Support the Arctic Sea Ice Forum and Blog

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - Anne

Pages: [1] 2 3 ... 11
1
Sun disappears over sub-Arctic Verkhoyansk district of Yakutia. Wildfires and CO held culprits:

Snippage:
Quote
There was no trace of light until after 8am local time over the Verkhoyansk district in the north of Yakutia.

Almost exactly a year ago - in July 2018  - there was another pitch black morning over three major areas of Yakutia, Eveno-Bytantaisky, Zhigansky and the same Verkhoyansky district.

Darkness which had a yellow tinge lasted for over three hours and was followed by drop in air temperature. 

The territory impacted by the gloom was larger than Italy.

This time weather experts thought the blackout was caused by smoke from wildfires mixing with heavy rain clouds, and they didn’t register change in temperature
<snip>
It was a high amount of carbon monoxide in the air that sped up and intensified the process of clouds formation, said chief specialist of Fobos weather station Yevgeny Tishkovets.

‘This situation can be compared to what is happening during cloud spiking which is done to cause rain. The cloud cover was as thick as it can possibly be,  add to this the wildfires smoke and precipitation. This is still, of course, rather approximate and we need to analyse what happened in a lot more details’, he said on Yakutia-24 TV channel.

The Fobos weather centre shared two maps, one showing extremely high amounts of carbon monoxide (7,19mg/m3 while the allowed maximum is 5mg/m3) in the air, and another one confirming very high level of cloudiness.

Currently heaviest wildfires are in the south of Yakutia, with smoke moving north.

More, with pictures, from that fount of weirdness, The Siberian Times (9 August)

2
Walking the walk / Re: When was the last flight you took?
« on: August 08, 2019, 03:27:02 PM »
The Shame Plane site claims to calculate how much Arctic ice is lost as a result of an individual flight between named destinations, and takes into account lifestyle offsets.

I can't vouch for its reliability but perhaps someone here can help. There's a brief discussion of it on Vox here.

(My last flight was in 2011, btw. ETA: I ticked the wrong box by mistake, can't seem to change it.)

3
Arctic background / Re: Arctic Maps
« on: May 14, 2018, 07:40:23 PM »
Slightly OT but interesting:
Greenland’s Hand-Sized Wooden Maps Were Used for Storytelling, Not Navigation
<snip>
Quote
On February 8, 1885, a hunter named Kunit approached Holm (Danish explorer) with a driftwood carving he had made—a representation of unbroken coastline that could be flipped around as one followed the contours of the coast. “[Kunit] had carved the chart himself and declared that it was not unusual to make such charts when one wanted to tell others about regions they did not know,” Holm wrote. The hunter produced three maps in total, now collectively referred to as the “Ammassalik maps.”

One carving, 5.5 inches in length, is highly detailed, embedded with all sorts of information and place names for the fjords above and beyond the 65th parallel. It even indicates locations where a traveler would need to carry his kayak overland to get to the next fjord. Another carving measures a little over 8.5 inches long and depicts a specific chain of islands along the coast, connected by narrow stems. These two maps could be placed next to one another to demonstrate the relative positions of the islands along the coast. A third, smaller map was also commissioned by Holm and shows the fjords stretching from Sermiligaaq to Kangerlussuatsiaq and includes valleys, shores, and inlets farther inland. Holm never actually traveled through the regions represented by the maps, but they helped him get a larger understanding of the local geography.

Much more, including pictures and video, at the link.
Atlas Obscura

4
Permafrost / Re: Siberian Caves Reveal Advancing Permafrost Thaw
« on: January 27, 2018, 12:10:49 AM »
I'm not taking any salt with that! The reconstitution of the Spanish flu virus from a recovered frozenSiberian cadaver was reported in Science in 2005:
Quote
Abstract
The pandemic influenza virus of 1918–1919 killed an estimated 20 to 50 million people worldwide. With the recent availability of the complete 1918 influenza virus coding sequence, we used reverse genetics to generate an influenza virus bearing all eight gene segments of the pandemic virus to study the properties associated with its extraordinary virulence. In stark contrast to contemporary human influenza H1N1 viruses, the 1918 pandemic virus had the ability to replicate in the absence of trypsin, caused death in mice and embryonated chicken eggs, and displayed a high-growth phenotype in human bronchial epithelial cells. Moreover, the coordinated expression of the 1918 virus genes most certainly confers the unique high-virulence phenotype observed with this pandemic virus.

Characterization of the Reconstructed 1918 Spanish Influenza Pandemic Virus
Terrence M. Tumpey &c
http://science.sciencemag.org/content/310/5745/77

And the US Government takes it seriously, at length here, including discussion of biohazard precautions: https://www.cdc.gov/flu/about/qa/1918flupandemic.htm

5
Greenland and Arctic Circle / Re: What's new in Greenland?
« on: January 10, 2018, 02:57:00 PM »
GEM Data project now publicly available
Quote
A treasure trove of information about Greenland and the Arctic is now at the disposal of the world’s researchers, thanks to a project under the auspices of Aarhus University.

The database is part of the Greenland Ecosystem Monitoring (GEM) project and the data has been collected by researchers who have returned again and again to the same places to measure the same things in the same way, reports Videnskab.dk.

A treasure trove of information about Greenland and the Arctic is now at the disposal of the world’s researchers, thanks to a project under the auspices of Aarhus University.

The database is part of the Greenland Ecosystem Monitoring (GEM) project and the data has been collected by researchers who have returned again and again to the same places to measure the same things in the same way, reports Videnskab.dk.

And here's the link to the site: http://data.g-e-m.dk/

6
Permafrost / Re: Siberian permafrost hole/blowout
« on: September 11, 2017, 05:20:42 PM »
Two months after it erupted, methane is still escaping from the Seyakha blowhole on the Yamal peninsula.
Quote
Fresh analysis of a new geological phenomenon shows how gas is still gushing from a submerged crater caused by a fierce methane gas explosion in northern Siberia in June.
A 'pillar of fire' from the eruption was caused by stones and pebbles being thrown together as they were thrust out of the ground, sparking the swoosh of gas, like in an oven, a leading expert believes.
Reindeer and dogs from a nearby nomadic encampment fled in terror at the fireball, with some debris thrown as far as 200 metres from the epicentre.
A 50-metre deep funnel or crater was immediately filled by water from the Myudriyakha River flowing beside the site of the explosion.
Quote
Dr Anton Sinitasky, director of the Arctic research Centre in Yamalo-Nenets region [...]said: 'I can confirm that there was really a fire burning over the Seyakha funnel. We need to rely on the words of eyewitnesses. It lasted for one or one-and-a-half hours.
'Everything depended on the gas jet power.
'We think that the cause of the ignition was pebbles thrown by the eruption.
'The pebbles collided and struck a spark.
'It was like in gas oven - one spark was enough to set the gas on fire.
'When the power of gas jet began to decrease, the burning stopped.
'But the methane continues to leak from the funnel, so we have been able to take samples.'
Much more, including video, photographs and further speculation, in The Siberian Times. (Usual caveats apply.)
http://siberiantimes.com/other/others/news/video-shows-methane-leaking-from-beneath-an-arctic-river-after-spectacular-eruption/

7
Arctic sea ice / Re: Stupid Questions :o
« on: September 05, 2017, 03:02:48 AM »
Erm, it occurs to me that my stupid question isn't specifically Arctic and maybe someone should start a Stupid Questions thread on The Rest forum.  :-[

8
Arctic sea ice / Re: Stupid Questions :o
« on: September 05, 2017, 02:55:39 AM »
Thanks, solartim27 and CalamityCountdown. I sometimes need to give an instant response to fuckwittery and it can be hard to know where to start.
One of my lines is "It's global climate change, not <insert villlage name> climate change."

9
Arctic sea ice / Re: Stupid Questions :o
« on: August 29, 2017, 09:21:13 AM »
Does anyone have a good elevator pitch for sceptics (assuming anything would sway them anyway)?
Scientists outside the sphere are the stubbornest, IME. 

10
Arctic sea ice / Re: The 2017 melting season
« on: August 03, 2017, 03:35:41 PM »
FSM!

11
Consequences / Re: Arctic Thermal Oases and agriculture?
« on: July 02, 2017, 12:25:11 PM »
Great post. Those thermal oases look promising. Whatever the costs and drawbacks, it's going to be a helluva lot easier than farming on Mars!

There seems to be a lot happening already. For example, this project in Nunavut uses a geodesic greenhouse and hydroponics to produce affordable fresh food for the local community, which suffers severe food insecurity. It's just won a $250,000 prize from the the Google Impact Challenge. http://www.growfarnorth.com/

Meanwhile, a 2014 article in Modern Farmer looks at farming in Nunavut, Iqaluit (and barley much further south in Alaska). http://modernfarmer.com/2013/10/arctic-farming/
And there seem to be a lot more initiatives...

12
Arctic sea ice / Re: The 2017 melting season
« on: June 25, 2017, 11:27:51 PM »
So, the story so far.
Neven your images are not being displayed properly. Something to do with google user content.
Displaying fine for me, oren. I'm using Chrome. Perhaps it's your browser?

13
Antarctica / Re: Halley base shut down and new crack in Brunt shelf
« on: June 13, 2017, 01:00:17 PM »
Did anyone catch the Horizon programme on moving the Halley base ? - It was on late last night on BBC2.  Sadly I only managed to catch 4 minutes of it & it looked interesting .....
It's still available here (with 29 days left to watch): http://www.bbc.co.uk/programmes/b08tj2zr

14
Hotel Arctic's webcam has been showing a frozen bay for some while now but perhaps there's a bit of melt showing this morning.

http://hotelarctic.com/om_hotel_arctic/webcam/

15
The forum / Re: What is Off Topic and What is Not?
« on: March 11, 2017, 11:22:33 AM »
I'd put the puffins in the Consequences ->Effects on Arctic wildlife thread. The post about puffins is not about the state of the ice, which is what the melting season thread is for; nor about the feedback effects of the state of the ice - it's about the effects of the state of the ice on other things.

It's vitally important imo for the integrity of the forum to keep on topic.

16
The forum / Re: Moderation
« on: March 10, 2017, 08:54:37 AM »
Great news, Neven. And many thanks to Jim Pettit for stepping up for this necessary and unenviable job.

17
Permafrost / Re: Arctic Methane Release
« on: March 04, 2017, 09:05:27 AM »
28 February. A roundup of permafrost degradation studies in Canada and Siberia.
Quote
Huge slabs of Arctic permafrost in northwest Canada are slumping and disintegrating, sending large amounts of carbon-rich mud and silt into streams and rivers. A new study that analyzed nearly a half-million square miles in northwest Canada found that this permafrost decay is affecting 52,000 square miles of that vast stretch of earth—an expanse the size of Alabama.

According to researchers with the Northwest Territories Geological Survey, the permafrost collapse is intensifying and causing landslides into rivers and lakes that can choke off life downstream, all the way to where the rivers discharge into the Arctic Ocean.

Similar large-scale landscape changes are evident across the Arctic including in Alaska, Siberia and Scandinavia, the researchers wrote in a paper published in the journal Geology in early February. The study didn't address the issue of greenhouse gas releases from thawing permafrost. But its findings could help quantify the immense global scale of the thawing, which will contribute to more accurate estimates of carbon emissions.
More at the link: https://insideclimatenews.org/news/27022017/global-warming-permafrost-study-melt-canada-siberia

18
The rest / Re: 2017 open thread
« on: March 04, 2017, 08:08:47 AM »
I'm not sure an "open thread" like this really belongs in the Cryosphere subforum - worth moving it to "The Rest" subforum with the rest of the general threads?

Yes Please.
+1

19
The rest / Re: The Trump Presidency (was "Presidential Poll")
« on: February 12, 2017, 09:13:58 AM »
A discussion similar to the ones we have had here:

! No longer available

I'm with Piers Morgan for the most part.
Words I never expected to see here, or to agree with. But three cheers!
For the greatest part of this discussion, Piers Morgan (PIERS MORGAN wtf?) is the grown-up. This is  the problem: a political bubble, a refusal to venture outside it, a refusal to meet others on their own terms or see them as reasonable or even capable of reason, and shouting down.
If we - I mean, broadly the people here who think climate change is an imminent and deadly threat to our way of life - can't talk and listen sensibly and respectfully with people who don't get it, we are lost.

20
The rest / Re: Article links: drop them here!
« on: February 12, 2017, 02:25:51 AM »
Maybe we should have a thread for dodgy journalism. This is disappointing from the Guardian:
https://www.theguardian.com/world/2017/feb/12/plan-to-refreeze-arctic-before-ice-goes-for-good-climate-change
Quote
Physicist Steven Desch has come up with a novel solution to the problems that now beset the Arctic. He and a team of colleagues from Arizona State University want to replenish the region’s shrinking sea ice – by building 10 million wind-powered pumps over the Arctic ice cap. In winter, these would be used to pump water to the surface of the ice where it would freeze, thickening the cap.

The pumps could add an extra metre of sea ice to the Arctic’s current layer, Desch argues. The current cap rarely exceeds 2-3 metres in thickness and is being eroded constantly as the planet succumbs to climate change.

“Thicker ice would mean longer-lasting ice. In turn, that would mean the danger of all sea ice disappearing from the Arctic in summer would be reduced significantly,” Desch told the Observer.

Desch and his team have put forward the scheme in a paper that has just been published in Earth’s Future, the journal of the American Geophysical Union, and have worked out a price tag for the project: $500bn (£400bn).

21
The rest / Re: Political discussion on the Arctic Sea Ice Forum
« on: January 17, 2017, 09:55:01 AM »
I didn't notice the poll until today but would have voted for the second option. What counts as 'politics' is in itself contentious. For many people (not on this forum!) any discussion of Anthropogenic climate change is ipso facto political. When you have lobbysists spreading disinformation and politicians denying the science and withholding funding, it's impossible to avoid the subject. When those lobbyists are inside government it would be wrong to try.

22
Greenland and Arctic Circle / Re: What's new in Greenland?
« on: January 02, 2017, 11:25:42 PM »
Using Landsat to Take the Long View on Greenland's Glaciers

A new publicly accessible data portal for analysing changes in outlet glacier flow velocities. EOS article from 29 December:
Quote
<snip>We based our project on more than 37,000 optical images collected by multiple sensors aboard the U.S. Geological Survey (USGS) and NASA’s Landsat satellites. The data span the period between 1972, when Landsat 1 was launched, and 2015, using data from Landsat 8 (launched in 2013), although most of the Landsat scenes were acquired after 1998.

We will continue to extend the database using new scenes recorded by the ongoing Landsat 7 and 8 missions. The USGS Landsat Global Archive Consolidation (LGAC) will add even more scenes, providing access to Landsat data that are archived at individual international ground stations [Wulder et al., 2016]. For Greenland, this could provide a considerable number of scenes from Landsat 4 and 5, dating back to 1982.

These additional images are valuable for extending the time span of the velocity time series. This greater time span is particularly important for inferring flow velocity variations that occur within the span of one season, and it may help to close observation gaps that occurred before 1999, when Landsat 7 was launched. Moreover, in regions of extensive cloud coverage, collecting Landsat scenes over a longer time span increases the chance of obtaining cloud-free data.

Enhanced Data Processing Provides a Clearer Picture
For 302 glaciers all around Greenland, we have processed more than 100,000 flow velocity fields from 1972 to 2012. We have extended this processing to include velocity fields for about 50 major glaciers up to 2015 so far.

By adding a quality flag that indicates the reliability of the data, we reduced the number of existing velocity fields with extensive outliers. We used an outlier detection strategy that compared the differences between each observed velocity product and a theoretically derived velocity field to compile the statistical parameters for our evaluation. Altogether, we have made more than 40,000 flow velocity fields accessible so far, and we continue to add new velocity fields as we process more data.

Rosenau et al. [2015] described a number of steps included in the processing procedure. We have improved the correction for tilt and terrain effects (orthorectification) using the Global Digital Elevation Map Version 2 (GDEM V2) from NASA’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). The improved orthorectification step, in particular, facilitates the usage of overlapping scenes from orbits that are not repeat passes. The ability to include these additional scenes provides a much higher effective sampling rate than would be provided by repeat-pass sampling, which is limited to the repeat orbit of 16 days (Landsat 4 to 8 ) or 18 days (Landsat 1 to 3).

In 2003, a small pair of mirrors (the scan line corrector) aboard Landsat 7 failed, introducing data gaps as well as small shifts between the scan lines. We applied a destriping correction to mitigate the impact on the resulting velocity fields. In addition, we removed outliers using an adaptive, recursive filter approach. The combination of all these improvements leads to higher accuracy of the inferred velocity fields.

Long-Term and Seasonal Trends in Flow Velocity
The long time span covered by the Landsat scenes allows us to determine long-term flow velocity trends. The high temporal resolution lets us analyze seasonal flow velocity variations of numerous outlet glaciers. However, the pattern of temporal and spatial distributions of the flow velocity changes is not uniform (Figure 1). The monitoring system provides a powerful tool to examine the flow velocity pattern throughout time and space, and we have detected an acceleration pattern for a number of outlet glaciers.
More at the link: https://eos.org/project-updates/using-landsat-to-take-the-long-view-on-greenlands-glaciers
and at Technische Universität Dresden’s site here: https://data1.geo.tu-dresden.de/flow_velocity/

23
Arctic background / Re: Ice Gain and Loss - Key Mechanisms
« on: December 12, 2016, 07:17:59 AM »
Really clear and helpful, thank you. It's great to have a summary like this to link to.

24
Arctic sea ice / Re: IJIS
« on: December 01, 2016, 05:19:04 PM »
Bill, there's a slider underneath the graph, which reveals the key.

25
Permafrost / Re: This is not good.
« on: November 09, 2016, 07:36:34 AM »
I wasn't really talking about the Inuit stories of catastrophe (though they are interesting in themselves) but rather the first hand evidence (if you can call it that - my friend doesn't) of hunters who say that the ice was thicker when they were young men, that the ice stretched further, that they can no longer travel safely by sled on places they always used to when they were young, and so on - the personal stories told in Thin Ice.

26
The rest / Re: Arctic Café
« on: November 07, 2016, 01:53:51 AM »
I heard Rachel McCarthy read at Poetry in Aldeburgh today. A climate scientist and a poet. she is a wonderful communicator. Check her out: http://www.rachelmccarthy.com/about.html

27
Permafrost / Re: This is not good.
« on: November 07, 2016, 01:38:45 AM »
The thing that gets me is that a good friend of mine, who read physics at university and now works in sophisticated software design and who prides himself on scepticism watched Thin Ice and was contemptuous of the anecdotal evidence of Inuit. He thought it weakened the force of the science and chuntered on about belief in climate change being a religion reinforced by old people going on about "the good old days when I were a lad". To me, it seemed as if his professional training in science (don't get me wrong, I'm all for science, it's the style of training I'm criticising) went much further than making him critical of anecdotal evidence - it made him regard it as the antithesis of science rather than an adjunct. I've come across this a lot with classically educated natural scientists in the UK - a disposition to regard AGW as a religious sect, and inclined to disregard anything that hasn't been scientifically coded and measured.

28
Consequences / Re: Climate change, the ocean, agriculture, and FOOD
« on: October 05, 2016, 05:46:31 PM »
From Science Daily:
Historical records may underestimate global sea level rise
Quote
New research published in Geophysical Research Letters shows that the longest and highest-quality records of historical ocean water levels may underestimate the amount of global average sea level rise that occurred during the 20th century. Dr. Philip Thompson, associate director of the University of Hawai'i Sea Level Center in the School of Ocean and Earth Science and Technology (SOEST), led the study.

"It's not that there's something wrong with the instruments or the data," said Thompson, "but for a variety of reasons, sea level does not change at the same pace everywhere at the same time. As it turns out, our best historical sea level records tend to be located where past sea level rise was most likely less than the true global average."

A team of earth scientists from the University of Hawai'i at Mānoa, Old Dominion University, and the NASA Jet Propulsion Laboratory worked together to evaluate how various processes that cause sea level to change differently in different places may have affected past measurements. One particularly important concept is the existence of "ice melt fingerprints," which are global patterns of sea level change caused by deviations in Earth's rotation and local gravity that occur when a large ice mass melts. Each glacier, ice cap, or ice sheet has a unique melt fingerprint that can be determined using NASA's GRACE satellite measurements of Earth's changing gravitational field.

During the 20th century, the dominant sources of global ice melt were in the Northern Hemisphere. The results of this study showed that many of the highest-quality historical water level records are taken from places where the melt fingerprints of Northern Hemisphere sources result in reduced local sea level change compared to the global average. Furthermore, the scientists found that factors capable of enhancing sea level rise at these locations, such as wind or Southern Hemisphere melt, were not likely to have counteracted the impact of fingerprints from Northern Hemisphere ice melt.

"This is really important, because it is possible that certain melt fingerprints or the influence of wind on ocean circulation might cause us to overestimate past sea level rise," said Thompson, "but these results suggest that is not likely and allow us to establish the minimum amount of global sea level rose that could have occurred during the last century."

The investigation concludes that it is highly unlikely that global average sea level rose less than 14 centimeters during the 20th century, while the most likely amount was closer to 17 centimeters.
Link

Journal reference: P. R. Thompson, B. D. Hamlington, F. W. Landerer, S. Adhikari. Are long tide gauge records in the wrong place to measure global mean sea level rise? Geophysical Research Letters, 2016; DOI: 10.1002/2016GL070552

29
Permafrost / Re: This is not good.
« on: October 05, 2016, 10:56:09 AM »
The Siberian Times is carrying a story about the latest Semiletov research in the Laptev
Quote
New expedition in Laptev Sea suggests increase in the rate of underwater permafrost degradation.
The findings come from an expedition now underway led by Professor Igor Semiletov, of Tomsk Polytechnic University, on the research vessel 'Academic M.A. Lavrentyev' which left Tiksi on 24 September on a 40 day mission.

The seeping of methane from the sea floor is greater than in previous research in the same area, notably carried out between 2011 and 2014.

'The area of spread of methane mega-emissions has significantly increased in comparison with the data obtained in the period from 2011 to 2014,' he said. 'These observations may indicate that the rate of degradation of underwater permafrost has increased.'

Detailed findings will be presented at an international conference in Tomsk on 21 to 24 November. The research enables comparison with previously obtained data on methane emissions.
http://siberiantimes.com/ecology/others/news/n0760-arctic-methane-gas-emission-significantly-increased-since-2014-major-new-research/

30
Policy and solutions / Re: Pope Francis' Encyclical on Climate Change
« on: September 05, 2016, 12:49:33 AM »
BBC Radio 4 has a thinkish godbothering spot on Sunday evenings called Something Understood, which is often worth a listen even for those, like me, beyond redemption. It was heartening to hear Mary Robinson (former Irish president, former UN Commissioner for Human Rights) tonight dedicate the whole programme to the issue of climate change, with a mea culpa for her late conversion to the issue - even if her take is wholly anthropocentric.
http://www.bbc.co.uk/programmes/b07sx9z5

31
Arctic sea ice / Re: What the Buoys are telling
« on: August 28, 2016, 10:31:30 AM »

32
Policy and solutions / Re: Airlander
« on: August 17, 2016, 11:02:09 PM »
Airlander's much delayed maiden flight took place today. Things are looking up.
https://www.theguardian.com/world/2016/aug/17/airlander-10-is-this-the-dawning-of-a-new-age-of-the-airship

33
Policy and solutions / Re: Aviation
« on: August 13, 2016, 09:56:32 PM »
An airship to rival the Airlander?
Quote
<snip>The Russian Security Council is reported to have presented a draft to the government for consideration. It envisages 'transport and logistic' corridors linking Siberia, the Far East and the Arctic.
The advanced airships would enable passenger and cargo traffic between, or example, the Northern Sea Route along the north of the Russian land mass, and the Trans-Siberian and Baikal-Amur Mainline railways.
The scheme offers integrated shipping and aviation 'hubs' to create conditions 'for the country to move to a new social and economic level through the deep exploration of Siberia, the Far East and the Arctic', according to a letter on the plan presented to Deputy Prime Minister Arkady Dvorkovich.
It is claimed that a single new-style airship could do the work of five Mi-8 helicopters in the Russian far north.
Russia is one of a number of countries where new generation airships are being built. The Augur-RosAeroSystems Holding is set to build the futuristic airship Atlant by the end of 2018.
These vast flying machines have been called 'half plane, half airship', with the versatility to remain in the air for days at a time, and land without requiring a traditional airport.
Larger versions are expected to outsize a Boeing 747.
Pictures and more at the link.
http://siberiantimes.com/other/others/news/n0707-futuristic-airship-scheme-plan-unveiled-to-transform-siberia-and-the-arctic/

More about the Airlander here:
http://forum.arctic-sea-ice.net/index.php/topic,1494.0.html

35
Bed geometry revealed by Operation Ice Bridge

'Huge ancient river basin may help explain the location, size and velocity of Jakobshavn Isbræ' - Bristol University press release Link

Palaeofluvial landscape inheritance for Jakobshavn Isbrae catchment, Greenland
Authors: M. A. Cooper, K. Michaelides, M. J. Siegert, J. L. Bamber

Abstract

Subglacial topography exerts strong controls on glacier dynamics, influencing the orientation and velocity of ice flow, as well as modulating the distribution of basal waters and sediment. Bed geometry can also provide a long-term record of geomorphic processes, allowing insight into landscape evolution, the origin of which may pre-date ice sheet inception. Here, we present evidence from ice-penetrating radar data for a large dendritic drainage network, radiating inland from Jakobshavn Isbræ, Greenland's largest outlet glacier. The size of the drainage basin is ∼ 450,000 km2 and accounts for about 20% of the total land area of Greenland. Topographic and basin morphometric analyses of an isostatically uplifted (ice-free) bedrock topography suggests that this catchment pre-dates ice sheet initiation and has likely been instrumental in controlling the location and form of the Jakobshavn ice stream, and ice flow from the deep interior to the margin, now and over several glacial cycles.
http://onlinelibrary.wiley.com/doi/10.1002/2016GL069458/full



36
The rest / Re: Arctic Café
« on: June 10, 2016, 06:12:51 PM »

37
The forum / Re: Suggestionsk
« on: June 09, 2016, 01:50:27 AM »
You're welcome, Oren!

Also want to remind people about the message facility. Depending on what options you've ticked you may get an email but in any case keep an eye out for the signal by My Messages along the top left toolbar. It's really useful but easy to miss.

39
*Bump*
A passionate plea from an unexpected quarter:
The Louvre's closure proves art cannot survive climate change
Jonathan Jones
Quote
<snip>It is scarily symbolic to see the Louvre menaced by flooding, as the world’s weather becomes ever less predictable and the signs of climate change impossible to ignore. No other museum so grandly preserves the finest achievements of our species.
Quote
<snip>If any museum sums up the best of human creativity through millennia, it is the Louvre. Now that it has been forced to close its doors, to take emergency measures against another of those weather events in which only the most foolhardy or corrupt refuse to see human-induced climate change, we can glimpse how our destructive side will wreck our best hopes if we don’t change.

Some environmentalists, of course, would say the fate of nature matters more than the fate of civilisation: that we humans have proved a pretty nasty little species. That is wrong. The great art that fills the Louvre proves it is wrong.

The most apocalyptic masterpiece in the Louvre is Géricault’s The Raft of the Medusa. As they cling to a raft on a savage sea, the last survivors of catastrophe have apparently been driven to cannibalism. Civilisation has died. Bare survival is all they have. Is that enough?
Jonathan Jones's Guardian blog

Géricault’s The Raft of the Medusa. Photograph: Universal History Archive/UIG via Getty Images

40
The forum / Re: Suggestions
« on: June 06, 2016, 12:35:15 PM »
Mentioning this to draw to people's attention to some really useful functions already here for writing your posts. In particular, some people overlook the availability of superscript and subscript buttons, which appear just after the motion button above the Compose box: helpful if you want to write 0Co, km2, or CO2:)

Not sure if they show up on mobile, though?

41
In a now annual tradition, I refuse to vote because I don't have a clue.

Then use your vote to add weight to one of our highly esteemed members, by waiting for someone like Neven or Wipneus to vote, then agreeing with them :) you could think of yourself as supporting the opinions of our senior staff :) just a thought.  Choosing not to vote is an honorable option too, when you know you're outside your element.
Has anyone done a comparative analysis of the prediction performance of our various contributors?
 ;)

42
Glaciers / Re: Tibet, the "third pole"
« on: June 03, 2016, 01:14:21 PM »
Ice core samples from Tibet reveal the higher the elevation, the greater the warming. (SA human interest story, rather than science paper.)
Quote
Lonnie Thompson, a glaciologist at The Ohio State University (O.S.U.) in Columbus, does not believe in the impossible. More than three decades ago he led an expedition that retrieved ice cores from the Quelccaya Ice Cap in Peru at 5,670 meters above sea level, which most glaciologists at the time considered too high for humans to conduct this kind of work. The exquisitely preserved layers of dust and air bubbles in the cores provided an unprecedented climate history of the tropics, and Thompson’s work has come to focus on the increasingly important climate change lessons to be learned from Earth’s so-called “third pole”—the ancient and massive buildup of glacial ice straddling the subtropics in Tibet.
Thompson has since led more than 60 expeditions around the world, painstakingly retrieving ice cores from low and middle latitudes in 16 countries, including the world’s highest ice-core site on the Dasuopu Glacier in Tibet at 7,200 meters. In September 2015—three and half years after having a heart transplant—the 67-year-old glaciologist reached 6,700 meters on Tibet’s Guliya Ice Cap.
Quote
[Tibetan ice cores] have given us a glimpse of Tibet’s climate history going back to more than half a million years. We learned that the extent of glaciation is related to how far monsoonal rains penetrate the Tibetan Plateau. This is in step with the slow wobbling of Earth’s rotational axis, which drives tropical rainfall in 21,000-year cycles. We also identified periods when average temperatures in Tibet went up and down by several degrees Celsius in roughly 200-year cycles. It’s still a mystery why that was the case, but we suspect this may be related to the 205-year cycle of solar activity.
In more recent times an interesting discovery is that the higher the elevation, the greater warming we have. This is in line with the observation that the vast majority of glaciers in Tibet and the Himalayas are retreating. In some extreme cases, as ice cores from the Naimona’nyi Glacier in southern Tibet show, all the snow and ice that accumulated since 1950 has melted or sublimated away at altitudes as high as 6,000 meters above sea level.
[This ice loss] is not unique to Tibetan and Himalayan glaciers. The picture is the same for nearly all mountain glaciers around the world. The summit ice cover of Tanzania’s Mount Kilimanjaro, for instance, has shrunk by 85 percent in the past century. If the current climate conditions persist, it won’t be long before Africa’s highest mountain is ice-free. At the Quelccaya Ice Cap in the Peruvian Andes, glaciers that accumulated over 1,600 years have melted in just 25 years.
Such analyses provide some of the strongest evidence to date that our climate is going through a period of unprecedented warming on a large scale. One of the biggest challenges we face in the 21st century is how to get along with each other, and another is how to get along with our planet. The world should act together to curb emissions of greenhouse gases and other pollutants.
Scientific American
H/T Colorado Bob

43
The forum / Re: Suggestions
« on: June 02, 2016, 08:52:47 AM »
check under "killfiles"

https://forum.arctic-sea-ice.net/index.php/topic,444.msg49157.html#msg49157
OK, thanks. I'll probably refrain from using it for now but it's helpful to know it's there. (See, this is where a Like/Appreciate button would work.)

44
The forum / Re: Suggestions
« on: June 02, 2016, 08:25:07 AM »
How about limiting length of signature based on your ASIF status? So that a newbie cannot have a 10-line long signature and then fill up whole threads unthinkingly (my bold), before forum decorum is assimilated.
But some people seem incapable of assimilating forum decorum, and immune to hints and public rebukes. Is perhaps the very point of contentless posts by certain newbie posters purely to gain a higher status? (I'm beginning to think I'd appreciate an Ignore button... ;) )

45
Consequences / Re: Wildfires
« on: June 01, 2016, 10:36:18 PM »
Ah, that's the story I linked to earlier at #108. The Siberian Times headline's a bit misleading: the 219 million hectares aren't actually burning, they are just in an area designated as 'distant and hard-to-reach territories' which could be left to burn if they caught fire.

46
Consequences / Re: Wildfires
« on: June 01, 2016, 05:54:40 PM »
Siberian forest fires may be left to burn, according to The Siberian Times.
On 26 May, some about 129,000 hectares of forests, mainly in the Republic of Buryatia, and TransBaikal and Amur regions were on fire. Up to 219 million hectares fall into the category of 'distant and hard-to-reach territories' which could be left to burn if they caught fire.

Quote
29 May 2016
A quarter of all Russian forests, 89% of stocks in Sakha Republic, could be left to burn, even though they are essential to fight global warming.
These vast tracts of forest have been labelled 'distant and hard-to-reach territories', and as such it is officially permitted not to extinguish forest fires if they do not constitute a threat to settlements or if a fire fighting operation is extremely expensive.
At the same time, there is official recognition that some regions in Siberia are underreporting the extent of forest fires for 'political reasons', an accusation long made by environmental campaigners.
Some 86% of forest in Sakha - also known as Yakutia, and the largest constituent of the Russian Federation - is deemed to fall into the category of 'distant and hard-to-reach territories', according to reports.
Some 219 million hectares - or 2.19 million square kilometres, a larger area than either Saudi Arabia or Greenland - is covered by the definition. This amounts to quarter of all forests in Russia, where trees - especially in Siberia - are seen as an essential brake on climate change.
A new decree in Sakha Republic says the emergency services may stop extinguishing fires in such territories if there is no threat to residential areas, or if costs are disproportionate. The move comes as the forest fire season is once more biting across Siberia.
On 26 May, some about 129,000 hectares of forests, mainly in the Republic of Buryatia, and TransBaikal and Amur regions were on fire. Greenpeace Russia believes that officials and regional authorities intentionally announce figures underestimate the scale of forest fires. According to the environmental activists, open satellite sources indicated fires covering up to 3 million hectares of forests as of 23 May.
Rosleskhoz - the Federal Agency for Forestry, a federal executive body responsible for oversight of forestry issues - admitted that official figures from regions may be at odds with the actual area of raging fires. Among other reasons this could be 'because of political factors'.
The agency promised to provide correct data about damage at the end of the [fire] season.
Nikolai Krotov, deputy head of Rosleskhoz, said: 'We have concerns about differences in Amur region, Buryatia, Chelyabinsk and Irkutsk regions. We don't rule out that there can be political factors, subjective factors, when information is submitted in a different way.'
Greenpeace has argued for information in real time, not at the end of the season, so fire-fighting resources can be switched between regions to be deployed in most needed areas.
Rosleskhoz told Kommersant newspaper that the move by the authorities in Yakutsk is 'not a refusal to extinguish forest fires'.
'It shouldn't be ruled out that the local forestry service will extinguish all the fires because significant part of the republic's population leads a nomadic lifestyle and is always moving around,' said a source.
Mikhail Kreindlin, an expert on specially protected areas at Greenpeace Russia, said other countries sometimes have a rule 'not to extinguish fire of natural origin' but this practice is not always successful because there is always a risk that the heart of the blaze may grow bigger.
He pointed to massive forest fires in Canada which resulted in the evacuation of up to 80,000 people in recent weeks. Greenpeace Russia also warned that failing to tackle forest fires can destroy rare animals.
The Siberian Times.

47
Consequences / Re: Places becoming less livable
« on: June 01, 2016, 05:39:44 PM »
Extreme warnings issued that Lake Baikal could 'drain dry like the Aral Sea'
Basically a row over energy supply

Quote
Newspaper Izvestia this week was blunt in assessing the eco-damage threat to Baikal, a natural reservoir which contains around 20% of the world's unfrozen freshwater.
'Baikal might share the destiny of the Aral Sea,' it stated. 'Construction of three hydro power stations on the Selenga River and its tributaries can cause the unique lake to dry out.'
The 25 million year old lake - a UNESCO world heritage site - is 'on the edge of environmental catastrophe and if certain measures are not taken, it might disappear just like the Aral sea.'
The impact of proposed Mongolian hydro projects could also be to threaten the Buryatian capital city, Ulan-Ude, in the event of an accident to one of three planned dams.
Environmental activist Sergey Shapkhayev warned: 'Potential damage from the third hydro power station which will be located on the Eg River (a Selenga tributary) could cause a huge catastrophe. Hydrological experts believe that this power station is the most dangerous of all. 'This power station will be located in the seismically active part of Mongolia. And any seismic activity can cause  all the stored water to wash away part of Mongolia and in half a day it would reach Ulan-Ude' - a city with a population of 415,000. At the same time, speed of water will be compatible to tsunami.'
The warnings come amid new hopes in Russia that ways can be found to persuade Mongolia not to go ahead with the the hydro schemes - see our earlier story here.
Izvestia said that the claims about an Aral-like denuding of Baikal were aired at a closed doors meeting at the Energy Ministry. Crucial to the dams not being built are an offer acceptable to Mongolia of guaranteed cheap energy - from Russia.
The Siberian Times adds drily that "The comparison with the Aral Sea [...] appears far-fetched even allowing for a grave threat now facing Baikal."

More here in The Siberian Times.

48
The forum / Re: Suggestions
« on: May 31, 2016, 09:04:53 AM »
So, is this really necessary?
Not really necessary, just one I've seen work well elsewhere. I'm aware that posts that say nothing but "Good post!" or "Great charts!" can be annoying, particularly if people are reading on a cellphone. So a Like button may save a few centimetres on a thread.
It would be a pity if it turned things into a beauty contest, though.

49
The forum / Re: Suggestions
« on: May 29, 2016, 11:24:14 PM »
Crossposting from Forum Decorum because (a) I'd forgotten this thread  :-[
and (b) it might get noticed  :)
I don't know if it's possible, or whether if it's possible it would be a good idea, but I for one would really like a 'Like' button. I often want to express appreciation of a post but don't because I don't want to clog up the threads. Other people are less inhibited. I reckon it would reduce the number of contentless posts.

50
The forum / Re: Forum Decorum
« on: May 29, 2016, 12:06:39 PM »
I don't know if it's possible, or whether if it's possible it would be a good idea, but I for one would really like a 'Like' button. I often want to express appreciation of a post but don't because I don't want to clog up the threads. Other people are less inhibited. I reckon it would reduce the number of contentless posts.

Pages: [1] 2 3 ... 11