Jobbagy and Jackson 2000). The soil carbon from the northern circumpolar permafrost region adds another 50% to this 3-m inventory, even though it occupies only 15% of the total global soil area (Schuur et al. 2015).

Ecosystem-atmosphere carbon exchange: Is the Arctic currently releasing additional net carbon dioxide emissions to the atmosphere?
....
A new comprehensive synthesis study of non-summer ecosystem CO2 fluxes across the circumpolar region showed that carbon release during the Arctic winter was 2 to 3 times higher than previously estimated from ground-based measurements (Fig. 3) (Natali et al. 2019). This circumpolar estimate suggests that carbon release in the cold season offsets net carbon uptake during the growing season (derived from models) such that the region as a whole could already be a source of 0.6 Pg C per year to the atmosphere.
Title: Re: Permafrost general science thread
Post by: TerryM on December 12, 2019, 03:07:21 AM
^^
Northern Ontario's vast permafrost regions seem destined to emit large quantities of GHGs regardless of what steps we take.  To the east of James Bay in Northern Quebec, the flooding of an area twice the size of Scotland with relatively warm water will speed the melting of the permafrost layers and increase GHG emissions year round. The Eastmain Hydro project is being expanded and will again be the world's largest producer of hydroelectric power.
These emissions don't appear on your charts - yet.


The warmest, most southerly permafrost regions are presently the largest emitters, but as the Arctic warms the melting regions will expand, and emissions will expand with them. The last time this occurred we had turtles, alligators and primates living year round on Ellesmere Island. Six months without insolation apparently wasn't enough to freeze them out.


I question whether primates will survive this accelerated warming.
Terry
Title: Re: Permafrost general science thread
Post by: Juan C. García on December 13, 2019, 11:22:25 AM
Quote
The Arctic may have crossed key threshold, emitting billions of tons of carbon into the air, in a long-dreaded climate feedback

The Arctic is undergoing a profound, rapid and unmitigated shift into a new climate state, one that is greener, features far less ice and emits greenhouse gas emissions from melting permafrost, according to a major new federal assessment of the region released Tuesday.

The consequences of these climate shifts will be felt far outside the Arctic in the form of altered weather patterns, increased greenhouse gas emissions and rising sea levels from the melting Greenland ice sheet and mountain glaciers.

The findings are contained in the 2019 Arctic Report Card, a major federal assessment of climate change trends and impacts throughout the region. The study paints an ominous picture of a region lurching to an entirely new and unfamiliar environment.

Especially noteworthy is the report’s conclusion that the Arctic already may have become a net emitter of planet-warming carbon emissions due to thawing permafrost, which would only accelerate global warming.
https://www.washingtonpost.com/weather/2019/12/10/arctic-may-have-crossed-key-threshold-emitting-billions-tons-carbon-into-air-long-dreaded-climate-feedback/?wpisrc=al_environment__alert-hse&wpmk=1 (https://www.washingtonpost.com/weather/2019/12/10/arctic-may-have-crossed-key-threshold-emitting-billions-tons-carbon-into-air-long-dreaded-climate-feedback/?wpisrc=al_environment__alert-hse&wpmk=1)
Title: Re: Permafrost general science thread
Post by: ArcticMelt2 on December 14, 2019, 06:54:45 AM
https://twitter.com/ckatz99/status/1205573106972033024

(https://pbs.twimg.com/media/ELsOWRiXkAA5P2X.jpg)
Title: Re: Permafrost general science thread
Post by: nanning on December 14, 2019, 11:10:22 AM
^^
I don't understand that presentation.
It reads:

5% - 15% (vulnerable fraction of permafrost)
146 - 160 billion tons (emissions)

160?

15% should be 3*146 = 438GT I think. A 'bit' more than 160GT.

Or 5% should be 160/3 = 53GT. A 'bit' less than 146GT.

That's a lot of carbon (75ppm in the presentation) and the "5% - 15%" may well increase to "5% - 20%" or more in the future with new and better understanding.
Title: Re: Permafrost general science thread
Post by: kassy on December 14, 2019, 11:40:17 AM
The slide could be clearer. See the report card quote in #54 above.

Northern permafrost region soils contain 1,460-1,600 billion metric tons of organic carbon

So that number is the total in play but working out the emissions is not straightforward.
I think the 5-15% is also a base input.

It would be nice to have a name of a scientist or an article to go with the slide (not a Twitter fan but looking at the feed it seems to come from the Report Card so delve into that to see how they arrive at the numbers.
Title: Re: Permafrost general science thread
Post by: gerontocrat on December 14, 2019, 12:03:27 PM
^^
I don't understand that presentation.
It reads:

5% - 15% (vulnerable fraction of permafrost)
146 - 160 billion tons (emissions)

160?

15% should be 3*146 = 438GT I think. A 'bit' more than 160GT.

Or 5% should be 160/3 = 53GT. A 'bit' less than 146GT.

That's a lot of carbon (75ppm in the presentation) and the "5% - 15%" may well increase to "5% - 20%" or more in the future with new and better understanding.
Total Arctic Permafrost (on land) is estimated to contain 1400 to 1600 GT of CARBON.

The 140-160 GT guess of possible carbon emissions from Arctic permafrost to 2100 in the presentation is 10%, i.e. the mid-point of 5% to 15%.

If released as CO2 that is 160 GT of carbon x 3.67 = 590 GT of CO2.

1 ppm of atmospheric CO2 = 7.81 GT

So 160 GT of carbon released into the atmosphere equates to 75 ppm.

But that ignores any increase in absorption by the carbon sinks (currently 50%)
BUT who knows what the future of carbon sinks will be? Most of the news is not good about either the land or the ocean sinks.

The presentation also does not consider possible CO2 and CH4 emissions from undersea permafrost (e.g. from the shallow East Siberian Arctic Shelf).

A recent paper suggests that current emissions may already be at about 2.2 GT of CO2 per annum, i.e. if continued at that rate to 2100 = 176 billion GT of CO2. Obviously AGW + polar amplification would increase that rate substantially.
(see post #54 by me above)
Link is https://arctic.noaa.gov/Report-Card/Report-Card-2019/ArtMID/7916/ArticleID/844/Permafrost-and-the-Global-Carbon-Cycle
Title: Re: Permafrost general science thread
Post by: nanning on December 14, 2019, 04:37:35 PM
I haven't read the Report Card, sorry. I've lost my interest in details I think.
Thank you for explaining and for your view gerontocrat.

Quote from: kassy
It would be nice to have a name of a scientist or an article to go with the slide

That would've been nice in retrospect (I thought it was an error).
And thank you for your response.
Title: Re: Permafrost general science thread
Post by: wdmn on December 19, 2019, 12:41:15 AM
The Arctic’s grand reveal

https://news.uaf.edu/the-arctics-grand-reveal/

"University of Alaska Fairbanks scientists presented their work at the American Geophysical Union’s fall meeting in San Francisco this week.

...

Most experts suggest permafrost thaw will continue and even speed up as we go into the next century.

However, calculated rates of thaw may be far lower than what will really happen. According to Farquharson, a key accelerating factor in permafrost thaw has been dramatically underestimated.

“It’s the Arctic’s ‘grand reveal,’” Farquarson said. “We thought we saw what was happening, then it really stepped out from behind the curtain.”

This factor is called talik, thawed zones in permafrost areas.

The mixture of wet, frigid dirt is commonly associated with Arctic thermokarst lakes that form when enough ice-rich permafrost thaws to create a body of water.

The talik beneath these lakes significantly contributes to the thawing process. Just as icewater melts faster than a lone cube of ice, the waterlogged ground accelerates thawing of the permafrost around it.

Normally talik has been thought of as limited to the areas just below and around thermokarst lakes, but Farquharson’s work shows they are much more extensive.

Farquharson and her collaborators, including Vladimir Romanovsky, also at the Geophysical Institute, observed substantial evidence from 28 sites across Alaska showing these taliks are larger, and extend deeper in the ground, than previously thought — even in many areas scientists didn’t know it existed.

This could have dramatic effects on permafrost, making previous thaw forecasts and estimates of subsequent carbon release pale in comparison to what is coming.

“You look at your lake distribution of taliks and how much of the landscape that accounts for, and then you take that number and you spread it across pretty much the entire landscape in Interior Alaska,” she said.

“We’re going to basically change the calculations for global carbon emissions.”

...

Her reserved tone hid a bombshell message — by 2035 permafrost thaw may continue on its own, disregarding the processes that have kept it frozen for thousands of years."
Title: Re: Permafrost general science thread
Post by: vox_mundi on December 19, 2019, 02:44:48 AM
Thawing Permafrost Affecting Northern Alaska's Land-to-Ocean River Flows
https://phys.org/news/2019-12-permafrost-affecting-northern-alaska-land-to-ocean.html

A new analysis of the changing character of runoff, river discharge and other hydrological cycle elements across the North Slope of Alaska reveals significant increases in the proportion of subsurface runoff and cold season discharge, changes the authors say are "consistent with warming and thawing permafrost."

First author and lead climate modeler Michael Rawlins, associate professor of geosciences at the University of Massachusetts Amherst and associate director of its Climate Systems Research Center, says warming is expected to shift the Arctic from a surface water-dominated system to a groundwater-dominated system, with deeper water flow paths through newly thawed soils.

... The researchers observed significant increases in cold season discharge, such as 134% of the long-term average for the North Slope, and 215% in the Colville River basin, for example. They report a significant increase in the ratio of subsurface runoff to total runoff for the region and for 24 of the 42 study basins, with the change most prevalent across the northern foothills of the Brooks Range. They also observed a decline in terrestrial water storage, which they attribute to losses in soil ice that outweigh gains in soil liquid water storage. The timing of peak spring freshet discharge, the flow of snowmelt into the sea, also has shifted earlier by 4.5 days.

(https://www.the-cryosphere.net/13/3337/2019/tc-13-3337-2019-f01-thumb.png)

"Our model estimates of permafrost thaw are consistent with the notion that permafrost region ecosystems are shifting from a net sink to a net source of carbon," he says.

Open Access: Michael A. Rawlins et al, Changing characteristics of runoff and freshwater export from watersheds draining northern Alaska (https://www.the-cryosphere.net/13/3337/2019/), The Cryosphere (2019)
Title: Re: Permafrost general science thread
Post by: kassy on December 19, 2019, 03:24:16 PM
Thanks for the articles.

Earlier but related publication by Farquharson

We find that observed maximum thaw depths at all sites are already regularly exceeding modeled future thaw depths for 2090 under IPCC RCP 4.5. Our data show that very cold permafrost (<−10 °C) at high latitudes is highly vulnerable to rapid near‐surface permafrost degradation due to climate change.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL082187
Title: Re: Permafrost general science thread
Post by: Ken Feldman on December 19, 2019, 07:51:27 PM
While the news from the Arctic seems dire, keep in mind that in both the cases of the Alaskan tundra carbon emissions highlighted in the 2019 Arctic Report Card and the attention given to thermokarst emissions are based on a few measurements over a short period of time in smaller areas extrapolated to the entire globe. 

Here are the details from the Arctic Report Card.

https://arctic.noaa.gov/Report-Card/Report-Card-2019/ArtMID/7916/ArticleID/844/Permafrost-and-the-Global-Carbon-Cycle (https://arctic.noaa.gov/Report-Card/Report-Card-2019/ArtMID/7916/ArticleID/844/Permafrost-and-the-Global-Carbon-Cycle)

Quote
Another approach to this same question is to measure changes in atmospheric greenhouse gas concentrations and to separate out contributions from different sources. Given the extent of fossil fuel carbon emissions, it remains a challenge to quantify and separate the effect of ecosystem carbon exchange, but regional atmospheric measurement campaigns can help to focus in on local influences (Parazoo et al. 2016). Recent measurements of atmospheric greenhouse gas concentrations over Alaska by NASA aircraft have been used to the estimate the net regional impact on the atmosphere by those Arctic and boreal ecosystems for 2012 to 2014 (Commane et al. 2017). This recent NASA campaign was able to provide important insight into the aggregate influence of the carbon exchange for the Alaska permafrost region, across tundra, boreal forests, and wetland/lake/freshwater ecosystems as a whole. During this three-year time period, the tundra region of Alaska was found to be a consistent net CO2 source to the atmosphere, whereas the boreal forest region was either neutral or a net CO2 sink. The boreal forest region exhibited larger interannual variability due both to changes in the balance of photosynthesis and respiration and to the amount of combustion emissions by wildfire.

The Alaska study region as a whole was estimated to be a net carbon source of 0.025 ± 0.014 Pg C per year averaged over the land area of both tundra and boreal forest regions for the three-year study period. If this Alaskan region (1.6 × 106 km2) was representative of the entire northern circumpolar permafrost region soil area (17.8 × 106 km2), this amount would be equivalent to a circumpolar net source of 0.3 Pg C per year. Historically (over hundreds to thousands of years), the Arctic region was accumulating carbon in soils and vegetation and thus was acting as a net sink of atmospheric CO2. Assuming this three-year snapshot provided by NASA aircraft monitoring is indicative of the Arctic's current physical and biological environment, a significant and major threshold has been crossed in the high latitude region whereas the aggregate effect of terrestrial ecosystems is now contributing to, rather than slowing, climate change.

Alaska has a large and active oil and gas industry, which most of the Arctic doesn't.  The oil and gas industry is notorious for having a lot of methane leaks and flaring (which enhances both CH4 and CO2 concentrations in the oil fields).

While the report card does acknowledge that global warming may increase the growing season and thus increase the sinks, the calculations that lead to the headline grabbing results didn't include the effects of the increased growing season.

Another impact of global warming is that the area of tundra (the portion of the Arctic that is increasing emissions) is shrinking and the area of the boreal forest is increasing.  The Report Card states that the boreal forests are either neutral or sinks.

Here's a 2016 paper on the change in the Arctic from tundra to forests.

https://www.researchgate.net/profile/Matthias_Forkel/publication/291346720_Enhanced_seasonal_CO2_exchange_caused_by_amplified_plant_productivity_in_northern_ecosystems/links/573ed08c08ae9f741b31ef1d.pdf (https://www.researchgate.net/profile/Matthias_Forkel/publication/291346720_Enhanced_seasonal_CO2_exchange_caused_by_amplified_plant_productivity_in_northern_ecosystems/links/573ed08c08ae9f741b31ef1d.pdf)

Quote
Enhanced seasonal CO2 exchange caused by amplified plant productivity in northern ecosystems
Matthias Forkel,1*†Nuno Carvalhais,1,2*Christian Rödenbeck,1Ralph Keeling,3Martin Heimann,1,4Kirsten Thonicke,5Sönke Zaehle,1Markus Reichstein1,6

Atmospheric monitoring of high northern latitudes (above 40°N) has shown an enhanced seasonal cycle of carbon dioxide (CO2) since the 1960s, but the underlying mechanisms are not yet fully understood. The much stronger increase in high latitudes relative to low ones suggests that northern ecosystems are experiencing large changes in vegetation and carbon cycle dynamics. We found that the latitudinal gradient of the increasing CO2 amplitude is mainly driven by positive trends in photosynthetic carbon uptake caused by recent climate change and mediated by changing vegetation cover in northern ecosystems. Our results underscore the importance of climate–vegetation–carbon cycle feedbacks at high latitudes; moreover, they indicate that in recent decades, photosynthetic carbon uptake has reacted much more strongly to warming than have carbon release processes.

Quote
A variety of factors may contribute to the CO2amplitude trend. Arctic and boreal regions have experienced strong warming in recent decades(6), and a“greening” trend has been detected from satellites, indicating enhanced plant growth(7,8) (Fig. 1, A and B). These satellite observations are confirmed by ground observations showing increases in shrub coverage in the tundra (9),tree growth along the tundra–boreal forest transition zone (10), and deciduous tree cover from recovery after severe boreal forest fires (11). Additionally, various estimates show positive trends in both annual amplitudes and annual totals of GPP (12,13) and in net biome productivity (NBP)(14)in northern ecosystems (Fig.1,CandD).The intensification of agriculture in the midlatitudes also likely contributes to the CO2 amplitude trends (15,16). These multiple observational signals point to amplified plant productivity as a likely cause of the increase in CO2 amplitude(1,3,7,17). Nonetheless, a quantitative explanation of the amplitude trends is still lacking. Current Earth system models consistently under-estimate the CO2 amplitude trend (4) and its gradient with latitude, which suggests that these models are missing or underrepresenting key processes (18).

Quote
Title: Re: Permafrost general science thread
Post by: Ken Feldman on December 19, 2019, 08:48:14 PM
The following paper provides a good overview of why there is so much uncertainty about whether Arctic tundra regions are sources or sinks.  And it indicates that in 2014 and 2015, the Lena River floodplain was a sink for carbon emissions.

https://www.biogeosciences.net/16/2591/2019/ (https://www.biogeosciences.net/16/2591/2019/)

Quote
Rößger, N., Wille, C., Holl, D., Göckede, M., and Kutzbach, L.: Scaling and balancing carbon dioxide fluxes in a heterogeneous tundra ecosystem of the Lena River Delta, Biogeosciences, 16, 2591–2615, https://doi.org/10.5194/bg-16-2591-2019, 2019.

Abstract

The current assessments of the carbon turnover in the Arctic tundra are subject to large uncertainties. This problem can (inter alia) be ascribed to both the general shortage of flux data from the vast and sparsely inhabited Arctic region, as well as the typically high spatiotemporal variability of carbon fluxes in tundra ecosystems. Addressing these challenges, carbon dioxide fluxes on an active flood plain situated in the Siberian Lena River Delta were studied during two growing seasons with the eddy covariance method. The footprint exhibited a heterogeneous surface, which generated mixed flux signals that could be partitioned in such a way that both respiratory loss and photosynthetic gain were obtained for each of two vegetation classes. This downscaling of the observed fluxes revealed a differing seasonality in the net uptake of bushes (−0.89 µmol m−2 s−1) and sedges (−0.38 µmol m−2 s−1) in 2014. That discrepancy, which was concealed in the net signal, resulted from a comparatively warm spring in conjunction with an early snowmelt and a varying canopy structure. Thus, the representativeness of footprints may adversely be affected in response to prolonged unusual weather conditions. In 2015, when air temperatures on average corresponded to climatological means, both vegetation-class-specific flux rates were of similar magnitude (−0.69 µmol m−2 s−1). A comprehensive set of measures (e.g. phenocam) corroborated the reliability of the partitioned fluxes and hence confirmed the utility of flux decomposition for enhanced flux data analysis. This scrutiny encompassed insights into both the phenological dynamic of individual vegetation classes and their respective functional flux to flux driver relationships with the aid of ecophysiologically interpretable parameters. For comparison with other sites, the decomposed fluxes were employed in a vegetation class area-weighted upscaling that was based on a classified high-resolution orthomosaic of the flood plain. In this way, robust budgets that take the heterogeneous surface characteristics into account were estimated. In relation to the average sink strength of various Arctic flux sites, the flood plain constitutes a distinctly stronger carbon dioxide sink. Roughly 42 % of this net uptake, however, was on average offset by methane emissions lowering the sink strength for greenhouse gases. With growing concern about rising greenhouse gas emissions in high-latitude regions, providing robust carbon budgets from tundra ecosystems is critical in view of accelerating permafrost thaw, which can impact the global climate for centuries.

Quote
The Arctic north of 60∘ N latitude has warmed at a rate of 1.36 ∘C per century since 1875, i.e. roughly twice as fast as the global average (Masson-Delmotte et al., 2013). And this rapid warming trend is projected to continue (Collins et al., 2013). Due to ambiguous model results and their large confidence intervals, it currently remains unclear whether the permafrost areas maintain their sink function or convert into a carbon source in the future (Heimann and Reichstein, 2008; Schuur et al., 2015). These uncertainties do not only arise from the limited knowledge of the physical thawing rates, the fraction of released carbon after thawing and the timescales of release but also from the general shortage of flux data in Arctic ecosystems (Ciais et al., 2013). The scarce data availability particularly applies to the extensive Siberian tundra, which covers around 3 million km2, i.e. more than half of northern high-latitude tundra ecosystems (Chapin et al., 2005; Sachs et al., 2010). The low density of flux observation sites is due to both harsh environmental conditions as well as challenging logistics in these remote and sparsely inhabited areas that are often without line power. Consequently, current estimates of the tundra's sink strength for carbon dioxide are associated with large uncertainties: −103±193 Tg C yr−1 (McGuire et al., 2012). The same issue applies to estimates that indicate a shift to a source for carbon dioxide: 462±378 Tg C yr−1 (Belshe et al., 2013). The refinement of these macroscale estimates and the reduction of their uncertainties can be achieved via providing both more flux budgets (in particular from the Siberian tundra) and more reliable information on the variation in habitats (e.g. bogs, fens,) plus their associated surface heterogeneities (e.g. tussocks, hummocks).

Tundra ecosystems are frequently characterised by a pronounced vegetation patchiness with sharply defined boundaries between different vegetation classes (Shaver et al., 2007). Besides vegetation, surface classifications can also be based on differences in soil moisture, snow cover, permafrost features or combinations of them (Fox et al., 2008; Virkkala et al., 2018). The consequently high spatial variability in carbon fluxes complicates the estimation of robust carbon budgets that are accurate and precise. The omission of accounting for the spatial distribution of different surface types is likely to lead to incorrect budgets (Oechel et al., 1998). Therefore, an improved understanding of the effects of surface heterogeneity on these budgets, e.g. through a better characterisation of both spatial flux variability as well as associated key factors such as vegetation composition and structure, is necessary (Kade et al., 2012; Kwon et al., 2006). For quantifying vegetation properties, NDVI (normalised difference vegetation index), LAI (leaf area index) and foliar nitrogen content have been found suitable (Marushchak et al., 2013; Shaver et al., 2013). All of these predictors can be estimated by remote sensing, thereby neglecting the patchy nature of tundra ecosystems, but also offering the potential for macroscale modelling of both carbon dioxide budgets plus their prospective alterations through climate change. Such assessments are based on biome-level monitoring of the global warming-induced impacts on Arctic vegetation such as growing season prolongation as well as expansion of plant's growing range and size, e.g. the enhanced growth of shrubs and their northward migration into typical graminoid tundra ecosystems (Jia et al., 2009; Sweet et al., 2015). On the other side, microscale observations are crucial in order to reflect the individual biogeochemical dynamics in the mosaic of vegetation patches. The direct appraisal of the vegetation's responses to global warming through field surveys on the plant community level involves aspects such as enhanced primary productivity, deeper rooting depths, as well as augmented ground shading and snow accumulation trough taller growth forms (Myers-Smith et al., 2011; Sitch et al., 2007).

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3.5 Greenhouse gas balances

The evaluation of the flood plain's sink/source strength for greenhouse gases required the corresponding methane emission budgets and their conversion to carbon dioxide equivalents (Rößger et al., 2019a). Despite methane's minor percentage of roughly 3 % in the entire greenhouse gas exchange (specified in molar units), its carbon dioxide equivalents diminished the greenhouse gas sink strength (given by the carbon dioxide net uptake) by half in 2014 and by one-third in 2015. Accordingly, the greenhouse gas balances specify that the flood plain formed a moderate sink of −2.21±0.61
 mol CO2 eq. m−2 and a stronger sink of −3.81±0.74

 mol CO2 eq. m−2 during the warm season in 2014 and 2015, respectively (Table 2). The lower sink strength in 2014 was a result of a reduced carbon dioxide net uptake rather than an augmented methane efflux. And this reduced carbon dioxide net uptake in turn was caused by a lowered net uptake in vegetation class 2 that effectively counteracted the elevated early season net uptake in vegetation class 1. This class constituted a stronger greenhouse gas sink than vegetation class 2 in both years, which is mainly due to the fact that methane emissions were only present in vegetation class 2. Since these emissions hardly changed between the years along with the negligible methane release in vegetation class 1, the interannual variability in the greenhouse gas sink strength was governed by the carbon dioxide net uptake.

These balances are the first greenhouse gas budgets of a flood plain in the Lena River Delta. Based on these budgets, the sink strength of the adjacent river terrace, where another eddy covariance system has been in operation for many years, could finally be put in context within the domain of the Lena River Delta (Table 2). In 2014 and 2015, the flood plain sequestered per square metre roughly 20 % and 60 % more carbon dioxide, respectively, but it also emitted approximately 70 % more methane. Hence, the flood plain constituted a sink for greenhouse gases that resembled (2014) or was 1.5 times (2015) the sink strength of the polygonal tundra on the river terrace.

Quote
4.5 Comparison of the budgets with other Arctic sites

Across various Arctic flux sites, the flood plain of Samoylov Island exhibits a carbon dioxide sink strength that is distinctly greater than the average (Fig. 1 and Table 3). This aspect appears noteworthy when local conditions are taken into consideration: the mean net radiation during the growing season is lower than for most Arctic sites, and the underlying permafrost displays one of the lowest ground temperatures in the world (Boike et al., 2013; Obu et al., 2018; Romanovsky et al., 2010). The diminishing effects of these climate factors are counterbalanced by the deposition of nutrients in the course of spring flooding (van Huissteden et al., 2005). Among the three great Siberian rivers draining into the Arctic Ocean (Ob, Yenisei, Lena), the Lena River ranks first in terms of total suspended matter (Cauwet and Sidorov, 1996). A large portion of this matter is transported during the annual spring flood, thereby regularly mitigating the nutrient limitation that affects many Arctic ecosystems (Beermann et al., 2014; Fedorova et al., 2015).

More specifically, the net uptake of the flood plain on Samoylov Island is distinctly weaker compared to flood plains of the Siberian rivers Kolyma and Indigirka (Kittler et al., 2017; Parmentier et al., 2011). Other Siberian sites encompass Seida and Lavrentiya, which exhibit a similar and stronger net uptake, respectively (Marushchak et al., 2013; Zamolodchikov et al., 2003). Furthermore, the flood plain's net uptake is considerably stronger than budgets of high Arctic sites in Svalbard, Greenland and Canada (Lafleur et al., 2012; López-Blanco et al., 2017; Lüers et al., 2014; Lund et al., 2012). In comparison with sites in either the low Arctic or sub-Arctic, no general conclusions can be drawn, which is likely due to the ubiquitously high spatiotemporal flux variability in the Arctic region. Also, no uniform picture emerges in comparison to Scandinavian peatlands (Aurela et al., 2002, 2009; Fox et al., 2008). Compared with sites in the northern part of the north slope of Alaska, the flood plain exhibits a substantially stronger net uptake (Oechel et al., 2014; Raz-Yaseef et al., 2017); in the southern part, however, similar net uptakes seem to prevail (Euskirchen et al., 2016).

Title: Re: Permafrost general science thread
Post by: kassy on December 24, 2019, 12:33:57 PM
ALSR posted an interesting article on the situation near Barrow:

The linked reference provides field evidence that aquatic plants in arctic tundra wetlands is a major source of methane emissions, and will likely serve as a positive feedback mechanism with continued global warming (the AR5 & CMIP5 projections do not account for this source of methane):

C G Andresen, M J Lara, C E Tweedie & V L Lougheed (19 August 2016) "Rising Plant-mediated Methane Emissions from Arctic Wetlands", Global Change Biology, DOI: 10.1111/gcb.13469

http://onlinelibrary.wiley.com/doi/10.1111/gcb.13469/abstract

Abstract: "Plant-mediated CH4 flux is an important pathway for land-atmosphere CH4 emissions but the magnitude, timing, and environmental controls, spanning scales of space and time, remain poorly understood in arctic tundra wetlands, particularly under the long term effects of climate change. CH4 fluxes were measured in situ during peak growing season for the dominant aquatic emergent plants in the Alaskan arctic coastal plain, Carex aquatilis and Arctophila fulva, to assess the magnitude and species-specific controls on CH4 flux. Plant biomass was a strong predictor of A. fulva CH4 flux while water depth and thaw depth were co-predictors for C. aquatilis CH4 flux. We used plant and environmental data from 1971-72 from the historic International Biological Program (IBP) research site near Barrow, Alaska, which we resampled in 2010-13, to quantify changes in plant biomass and thaw depth, and used these to estimate species-specific decadal-scale changes in CH4 fluxes. A ~60% increase in CH4 flux was estimated from the observed plant biomass and thaw depth increases in tundra ponds over the past 40 years. Despite covering only ~5% of the landscape, we estimate that aquatic C. aquatilis and A. fulva account for two-thirds of the total regional CH4 flux of the Barrow Peninsula. The regionally observed increases in plant biomass and active layer thickening over the past 40 years not only have major implications for energy and water balance, but have significantly altered land-atmosphere CH4 emissions for this region, potentially acting as a positive feedback to climate warming."
Title: Re: Permafrost general science thread
Post by: vox_mundi on January 08, 2020, 10:07:48 PM
Sea-Ice-Free Arctic Increases Permafrost Vulnerablety to Thawing
https://m.phys.org/news/2020-01-sea-ice-free-arctic-permafrost-vulnerable.html

... The new research relies on challenging field work to discover and explore Siberian caves. Caves are powerful recorders of periods when permafrost was absent in the past. Stalagmites, stalactites and flowstones can only form when there is liquid water, and therefore not when overlying land is permanently frozen. The presence of stalagmites in caves under present permafrost thus demonstrate periods when permafrost was absent in the past.

Development of new approaches to date stalagmites using measurements of natural uranium and lead, allow dating of the recovered stalagmites—and therefore of periods of permafrost absence—for the last one and a half million years. Stalagmites grew intermittently from 1,500,000 to 400,000 years ago, and have not grown for the last 400,000 years. The timing of stalagmite formation, and therefore absence of permafrost, do not relate simply to global temperatures in the past but are notably more common when the Arctic Ocean was free of summer sea-ice.

This study shows that several processes may lead to the relationship between Arctic sea-ice and permafrost. The absence of sea ice leads to an increase in heat and moisture transfer from ocean to atmosphere and therefore to warmer air transported far overland into Siberia. Moisture transport also increases snow fall over Siberia during the autumn months. This blanket of snow insulates the ground from the extreme cold of winters leading to an increase in average annual ground temperatures, destabilising the permafrost. Consequently, in regions with increased snow cover and insulation, permafrost will start to thaw, releasing carbon dioxide that was trapped for millennia.

A. Vaks, G. Henderson, et.al. Palaeoclimate evidence of vulnerable permafrost during times of low sea ice (https://www.nature.com/articles/s41586-019-1880-1 ), Nature, 2020
Title: Re: Permafrost general science thread
Post by: kassy on January 12, 2020, 10:22:05 PM
Changing characteristics of runoff and freshwater export from watersheds draining northern Alaska

The quantity and quality of river discharge in Arctic regions is influenced by many processes including climate, watershed attributes and, increasingly, hydrological cycle intensification and permafrost thaw. We used a hydrological model to quantify baseline conditions and investigate the changing character of hydrological elements for Arctic watersheds between Utqiagvik (formerly known as Barrow)) and just west of Mackenzie River over the period 1981–2010. A synthesis of measurements and model simulations shows that the region exports 31.9 km3 yr−1 of freshwater via river discharge, with 55.5 % (17.7 km3 yr−1) coming collectively from the Colville, Kuparuk, and Sagavanirktok rivers. The simulations point to significant (p<0.05) increases (134 %–212 % of average) in cold season discharge (CSD) for several large North Slope rivers including the Colville and Kuparuk, and for the region as a whole. A significant increase in the proportion of subsurface runoff to total runoff is noted for the region and for 24 of the 42 study basins, with the change most prevalent across the northern foothills of the Brooks Range. Relatively large increases in simulated active-layer thickness (ALT) suggest a physical connection between warming climate, permafrost degradation, and increasing subsurface flow to streams and rivers. A decline in terrestrial water storage (TWS) is attributed to losses in soil ice that outweigh gains in soil liquid water storage. Over the 30-year period, the timing of peak spring (freshet) discharge shifts earlier by 4.5 d, though the time trend is only marginally (p=0.1) significant. These changing characteristics of Arctic rivers have important implications for water, carbon, and nutrient cycling in coastal environments.

Rawlins, M. A., Cai, L., Stuefer, S. L., and Nicolsky, D.: Changing characteristics of runoff and freshwater export from watersheds draining northern Alaska, The Cryosphere, 13, 3337–3352, https://doi.org/10.5194/tc-13-3337-2019, 2019.

https://www.the-cryosphere.net/13/3337/2019/
Title: Re: Permafrost general science thread
Post by: TerryM on January 13, 2020, 11:50:46 PM
Today my canoe club issued a flood warning for one of the major tributaries to the Grand River.


This is the time for towering snow banks, those that melt into our Spring floods.


Who canoes in January in Canada?
Terry
Title: Re: Permafrost general science thread
Post by: wdmn on January 14, 2020, 04:15:36 AM
@Terry

Paddle to the Sea starts his journey when there's still snow on the ground, but I think it's mid-April.

https://www.youtube.com/watch?v=uhjb1IG1pnQ

Stay dry!
Title: Re: Permafrost general science thread
Post by: TerryM on January 17, 2020, 05:54:31 AM
^^
Yea
It's a great flick!


Terry
Title: Re: Permafrost general science thread
Post by: kassy on January 28, 2020, 02:52:00 PM
Rewilding the Arctic could stop permafrost thaw and reduce climate change risks

The wide-scale introduction of large herbivores to the Arctic tundra to restore the ‘mammoth steppe’ grassland ecosystem and mitigate global warming is economically viable, suggests a new paper from the University of Oxford.

http://www.ox.ac.uk/news/2020-01-27-rewilding-arctic-could-stop-permafrost-thaw-and-reduce-climate-change-risks

You might remember the story about Pleistocene Park in Russia which is also referenced in the story. This research is about scaling that up:

Quote
Natural climate solutions (NCS) in the Arctic hold the potential to be implemented at a scale able to substantially affect the global climate. The strong feedbacks between carbon-rich permafrost, climate and herbivory suggest an NCS consisting of reverting the current wet/moist moss and shrub-dominated tundra and the sparse forest–tundra ecotone to grassland through a guild of large herbivores. Grassland-dominated systems might delay permafrost thaw and reduce carbon emissions—especially in Yedoma regions, while increasing carbon capture through increased productivity and grass and forb deep root systems. Here we review the environmental context of megafaunal ecological engineering in the Arctic; explore the mechanisms through which it can help mitigate climate change; and estimate its potential—based on bison and horse, with the aim of evaluating the feasibility of generating an ecosystem shift that is economically viable in terms of carbon benefits and of sufficient scale to play a significant role in global climate change mitigation.

https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0122
Title: Re: Permafrost general science thread
Post by: kassy on February 04, 2020, 02:45:09 PM
Rapidly thawing permafrost could double carbon emissions

A new study has found that the abrupt thawing of permafrost in the Arctic will double the carbon emissions suggested by previous estimates.

Scientists at the University of Colorada at Boulder have analysed the permafrost regions towards the Earth's polar north, which is already dramatically altered by climate change.

...

The change in emissions between previous estimates and those in the new study comes from the researchers' distinguishing gradual permafrost thaw - which slowly releases the carbon stores - from abrupt thaws.

The issue is that 20% of the Arctic permafrost layer is rich in ice, meaning it is more susceptible to temperature changes and could thaw more rapidly.

Abrupt thaws are a large emitter of carbon, particularly carbon dioxide but also methane, which is an even more potent greenhouse gas.

According to the researchers, even though less than 5% of the Arctic permafrost is going to be rapidly thawing at any given time, emissions from that rapid thawing will equal the emissions from all of the other areas thawing more gradually.

Although there are a number of ways that abrupt permafrost thaw can happen, the results are always a dramatic change to the ecology.

for much more details see:
https://news.sky.com/story/rapidly-thawing-permafrost-could-double-carbon-emissions-11925962

or
https://phys.org/news/2020-02-arctic-permafrost-greater-role-climate.html

Article:
https://www.nature.com/articles/s41561-019-0526-0
Title: Re: Permafrost general science thread
Post by: longwalks1 on February 04, 2020, 10:10:56 PM
Primary article
 
Carbon release through abrupt permafrost thaw
DOI        https://doi.org/10.1038/s41561-019-0526-0

Quote
However, in areas with excess ground ice, surface subsidence called thermokarst can occur during permafrost  degradation.  Abrupt  thaw  processes  such  as  thermo-karst have long been recognized as influential but are complex and understudied,  and  thus  are  insufficiently  represented  in  coupled  models14. While gradual thaw slowly affects soil by centimetres over decades, abrupt thaw can affect many metres of permafrost soil in periods of days to several years15.

Quote
Data synthesis and first-order models  ...     Here, we describe the numerical, inventory models of initial thaw and ecosystem recovery and present details of the first-order estimates of abrupt thaw carbon release. The goal of our study was to compare the magnitude of emissions from abrupt thaw relative to gradual thaw under similar model  conditions.  To  achieve  this,  we  developed  a  simple,  unified  framework for exploring ecosystem carbon balance across a diverse set  of  abrupt  thaw  processes.  Our  first-order  inventory  method  is  similar  to  initial  assessments  of  land-use  carbon  emissions21,  and  was  used  to  simulate  changes  in  ecosystem  carbon  balance  during  the  initial  abrupt  thaw  stage,  as  well  as  longer-term  ecosystem  recovery (Fig. 1)

Several of their graphs extend from 1900 to 2300 a.d. with Y as  Net radiative forcing (W m2)   
Title: Re: Permafrost general science thread
Post by: TerryM on February 05, 2020, 04:50:43 AM
To limit temperatures to +1.50C we were told we needed to begin by lowering our emissions by 7.6% per year for the next 10 years.


Is there any indication of how much deeper we'll have to dig to accommodate these additional permafrost emissions?


In reality I've seen no appetite for cutting back on our use of fossil fuels, unless a short term profit is somehow to be had. BAU competes with Green BAU because no politician will suggest that any sacrifices need to be made until after he has safely transitioned to the private sector.


We stride bravely into a dystopian future without a thought that perhaps we are the problem.
Terry
Title: Re: Permafrost general science thread
Post by: Florifulgurator on February 05, 2020, 05:42:31 AM
You might remember the story about Pleistocene Park in Russia which is also referenced in the story.
I find the short mention a bit insulting to Sergey Zimov's life work: "The Pleistocene Park, a family-run grassland restoration project". His son Nikita Zimov is actually a coauthor of the paper.

https://en.wikipedia.org/wiki/Sergey_Zimov

https://youtu.be/nEzskUGJ_1I

Slightly older docu:
https://youtu.be/9vP7DiQSPbc
Title: Re: Permafrost general science thread
Post by: kassy on February 05, 2020, 11:11:04 AM
Collapsing permafrost is transforming the Arctic’s waterways

...

It is critically important to realize that permafrost thaw will not stop once the global climate has stabilized, whether at the Paris Agreement limits of 1.5C or 2C, or at much higher levels. Even if anthropogenic carbon emissions are reduced over the coming decades, the concentration of carbon dioxide in the atmosphere will remain above pre-industrial levels for centuries — and likely millennia. Temperatures will also remain high.

As long as the global average temperature stays above the pre-industrial average, permafrost will continue to thaw, ground ice will melt, the land will subside, lakes and streams and freshwater ecosystems will change dramatically, with devastating effects on the peoples of the Arctic who have used these freshwater systems for generations.

Over the next year, governments will make decisions that will limit the increase in global temperature to below 1.5C or allow global warming to further increase to 2C or more. Our decisions will impact the Arctic and the globe for generations.

https://thenarwhal.ca/collapsing-permafrost-is-transforming-the-arctics-waterways/

A general article on permafrost.
Just quoted the conclusion because it bears repeating.
Title: Re: Permafrost general science thread
Post by: Jim Hunt on February 16, 2020, 11:52:19 AM
An enquiry from Claire O’Neill (https://en.wikipedia.org/wiki/Claire_Perry_O%27Neill) via Twitter (https://twitter.com/copwatch26/status/1228932588452155392):

Quote
Does anyone have good data on current permafrost melt rates? Sorry to ask so early on a Sunday!

Any suggestions?
Title: Re: Permafrost general science thread
Post by: kassy on February 16, 2020, 12:19:08 PM
If you look at #50 and #74 #75 most work is about the carbon budget where we see that more carbon is released in winter months then is added as biomass over the summer.

The first post in this thread is a general study so might be closest to what you are looking for.

Some general stuff, no hard numbers but impressions from scientist doing field work:
https://www.nationalgeographic.com/environment/2019/08/arctic-permafrost-is-thawing-it-could-speed-up-climate-change-feature/
https://www.theguardian.com/environment/2019/jun/18/arctic-permafrost-canada-science-climate-crisis

ETA: Direct link to the paper in post #1
https://www.nature.com/articles/s41467-018-08240-4
Title: Re: Permafrost general science thread
Post by: Ken Feldman on February 18, 2020, 06:14:12 PM
An enquiry from Claire O’Neill (https://en.wikipedia.org/wiki/Claire_Perry_O%27Neill) via Twitter (https://twitter.com/copwatch26/status/1228932588452155392):

Quote
Does anyone have good data on current permafrost melt rates? Sorry to ask so early on a Sunday!

Any suggestions?

Start with the latest IPCC Report, the Special Report on Oceans and the Cryosphere from last year. 

https://www.ipcc.ch/srocc/ (https://www.ipcc.ch/srocc/)

Here's a quote from the Executive Summary:

Quote
B.1.4 Widespread permafrost thaw is projected for this century (very high confidence) and beyond. By 2100, projected near-surface (within 3–4 m) permafrost area shows a decrease of 24 ± 16% (likely range) for RCP2.6 and 69 ± 20% (likely range) for RCP8.5. The RCP8.5 scenario leads to the cumulative release of tens to hundreds of billions of tons (GtC) of permafrost carbon as CO2 and methane to the atmosphere by 2100 with the potential to exacerbate climate change (medium confidence). Lower emissions scenarios dampen the response of carbon emissions from the permafrost region (high confidence). Methane contributes a small fraction of the total additional carbon release but is significant because of its higher warming potential. Increased plant growth is projected to replenish soil carbon in part, but will not match carbon releases over the long term (medium confidence). {2.2.4, 3.4.2, 3.4.3, Figure SPM.1, Cross-Chapter Box 5 in Chapter 1}

The numbers in the last sentence lead you to sections of the report for more details.

Section 2.2.4 deals with mountain permafrost.  Here are some details on current thaw rates:

Quote
Permafrost in the European Alps, Scandinavia, Canada, Mongolia, the Tien Shan and the Tibetan Plateau has warmed during recent decades and some observations reveal ground-ice loss and permafrost degradation (high confidence). The heterogeneity of mountain environments and scarcity of long-term observations challenge the quantification of representative regional or global warming rates. A recent analysis finds that permafrost at 28 mountain locations in the European Alps, Scandinavia, Canada as well as High Mountain Asia and North Asia, warmed on average by 0.19 ± 0.05 °C per decade between 2007–2016 (Biskaborn et al., 2019). Over longer periods, observations in the European Alps, Scandinavia, Mongolia, the Tien Shan and the Tibetan Plateau (see also Cao et al., 2018) show general warming (Table 2.1, Figure 2.5) and degradation of permafrost at individual sites (e.g., Phillips et al., 2009). Permafrost close to 0ºC warms at a lower rate than colder permafrost because ground-ice melt slows warming. Similarly, bedrock warms faster than debris or soil because of low ice content. For example, several European bedrock sites (Table 2.1) have warmed rapidly, by up to 1ºC per decade, during the past two decades. By contrast, total warming of 0.5ºC–0.8ºC has been inferred for the second half of the 20th century based on thermal gradients at depth in an ensemble of European bedrock sites (Isaksen et al., 2001; Harris et al., 2003). Warming has been shown to accelerate at sites in Scandinavia (Isaksen et al., 2007) and in mountains globally within the past decade (Biskaborn et al., 2019). During recent decades, rates of permafrost warming in the European Alps and Scandinavia exceeded values of the late 20th century (limited evidence, high agreement).

The observed thickness of the active layer (see Annex I: Glossary), the layer of ground above permafrost subject to annual thawing and freezing, increased in the European Alps, Scandinavia (Christiansen et al., 2010), and on the Tibetan Plateau during the past few decades (Table 2.2), indicating permafrost degradation. Geophysical monitoring in the European Alps during approximately the past 15 years revealed increasing subsurface liquid water content (Hilbich et al., 2008; Bodin et al., 2009; PERMOS, 2016), indicating gradual ground-ice loss.

Section 3.4.2 deals with Arctic permafrost.  Here is the paragraph on temperatures:

Quote
Record high temperatures at ~10–20 m depth in the permafrost (near or below the depths affected by intra-annual fluctuation in temperature) have been documented at many long-term monitoring sites in the Northern Hemisphere circumpolar permafrost region (AMAP, 2017d) (Figure 3.10) (very high confidence). At some locations, the temperature is 2°C–3°C higher than 30 years ago. During the decade between 2007 and 2016, the rate of increase in permafrost temperatures was 0.39°C ± 0.15°C for colder continuous zone permafrost monitoring sites, 0.20°C ± 0.10°C for warmer discontinuous zone permafrost, giving a global average of 0.29 ± 0.12°C across all polar and mountain permafrost (Biskaborn et al., 2019). Relatively smaller increases in permafrost temperature in warmer sites indicate that permafrost is thawing with heat absorbed by the ice-to-water phase change, and as a result, the active layer may be increasing in thickness. In contrast to temperature, there is only medium confidence that active layer thickness across the region has increased. This confidence level is because decadal trends vary across regions and sites (Shiklomanov et al., 2012) and because mechanical probing of the active layer can underestimate the degradation of permafrost in some cases because the surface subsides when ground ice melts and drains (Mekonnen et al., 2016; AMAP, 2017d; Streletskiy et al., 2017). Permafrost in the Southern Hemisphere polar region occurs in ice-free exposed areas (Bockheim et al., 2013), 0.18% of the total land area of Antarctica (Burton-Johnson et al., 2016). This area is three orders of magnitude smaller than the 13–18 x 106 km2 area underlain by permafrost in the Northern Hemisphere terrestrial permafrost region (Gruber, 2012). Antarctic permafrost temperatures are generally colder (Noetzli et al., 2017) and increased 0.37°C ± 0.10°C between 2007 and 2016 (Biskaborn et al., 2019).

If you want more detail, you can follow links in the SROCC to the references.  You could then enter the titles of the references into a search engine and see if there are more recent reports that also cite that reference.

Title: Re: Permafrost general science thread
Post by: gerontocrat on February 18, 2020, 06:47:08 PM
An enquiry from Claire O’Neill (https://en.wikipedia.org/wiki/Claire_Perry_O%27Neill) via Twitter (https://twitter.com/copwatch26/status/1228932588452155392):

Quote
Does anyone have good data on current permafrost melt rates? Sorry to ask so early on a Sunday!

Any suggestions?

Start with the latest IPCC Report, the Special Report on Oceans and the Cryosphere from last year. 

https://www.ipcc.ch/srocc/ (https://www.ipcc.ch/srocc/)
There are studies suggesting things are happening somewhat faster than in the IPCC reports.

https://www.nature.com/articles/d41586-019-01313-4
Permafrost collapse is accelerating carbon release
The sudden collapse of thawing soils in the Arctic might double the warming from greenhouse gases released from tundra, warn Merritt R. Turetsky and colleagues.


Merritt R. Turetsky,
Benjamin W. Abbott, Miriam C. Jones, Katey Walter Anthony, David Olefeldt, Edward A. G. Schuur,
Charles Koven, A. David McGuire, Guido Grosse, Peter Kuhry, Gustaf Hugelius, David M. Lawrence, Carolyn Gibson & A. Britta K. Sannel
 
Title: Re: Permafrost general science thread
Post by: Ken Feldman on February 18, 2020, 09:59:24 PM
An enquiry from Claire O’Neill (https://en.wikipedia.org/wiki/Claire_Perry_O%27Neill) via Twitter (https://twitter.com/copwatch26/status/1228932588452155392):

Quote
Does anyone have good data on current permafrost melt rates? Sorry to ask so early on a Sunday!

Any suggestions?

Start with the latest IPCC Report, the Special Report on Oceans and the Cryosphere from last year. 

https://www.ipcc.ch/srocc/ (https://www.ipcc.ch/srocc/)
There are studies suggesting things are happening somewhat faster than in the IPCC reports.

https://www.nature.com/articles/d41586-019-01313-4
Permafrost collapse is accelerating carbon release
The sudden collapse of thawing soils in the Arctic might double the warming from greenhouse gases released from tundra, warn Merritt R. Turetsky and colleagues.


Merritt R. Turetsky,
Benjamin W. Abbott, Miriam C. Jones, Katey Walter Anthony, David Olefeldt, Edward A. G. Schuur,
Charles Koven, A. David McGuire, Guido Grosse, Peter Kuhry, Gustaf Hugelius, David M. Lawrence, Carolyn Gibson & A. Britta K. Sannel
 

While that is an interesting article on possible future emissions, it doesn't really address the question of current thaw rates.  The 2019 IPCC report still appears to be the best overall summary that addresses the question that was asked.

BTW, the authors of the Nature Comment linked to in the quote box have released their paper on the subject.  It appeared a couple of weeks ago in Nature Geoscience.

https://www.nature.com/articles/s41561-019-0526-0 (https://www.nature.com/articles/s41561-019-0526-0)

Quote
Turetsky, M.R., Abbott, B.W., Jones, M.C. et al. Carbon release through abrupt permafrost thaw. Nat. Geosci. 13, 138–143 (2020). https://doi.org/10.1038/s41561-019-0526-0

Abstract

The permafrost zone is expected to be a substantial carbon source to the atmosphere, yet large-scale models currently only simulate gradual changes in seasonally thawed soil. Abrupt thaw will probably occur in <20% of the permafrost zone but could affect half of permafrost carbon through collapsing ground, rapid erosion and landslides. Here, we synthesize the best available information and develop inventory models to simulate abrupt thaw impacts on permafrost carbon balance. Emissions across 2.5 million km2 of abrupt thaw could provide a similar climate feedback as gradual thaw emissions from the entire 18 million km2 permafrost region under the warming projection of Representative Concentration Pathway 8.5. While models forecast that gradual thaw may lead to net ecosystem carbon uptake under projections of Representative Concentration Pathway 4.5, abrupt thaw emissions are likely to offset this potential carbon sink. Active hillslope erosional features will occupy 3% of abrupt thaw terrain by 2300 but emit one-third of abrupt thaw carbon losses. Thaw lakes and wetlands are methane hot spots but their carbon release is partially offset by slowly regrowing vegetation. After considering abrupt thaw stabilization, lake drainage and soil carbon uptake by vegetation regrowth, we conclude that models considering only gradual permafrost thaw are substantially underestimating carbon emissions from thawing permafrost.

Title: Re: Permafrost general science thread
Post by: Gray-Wolf on February 20, 2020, 10:24:50 AM
Hmmmm;

https://theecologist.org/2020/feb/20/methane-shock

"Analysis published in the journal Nature shows methane emissions from fossil fuels owing to human activity is around 25 percent to 40 percent higher than thought."
Title: Re: Permafrost general science thread
Post by: kassy on February 28, 2020, 11:53:29 PM
Rather general article;
https://e360.yale.edu/features/how-melting-permafrost-is-beginning-to-transform-the-arctic
Title: Re: Permafrost general science thread
Post by: Ken Feldman on March 09, 2020, 06:15:43 PM
Two recent studies addressing permafrost thaw and the effect on the global carbon budget.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JG005501?af=R (https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JG005501?af=R)

Quote
Long‐term impacts of permafrost thaw on carbon storage in peatlands: deep losses offset by surficial accumulation
Liam Heffernan
Cristian Estop‐Aragonés, Klaus‐Holger Knorr, Julie Talbot, David Olefeldt
First published: 19 February 2020

 Abstract

Peatlands in northern permafrost regions store a significant proportion of global soil carbon. Recent warming is accelerating peatland permafrost thaw and thermokarst collapse, exposing previously frozen peat to microbial decomposition and potential mineralization into greenhouse gases. Here we show from a site in the sporadic permafrost zone of western Canada that thermokarst collapse leads to neither large losses nor gains following thaw, as deep carbon losses are offset by surficial accumulation. We collected peat cores along two thaw chronosequences, from peat plateau, through young (~30 years since thaw), intermediate (~70 years) and mature (~200 years) thermokarst bog locations. Macrofossil and 14C analysis showed synchronicity of peatland development until recent thaw, with wetland initiation ~8,500 cal yr BP followed by succession through peatland stages prior to permafrost aggradation ~1,800 cal yr BP. Analysis and modelling of soil carbon stocks indicated 8.7 ± 12.4 kg C m‐2 of carbon accumulated prior to thaw was lost in ~200 years post‐thaw. Despite these losses, there was no observed increase in peat humification as assessed by FTIR and C:N ratios. Rapid peat accumulation post‐thaw (9.8 ± 1.6 kg C m‐2 over 200 years) offset deeper losses. Our approach constrains the net carbon balance to be between uptake of 27.3 g C m‐2 yr‐1 and loss of 106.6 g C m‐2 yr‐1 over 200 years post‐thaw. While our approach cannot determine whether thermokarst bogs in the sporadic permafrost zone act as long‐term carbon sinks or sources post‐thaw, our study better constrains post‐thaw C losses and gains.

https://onlinelibrary.wiley.com/doi/abs/10.1111/geb.13081?af=R (https://onlinelibrary.wiley.com/doi/abs/10.1111/geb.13081?af=R)

Quote
The role of northern peatlands in the global carbon cycle for the 21st century
Chunjing Qiu, Dan Zhu, Philippe Ciais, Bertrand Guenet, Shushi Peng
First published: 03 March 2020


Abstract
Aim

Persistent sinks of atmospheric CO2 in undisturbed peatlands are not included in future projections of the global carbon budget. We aimed to explore possible responses of northern peatlands to future climate change and to quantify the role of northern peatlands in the carbon balance of the Northern Hemisphere.
Location

The terrestrial Northern Hemisphere (>30° N).
Time period

1861–2099.
Major taxa studied

Not a specific plant species, but a plant functional type is used by the model to represent an average of all vegetation growing in northern peatlands.
Methods

The ORCHIDEE‐PEAT v.2.0 process‐based land surface model was used to simulate area and carbon dynamics of northern peatlands. The model was driven up to the year 2099 by the global CO2 concentration from representative concentration pathways (RCPs) 2.6, 6.0 and 8.5 by corresponding climate projections from two general circulation models after bias correction.
Results

First, from 1861 to 2005 the mean annual carbon balance of northern peatlands was an atmospheric CO2 sink of 0.10 PgC/year, and this sink will roughly double in the future under both RCP2.6 and RCP6.0, whereas the total northern peatlands will be either a source of CO2 (IPSL‐CM5A‐LR) or near neutral (GFDL‐ESM2M) by the end of the century under RCP8.5. Second, the peatlands in western Canada, western and northern Europe may experience reducing areas and may shift from being CO2 sinks to sources, especially under rapid climate warming. Third, peatland enhances soil carbon accumulation in the Northern Hemisphere (lands north of 30° N).
Main conclusions

In this study, future changes in both northern peatland extent and peatland carbon storage are simulated. We highlight that undisturbed northern peatlands are small but persistent carbon sinks in the future; thus, it is important to protect these ecosystems.
Title: Re: Permafrost general science thread
Post by: kassy on April 03, 2020, 11:05:22 AM
Arctic climate change – it’s recent carbon emissions we should fear, not ancient methane ‘time bombs’

...

Over thousands of years, carbon has built up in these frozen soils, and they’re now estimated to contain twice the carbon currently in the atmosphere. Some of this carbon is more than 50,000 years old, which means the plants that decomposed to produce that soil grew over 50,000 years ago. These soil deposits are known as “Yedoma”, which are mainly found in the East Siberian Arctic, but also in parts of Alaska and Canada.

As the region warms, the permafrost is thawing, and this frozen carbon is being released to the atmosphere as carbon dioxide and methane. Methane release is particularly worrying, as it’s a highly potent greenhouse gas.

This study suggested to many that ancient methane emissions are not something we should be worried about this century. But in new research, we found that this optimism may be misplaced.

We went to the East Siberian Arctic to compare the age of different forms of carbon found in the ponds, rivers and lakes. These waters thaw during the summer and leak greenhouse gases from the surrounding permafrost. We measured the age of the carbon dioxide, methane and organic matter found in these waters using radiocarbon dating and found that most of the carbon released to the atmosphere was overwhelmingly “young”. Where there was intense permafrost thaw, we found that the oldest methane was 4,800 years old, and the oldest carbon dioxide was 6,000 years old. But over this vast Arctic landscape, the carbon released was mainly from young plant organic matter.

This means that the carbon produced by plants growing during each summer growing season is rapidly released over the next few summers. This rapid turnover releases much more carbon than the thaw of older permafrost, even where severe thaw is occurring.

So what does this mean for future climate change? It means that carbon emissions from a warming Arctic may not be driven by the thawing of an ancient frozen carbon bomb, as it’s often described. Instead, most emissions may be relatively new carbon that is produced by plants that grew fairly recently.

...

The East Siberian Arctic is a generally flat and wet landscape, and these are conditions which produce lots of methane, as there’s less oxygen in soils which might otherwise create carbon dioxide during thaws instead. As a result, potent methane could well dominate the greenhouse gas emissions from the region.

https://theconversation.com/arctic-climate-change-its-recent-carbon-emissions-we-should-fear-not-ancient-methane-time-bombs-135270

Papers mentioned:
Old carbon reservoirs were not important in the deglacial methane budget (PW)
https://science.sciencemag.org/content/367/6480/907

and

East Siberian Arctic inland waters emit mostly contemporary carbon (Open Access)
https://www.nature.com/articles/s41467-020-15511-6

Title: Re: Permafrost general science thread
Post by: kassy on April 07, 2020, 03:31:11 PM
Organic Matter in Arctic River Shows Permafrost Thaw

Samples from two waterways in northern Siberia—the main stem of the Kolyma River and a headwater stream in the river’s watershed—indicate the differing sources and ages of carbon they contain.

...

Arctic rivers receive carbon both from the seasonally thawing top layer of the soil and from eroding riverbanks. Besides the ongoing permafrost thaw, warming of the region also affects the rivers by extending the ice-free season and by changing the way water flows through the landscape and interacts with carbon in the soil.

In a new study, Bröder et al. analyze water from two sites in the Kolyma River watershed in northern Siberia. The Kolyma River flows northward across the easternmost part of Russia, eventually draining into the East Siberian Sea; its watershed is the largest on Earth that is entirely underlain by continuous permafrost. For half of the year, the river is covered by ice; its flow peaks after snowmelt in early summer.

...

The team analyzed both water sources for suspended particulate organic carbon (POC) and dissolved organic carbon (DOC); they also conducted isotope analyses to help understand where the carbon was coming from. The carbon in both sample sites followed a typical pattern, with the highest concentrations showing up in the first few weeks after the ice breakup and tapering off later in the summer. Overall, the main stem of the Kolyma contained more POC, as well as older carbon, than the Y3 headwater stream. Conversely, the Y3 stream had higher DOC than the Kolyma.

The researchers say these findings indicate that POC in the main Kolyma comes from both recent vegetation and permafrost, whereas the POC in the Y3 stream comes primarily from younger plants. The researchers attribute the increased POC concentration in the main Kolyma to active riverbank erosion

https://eos.org/research-spotlights/organic-matter-in-arctic-river-shows-permafrost-thaw

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019JG005511
Title: Re: Permafrost general science thread
Post by: kassy on May 05, 2020, 11:12:25 AM
Scientists are racing to understand permafrost before it’s gone

To enter the Fox Permafrost Tunnel—one of the only places in the world dedicated to the firsthand scientific study of the mix of dirt and ice that covers much of the planet’s far northern latitudes—you must don a hard-hat, then walk into the side of a hill. The hill stands in the rural area of Fox, Alaska, 16 miles north of Fairbanks. The entrance is in a metal wall that’s like a partially dissected Quonset hut, or an enlarged hobbit hole. A tangle of skinny birches and black spruce adorn the top of the hill, and a giant refrigeration unit roars like a jet engine outside the door— o prevent the contents of the tunnel from warping or thawing.

...

https://thebulletin.org/2020/05/scientists-are-racing-to-understand-permafrost-before-its-gone/

Nothing new but an interesting piece of the Fox tunnel.
Title: Re: Permafrost general science thread
Post by: kassy on May 11, 2020, 06:07:55 PM
The linked reference not only finds that the mean annual air temperature, MAAT, in Northwestern Alaska is already within the range that consensus climate models projected would not occur until 2100 following RCP6.0, but also that the projected drainage of future thermokarst lakes will reduce the ability of the associate permafrost areas to sequester carbon in the lake bed sediments as indicated by the following extract:

"Recent MAAT are already within the range of predictions by UAF SNAP ensemble climate predictions in scenario RCP6.0 for 2100.  With MAAT in 2019 exceeding 0 °C at the nearby Kotzebue, Alaska climate station for the first time since continuous recording started in 1949, permafrost aggradation in drained lake basins will become less likely after drainage, strongly decreasing the potential for freeze-locking carbon sequestered in lake sediments, signifying a prominent regime shift in ice-rich permafrost lowland regions."

Nitze, I., Cooley, S., Duguay, C., Jones, B. M., and Grosse, G.: The catastrophic thermokarst lake drainage events of 2018 in northwestern Alaska: Fast-forward into the future, The Cryosphere Discuss., https://doi.org/10.5194/tc-2020-106, in review, 2020.

https://www.the-cryosphere-discuss.net/tc-2020-106/

Abstract. Northwestern Alaska has been highly affected by changing climatic patterns with new temperature and precipitation maxima over the recent years. In particular, the Baldwin and northern Seward peninsulas are characterized by an abundance of thermokarst lakes that are highly dynamic and prone to lake drainage, like many other regions at the southern margins of continuous permafrost. We used Sentinel-1 synthetic aperture radar (SAR) and Planet CubeSat optical remote sensing data to analyze recently observed widespread lake drainage. We then used synoptic weather data, climate model outputs and lake-ice growth simulations to analyze potential drivers and future pathways of lake drainage in this region. Following the warmest and wettest winter on record in 2017/2018, 192 lakes were identified to have completely or partially drained in early summer 2018, which exceeded the average drainage rate by a factor of ~ 10 and doubled the rates of the previous extreme lake drainage years of 2005 and 2006. The combination of abundant rain- and snowfall and extremely warm mean annual air temperatures (MAAT), close to 0 °C, may have led to the destabilization of permafrost around the lake margins. Rapid snow melt and high amounts of excess meltwater further promoted rapid lateral breaching at lake shores and consequently sudden drainage of some of the largest lakes of the study region that likely persisted for millenia. We hypothesize that permafrost destabilization and lake drainage will accelerate and become the dominant drivers of landscape change in this region. Recent MAAT are already within the range of predictions by UAF SNAP ensemble climate predictions in scenario RCP6.0 for 2100. With MAAT in 2019 exceeding 0 °C at the nearby Kotzebue, Alaska climate station for the first time since continuous recording started in 1949, permafrost aggradation in drained lake basins will become less likely after drainage, strongly decreasing the potential for freeze-locking carbon sequestered in lake sediments, signifying a prominent regime shift in ice-rich permafrost lowland regions.

Extract: "The recent events potentially show the fate of lake-rich landscapes in continuous permafrost along its current southern margins, where near-surface permafrost degradation accelerates and permafrost will become discontinuous in the next decades. The colder less dynamic lake-rich coastal plain of northern Alaska may become more dynamic once climatic patterns will have moved towards the middle-to-end of the century.

Under a rapidly warming and wetting climate, in conjunction with ongoing sea ice loss in the Bering Strait, we expect a further intensification of permafrost degradation, reshaping the landscape and a transition from continuous to discontinuous permafrost, and significant changes in hydrology and ecology."

Bolding mine.
Title: Re: Permafrost general science thread
Post by: Juan C. García on May 29, 2020, 11:15:55 AM
‘Zombie fires’ are erupting in Alaska and likely Siberia, signaling severe Arctic fire season may lie ahead
Move over, ‘murder hornets.’ There’s a new 2020 phenomenon to worry about.

https://www.washingtonpost.com/weather/2020/05/28/zombie-fires-burning-arctic-siberia/ (https://www.washingtonpost.com/weather/2020/05/28/zombie-fires-burning-arctic-siberia/)
By Andrew Freedman
May 28 at 1:19 PM
Quote
The bitterly cold Arctic winter typically snuffs out the seasonal wildfires that erupt in this region. But every once in a while, a wildfire comes along that refuses to die.

These blazes, known as “zombie fires” or “holdover fires,” can burrow into the rich organic material beneath the surface, such as the vast peatlands that ring the Arctic, and smolder under the snowpack throughout the frigid winter.

With the Siberian Arctic seeing record warm conditions in recent weeks and months, scientists monitoring Arctic wildfire trends are becoming more convinced that some of the blazes erupting in the Arctic this spring are actually left over from last summer.

Last year brought a record surge in fires to a region that is warming at more than twice the rate of the rest of the world. The Arctic contains vast stores of carbon and other planet-warming greenhouse gases in its soils, in peat as well as frozen soil known as permafrost, that can be freed up through combustion. Peatlands are wetlands that contain ancient, decomposed and partially decomposed organic matter.

According to Mark Parrington, senior scientist and wildfire expert at the European Union’s Copernicus Atmosphere Monitoring Service (CAMS), recent Arctic fire detections have been found in areas where blazes were burning last summer, which lines up with regions affected by warmer-than-average and unusually dry surface conditions.
Picture 1 footnote:
Quote
A forest fire rages outside Atka, Russia, in July 2019. (Michael Robinson Chavez/The Washington Post)
Picture 2 footnote:
Quote
January-to-April temperature departures from average, showing the most significant temperature anomalies across Russia, including Siberia. (Berkeley Earth)
Title: Re: Permafrost general science thread
Post by: Juan C. García on May 29, 2020, 11:58:48 AM
Quote
Dr Thomas Smith
Are these 'zombie' fires? As the snow melted in Arctic Siberia last week, a number of fires have been detected by satellites. Did these fires smoulder through the winter after widespread #wildfires last summer? [short thread 1/5]
https://twitter.com/DrTELS/status/1258045476731002882?s=20 (https://twitter.com/DrTELS/status/1258045476731002882?s=20)
Quote
Fire Science Highlight • Spring 2020
Spatiotemporal patterns of overwintering fire in Alaska
Rebecca Scholten and Sander Veraverbeke, Vrije Universiteit Amsterdam
Alaska Fire Science Consortium

What are holdover and overwintering fires?

Fires can appear to be out, but retain smoldering combustion deep in the fuelbed and flare up again when the weather favors flaming behavior and fire spread. This phenomenon occurs not unfrequently in boreal forests of North America, and presents a well-known challenge to firefighters. Over the last two decades, fire managers noted increasing occurrences where fires survive the cold and wet boreal winter months by smoldering, and re-emerged in the subsequent spring.
https://presentations.copernicus.org/EGU2020/EGU2020-6013_presentation.pdf (https://presentations.copernicus.org/EGU2020/EGU2020-6013_presentation.pdf)
Title: Re: Permafrost general science thread
Post by: Alumril on June 01, 2020, 01:19:19 PM
Apologies for the double post (this is also in the Arctic methane discussion)
Interesting research update on permafrost

https://youtu.be/4nGECF2qSO4
Title: Re: Permafrost general science thread
Post by: Juan C. García on June 02, 2020, 08:24:38 PM
Apologies for the double post (this is also in the Arctic methane discussion)
Interesting research update on permafrost

Great video, Alumril! Thanks for posting it!
Title: Re: Permafrost general science thread
Post by: Florifulgurator on June 05, 2020, 07:09:43 PM
On the recent catastrophic oil spill:

https://www.themoscowtimes.com/2020/06/05/russia-to-review-structures-on-permafrost-after-arctic-spill-a70498

Quote
Russia's prosecutor general on Friday ordered a review of hazardous structures built on permafrost after concluding that a huge Arctic fuel spill last week was caused by shifting ground.

The office of the prosecutor general said in a statement that a preliminary conclusion of the spill's causes is the "sagging of the ground and the concrete foundation" which caused the reservoir's failure.
Title: Re: Permafrost general science thread
Post by: kassy on June 12, 2020, 07:39:27 AM
From the ASLR thread:

The linked reference indicates that:

"… current estimates of additional global warming from the permafrost carbon feedback are too low.

J. C. Bowen, C. P. Ward, G. W. Kling and R. M. Cory (09 June 2020), "Arctic amplification of global warming strengthened by sunlight oxidation of permafrost carbon to CO2", Geophysical Research Letters,  https://doi.org/10.1029/2020GL087085

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL087085

Abstract
Once thawed, up to 15% of the ∼1,000 Pg of organic carbon (C) in arctic permafrost soils may be oxidized to carbon dioxide (CO2) by 2100, amplifying climate change. However, predictions of this amplification strength ignore the oxidation of permafrost C to CO2 in surface waters (photomineralization). We characterized the wavelength dependence of permafrost dissolved organic carbon (DOC) photomineralization and demonstrate that iron catalyzes photomineralization of old DOC (4,000‐6,300 a BP) derived from soil lignin and tannin. Rates of CO2 production from photomineralization of permafrost DOC are two‐fold higher than for modern DOC. Given that model predictions of future net loss of ecosystem C from thawing permafrost do not include the loss of CO2 to the atmosphere from DOC photomineralization, current predictions of an average of 208 Pg C loss by 2299 may be too low by ~14%.

Plain Language Summary
The thawing of organic carbon stored in arctic permafrost soils, and its oxidation to carbon dioxide (a greenhouse gas), is predicted to be a major, positive feedback on global warming. However, current estimates of the magnitude of this feedback do not include the oxidation of permafrost soil organic carbon flushed to sunlit lakes and rivers. Here we show that ancient dissolved organic carbon (> 4,000 years old) draining permafrost soils is readily oxidized to carbon dioxide by sunlight. As a consequence, current estimates of additional global warming from the permafrost carbon feedback are too low.
Title: Re: Permafrost general science thread
Post by: kassy on June 13, 2020, 08:45:08 AM
Patterns in permafrost soils could help climate change models

The Arctic covers about 20% of the planet. But almost everything hydrologists know about the carbon-rich soils blanketing its permafrost comes from very few measurements taken just feet from Alaska's Dalton Highway.

The small sample size is a problem, particularly for scientists studying the role of Arctic hydrology on climate change. Permafrost soils hold vast amounts of carbon, which could turn into greenhouse gases. But the lack of data makes it difficult to predict what will happen to water and carbon as warming temperatures melt permafrost.

New National Science Foundation-funded research led by scientists at the University of Texas at Austin may help solve that problem. The work was conducted at NSF's Arctic Long-Term Ecological Research site.

The scientists spent the past four summers measuring permafrost soils across a 5,000-square-mile swath of Alaska's North Slope, an area about the size of Connecticut. While working to build up a much-needed soil dataset, their measurements revealed an important pattern: The hydrologic properties of different permafrost soil types are very consistent and can be predicted based on the surrounding landscape.

...

https://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=300756&WT.mc_id=USNSF_1

Open access:
Empirical Models for Predicting Water and Heat Flow Properties of Permafrost Soils
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020GL087646
Title: Re: Permafrost general science thread
Post by: kassy on June 13, 2020, 08:47:28 AM
And using this post from ASLR instead of my article link because he adds some other research:

Short intro from the article:
Nitrogen is a constituent part of nitrous oxide (N2O)--an often overlooked greenhouse gas, and there is a vast amount of nitrogen stored in permafrost soils.

But little is known about N2O emissions from permafrost soils and until recently, it was assumed that releases had to be fairly minimal because of the cold climate.

Decomposition of organic matter is slow in low temperatures. Exacerbating this, there would have to be high competition amongst organisms for what little nitrogen there was in a form that they can use. So there couldn't be much nitrogen left over to contribute to N2O releases.

In recent years however, a growing number of papers have started to hint that there might be very high N2O emissions from such soils, perhaps as much as those from tropical forests or croplands, which suggests that there's a gap in our understanding of what happens to nitrogen in permafrost soils.



The linked article, and associated linked reference, indicate N20 releases from future permafrost degradation are likely higher than previously assumed by consensus climate science:

Title: "Nitrogen in permafrost soils may exert great feedbacks on climate change"

https://www.eurekalert.org/pub_releases/2020-06/ioap-nip061220.php

Extract: "Decomposition of organic matter is slow in low temperatures. Exacerbating this, there would have to be high competition amongst organisms for what little nitrogen there was in a form that they can use. So there couldn't be much nitrogen left over to contribute to N2O releases.

In recent years however, a growing number of papers have started to hint that there might be very high N2O emissions from such soils, perhaps as much as those from tropical forests or croplands, which suggests that there's a gap in our understanding of what happens to nitrogen in permafrost soils.

To get to the bottom of the issue, Dr. Michael Dannenmann from the Karlsruhe Institute of Technology and Dr. Chunyan Liu from the Institute of Atmospheric Physics at the Chinese Academy of Sciences with their colleagues have established the "NIFROCLIM" project in a high-latitude permafrost region in northeast China that is part of the Eurasian permafrost complex--the world's largest permafrost area."

See also:

Ramm, E., Liu, C., Wang, X. et al. The Forgotten Nutrient—The Role of Nitrogen in Permafrost Soils of Northern China. Adv. Atmos. Sci. (2020). https://doi.org/10.1007/s00376-020-0027-5

https://link.springer.com/article/10.1007/s00376-020-0027-5
https://link.springer.com/content/pdf/10.1007/s00376-020-0027-5.pdf
Title: Re: Permafrost general science thread
Post by: jens on June 13, 2020, 09:04:05 AM
With the collapse of a Norilsk oil reservoir, I wonder, what is the tipping point, when entire cities/towns in Siberia and Alaska start collapsing? It can't be far away any more and with each passing year more and more buildings are going to collapse. And then I wonder, what will people in those regions do. Will they build new houses and keep living there or evacuate somewhere?
Title: Re: Permafrost general science thread
Post by: nanning on June 13, 2020, 05:24:06 PM
Good post jens imo.

In a global all-lifeforms context:
N₂O is a powerful GHG, then there's also the high-impact threat of large marine methane bursts and in general the likely increasing permafrost emissions in all areas that will be warmed up in an accelerating, step-wise manner because of AGW (BAU).

These permafrost emissions are out of our control!
These emissions will go on. Even when we stop with our anthropogenic emissions. And they are accelerating.

Long term (?) consequences:
A hothouse Earth is coming for certain I think, taking the above in consideration together with all other tipping points. A hyperthermal is likely imo. But that is off-topic here. Sorry, just connecting dots. There are many more dots but I realised that I drifted from the thread topic. Cheers.
Title: Re: Permafrost general science thread
Post by: kassy on June 17, 2020, 06:45:43 AM
Article about the research in #96:

https://e360.yale.edu/digest/climate-models-underestimate-co2-emissions-from-permafrost-by-14-percent-study-finds

Scientists estimate there are about 1,500 billion metric tons of carbon locked away in Arctic permafrost, and that 5 to 15 percent of this carbon could be emitted as carbon dioxide by 2100 — enough to increase global temperatures 0.3 to 0.4 degrees Celsius. But these estimates do not include the CO2 that forms when permafrost carbon escapes into Arctic lakes and rivers and is oxidized by ultraviolet and visible light, a process known as photomineralization.

Researchers at the University of Michigan studied organic carbon from six different Arctic locations and found that substantial carbon dioxide emissions could be released through photomineralization — enough to raise permafrost-related CO2 emissions by 14 percent.
...
“Only recently have global climate models included greenhouse gases from thawing permafrost soils. But none of them contain this feedback pathway,”

Title: Re: Permafrost general science thread
Post by: vox_mundi on July 01, 2020, 03:09:45 AM
Beavers Gnawing Away at the Arctic Permafrost
https://phys.org/news/2020-06-beavers-gnawing-arctic-permafrost.html

Alaska's beavers are profiting from climate change, and spreading rapidly. In just a few years' time, they have not only expanded into many tundra regions where they'd never been seen before; they're also building more and more dams in their new homes, creating a host of new water bodies. This could accelerate the thawing of the permafrost soils, and therefore intensify climate change, as an International American-German research team reports in the journal Environmental Research Letters.

(https://cdn.iopscience.com/images/1748-9326/15/7/075005/Full/erlab80f1f2_lr.jpg)
The upper two images are photos taken within the study area in 2016 showing the tundra region setting. The bottom two images are taken from similar tundra across Hotham Inlet in 2015 (lower left) and 2011 (lower right) showing beaver dams in a drained lake basin outlet and along a beaded stream course, respectively.

... Back in 2018, Ingmar Nitze and Guido Grosse from the AWI, together with colleagues from the U.S., determined that the beavers living in an 18,000-square-kilometer section of northwest Alaska had created 56 new lakes in just five years. For their new study, the team from the AWI, the University of Alaska in Fairbanks, and the University of Minnesota in Minneapolis have now taken a closer look at this trend. Using detailed satellite data and extended time series, the experts tracked the beavers' activities in two other regions in Alaska—and were surprised by what they found.

"Of course, we knew that the beavers there had spread substantially over the last few decades," says Nitze. This is partly due to climate change; thanks to rising temperatures, now more and more habitats offer the shrubs that the animals need for food and building material. Furthermore, the lakes, which used to freeze solid, now offer beaver-friendlier conditions, thanks to their thinner seasonal winter ice cover. Lastly, the rodents aren't hunted as intensively as in the past. As a result, it's a good time to be a beaver in the Arctic.

"But we never would have dreamed they would seize the opportunity so intensively," says Nitze. The high-resolution satellite images of the roughly 100-square-kilometer study area near the town of Kotzebue reveal the scale of the animals' activities there. From just two dams in 2002, the number had risen to 98 by 2019—a 5,000-percent increase, with more than 5 new dams being constructed per year. And the larger area surveyed, which covers the entire northern Baldwin Peninsula, also experienced a beaver dam boom. According to Nitze, "We're seeing exponential growth there. The number of these structures doubles roughly every four years."

This has already affected the water balance. Apparently, the rodents intentionally do their work in those parts of the landscape that they can most easily flood. To do so, sometimes they dam up small streams, and sometimes the outlets of existing lakes, which expand as a result. "But they especially prefer drained lake basins," Benjamin Jones, lead author of the study, and Nitze report. In many cases, the bottoms of these former lakes are prime locations for beaver activity. "The animals have intuitively found that damming the outlet drainage channels at the sites of former lakes is an efficient way to create habitat. So a new lake is formed which degrades ice-rich permafrost in the basin, adding to the effect of increasing the depth of the engineered waterbody," added Jones. These actions have their consequences: in the course of the 17-year timeframe studied, the overall water area in the Kotzebue region grew by 8.3 percent. And roughly two-thirds of that growth was due to the beavers.

The researchers suspect that there have been similar construction booms in other regions of the Arctic; accordingly, they now want to expand their 'beaver manhunt' across the Arctic. "The growth in Canada, for example, is most likely even more extreme," says Nitze. And each additional lake thaws the permafrost below it and on its banks. Granted, the frozen soil could theoretically bounce back after a few years, when the beaver dams break; but whether or not the conditions will be sufficiently cold for that to happen is anyone's guess.

(https://cdn.iopscience.com/images/1748-9326/15/7/075005/Full/erlab80f1f3_lr.jpg)
Mapping beaver dams in high-resolution satellite imagery available for the northern Baldwin Peninsula, Alaska. The location of individual dams indicated with red arrow and the flow direction with a light blue arrow. (a) A series of four dams at the outlet of a lake, (b) a ~60 m long dam built in a drained lake basin, (c) a series of dams at the outlet of a lake near a confluence with a beaded stream, (d) a series of dams in a channel running through the middle of a drained lake basin, (e) five dams progressing down the outlet channel of a thermokarst lake, and (f) a series of dams in a beaded stream gulch. Examples shown here taken from 2019 images; note differences in scale across image frames. All dams were constructed after 2002.

Benjamin M. Jones et al, Increase in beaver dams controls surface water and thermokarst dynamics in an Arctic tundra region, Baldwin Peninsula, northwestern Alaska, Environmental Research Letters (2020).
https://iopscience.iop.org/article/10.1088/1748-9326/ab80f1
Title: Re: Permafrost general science thread
Post by: vox_mundi on July 20, 2020, 10:20:19 PM
40 More Gt of CO2 Baked In: Plant Roots Increase Carbon Emission from Permafrost Soils
https://phys.org/news/2020-07-roots-carbon-emission-permafrost-soils.html

Plant roots in soil stimulate microbial decomposition, a mechanism called the priming effect. An international research team co-lead by Frida Keuper from INRAE and Umeå University and Birgit Wild from Stockholm University shows that the priming effect alone can cause emission of 40 billion tons carbon from permafrost by 2100. The study was published today in Nature Geoscience.

Scientists have previously anticipated that rapidly rising temperatures will drive the emission of 50-100 billion ton permafrost carbon by 2100. On top of that, plant roots feed sugar to the microorganisms in the soil, which the microbes can use to break down more soil organic matter—the priming effect—resulting in even higher greenhouse gas emissions.

The researchers combined maps of plant activity and data on soil carbon content from the Northern Circumpolar Soil Carbon Database with an extensive literature survey on priming and plant root properties, to estimate the priming effect in permafrost ecosystems and its influence on greenhouse gas emissions.

They show that the priming effect increases soil microbial respiration by 12 percent, which causes the additional loss of 40 billion tons of carbon by 2100 compared to current predictions for permafrost. This equals almost a quarter of the remaining "carbon budget" for human activities to limit global warming to max 1.5°C.

Carbon loss from northern circumpolar permafrost soils amplified by rhizosphere priming, Nature Geoscience (2020).
https://www.nature.com/articles/s41561-020-0607-0
Title: Re: Permafrost general science thread
Post by: vox_mundi on July 25, 2020, 02:53:37 AM
Alaska Is Getting Wetter. That's Bad News for Permafrost and the Climate
https://phys.org/news/2020-07-alaska-wetter-bad-news-permafrost.html

Alaska is getting wetter. A new study spells out what that means for the permafrost that underlies about 85% of the state, and the consequences for Earth's global climate.

The study, published today in Nature Publishing Group journal Climate and Atmospheric Science, is the first to compare how rainfall is affecting permafrost thaw across time, space, and a variety of ecosystems. It shows that increased summer rainfall is degrading permafrost across the state.

As Siberia remains in the headlines for record-setting heat waves and wildfires, Alaska is experiencing the rainiest five years in its century-long meteorological record. Extreme weather on both ends of the spectrum—hot and dry versus cool and wet—are driven by an aspect of climate change called Arctic amplification.
"In our research area the winter has lost almost three weeks to summer," says study lead author and Fairbanks resident Thomas A. Douglas, who is a scientist with the U.S. Army Cold Regions Research and Engineering Laboratory. "This, along with more rainstorms, means far more wet precipitation is falling every summer."

Over the course of five years, the research team took 2750 measurements of how far below the land's surface permafrost had thawed by the end of summer across a wide range of environments near Fairbanks, Alaska. The five-year period included two summers with average precipitation, one that was a little drier than usual, and the top and third wettest summers on record. Differences in annual rainfall were clearly imprinted in the amount of permafrost thaw.

More rainfall led to deeper thaw across all sites. After the wettest summer in 2014, permafrost didn't freeze back to previous levels even after subsequent summers were drier. Wetlands and disturbed sites, like trail crossings and clearings, showed the most thaw. Tussock tundra, with its deep soils and covering of tufted grasses, has been found to provide the most ecosystem protection of permafrost. While permafrost was frozen closest to the surface in tussock tundra, it experienced the greatest relative increase in the depth of thaw in response to rainfall, possibly because water could pool on the flat surface. Forests, especially spruce forests with thick sphagnum moss layers, were the most resistant to permafrost thaw. Charlie Koven, an Earth system modeler with the Lawrence Berkeley National Laboratory, used the field measurements to build a heat balance model that allowed the team to better understand how rain was driving heat down into the permafrost ground.

(https://media.springernature.com/lw685/springer-static/image/art%3A10.1038%2Fs41612-020-0130-4/MediaObjects/41612_2020_130_Fig5_HTML.png)
Relationships between active layer depth and summer precipitation.

Thomas A. Douglas et al, Increased rainfall stimulates permafrost thaw across a variety of Interior Alaskan boreal ecosystems, npj Climate and Atmospheric Science (2020)
https://www.nature.com/articles/s41612-020-0130-4
Title: Re: Permafrost general science thread
Post by: kassy on July 25, 2020, 07:46:42 AM
Experiments Reveal How Permafrost Carbon Becomes Carbon Dioxide

Field samples from Alaska show how sunlight and iron convert permafrost carbon to carbon dioxide. Climate models ignore this process.

...

Researchers have now experimentally studied how sunlight triggers carbon dioxide production from permafrost carbon that’s been flushed to lakes and rivers, a process long ignored in climate models.

Current estimates of global warming from permafrost carbon feedback are biased low, the team concluded.

...

Microbes and Sunlight
One way in which permafrost carbon gets converted to carbon dioxide is via microbes—some microscopic life-forms chow down on carbon and respire carbon dioxide.

Although this microbial process is generally taken into account in climate models, comparably little is known about the permafrost carbon that’s flushed to lakes and rivers, where it’s exposed to sunlight. “We’ve known for a while that sunlight converts organic carbon to carbon dioxide, but the governing control of this process has escaped us,” said Ward.

It’s been hypothesized that this photomineralization might be controlled by the presence of iron, which is abundant in Arctic fresh waters. “There have been lots of lab-based studies suggesting that iron is a key player, but this is the first to let nature tell us what controls this process,” said Ward.

In 2018, Ward and his colleagues collected five samples of permafrost from northern Alaska. Back in the laboratory, they thawed the permafrost, filtered out the microbes, and isolated the dissolved organic carbon and other constituents, including iron. They then exposed the samples to different wavelengths of ultraviolet and visible light.

Visible Light Wins
In nature, the highest rates of photomineralization occur in the presence of visible light, Ward and his colleagues calculated. Two factors contribute to this finding. First, Earth’s surface receives significantly more visible light than ultraviolet light. Second, iron kick-starts reactions at longer wavelengths, the team showed. (Visible light is characterized by longer wavelengths than ultraviolet light.)

Photomineralization’s wavelength dependence has important implications, said Ward. It means that permafrost carbon in deep lakes or rivers is still apt to be converted to carbon dioxide. “As you move deeper into the water column, there’s less ultraviolet light available and more visible light,” said Ward.

Older and More Effective
The researchers also determined that the older carbon found in permafrost—several thousand years old—was roughly twice as effective at producing carbon dioxide as modern carbon. Modern carbon has more sunlight-absorbing compounds, said team member Jenny Bowen, a biogeochemist at the University of Michigan, but permafrost carbon is better at reaping the reaction-promoting benefits of iron.

This unaccounted-for contribution from old carbon has the potential to fundamentally change the carbon cycle, said Ted Schuur, an ecosystem ecologist at Northern Arizona University in Flagstaff not involved in the research. “Stuff that wasn’t part of the atmosphere is suddenly ending up in the atmosphere.”
Since photomineralization of permafrost carbon isn’t presently included in climate models, estimates of future global warming are biased low, the researchers concluded. “Sunlight increases the amount of carbon dioxide coming from thawing permafrost by 14%,” said Bowen. “The planet will warm even more than expected.”

These results were published last month in Geophysical Research Letters.

...

https://eos.org/articles/experiments-reveal-how-permafrost-carbon-becomes-carbon-dioxide



Arctic Amplification of Global Warming Strengthened by Sunlight Oxidation of Permafrost Carbon to CO2

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020GL087085

Title: Re: Permafrost general science thread
Post by: blumenkraft on August 11, 2020, 03:02:10 PM
Anthrax Outbreak In Russia Thought To Be Result Of Thawing Permafrost

Quote
Russia is fighting a mysterious anthrax outbreak in a remote corner of Siberia. Dozens of people have been hospitalized; one child has died. The government airlifted some families out because more than 2,000 reindeer have been infected.

Link >> https://www.npr.org/sections/goatsandsoda/2016/08/03/488400947/anthrax-outbreak-in-russia-thought-to-be-result-of-thawing-permafrost
Title: Re: Permafrost general science thread
Post by: kassy on August 12, 2020, 12:26:45 PM
Climate change: Warming world will be 'devastating' for frozen peatlands

The world's peatlands will become a large source of greenhouse gases as temperatures rise this century, say scientists.

Right now, huge amounts of carbon are stored in boggy, often frozen regions stretching across northern parts of the world.

But much of the permanently frozen land will thaw this century, say experts.

This will release warming gases at a rate that could be 30-50% greater than previous estimates.

Using data compiled from more than 7,000 field observations, the authors of this new study were able to generate the most accurate maps to date of the peatlands, their depth and the amount of warming gases they contain.

They show that the boggy terrain covers 3.7 million sq kilometres (1.42 million sq miles).

...

"But my best estimate is that this shift will occur in the second half of this century."

....

If this new peatland estimate is included with all the estimates for permafrost melting, it is projected to equal the annual emissions of the EU and UK by 2100.

"The only way to limit the permafrost carbon feedback is to reduce global warming," said Dr Hugelius.

https://www.bbc.com/news/science-environment-53726487

So this is both permafrost and non permafrost peatlands combined. That of course does not matter for the planet.

Large stocks of peatland carbon and nitrogen are
vulnerable to permafrost thaw
https://www.pnas.org/content/pnas/early/2020/08/04/1916387117.full.pdf
Title: Re: Permafrost general science thread
Post by: morganism on August 22, 2020, 07:13:48 PM
Electric mud’ teems with new, mysterious bacteria

"The bacteria also alter the mud’s chemistry, making layers closer to the surface more alkaline and deeper layers more acidic, Malkin has found. Such pH gradients can affect “numerous geochemical cycles,” she says, including those involving arsenic, manganese, and iron, creating opportunities for other microbes.

With vast swaths of the planet covered by mud, cable and nanowire bacteria are likely having an influence on global climate, researchers say. Nanowire bacteria, for example, can strip electrons from organic materials, such as dead diatoms, then shuttle them to other bacteria that produce methane—a potent greenhouse gas. Under different circumstances, cable bacteria can reduce methane production.

https://www.sciencemag.org/news/2020/08/electric-mud-teems-new-mysterious-bacteria

Title: Re: Permafrost general science thread
Post by: BornFromTheVoid on August 27, 2020, 11:45:35 AM
New paper is available now, feel free to ask any question about it.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL087917

Abstract
High overall rates of permafrost cliff retreat, coupled with spatial variability, have been accompanied by increased uncertainty over future landscape dynamics. We map long‐term (>80 years) retreat of the shoreline and photogrammetrically analyze historic aerial imagery to quantify the processes at a permafrost coast site with massive ground ice. Retreat rates have been relatively constant but topographic changes show that subsidence is a potentially critical but often ignored component of coastal sensitivity, exceeding landward recession by over 3 times during the last 24 years. We calibrate novel passive seismic surveys along clear and variable exposures of massive ground ice and then spatially map key sub‐surface layers. Combining decadal patterns of volumetric change with new ground ice variation maps enables past trends to be interpreted, future volumetric geomorphic behavior to be better constrained, and improves the assessment of permafrost coast sensitivity and the release of carbon‐bearing material.
Title: Re: Permafrost general science thread
Post by: Tor Bejnar on August 27, 2020, 05:39:26 PM
I wasn't familiar with the term "ground ice", so I looked it up on the inter-tubey thing:
From Glossary of Permafrost and Related Ground-Ice Terms (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiM97S61LvrAhXHtlkKHbDDBA8QFjANegQIBBAB&url=http%3A%2F%2Fglobalcryospherewatch.org%2Freference%2Fglossary_docs%2Fpermafrost_and_ground_terms_canada.pdf&usg=AOvVaw0n5K3MI0hCm4mHw-19wOWH) (a PDF)
Quote
ice, ground (see also ice, buried; ice, epigenetic; ice, intrusive; ice,
syngenetic)
[glace de sol]
A general term referring to all types of ice formed in freezing and frozen
ground(see Figure 10).
COMMENT: Ground ice occurs in pores, cavities, voids or other
openings in soil or rock and includes massiveice, but generally excludes
buriedice. Ground ice may be epigenetic or syngenetic,
contemporaneous or relict, aggrading or degrading, perennial or
seasonal. It may occur as lenses, wedges, veins, sheets, seams, irregular
masses, or as individual crystals or coatings on mineral or organic
particles. Perennial ground ice can only occur within permafrost bodies.
REFERENCES: Mackay, 1972b; Pollard and French, 1980.

So (from reading the plain language offering), when climate warms, permafrost melts.  A couple things happen:
Title: Re: Permafrost general science thread
Post by: longwalks1 on August 27, 2020, 06:38:08 PM
A short quote from BFV #109 post for  https://doi.org/10.1029/2020GL087917        Massive Ice Control on Permafrost Coast Erosion and Sensitivity

Quote
2.Regional Setting and Methods The Tuktoyaktuk Coastlands, northwest Canada,arelocated within the southern Beaufort Sea area  and aredominated  by  ice-rich permafrost landscapes(Rampton,  1988).  Thisgenerally flat, deltaiclandscape is punctuated by ice cored plateaus and domes acrossthe tundra. Here, we focus on Peninsula Point(Figure 1a), 6 km southwest of Tuktoyaktukandwithin the Pingo Canadian Landmark (a national historic site managed by Parks Canada), itis a representative type-site  for  intrasedimental  massive  ice (Gilbert  et  al.,  2016;  Mackay  &  Dallimore,  1992; Murton,  2009). Compoundingthe dynamic  erosion  processesin  the  area (Murton,  2005), reduced sea-ice (Overeem et al., 2011)and frozen ground seasons (Laberge & Payette, 1995; Liljedahl et al., 2016), increasing storm intensity (Vermaire et al., 2013)and a relative 2.5 mm a-1sea-level rise (Hill et al., 1993)have intensified the degradation of permafrost coasts in the region

Passive seismic surveys, nicer to the larger fauna, the caribou need all the TLC that they can get.   

Quote
3.2Mapping subsurface structure of massive iceThis work demonstrates that passive seismic surveys can determine the presence and depth of massive ice within challenging permafrost coast ground conditions.

Just a stellar usage of old data and new right sized technology. 

Just west of Tuktoyatuk.  About 30 - 35 km east of the McKenzie.  Quick background of the scene at
https://en.wikipedia.org/wiki/Pingo_National_Landmark
Title: Re: Permafrost general science thread
Post by: BornFromTheVoid on August 27, 2020, 08:40:14 PM
I wasn't familiar with the term "ground ice", so I looked it up on the inter-tubey thing:
From Glossary of Permafrost and Related Ground-Ice Terms (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiM97S61LvrAhXHtlkKHbDDBA8QFjANegQIBBAB&url=http%3A%2F%2Fglobalcryospherewatch.org%2Freference%2Fglossary_docs%2Fpermafrost_and_ground_terms_canada.pdf&usg=AOvVaw0n5K3MI0hCm4mHw-19wOWH) (a PDF)
Quote
ice, ground (see also ice, buried; ice, epigenetic; ice, intrusive; ice,
syngenetic)
[glace de sol]
A general term referring to all types of ice formed in freezing and frozen
ground(see Figure 10).
COMMENT: Ground ice occurs in pores, cavities, voids or other
openings in soil or rock and includes massiveice, but generally excludes
buriedice. Ground ice may be epigenetic or syngenetic,
contemporaneous or relict, aggrading or degrading, perennial or
seasonal. It may occur as lenses, wedges, veins, sheets, seams, irregular
masses, or as individual crystals or coatings on mineral or organic
particles. Perennial ground ice can only occur within permafrost bodies.
REFERENCES: Mackay, 1972b; Pollard and French, 1980.

So (from reading the plain language offering), when climate warms, permafrost melts.  A couple things happen:
  • what was once hard (frozen hard) is now soft and erodible
  • what was once frozen H2O in the ground is now liquid and it flows away, causing the surface to 'slump' (locally or widespread)

We were dealing with a site that was specifically know for its massive ice bodies. These are thick  layers, up to 10s of meters, covered by permafrost and usually with permafrost below them too.

Here's an example from the field site, with the SfM models we used too.
(https://max.nwstatic.co.uk/newsimages2016/weekly/20200808/Picture6.jpg)

We examined the erosion process called retrogressive thaw slumps. Where cliffs form over these massive ice bodies and spread inland really quickly. They can cause so much material to flow towards the shoreline that it results in large mud lobes causing transient progradation, like the lobe in the pic above. This means you get mass loss through vertical changes in the landscape several times faster than from shoreline retreat
Title: Re: Permafrost general science thread
Post by: BornFromTheVoid on August 27, 2020, 08:44:21 PM
A short quote from BFV #109 post for  https://doi.org/10.1029/2020GL087917        Massive Ice Control on Permafrost Coast Erosion and Sensitivity

Quote
2.Regional Setting and Methods The Tuktoyaktuk Coastlands, northwest Canada,arelocated within the southern Beaufort Sea area  and aredominated  by  ice-rich permafrost landscapes(Rampton,  1988).  Thisgenerally flat, deltaiclandscape is punctuated by ice cored plateaus and domes acrossthe tundra. Here, we focus on Peninsula Point(Figure 1a), 6 km southwest of Tuktoyaktukandwithin the Pingo Canadian Landmark (a national historic site managed by Parks Canada), itis a representative type-site  for  intrasedimental  massive  ice (Gilbert  et  al.,  2016;  Mackay  &  Dallimore,  1992; Murton,  2009). Compoundingthe dynamic  erosion  processesin  the  area (Murton,  2005), reduced sea-ice (Overeem et al., 2011)and frozen ground seasons (Laberge & Payette, 1995; Liljedahl et al., 2016), increasing storm intensity (Vermaire et al., 2013)and a relative 2.5 mm a-1sea-level rise (Hill et al., 1993)have intensified the degradation of permafrost coasts in the region

Passive seismic surveys, nicer to the larger fauna, the caribou need all the TLC that they can get.   

Quote
3.2Mapping subsurface structure of massive iceThis work demonstrates that passive seismic surveys can determine the presence and depth of massive ice within challenging permafrost coast ground conditions.

Just a stellar usage of old data and new right sized technology. 

Just west of Tuktoyatuk.  About 30 - 35 km east of the McKenzie.  Quick background of the scene at
https://en.wikipedia.org/wiki/Pingo_National_Landmark

Cheers!
The combination of the passive seismics with the cm scale surface models generated from drone imagery meant we could create 3D models of sections of the site too. That way we can figure out how much of the ground is soil vs ice. This matters for how fast it will erode, the mechanism by which it will erode, and knowing the constituents (ice vs soil) we can better constrain the volume of carbon that will be released too.
Title: Re: Permafrost general science thread
Post by: Tor Bejnar on August 27, 2020, 08:46:49 PM
cleaned up quotes (without actual access to paper):
Quote
    2. Regional Setting and Methods.  The Tuktoyaktuk Coastlands, northwest Canada, are located within the southern Beaufort Sea area and are dominated by ice-rich permafrost landscapes (Rampton, 1988).  This generally flat, deltaic landscape is punctuated by ice cored plateaus and domes across the tundra.  Here, we focus on Peninsula Point (Figure 1a), 6 km southwest of Tuktoyaktuk and within the Pingo Canadian Landmark (a national historic site managed by Parks Canada), it is a representative type-site  for  intrasedimental massive ice (Gilbert et al., 2016; Mackay & Dallimore, 1992; Murton, 2009). Compounding the dynamic erosion processes in  the area (Murton, 2005), reduced sea-ice (Overeem et al., 2011) and frozen ground seasons (Laberge & Payette, 1995; Liljedahl et al., 2016), increasing storm intensity (Vermaire et al., 2013) and a relative 2.5 mm a-1 sea-level rise (Hill et al., 1993) have intensified the degradation of permafrost coasts in the region.




    3.2 Mapping subsurface structure of massive ice.  This work demonstrates that passive seismic surveys can determine the presence and depth of massive ice within challenging permafrost coast ground conditions.
Title: Re: Permafrost general science thread
Post by: Tor Bejnar on August 27, 2020, 09:24:13 PM
I've read a tiny bit about "retrogressive thaw slumps"  and was aware of how fast a multi-meter thick area (volume) of recent permafrost can mobilize, flowing into streams or the sea ("mud flows," we used to call them). 

I wasn't aware of how thick 'pure' ice could be within the permafrost.  At first (just now) I wondered how 'lenses' grew so thick, but then imagined a (10s-to-100s-of-centuries long) series of freeze/thaw [just above the ice] cycles could built up the ice layer to basically any thickness.  (I don't presume to understand the actual physics ... and my imagination is just my imagination.) 

Wow!  'Wouldn't want to be walking around that area on the wrong day!

A neighbor in New Hampshire, one Summer, paved his long-used mostly dirt driveway, and the next Spring (Mud Season) his pickup truck (well, one wheel) fell through the pavement up to its axle.  Solid ground really can become "quicksand". 
Title: Re: Permafrost general science thread
Post by: BornFromTheVoid on August 27, 2020, 10:27:58 PM
I've read a tiny bit about "retrogressive thaw slumps"  and was aware of how fast a multi-meter thick area (volume) of recent permafrost can mobilize, flowing into streams or the sea ("mud flows," we used to call them). 

I wasn't aware of how thick 'pure' ice could be within the permafrost.  At first (just now) I wondered how 'lenses' grew so thick, but then imagined a (10s-to-100s-of-centuries long) series of freeze/thaw [just above the ice] cycles could built up the ice layer to basically any thickness.  (I don't presume to understand the actual physics ... and my imagination is just my imagination.) 

Wow!  'Wouldn't want to be walking around that area on the wrong day!

A neighbor in New Hampshire, one Summer, paved his long-used mostly dirt driveway, and the next Spring (Mud Season) his pickup truck (well, one wheel) fell through the pavement up to its axle.  Solid ground really can become "quicksand".

The one on Peninsula Point formed as the Laurentide ice sheet was retreating, so the ground was freezing but there was loads of subsurface meltwater flowing and freezing too. it may have been up to 20 m thick at one stage.

The number and growth of thaw slumps are crazy. This study from the nearby Banks Island, showing a 60 fold increase in their numbers since the mid 80s

https://www.nature.com/articles/s41467-019-09314-7

I have some cool pics and animation of the slumps too. I'll post them up tomorrow if I get the time. You can literally watch them developing just standing there.
Title: Re: Permafrost general science thread
Post by: Sebastian Jones on August 28, 2020, 12:22:59 AM
I've read a tiny bit about "retrogressive thaw slumps"  and was aware of how fast a multi-meter thick area (volume) of recent permafrost can mobilize, flowing into streams or the sea ("mud flows," we used to call them). 
........................


The one on Peninsula Point formed as the Laurentide ice sheet was retreating, so the ground was freezing but there was loads of subsurface meltwater flowing and freezing too. it may have been up to 20 m thick at one stage.

The number and growth of thaw slumps are crazy. This study from the nearby Banks Island, showing a 60 fold increase in their numbers since the mid 80s

https://www.nature.com/articles/s41467-019-09314-7

I have some cool pics and animation of the slumps too. I'll post them up tomorrow if I get the time. You can literally watch them developing just standing there.

We have a community science thaw slump monitoring project on the Dempster Highway- the road that leads (most of the way) to BFTV's study area.
I'd love to read the entire paper, is there a way to get it out from behind the paywall? SciHub does not have it yet.
Title: Re: Permafrost general science thread
Post by: gerontocrat on October 02, 2020, 09:38:35 PM
This one is about the cascading effects of permafrost thaw on slopes - in NW Canada, but must be applicable over all the permafrosted tundra.

Quote
Short summary
We address knowledge gaps in the understanding the climate-driven amplification of slope thermokarst, the evolution of downstream linkages, and the cascade of consequences. The non-linear intensification of thaw-driven landslides in glaciated permafrost terrain of northwestern Canada has strengthened slope to stream connectivity. Primary effects to headwater systems indicate the major potential for long-term impacts and their propagation across watershed scales to coastal environments.
https://tc.copernicus.org/preprints/tc-2020-218/tc-2020-218.pdf
Permafrost thaw couples slopes with downstream systems and effects propagate through Arctic drainage networks
Quote
Abstract.
The intensification of thaw-driven mass wasting is transforming glacially-conditioned permafrost terrain, coupling slopes with aquatic systems, and triggering a cascade of downstream effects. Within the context of recent, rapidly evolving climate controls on the geomorphology of permafrost terrain we:
A) quantify three-dimensional slump enlargement and described the processes and thresholds coupling slopes to downstream systems;
B) investigate catchment-scale patterns of slope thermokarst (thaw slumps and slides) impacts and the geomorphic implications; and
C) project the propagation of effects through hydrological networks draining continuous permafrost of northwestern Canada.

Power-law relationships between thaw-slump area and volume (R2 = 0.90), and thickness of permafrost thawed (R2 = 0.63), combined with the multi-decadal (1985–2018) increase in areal extent of thaw-slump disturbance show a two-order of magnitude increase in catchment-scale geomorphic activity and the coupling of slope and hydrological systems.

Predominant catchment effects are to first- and second-order streams where sediment delivery commonly exceeds stream transport capacity by orders of magnitude indicating millennial-scale perturbation of downstream systems. Assessment of hydrological networks indicates thaw-driven mass wasting directly affects over 6,760 km of stream segments, 890 km of coastline, and 1,370 lakes in the 994,860 km2 study area.

Downstream propagation of slope thermokarst indicates a potential increase in the number of affected lakes by at least a factor of 4 (n > 5,600), impacted stream length by a factor of 7 (> 48,000 km) and defines several major impact zones to lakes, deltas, and coastal areas. Prince of Wales Strait is the receiving marine environment for greatly increased sediment and geochemical fluxes from numerous slump impacted hydrological networks draining the landmasses of Banks and Victoria Islands. Peel and Mackenzie Rivers are globally significant conveyors of the slope thermokarst cascade delivering effects to North America’s largest Delta and the Beaufort Sea.

Climate-driven erosion of ice-rich slopes in permafrost preserved glaciated terrain has triggered a time-transient cascade of downstream effects that signal the renewal of post-glacial landscape evolution. Glacial legacy and the patterns of continental drainage dictate that terrestrial, freshwater and marine environments of western Arctic Canada will be an interconnected hotspot of thaw-driven change through the coming millennia.
Title: Re: Permafrost general science thread
Post by: longwalks1 on October 03, 2020, 03:01:47 AM
I just went straight to the article. The phrases "non-linear increase",   "2 order of magnitude increase",   just jumped out at me.  Going back to the summation I see you italicized those.      I await comment from BTFV and others over the article especially  the Tuktoyaktuk  Coastland  implications.  Wow.   
Title: Re: Permafrost general science thread
Post by: icefisher on October 04, 2020, 01:20:44 AM
"Permafrost is melting from the top-down and bottom-up."  Response of Vladimir Romanovsky Professor at International Arctic Research Center, Fairbanks Alaska; to a question from Elizabeth Kolbert in her 2006 book "Field Notes from a Catastrophe".  Professor Romanovsky installed a series of temperature gauges in boreholes across a section of Alaskan permafrost.  He's been studying Alaskan permafrost for at least 20 years. Haven't had time to catch up on his publications. He can be reached at veromanovsky@alaska.edu. 
Title: Re: Permafrost general science thread
Post by: vox_mundi on October 16, 2020, 09:49:46 PM
Arctic Ocean Sediments Reveal Permafrost Thawing During Past Climate Warming
https://phys.org/news/2020-10-arctic-ocean-sediments-reveal-permafrost.html

Sea floor sediments of the Arctic Ocean can help scientists understand how permafrost responds to climate warming. A multidisciplinary team from Stockholm University has found evidence of past permafrost thawing during climate warming events at the end of the last ice age. Their findings, published in Science Advances, caution about what could happen in the near future: That Arctic warming by only a few degrees Celsius may trigger massive permafrost thawing, coastal erosion, and the release of the greenhouse gases carbon dioxide (CO2) and methane (CH4) into the atmosphere.

... "Our new study shows for the first time the full history of how warming at the end of the last ice age triggered permafrost thawing in Siberia. This also suggests the release of large quantities of greenhouse gases," says Jannik Martens, Ph.D. student at Stockholm University and lead author of the study. "It appears likely that past permafrost thawing at times of climate warming, about 14,700 and 11,700 years ago, was in part also related to the increase in CO2 concentrations that is seen in Antarctic ice cores for these times. It seems that Arctic warming by only a few degrees Celsius is sufficient to disturb large areas covered by permafrost and potentially affect the climate system."

In the current study, the scientists used an eight meters long sediment core that was recovered from the sea floor more than 1 000 meters below the surface of the Arctic Ocean during the SWERUS-C3 expedition onboard the Swedish icebreaker Oden back in 2014. To reconstruct permafrost thawing on land, the scientists applied radiocarbon (14C) dating and molecular analysis to trace organic remains that once were released by thawing permafrost and then washed into the Arctic Ocean.

"From this core we also learned that erosion of permafrost coastlines was an important driving force for permafrost destruction at the end of the last ice age. Coastal erosion continues to the present day, though ten times slower than during these earlier rapid warming period. With the recent warming trends, however, we see again an acceleration of coastal erosion in some parts of the Arctic, which is expected to release greenhouse gases by degradation of the released organic matter," says Örjan Gustafsson, Professor at Stockholm University and leader of the research program. "Any release from thawing permafrost mean that there is even less room for anthropogenic greenhouse gas release in the earth-climate system budget before dangerous thresholds are reached.

Gustafsson, Martens and their colleagues are now again in the Arctic Ocean as part of the International Siberian Shelf Study (ISSS-2020) onboard the Russian research vessel Akademik Keldysh. The expedition left the port of Arkhangelsk on September 26 and is currently in the East Siberian Sea, seeking more answers to how changing climate may trigger release of carbon, including greenhouse gases, from Arctic permafrost systems, including coastal erosion and permafrost below the sea bottom preserved from the past ice age.

(https://advances.sciencemag.org/content/advances/6/42/eabb6546/F1.large.jpg)

Remobilization of dormant carbon from Siberian-Arctic permafrost during three past warming events. Sci. Adv. 6, eabb6546 (2020)
https://advances.sciencemag.org/content/6/42/eabb6546

(https://advances.sciencemag.org/content/advances/6/42/eabb6546/F2.large.jpg)

... This demonstrates that Arctic warming by only a few degrees may suffice to abruptly activate large-scale permafrost thawing, indicating a sensitive trigger for a threshold-like permafrost climate change feedback.
Title: Re: Permafrost general science thread
Post by: gerontocrat on October 18, 2020, 01:59:09 PM
I didn't expect Tsunamis to be a permafrost melting consequence that is becoming a probability rather than a possibility.

https://www.theguardian.com/environment/2020/oct/18/alaska-climate-change-tsunamis-melting-permafrost
Alaska's new climate threat: tsunamis linked to melting permafrost
Quote
In Alaska and other high, cold places around the world, new research shows that mountains are collapsing as the permafrost that holds them together melts, threatening tsunamis if they fall into the sea.

Scientists are warning that populated areas and major tourist attractions are at risk.

One area of concern is a slope of the Barry Arm fjord in Alaska that overlooks a popular cruise ship route.

The Barry Arm slide began creeping early last century, sped up a decade ago, and was discovered this year using satellite photos. If it lets loose, the wave could hit any ships in the area and reach hundreds of meters up nearby mountains, swamping the popular tourist destination and crashing as high as 10 meters over the town of Whittier. Earlier this year, 14 geologists warned that a major slide was “possible” within a year, and “likely” within 20 years.

In 2015, a similar landslide, on a slope that had also crept for decades, created a tsunami that sheared off forests 193 meters up the slopes of Alaska’s Taan Fiord.

“When the climate changes,” said geologist Bretwood Higman, who has worked on Taan Fiord and Barry Arm, “the landscape takes time to adjust. If a glacier retreats really quickly it can catch the surrounding slopes by surprise – they might fail catastrophically instead of gradually adjusting.”

After examining 30 years of satellite photos, for instance, geologist Erin Bessette-Kirton has found that landslides in Alaska’s St Elias mountains and Glacier Bay correspond with the warmest years.

Warming clearly leads to slides, but knowing just when those slides will release is a much harder problem. “We don’t have a good handle on the mechanism,” Bessette-Kirkton said. “We have correlations, but we don’t know the driving force. What conditions the landslide, and what triggers it?”

Adding to the problem, global heating has opened up water for landslides to fall in. A recent paper by Dan Shugar, a geomorphologist at the University of Calgary, shows that as glaciers have shrunk, glacial lakes have grown, ballooning 50% in both number and size in 18 years. In the ocean, fjords lengthen as ice retreats. Slopes that used to hang over ice now hang over water.

Over the past century, 10 of the 14 tallest tsunamis recorded happened in glaciated mountain areas. In 1958, a landslide into Alaska’s Lituya Bay created a 524-meter wave – the tallest ever recorded. In Alaska’s 1964 earthquake, most deaths were from tsunamis set off by underwater landslides.

To deal with the hazard, experts hope to predict when a slope is more likely to fail by installing sensors on the most dangerous slopes to measure the barely perceptible acceleration of creeping that may presage a slide.
Title: Re: Permafrost general science thread
Post by: kassy on October 26, 2020, 01:24:12 PM
The linked reference uses new paleo-findings to indicate that the risk of an abrupt remobilization of dormant carbon in the Siberian-Arctic permafrost is higher than previously assumed by consensus climate scientists.  This is particularly true if abrupt sea level rise floods coastal Arctic permafrost regions in coming decades:

Jannik Martens et al (16 Oct 2020), "Remobilization of dormant carbon from Siberian-Arctic permafrost during three past warming events", Science Advances, Vol. 6, no. 42, eabb6546, DOI: 10.1126/sciadv.abb6546

https://advances.sciencemag.org/content/6/42/eabb6546

Abstract
Carbon cycle models suggest that past warming events in the Arctic may have caused large-scale permafrost thaw and carbon remobilization, thus affecting atmospheric CO2 levels. However, observational records are sparse, preventing spatially extensive and time-continuous reconstructions of permafrost carbon release during the late Pleistocene and early Holocene. Using carbon isotopes and biomarkers, we demonstrate that the three most recent warming events recorded in Greenland ice cores—(i) Dansgaard-Oeschger event 3 (~28 ka B.P.), (ii) Bølling-Allerød (14.7 to 12.9 ka B.P.), and (iii) early Holocene (~11.7 ka B.P.)—caused massive remobilization and carbon degradation from permafrost across northeast Siberia. This amplified permafrost carbon release by one order of magnitude, particularly during the last deglaciation when global sea-level rise caused rapid flooding of the land area thereafter constituting the vast East Siberian Arctic Shelf. Demonstration of past warming-induced release of permafrost carbon provides a benchmark for the sensitivity of these large carbon pools to changing climate.

See also:

Title: "New Climate Warnings in Old Permafrost: 'It’s a Little Scary Because it’s Happening Under Our Feet.'"

https://insideclimatenews.org/news/16102020/permafrost-study-arctic-ocean-climate-change

Extract: "The study, published today in Science Advances, shows that only a few degrees of warming in the Arctic is enough "to abruptly activate large-scale permafrost thawing," suggesting a "sensitive trigger" for greenhouse gas emissions from thawing permafrost. The results also support climate models that have shown "large injections of CO2 into the atmosphere" when glaciers, and the frozen lands beneath them, melted.

"If we consider the magnitude and the speed of anthropogenic climate warming, by 1 degree Celsius (1.8 Fahrenheit) globally and 2 degrees Celsius (3.6 Fahrenheit) in the Arctic, during the past 150 years, and compare this with the first abrupt temperature increase of about 1 degree Celsius at the Bölling-Alleröd, it appears likely that large-scale permafrost thawing and carbon release is going to happen again," he said. "Our study indeed suggests that abrupt permafrost thawing represents a tipping point in the climate system.""

Title: Re: Permafrost general science thread
Post by: morganism on October 27, 2020, 02:29:51 AM
this is partly OT but,


Microbial Diversity Below The Seafloor Is As Rich As On Earth's Surface



"D'Hondt analyzed 299 samples of marine sediment collected as core samples from 40 sites around the globe. Their sample depths ranged from the seafloor to 678 meters below it. To accurately determine the diversity of microbial communities, the authors extracted and sequenced DNA from each frozen sample under the same clean laboratory condition.

The 16S rRNA gene sequences (approximately 50 million sequences) obtained through comprehensive next-generation sequencing were analyzed to determine microbial community composition in each sample. From these 50 million sequences, the research team discovered nearly 40,000 different types of microorganisms in marine sediment, with diversity generally decreasing with depth. The team found that microbial community composition differs significantly between organic-rich sediment of continental margins and nutrient-poor sediment of the open ocean, and that the presence or absence of oxygen and the concentration of organic matter are major factors in determining community composition.

By comparing their results to previous studies of topsoil and seawater, the researchers discovered that each of these three global biomes--marine sediment, topsoil, and seawater--has different microbial communities but similar total diversity. "It was an unexpected discovery that microbial diversity in the dark, energy-limited world beneath the seafloor is as diverse as in Earth's surface biomes," said Hoshino.

Furthermore, by combining the estimates of bacterial and archaeal diversity for these three biomes, the researchers found that bacteria are far more diverse than archaea--microbes distinct from bacteria and known for living in extreme environments--on Earth."

http://astrobiology.com/2020/10/microbial-diversity-below-the-seafloor-is-as-rich-as-on-earths-surface.html

Title: Re: Permafrost general science thread
Post by: kassy on October 27, 2020, 01:43:34 PM
Maybe even completely since the articl/paper does not mention permafrost at all.
Title: Re: Permafrost general science thread
Post by: gerontocrat on October 27, 2020, 04:57:15 PM
But we have to wait for a peer-reviewd paper next year to find out how whoops! it really is.

https://www.theguardian.com/science/2020/oct/27/sleeping-giant-arctic-methane-deposits-starting-to-release-scientists-find
'Sleeping giant' Arctic methane deposits starting to release, scientists find
Exclusive: expedition discovers new source of greenhouse gas off East Siberian coast has been triggered

Quote
Scientists have found evidence that frozen methane deposits in the Arctic Ocean – known as the “sleeping giants of the carbon cycle” – have started to be released over a large area of the continental slope off the East Siberian coast, the Guardian can reveal.

High levels of the potent greenhouse gas have been detected down to a depth of 350 metres in the Laptev Sea near Russia, prompting concern among researchers that a new climate feedback loop may have been triggered that could accelerate the pace of global heating.

The slope sediments in the Arctic contain a huge quantity of frozen methane and other gases – known as hydrates. Methane has a warming effect 80 times stronger than carbon dioxide over 20 years. The United States Geological Survey has previously listed Arctic hydrate destabilisation as one of four most serious scenarios for abrupt climate change.

The international team onboard the Russian research ship R/V Akademik Keldysh said most of the bubbles currently are dissolving in the water but methane levels at the surface are four to eight times what would normally be expected and this is venting into the atmosphere.

At this moment, there is unlikely to be any major impact on global warming, but the point is that this process has now been triggered. This East Siberian slope methane hydrate system has been perturbed and the process will be ongoing,” said the Swedish scientist Örjan Gustafsson of Stockholm University in a satellite call from the vessel.

The scientists – who are part of a multi-year International Shelf Study Expedition – stressed their findings are preliminary. The scale of methane releases will not be confirmed until they return, analyse the data and have their studies published in a peer-reviewed journal.

But the discovery of potentially destabilised slope frozen methane raises concerns that a new tipping point has been reached that could increase the speed of global heating. The Arctic is considered ground zero in the debate about the vulnerability of frozen methane deposits in the ocean. With the Arctic temperature now rising more than twice as fast as the global average, the question of when – or even whether – they will be released into the atmosphere has been a matter of considerable uncertainty in climate computer models.

The 60-member team on the Akademik Keldysh believe they are the first to observationally confirm the methane release is already under way across a wide area of the slope about 600km offshore.


The latest discovery potentially marks the third source of methane emissions from the region. Semiletov, who has been studying this area for two decades, has previously reported the gas is being released from the shelf of the Arctic – the biggest of any sea.

For the second year in a row, his team have found crater-like pockmarks in the shallower parts of the Laptev Sea and East Siberian Sea that are discharging bubble jets of methane, which is reaching the sea surface at levels tens to hundreds of times higher than normal. This is similar to the craters and sinkholes reported from inland Siberian tundra earlier this autumn.
Title: Re: Permafrost general science thread
Post by: morganism on October 27, 2020, 11:03:40 PM
Scary.

Scarier how the russians and asians talk about the hydrate release, and the USA and brits say it will never happen, or will not be catastrophic if it does.

The post about the bacteria above was posted here because it is the only active soil bacteria thread going now.

It appears when the methanotrophs digest the methane, they split out the hydrogen, and release the C.

There is only one researcher working in Antartica, on ice core studies, that is looking at the C in the cores, and he says he thinks the 13/14 shows that the high CO2/CO has signatures that it has been processed by methanotrophs. He also says that in every sample that had bubbles he looked at, that there were dormant methanotrophs.  He believes it is possible that all these gas bubble samples were originally saturated with methane, and that the trophs have slowly been converting over the millennia.
He speculates that the very high geo record of CO2 peaks is actually times that the "hydrate gun" went off, by pointing out that the methanotrophs must have been lofted into the atmosphere to be found in all the ice cores he has looked at.

(citation lost on old hard drive, circa 2003-5 i think)

With the papers postulation of separate populations in the field, if you looked for fossilized bacteria populations in the ice cores, you might be able to ID if they were seabed, soil, or seawater water source. There have been recent studies on the aero populations of microbes of diff families also, they would also likely have a distinct group of families.
Title: Re: Permafrost general science thread
Post by: kassy on October 28, 2020, 08:35:28 PM
The Permafrost general science thread is mainly for just that. The methane release has it´s own thread:

https://forum.arctic-sea-ice.net/index.php/topic,12.0.html
Welcome to the Arctic Sea Ice Forum - Arctic Methane Topic!

Title: Re: Permafrost general science thread
Post by: nanning on November 03, 2020, 04:57:01 AM
The Observer / Archaeology
Secrets of the ice: unlocking a melting time capsule

https://www.theguardian.com/science/2020/nov/01/secrets-of-the-ice-unlocking-a-melting-time-capsule-archaeology-glaciers


This is Important imo.


Quote
In a year when the unthinkable has become the everyday, when profound changes to lifestyle, economy, travel, ambition and health have been forced upon billions of us by a tiny virus, at a time when science has trumped even the most bombastic rhetoric, it is surely important to stop and reflect on the environmental consequences of our prior economic model. We may soon look back on the Covid-19 pandemic as the good old days before climate change raced away from us.

Will we soon be swapping our smartphones for atlatl, those ingenious ancient spear-throwing devices? It’s too soon to say, but archaeologists have the luxury of a very long view.

“Technological advancement is not permanent. It can fluctuate back and forth,” says Jarman. “We’ve seen that happen throughout human history, and it would be hubris to think that it couldn’t happen again,” he says. “I hope that if it does, that is because we have intentionally managed a soft landing, choosing sustainable technology because we want to, and we know it’s the right thing to do, rather than being forced into it.”

Title: Re: Permafrost general science thread
Post by: Ken Feldman on November 10, 2020, 12:51:13 AM
A just-published study on methane emissions from Siberian lakes shows that the water column of deeper lakes acts as a microbial filter that prevents methane emissions into the atmosphere.

https://bg.copernicus.org/preprints/bg-2020-317/ (https://bg.copernicus.org/preprints/bg-2020-317/)

Quote
Savvichev, A., Rusanov, I., Dvornikov, Y., Kadnikov, V., Kallistova, A., Veslopolova, E., Chetverova, A., Leibman, M., Sigalevich, P., Pimenov, N., Ravin, N., and Khomutov, A.: The water column of the Yamal tundra lakes as a microbial filter preventing methane emission, Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-317, in review, 2020.

Abstract. Microbiological, molecular ecological, biogeochemical, and isotope geochemical research was carried out in four lakes of the central part of the Yamal Peninsula in the area of continuous permafrost. Two of them were large (73.6 and 118.6 ha) and deep (up to 10.6 and 12.3 m) mature lakes embedded into all geomorphological levels of the peninsula, and two others were smaller (3.2 and 4.2 ha) shallow (up to 2.3 and 1.8 m) lakes which appeared as a result of thermokarst on constitutional (segregated) ground ice. We collected samples in August 2019. The Yamal tundra lakes exhibited high phytoplankton production (340–1200 mg C m−2 day−1) during the short summer season. Allochthonous and autochthonous, both particulate and dissolved organic matter was deposited to the bottom sediments, where methane production occurred due to anaerobic degradation (90–1000 µmol СН4 dm−3). The rates of hydrogenotrophic methanogenesis appeared to be higher in the sediments of deep lakes than in those of the shallow ones. In the sediments of all lakes, Methanoregula and Methanosaeta were predominant components of the archaeal methanogenic community. Methane oxidation (1.4–9.9 µmol dm−3 day−1) occurred in the upper sediment layers simultaneously with methanogenesis. Methylobacter tundripaludum (family Methylococcaceae) predominated in the methanotrophic community of the sediments and the water column. The activity of methanotrophic bacteria in deep mature lakes resulted in a decrease of the dissolved methane concentration in lake water from 0.8–4.1 µmol CH4 L−1 to 0.4 µmol CH4 L−1, while in shallow thermokarst lakes the geochemical effect of methanotrophs was much less pronounced. Thus, only small shallow Yamal lakes may contribute significantly to the overall diffusive methane emissions from the water surface during the warm summer season. The water column of large deep lakes on Yamal acts, however, as a microbial filter preventing methane emission into the atmosphere.

 
Title: Re: Permafrost general science thread
Post by: oren on November 20, 2020, 10:08:27 AM
I wonder what the proportion of lakes in Yamal is between "shallow thermokarst lakes" and "deep mature lakes".
Title: Re: Permafrost general science thread
Post by: gerontocrat on November 20, 2020, 12:10:05 PM
I wonder what the proportion of lakes in Yamal is between "shallow thermokarst lakes" and "deep mature lakes".
Can one find a nice little table to tell us the answer? NO.

But as far as Western Siberia is concedrned, the topography suggests shallow (see image) and that new small lakes are appearing while large mature lakes are draining.

http://www.izdatgeo.ru/pdf/earth_cryo/2015-2/100_eng.pdf
Quote

Comparative analysis of the above data on the number of the disappeared and newly formed lakes and their total areas in the entire permafrost zone of Western Siberia indicates another important pattern: with the total areas of the disappeared (14,826 hectares) and newly formed lakes (13,649 hectares) lakes, the number of the newly formed lakes is approximately 18 times greater than the number of the disappeared lakes.

Hence, new thermokarst lakes are much smaller in size than the preceding ones. One can suppose then that the observed acceleration of the thermokarst processes caused by climate warming will be accompanied by significant growth in the number of small thermokarst lakes in the permafrost zone of Western Siberia

Acceleration of the thermokarst processes caused by climate warming and noted by many researchers results in more intense formation of new lakes, which is, according to the results obtained, the most characteristic process for the continuous permafrost subzone of Western Siberia. As follows from the above, the newly formed thermokarst lakes are usually small in
size. According to the experimental data by [Audry et al., 2011; Pokrovsky et al., 2011], small thermokarst lakes (in) Western Siberia are plentiful natural sources of methane. Therefore, one can assume increase in the methane emission into the air, as the number of small thermokarst lakes increases in the permafrost zone, which will contribute to intensification of the greenhouse effect.

https://tc.copernicus.org/articles/8/1177/2014/tc-8-1177-2014.pdf
Quote
The acceleration of the permafrost thaw in the northern portion of western Siberia (Kirpotin et al., 2009a, b; Bryksina et al., 2009; Dneprovskaya et al., 2009; Bryksina and Kirpotin, 2012) should increase the amount of small soil subsidence and permafrost depressions while decreasing the amount of large (mature) lakes. For example, a net increase in
the amount of lakes was observed for the Nadym watershed (north of western Siberia and close to continental sites of this #study), which is explained by the formation of small lakes, while the larger lakes fragment after partial drainage (Karlsson et al., 2014).
Title: Re: Permafrost general science thread
Post by: kassy on November 20, 2020, 05:05:16 PM
The large lakes are an established ecosystem so it makes sense that the bacteria over time evolve to take advantage of the extra methane higher in the watercolumn (the research does not strike me as new but it could be for these specific lakes).

All new lakes are shallow thermokarst lakes so it does not mean that much.
Title: Re: Permafrost general science thread
Post by: gerontocrat on December 10, 2020, 01:40:18 PM
A study on soil temperatures in Russia (open access)

https://www.sciencedirect.com/science/article/pii/S092181812030285X?dgcid=rss_sd_all
Significant shallow–depth soil warming over Russia during the past 40 years
Quote

Highlights
• Significant warming of shallow ground occurred in Russia during 1975–2016.

• Trends in soil temperature vary with depth in different frost-related areas.

• For the region as a whole, the intra-annual variability of soil temperature increased.

• Trends in soil temperature significantly respond to changes in snow cover.

3. Results
3.1. Trends in soil temperature from 1975 to 2016
It is found that MAST increased at 279, 286, and 197 sites, while it decreased at 4, 2, and 2 sites, and remained stable (within measurement accuracy) at 32, 31, and 17 sites at depths of 0.8, 1.6, and 3.2 m, respectively (Fig. 2a). The greatest warming of MAST at shallow depths (0.8 and 1.6 m) is 1.09 ± 0.20 °C/decade (mean ± SD, P < 0.01) at a site located in the northern Siberian permafrost area. At a deeper level (3.2 m), the greatest warming in MAST occurred in central Siberia at 0.89 ± 0.12 °C/decade (P < 0.01). However, a few sites that had decreased MAST are mainly located in the permafrost area. Trends in MAST from −0.11 to −0.21 °C/decade were observed at four sites at 0.8 m. For the depths of 1.6 and 3.2 m, MAST of the two sites located in the continuous permafrost area decreased by 0.15 ± 0.09 (P > 0.05) and 0.11 ± 0.05 °C/decade (P > 0.05), respectively, and a decrease in MAST at 3.2 m of 0.36 ± 0.06 °C/decade (P < 0.05) occurred at a seasonal frost site.
(https://ars.els-cdn.com/content/image/1-s2.0-S092181812030285X-gr2.jpg)

3.2. Impact of snow cover characteristics on soil temperature
It is found that MAST was, in general, higher than MAAT, accounting for 0.64 of MAAT at all sites (Fig. 5a). Meanwhile, the sites with smaller SSD and SCD (lighter dots) are closer to the 1:1 line, indicating the role of snow cover in offsetting MAST against MAAT. SSD and SCD were both positively related to ΔT0.8 (Fig. 5b and c), whereas the relations between ΔT0.8 and two snow cover parameters are different, with ΔT0.8–SSD relations being more linear than ΔT0.8–SCD relations. Moreover, SCD shows a higher R2 (0.49) than SSD (0.40) in the linear relationship with ΔT0.8.

(https://ars.els-cdn.com/content/image/1-s2.0-S092181812030285X-gr5.jpg)

Fig. 5. a. Relationships between the mean annual soil temperature (MAST, 0.8 m) and air temperature (MAAT). In total, 9722 annual values at 269 sites during 1975–2016 are scattered with colour representing the annual sum of snow depth (SSD, left) and snow cover duration (SCD, right). b, c. Relationships between the annual offset (ΔT0.8) and SSD (b) and SCD (c) with permafrost distribution.

4. Discussion
The annual mean and extreme soil temperatures of shallow ground significantly increased from 1975 to 2016 in Russia. The majority of the sites had warming trends, and a few sites mainly located in the permafrost areas remained thermally stable and even cooled during the period. The soil warming in the continuous permafrost area was faster than that in the discontinuous permafrost and seasonal frost areas at 0.8 m and 1.6 m, and was slower at 3.2 m (Fig. 4). Moreover, the annual maximum soil temperature increased faster than the minimum soil temperature, which leads to increased intra-annual variability of soil temperature (Fig. 3). The study provides an unprecedentedly detailed picture of soil temperature evolution over the past four decades in Russia by quantifying the trends in the multilayer soil temperature parameters at 457 sites.
Title: Re: Permafrost general science thread
Post by: gerontocrat on December 10, 2020, 02:05:09 PM
And a sort of connected study (not open access) on vegetation in the Tundra.

https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.15451?af=R
Divergent shrub‐cover responses driven by climate, wildfire, and permafrost interactions in Arctic tundra ecosystems

Quote
Abstract
The expansion of shrubs across the Arctic tundra may fundamentally modify land–atmosphere interactions. However, it remains unclear how shrub expansion pattern is linked with key environmental drivers, such as climate change and fire disturbance. Here we used 40+ years of high‐resolution (~1.0 m) aerial and satellite imagery to estimate shrub‐cover change in 114 study sites across four burned and unburned upland (ice‐poor) and lowland (ice‐rich) tundra ecosystems in northern Alaska.

Validated with data from four additional upland and lowland tundra fires, our results reveal that summer precipitation was the most important climatic driver (r = 0.67, p < 0.001), responsible for 30.8% of shrub expansion in the upland tundra between 1971 and 2016. Shrub expansion in the uplands was largely enhanced by wildfire (p < 0.001) and it exhibited positive correlation with fire severity (r = 0.83, p < 0.001). Three decades after fire disturbance, the upland shrub cover increased by 1077.2 ± 83.6 m2 ha−1, ~7 times the amount identified in adjacent unburned upland tundra (155.1 ± 55.4 m2 ha−1).

In contrast, shrub cover markedly decreased in lowland tundra after fire disturbance, which triggered thermokarst‐associated water impounding and resulted in 52.4% loss of shrub cover over three decades. No correlation was found between lowland shrub cover with fire severity (r = 0.01). Mean summer air temperature (MSAT) was the principal factor driving lowland shrub‐cover dynamics between 1951 and 2007. Warmer MSAT facilitated shrub expansion in unburned lowlands (r = 0.78, p < 0.001), but accelerated shrub‐cover losses in burned lowlands (r = −0.82, p < 0.001).

These results highlight divergent pathways of shrub‐cover responses to fire disturbance and climate change, depending on near‐surface permafrost and drainage conditions. Our study offers new insights into the land–atmosphere interactions as climate warming and burning intensify in high latitudes.
Title: Re: Permafrost general science thread
Post by: kassy on December 23, 2020, 04:18:26 PM
Subsea Permafrost Still Waking Up After 12,000 Years

In the far north, the swelling Arctic Ocean inundated vast swaths of coastal tundra and steppe ecosystems. Though the ocean water was only a few degrees above freezing, it started to thaw the permafrost beneath it, exposing billions of tons of organic matter to microbial breakdown. The decomposing organic matter began producing CO2 and CH4, two of the most important greenhouse gases.

Though researchers have been studying degrading subsea permafrost for decades, difficulty collecting measurements and sharing data across international and disciplinary divides have prevented an overall estimate of the amount of carbon and the rate of release. A new study, led by Ph.D. candidate Sara Sayedi and senior researcher Dr. Ben Abbott at Brigham Young University (BYU) published in IOP Publishing journal Environmental Research Letters, sheds light on the subsea permafrost climate feedback, generating the first estimates of circumarctic carbon stocks, greenhouse gas release, and possible future response of the subsea permafrost zone.

Sayedi and an international team of 25 permafrost researchers worked under the coordination of the Permafrost Carbon Network (PCN), which is supported by the U.S. National Science Foundation. The researchers combined findings from published and unpublished studies to estimate the size of the past and present subsea carbon stock and how much greenhouse gas it might produce over the next three centuries.

Using a methodology called expert assessment, which combines multiple, independent plausible values, the researchers estimated that the subsea permafrost region currently traps 60 billion tons of methane and contains 560 billion tons of organic carbon in sediment and soil. For reference, humans have released a total of about 500 billion tons of carbon into the atmosphere since the Industrial Revolution. This makes the subsea permafrost carbon stock a potential giant ecosystem feedback to climate change.

“Subsea permafrost is really unique because it is still responding to a dramatic climate transition from more than ten thousand years ago,” Sayedi said. “In some ways, it can give us a peek into the possible response of permafrost that is thawing today because of human activity.”

Estimates from Sayedi’s team suggest that subsea permafrost is already releasing substantial amounts of greenhouse gas. However, this release is mainly due to ancient climate change rather than current human activity. They estimate that subsea permafrost releases approximately 140 million tons of CO2 and 5.3 million tons of CH4 to the atmosphere each year. This is similar in magnitude to the overall greenhouse gas footprint of Spain.

The researchers found that if human-caused climate change continues, the release of CH4 and CO2 from subsea permafrost could increase substantially. However, this response is expected to occur over the next three centuries rather than abruptly. Researchers estimated that the amount of future greenhouse gas release from subsea permafrost depends directly on future human emissions. They found that under a business-as-usual scenario, warming subsea permafrost releases four times more additional CO2 and CH4 compared to when human emissions are reduced to keep warming less than 2°C.

“These results are important because they indicate a substantial but slow climate feedback,” Sayedi explained. “Some coverage of this region has suggested that human emissions could trigger catastrophic release of methane hydrates, but our study suggests a gradual increase over many decades.”

Even if this climate feedback is relatively gradual, the researchers point out that subsea permafrost is not included in any current climate agreements or greenhouse gas targets. Sayedi emphasized that there is still a large amount of uncertainty about subsea permafrost and that additional research is needed.

“Compared to how important subsea permafrost could be for future climate, we know shockingly little about this ecosystem,” Sayedi said. “We need more sediment and soil samples, as well as a better monitoring network to detect when greenhouse gas release responds to current warming and just how quickly this giant pool of carbon will wake from its frozen slumber.”

https://www.eurasiareview.com/23122020-subsea-permafrost-still-waking-up-after-12000-years/
Title: Re: Permafrost general science thread
Post by: kassy on December 23, 2020, 04:22:56 PM
The researchers found that if human-caused climate change continues, the release of CH4 and CO2 from subsea permafrost could increase substantially. However, this response is expected to occur over the next three centuries rather than abruptly. Researchers estimated that the amount of future greenhouse gas release from subsea permafrost depends directly on future human emissions. They found that under a business-as-usual scenario, warming subsea permafrost releases four times more additional CO2 and CH4 compared to when human emissions are reduced to keep warming less than 2°C.

"These results are important because they indicate a substantial but slow climate feedback," Sayedi explained. "Some coverage of this region has suggested that human emissions could trigger catastrophic release of methane hydrates, but our study suggests a gradual increase over many decades."

Even if this climate feedback is relatively gradual, the researchers point out that subsea permafrost is not included in any current climate agreements or greenhouse gas targets. Sayedi emphasized that there is still a large amount of uncertainty about subsea permafrost and that additional research is needed.

https://www.sciencedaily.com/releases/2020/12/201222081307.htm

bit more detail via SD and the research (OA):

Subsea permafrost carbon stocks and climate change sensitivity estimated by expert assessment
Sayedi, abbott et al
https://iopscience.iop.org/article/10.1088/1748-9326/abcc29


Title: Re: Permafrost general science thread
Post by: morganism on December 23, 2020, 10:51:20 PM
interesting at the end of the IOP paper

"One unexpected finding of this research was that the dearth of data on the subsea permafrost domain is partially due to divisions in the subsea permafrost research community. While previous expert assessments on other topics have always involved strong opinions and evidence-based disagreements (Schuur et al 2013, Abbott et al 2016), we found that many invited experts declined to participate or at least expressed serious concerns because of political and territorial considerations, including perceived or real threat of retribution or negative professional consequences. These rifts between research groups and culture of antagonistic competition long precede this paper, as evidenced by unsuccessful synthesis efforts in the past and frequent rebuttals and conflict surrounding published and presented research products (e.g. Thornton et al (2019)). We hope that this exercise, which involved permafrost researchers from many research groups, institutions, career stages, and cultural backgrounds, can contribute to a détente and improvement of collaborative research"
Title: Re: Permafrost general science thread
Post by: vox_mundi on December 24, 2020, 04:50:25 PM
Earthquakes Generated Permafrost Release; Linkage to Abrupt Arctic Warming: Study
https://phys.org/news/2020-12-great-earthquakes-arctic.html

(https://scx2.b-cdn.net/gfx/news/2020/30-studysuggest.jpg)

In the Arctic, one of the factors driving climate warming is the release of methane from permafrost and metastable gas hydrates in the shelf zone. Since researchers began to monitor temperatures in the Arctic, the region has seen two periods of abrupt warming: first in the 1920s and '30s, and then beginning in 1980 and continuing to this day.

Leopold Lobkovsky, member of the Russian Academy of Sciences and the head of the MIPT Laboratory for Geophysical Research of the Arctic and Continental Margins of the World Ocean, hypothesized that the unexplained abrupt temperature changes could have been triggered by geodynamic factors. Specifically, he pointed to a series of great earthquakes in the Aleutian Arc, which is the closest seismically active area to the Arctic.

To test his hypothesis, Lobkovsky had to answer three questions. First, did the dates of the great earthquakes coincide with temperature jumps? Second, what is the mechanism that enables the lithospheric disturbances to propagate over more than 2,000 kilometers from the Aleutian Islands to the Arctic shelf region? Third, how do these disturbances intensify methane emissions?

... It took a model of lithospheric excitation dynamics to answer the second question. The model used by the researcher describes the propagation of so-called tectonic waves and predicts that they should travel at about 100 kilometers per year. This agrees with the delay between each of the great earthquake series and the subsequent temperature hike, as it took the disturbances 15 to 20 years to get transmitted over 2,000 kilometers.

... "There is a clear correlation between the great earthquakes in the Aleutian Arc and the phases of climate warming. A mechanism exists for physically transmitting the stresses in the lithosphere at the appropriate velocities. And these added stresses are capable of destroying metastable gas hydrates and permafrost, releasing methane. Each of the three components in this scheme is logical and lends itself to mathematical and physical explanation. Importantly, it explains a known fact—the abrupt rise in temperature anomalies in the Arctic—which remained unaccounted for by the previous models," Lobkovsky commented.

Leopold Lobkovsky. Seismogenic-Triggering Mechanism of Gas Emission Activizations on the Arctic Shelf and Associated Phases of Abrupt Warming, Geosciences (2020).
https://www.mdpi.com/2076-3263/10/11/428

... or not
Title: Re: Permafrost general science thread
Post by: kassy on December 24, 2020, 08:13:26 PM
That is a fun piece. I think there might very well be an effect but not quite the strong one the author claims.

Quote
After this series of huge shocks, the Aleutian island arc has been in seismic “silence” until present time, with no earthquakes having magnitudes higher than 8.0, but the only exception—an M 8.0 event that took place in the central part of the arc in 1986. Thus, one can see there is a 15–20-year lag between the strongest shock series that hit the Aleutian arc, and the beginning of abrupt Arctic warming, which started in 1980.

So 1986 that is also the last year with a global temp under the average. Does that mean anything? I don´t think so. The first red line is related to 3 big ones and the second one is drawn because one happened. Since it happened too late that ruins the causality.

There is also no details on the size of the extra emissions or how they relate to the overall trends.

Earthquakes promoting release of some extra gas: with all that shaking yes, probably. Link to abrupt warming: unproven and by known science caused by other factors for the eighties so overall rating bunk.
Title: Re: Permafrost general science thread
Post by: ArgonneForest on December 25, 2020, 05:47:14 AM
From what I've heard about the MOSAIC expeditions, CH4 measurements were taken all over the Arctic seas, including the Siberian ones. It will be interesting to see what they reveal. I tend to think there will be a lean on that
Title: Re: Permafrost general science thread
Post by: kassy on December 25, 2020, 05:09:13 PM
What do you mean by there will be a lean on that? Do you expect low outcomes or do you mean something else? (Not sure if the sentence is missing just the period or maybe more fell of. 
Title: Re: Permafrost general science thread
Post by: ArgonneForest on December 26, 2020, 12:48:15 AM
I tend to think it will probably be in the moderate range