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Messages - sesyf

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1
Arctic sea ice / Re: 2019 vs 2012
« on: July 10, 2019, 12:07:46 AM »
For those interested in anecdotal evidence of what happened in 2012 around this time, I can highly recommend my own writings (someone has to do it) on the ASIB at the time: ASI 2012 Update 6: piggy bank

3
Consequences / Re: Global Surface Air Temperatures
« on: June 25, 2019, 01:06:58 PM »
Chart shows worlds temperature changes:
https://www.bbc.com/news/science-environment-48678196

I made a somewhat similar graphic for the Central England Temperature earlier this year. It goes from 1659, top to bottom, is colour coded based on ranking, has all months and annual temperature for the last column, and includes the max and min data from 1878 onward. If you zoom in, you can see the dates and actual temperature for each month, as well as a few notable years and periods are highlighted

https://amz.nwstatic.co.uk/monthly_2019_04/CET.png.6f4b9c3691b925fd5687ea0e85b41846.png

4
Arctic sea ice / Re: What's new in the Arctic ?
« on: May 31, 2019, 12:33:55 AM »
I made a quick and lightweight sea ice comparison page for the entire NSIDC data set. At the moment it's just for the 1st of the month, but soon I add the 15th of the month as well.

https://cryospherecomputing.tk/PastSIC

5
The rest / Re: Wildlife
« on: May 10, 2019, 05:05:03 AM »
New family of small lepidoptera (butterflies and moths) discovered, two previously unknown species found in Kazakhstan proved not to belong to Urodidae but to a linking group. The placement of Urodidae in the systematic order has been in dispute. The newly formed family of 2 species, Ustyurtiidae, fly during the day, in the early summer, and the caterpillars live above ground during the summer of the desert. Kazakh desert temperatures may rise well above 40°C (105°F).

https://www.helsinki.fi/en/news/life-science-news/finnish-researchers-discover-a-new-moth-family

The image of the habitat and the hostplant (© Lauri Kaila)

6
Antarctica / Re: What's new in Antarctica ?
« on: April 23, 2019, 01:49:47 AM »
The Antarctic Bedrock data was over 10 times harder to align than Greenland. There are hardly any landmarks, just plain white and with fast ice or ice shelfs you don't even know where the land begins. I had to use huge area images to align islands and then cut it down to individual glaciers. The bedrock resolution is just 1km/px as opposed to 0.15km/px for Greenland data.

https://cryospherecomputing.tk/Bedrock-Antarctica

7
Greenland and Arctic Circle / Re: Bedrock overlay poll
« on: April 20, 2019, 11:34:33 AM »
Thanks everyone for voting. As I suspected both options have a use case. The problem with combining them was that the template for the image overlay slider and the template for the range slider both had "slider" in the name and interferred with another. I solved it by setting the opacity with a number input field and a button.

The test pages are now removed and the overlays have an offical page:
https://cryospherecomputing.tk/Bedrock

8
Arctic sea ice / Re: Northwest Passage thread
« on: March 25, 2019, 10:20:10 AM »
Since the remelt season has begun I thought I would resurrect this idle thread last posted 9/11 last year:

Recently I found a buried treasure in the Internet Archives:

Roald Amundsen's "The North West passage" : being the record of a voyage of exploration of the ship "Gjöa" 1903-1907 by Amundsen, Roald, 1872-1928; Hansen, Godfred, 1876-1937 Publication date 1908

Volume 1 link:
https://archive.org/details/roaldamundsensth01amun/page/n10
Volume 2 link:
https://archive.org/details/roaldamundsensth02amun/page/n10

This is a multi-faceted book that will surely delight anyone who is interested in the history of the NW passage. Amundsen had a dual purpose mission:
1-Be the first to transit the NW Passage
2-Setup an observatory to locate the Magnetic North Pole

He was extremely lucky in both regards as he was able to sail via Davis Strait, Lancaster Sound, Bering Strait, Peel Inlet, Rae Strait to what he christened "Gjoa Haven" on the SW coast of King William Island relatively unimpeded while sailing right past the 1903 position of the MNP on the Boothia Peninsula.

He and his small crew wintered on KWI for several winters to complete observations of the MNP during which time he befriended the local Inuits, who taught him many things that would be crucial for his success during his South Pole expedition. Amundsen was an uncanny observer and his detailed descriptions of the paleolithic way of life of the Inuits of KWI is worth the read in itself. The brilliance of their arctic survival skills passed down by word-of-mouth for hundreds of years is fascinating.

He also found artifacts from the Franklin Expedition tragedy which had unfolded on KWI some 60 years before and also heard reliable reports on what had transpired from the Inuit point of view.

His exit out of the CAA via Simpson Strait, Coronation Gulf, Amundsen Gulf, Beaufort Sea, Chukchi Sea and the Bering Strait was more problematic than his entry voyage in terms of sea ice and entailed some harrowing experiences in the diminutive "Gjoa".

This chronicle of the Amundsen's expedition in a converted herring fishing boat with a skeleton crew also contains amazing photos, that coupled with Amundsen's first-hand account, make for a captivating read as he succeeded in a venture that had stymied the great wealth and power of England's maritime genius for hundreds of years.

All in all, this book will provide many hours of enjoyment whilst sitting in the rocking chair waiting for the sea ice to melt  8)

 







9
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: March 17, 2019, 08:31:02 PM »
NSIDC Total Area as at 16 March 2019 (5 day trailing average)  13,113,396 km2
         
Total Area         
 13,113,396    km2      
 162,395    km2   >   2010's average.
 371,029    k   >   2018
-220,565    k   <   2000's average.
         
Total gain/loss   -10    k   loss
Peripheral Seas    15    k   gain
Central Seas__    1    k   gain
Other Seas___   -26    k   loss
         
Peripheral Seas         
Bering _______    15    k   gain
Baffin  Bay____   -1    k   loss
Greenland____   -0    k   loss
Barents ______    1    k   gain
         
CAB Seas         
Beaufort_____   -1    k   loss
CAA_________    1    k   gain
East Siberian__   -1    k   loss
Central Arctic_    1    k   gain
         
Kara_________   -4    k   loss
Laptev_______   -1    k   loss
Chukchi______    5    k   gain
         
Other Seas         
Okhotsk______   -10    k   loss
St Lawrence___   -11    k   loss
Hudson Bay___   -5    k   loss
Area LOSS 10 k, 23 k less than the 2010's average GAIN of 13 k on this day.

Other Stuff
GFS indicates that overall the Arctic temperature anomaly will gradually change from around -0.5 degrees to +3 over the next 10 days, with the additional warmth mainly from the Pacific side. 

A surprising swift switch from area gain to area loss, entirely due to losses in the Okhotsk, St Lawrence and Hudson seas. From today posting will assume the melting season is getting underway.

10
Policy and solutions / Re: Cars, cars and more cars. And trucks, and....
« on: February 23, 2019, 10:01:35 PM »
Archimid , We boomers have ridden a one time economic boom that will never be repeated. Although I have been lucky and I have a farm I am not sure most people would settle for the 365 days a year I work or the $30 a day it pays after I write off about everything most people would consider the cost of living expenses like fuel , boots , fences , a solar array,animal feed etc.  I write it off because that's how the US tax code works. 
 If you could please put yourself in a young person shoes who around here needs to pay $1,200 to
$3,000 a month rent, or buy fuel for the commute ,a car and insurance or maybe pay for children. Even if they do make $33,000 a year in wages they are going to be broke, yes the top one percent of income earners are broke, can't save for a house down payment, and can't buy a solar system.
 Now if you think it's silly that I struggle to make my own biodiesel for my tractor or farm or try to maintain some connection to nature because I think those things will be necessary to others as this whole economic system implodes go ahead and think what you will. I will maintain my opinion that servicing the desires of the top .1 percent is a planet suicide pact. I try to avoid being accusatory or angry but when it all comes apart I hope I can somehow show a few people how to feed themselves and their families, probably won't save me.  My chances are likely no better than yours when the rage at the bottom finally bubbles up .
 
https://www.investopedia.com/articles/personal-finance/050615/are-you-top-one-percent-world.asp

11
Consequences / Re: 2019 World Economic Forum: Global Risk Report
« on: January 27, 2019, 04:34:12 AM »
My Message to Davos Elites: Act As If Our House Is on Fire. Because It Is   
http://smirkingchimp.com/thread/greta-thunberg/83220/my-message-to-davos-elites-act-as-if-our-house-is-on-fire-because-it-is 

Quote


At places like Davos, people like to tell success stories. But their financial success has come with an unthinkable price tag. ...  We are facing a disaster of unspoken sufferings for enormous amounts of people. And now is not the time for speaking politely or focusing on what we can or cannot say. Now is the time to speak clearly.

Solving the climate crisis is the greatest and most complex challenge that Homo sapiens have ever faced. The main solution, however, is so simple that even a small child can understand it. We have to stop our emissions of greenhouse gases.

Either we do that or we don’t.

You say nothing in life is black or white. But that is a lie. A very dangerous lie. Either we prevent 1.5C of warming or we don’t. Either we avoid setting off that irreversible chain reaction beyond human control or we don’t.

Either we choose to go on as a civilization or we don’t. That is as black or white as it gets. There are no grey areas when it comes to survival.

... Adults keep saying: “We owe it to the young people to give them hope.” But I don’t want your hope. I don’t want you to be hopeful. I want you to panic. I want you to feel the fear I feel every day. And then I want you to act.

I want you to act as you would in a crisis. I want you to act as if our house is on fire. Because it is.



----------------------- 

Children's Climate Rallies Gain Momentum In Europe
https://www.bbc.com/news/world-europe-46999381

Quote
... In Brussels, home to the main EU institutions, students carried banners with slogans such as "Dinosaurs thought they had time too" ...

12
Permafrost / Re: Arctic Methane Release
« on: January 19, 2019, 05:37:23 PM »
A little off topic or pedantic prehaps, but ...
For those who use "ice age" to mean periods of glaciation advancement and near-peak ice coverage, know that in glaciology [i.e., "scientific"] terms, ice age implies the presence of extensive ice sheets in both northern and southern hemispheres. So by this definition, we are in the Quaternary Glaciation or Ice Age (and in an interglacial period—the Holocene—within it). We won't leave the current ice age until most (or all) of the ice fields in Greenland and Antarctica melt away.

Colloquially, of course, ice ages are interspersed with interglacial periods of time.  Although I believe Earth was slowly heading for the next glacial stage, human activities during the past 10,000 years or so (especially the last 300 and moreso, 70 years) have turned this Milankovitch Cycle on its head.  (Well, the Cycle is still operative, but (unintentional) geoengineering has overpowered the M. Cycle influences.)  And there are scientific papers out there [e.g. here] that occasionally use the "ice age = glacial stage" definition, so maybe you should just ignore me.

13
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: January 13, 2019, 05:04:12 PM »
NSIDC Total Area as at 12 January 2019 (5 day trailing average) =  11,860,854 km2

Total Area         
 11,860,854    km2      
 229,478    km2   >    2010's average.
 473,845    k   >   2018
-233,106    k   <    2000's average.
         
Total Gain    17    k   
Peripheral Seas    10    k   gain
Central Seas__    3    k   gain
Other Seas___    4    k   gain
         
Peripheral Seas         
Bering _______    9    k   gain
Baffin  Bay____    7    k   gain
Greenland____   -1    k   loss
Barents ______   -5    k   loss
         
CAB Seas         
Beaufort_____   -0    k   loss
CAA_________    0    k   gain
East Siberian__   -4    k   loss
Central Arctic_   -4    k   loss
         
Kara_________    11    k   gain
Laptev_______    0    k   gain
Chukchi______   -0    k   loss
         
Other Seas         
Okhotsk______    6    k   gain
St Lawrence___   -0    k   loss
Hudson Bay___   -2    k   loss
Area gain 17k, 16 k below average for the day.

Other stuff

GFS indicates that overall the Arctic temperature varies from zero to -2 degrees for the next week or more. This disguises the highly variable +ve and -ve anomalies at various times over the various regions of the Arctic. e.g. the Bering Sea looks like it will have strong +ve temp anomalies for some of the time interspersed with days of strong -ve anomalies.

14
Permafrost / Snow Cover changes on regional scale
« on: January 07, 2019, 01:25:37 AM »
I finished calculating regional snow extent data and will post my analysis here. The main snow cover thread doesn't quite fit for this detailed long term analysis. At the moment all data is still in one long list, but after formatting we can graph things like snow extent for region x in month y. I attached a map showing all regions and an example for Greenlands snow extent.

Eventually regional graphs should also get daily updates on my main snow cover webpage
https://sites.google.com/site/cryospherecomputing/snow-cover

Data Download (csv & formatted ExcelSheet)
https://github.com/NicoSun/CryosphereComputing/tree/master/ScienceData/Snow_Cover_Regional


15
During the current blast from the Arctic, Bay of Bothnia had wind speeds of category 1 hurricane equivalent. While not the first winter storm to do so, the record 10 min sustained speeds of wind is now 32,4m/s for the Finnish side of the bay. Gusts reached 40,2m/s, and hurricane-force limits also on coastal stations.
A gust of 41,6 m/s was recorded in Kökar, an island on Northern Baltic between Åland and Mainland Finland. This is among the fastest gusts measured here. Associated significant wave heights have also been the highest ever for Bothnian Bay, c.23,5 feet, top measured waveheights of near 11 meters have been observed

Update, the one fatality in Finland due the storm was after the storm, when a man clearing fallen trees had an accident with the tractor he used as help in claring the way. The three finnsh and one swedish person trekking out in Norway are still missing. And of course the same storm caused (at lest partially) the train accident in Denmark with 8 fatalities.

Update: the four ski-trekkers now presumed dead in an avalanche, two of them had some training to be wilderness guides.

16
Arctic sea ice / Re: The Mail's Great White Arctic Sea Ice Con
« on: January 01, 2019, 03:53:56 PM »
Thanks Neven!

A happy (and prosperous?) 2019 to you, your family and your extended family at the ASIF & ASIB.

Some more "kids" at festive play:


17
I have been periodically encouraged to post again in other threads, but I have decided not to do so; nevertheless, while the following information could easily be posted in the "Adapting to the Anthropocene", the "Systemic Isolation" and/or other threads, I post it here because I feel that it may help some readers to better understand why mankind seems to be barreling towards an "Ice Apocalypse" when it is within our collective 'free feel' to stop proceeding on such a harmful path.

All of the following links lead to information about Karl Friston's various efforts to explain his 'free energy principle' which uses formulae (e.g. see the attached image) from physics to define the 'prediction error' of models (or 'inference engines') where by minimizing the 'free energy' one minimizes the 'prediction error' and thus minimizes surprises.  Friston go on beyond considering only traditional Bayesian 'inference engines' to define 'active inference' where active systems (say human minds) can use their free will to deal with surprises by either accepting the short-comings of the model (or 'inference engine' associated with a particular 'Markov Blanket') and make changes to the model, or by acting to make their predictions come true.

The 'free energy principle' can used to better understand how human society has made the collective decision that it has made to stay on a BAU pathway, and its mathematics can also be used to improve AI projections; that could possibly help society to better deal with abrupt climate change in the coming decades:

Title: "The Genius Neuroscientist Who Might Hold the Key to True AI"

https://www.wired.com/story/karl-friston-free-energy-principle-artificial-intelligence/

Extract: "Friston calls this his first scientific insight, a moment when “all these contrived, anthropomorphized explanations of purpose and survival and the like all seemed to just peel away,” he says. “And the thing you were observing just was. In the sense that it could be no other way.”

Hinton described a new technique he’d devised to allow computer programs to emulate human decisionmaking more efficiently—a process for integrating the input of many different probabilistic models, now known in machine learning as a “product of experts.”

Inspired by Hinton’s ideas, and in a spirit of intellectual reciprocity, Friston sent Hinton a set of notes about an idea he had for connecting several seemingly “unrelated anatomical, physiological, and psychophysical attributes of the brain.” Friston published those notes in 2005—the first of many dozens of papers he would go on to write about the free energy principle.

The psychologist Christopher Frith—who has an h-index on par with Friston’s—once described a Markov blanket as “a cognitive version of a cell membrane, shielding states inside the blanket from states outside.”

In Friston’s mind, the universe is made up of Markov blankets inside of Markov blankets. Each of us has a Markov blanket that keeps us apart from what is not us. And within us are blankets separating organs, which contain blankets separating cells, which contain blankets separating their organelles. The blankets define how biological things exist over time and behave distinctly from one another. Without them, we’re just hot gas dissipating into the ether.

The concept of free energy itself comes from physics, which means it’s difficult to explain precisely without wading into mathematical formulas. In a sense that’s what makes it powerful: It isn’t a merely rhetorical concept. It’s a measurable quantity that can be modeled, using much the same math that Friston has used to interpret brain images to such world-¬changing effect. But if you translate the concept from math into English, here’s roughly what you get: Free energy is the difference between the states you expect to be in and the states your sensors tell you that you are in. Or, to put it another way, when you are minimizing free energy, you are minimizing surprise.

So far, as you might have noticed, this sounds a lot like the Bayesian idea of the brain as an “inference engine” that Hinton told Friston about in the 1990s. And indeed, Friston regards the Bayesian model as a foundation of the free energy principle (“free energy” is even a rough synonym for “prediction error”). But the limitation of the Bayesian model, for Friston, is that it only accounts for the interaction between beliefs and perceptions; it has nothing to say about the body or action. It can’t get you out of your chair.

This isn’t enough for Friston, who uses the term “active inference” to describe the way organisms minimize surprise while moving about the world. When the brain makes a prediction that isn’t immediately borne out by what the senses relay back, Friston believes, it can minimize free energy in one of two ways: It can revise its prediction—absorb the surprise, concede the error, update its model of the world—or it can act to make the prediction true.

And in fact, this is how the free energy principle accounts for everything we do: perception, action, planning, problem solving. When I get into the car to run an errand, I am minimizing free energy by confirming my hypothesis—my fantasy—through action.

For Friston, folding action and movement into the equation is immensely important. Even perception itself, he says, is “enslaved by action”: To gather information, the eye darts, the diaphragm draws air into the nose, the fingers generate friction against a surface. And all of this fine motor movement exists on a continuum with bigger plans, explorations, and actions.

So what happens when our prophecies are not self-fulfilling? What does it look like for a system to be overwhelmed by surprise? The free energy principle, it turns out, isn’t just a unified theory of action, perception, and planning; it’s also a theory of mental illness."

See also:

Title: "Free energy principle"

https://en.wikipedia.org/wiki/Free_energy_principle
&

Title: "Free Energy Principle — Karl Friston"


&

Title: "Karl Friston: Active inference and artificial curiosity"


&

Title: "Markov blanket"

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

Extract: "In statistics and machine learning, the Markov blanket for a node in a graphical model contains all the variables that shield the node from the rest of the network. This means that the Markov blanket of a node is the only knowledge needed to predict the behavior of that node and its children. The term was coined by Judea Pearl in 1988."

18
As I said that I would make a few posts (which I take to mean three posts today), I provide the following like to an article that cites research that confirms that current ice mass loss is contributing (see blue line in the attached image) to the drift of the Earth's rotational axis about the poles:

Scientists Identified Three Reasons Responsible for Earth’s Spin Axis Drift

http://www.geologyin.com/2018/09/scientists-identified-three-reasons.html

Extract: "A typical desk globe is designed to be a geometric sphere and to rotate smoothly when you spin it. Our actual planet is far less perfect—in both shape and in rotation.

Earth is not a perfect sphere. When it rotates on its spin axis—an imaginary line that passes through the North and South Poles—it drifts and wobbles. These spin-axis movements are scientifically referred to as "polar motion." Measurements for the 20th century show that the spin axis drifted about 4 inches (10 centimeters) per year. Over the course of a century, that becomes more than 11 yards (10 meters).

Using observational and model-based data spanning the entire 20th century, NASA scientists have for the first time identified three broadly-categorized processes responsible for this drift—contemporary mass loss primarily in Greenland, glacial rebound, and mantle convection.

"The traditional explanation is that one process, glacial rebound, is responsible for this motion of Earth's spin axis. But recently, many researchers have speculated that other processes could have potentially large effects on it as well," said first author Surendra Adhikari of NASA's Jet Propulsion Laboratory in Pasadena, California."

19
While in other threads I have stated that I would no longer post in the ASIF, I have decided that as the risk of abrupt sea level rise, SLR, this century is so much higher than many decisionmakers appreciate; I will periodically post in this one ASIF thread.  In this regard, I make a few posts illustrating how decisionmakers are confused about the topic of abrupt SLR, and I begin by providing the first linked reference by Pattyn (2018), which points out that many (most) current consensus ice-sheet model projections of Antarctic Ice Sheet, AIS, contribution to SLR used inappropriate equilibrium initial states for their models; while dynamical initial states are necessary for short-term projections on the order of decades.  Furthermore, Pattyn (2018) notes that such dynamical initial conditions need to properly account for not only Marine Ice Sheet Instability, MISI, but also for Marine Ice Cliff Instability, MICI, and for hydro-fracturing mechanisms (see the first attached image).

Frank Pattyn (2018 Jul 16), "The paradigm shift in Antarctic ice sheet modelling", Nat Commun. 2018; 9: 2728; doi:  10.1038/s41467-018-05003-z

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6048022/

Abstract: "The Antarctic ice sheet is one of the largest potential contributors to future sea level rise. Predicting its future behaviour using physically-based ice sheet models has been a bottleneck for the past decades, but major advances are ongoing."

Extract: "A key aspect of projecting future Antarctic mass loss with dynamical ice sheet models is related to the initial state of the model. Since ice sheet models were initially applied for palaeo-climatic studies on long time scales, initialisation was generally obtained from a long spin-up time leading to a steady-state ice sheet (both in terms of geometry and thermodynamics). However, for predictions on shorter time scales (decades to centuries), a stable spin-up generally leads to an ice sheet geometry far different from the one currently observed, which is one of the reasons why such ice sheet models may respond differently than observations suggest. Moreover, using a steady-state for initialising the ice sheet prevents models from properly accounting for the dynamical mass losses observed over the last decade, as the present-day ice sheet is not in steady state. Motivated by the increasing ice sheet imbalance of the ASE glaciers over the last 20 years, and supported by the recent boom in satellite data availability, data-assimilation methods are progressively used to evaluate unknown fields using time-evolving states accounting for the transient nature of observations and the model dynamics."

Next I note that, Bronselaer et al (2018) used an AIS model that does not account for MICI nor hydro-fracturing (which are not likely to be significant before 2040) to show that by 2040 upwelling of relatively warm circumpolar deep water, CDW, around Antarctic will shift the potential ice melting temperature difference upward from below 1,000 m depth to roughly 750 m depth, and will increasingly advect this warm CDW towards the grounding line (see the second attached image) for key marine glaciers such as the Pine Island Glacier, PIG (see the third image wrt the water depth of the grounding line) and the Thwaites Glacier (see the fourth image).  What is critical to note wrt Bronselaer et al (2018) is that by 2040 the temperature of the Southern Ocean would be thousands of years from full equilibrium, but for key AIS marine glaciers both the top and bottom ice surfaces exposed to air and water respectively will experience ice mass loss sufficient to trigger localized MICI and hydro-fracturing mechanisms (if they had been included in Bronselaer et al (2018)'s model.

Bronselaer, B. et al. (2018) Change in future climate due to Antarctic meltwater, Nature, doi:s41586-018-0712-z

https://www.nature.com/articles/s41586-018-0712-z

Abstract: "Meltwater from the Antarctic Ice Sheet is projected to cause up to one metre of sea-level rise by 2100 under the highest greenhouse gas concentration trajectory (RCP8.5) considered by the Intergovernmental Panel on Climate Change (IPCC). However, the effects of meltwater from the ice sheets and ice shelves of Antarctica are not included in the widely used CMIP5 climate models, which introduces bias into IPCC climate projections. Here we assess a large ensemble simulation of the CMIP5 model ‘GFDL ESM2M’ that accounts for RCP8.5-projected Antarctic Ice Sheet meltwater. We find that, relative to the standard RCP8.5 scenario, accounting for meltwater delays the exceedance of the maximum global-mean atmospheric warming targets of 1.5 and 2 degrees Celsius by more than a decade, enhances drying of the Southern Hemisphere and reduces drying of the Northern Hemisphere, increases the formation of Antarctic sea ice (consistent with recent observations of increasing Antarctic sea-ice area) and warms the subsurface ocean around the Antarctic coast. Moreover, the meltwater-induced subsurface ocean warming could lead to further ice-sheet and ice-shelf melting through a positive feedback mechanism, highlighting the importance of including meltwater effects in simulations of future climate."

Caption for the second attached image: "Fig. 5 | Mechanism for ocean warming. a, Hovmoller diagram of the meltwater-induced ocean temperature anomaly, averaged along the Antarctic coast, as a function of time. The black dotted line indicates the maximum warming in a given year. b, c, Schematic of the meltwater-induced Southern Ocean subsurface warming, shown as a zonal-mean cross-section. In the pre-industrial state (b), isopycnals (black lines) are tilted towards the ocean surface by westerly winds (black circles, directed out of the page), away from the continental shelf, with an upward heat flux transporting heat from the warm CDW (orange water) towards the cooler surface (blue water), as shown by the red arrow. In the perturbed state (c), meltwater from the Antarctic Ice Sheet freshens the surface (blue), depressing isopycnals (solid to dashed black lines) so that isopycnal mixing transports heat towards the continent rather than towards the ocean surface (red arrow), leading to coastal warming at depth around the shelf and cooling at the surface."

20
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 20, 2018, 11:41:05 PM »
Agreed. It looks like there is only movement in the Nares now.
Here is a comparison of 2017 and 2018, using amsr2-uhh, from oct1 to nov19. 2017 is outlined in green.

21
Consequences / Re: Weird Weather and anecdotal stories about climate change
« on: November 01, 2018, 08:21:02 PM »
Here's something weird and on topic that no-one (except Swedes) will understand.
Sweden's most popular meteorologist, John Pohlman celebrates his 83:rd birthday today!

A short and very white clip from 1999 about former winters. If you want to be even more confused, please use the automatic subtitling!


22
Greenland and Arctic Circle / Re: Greenland 2018 melt season
« on: September 01, 2018, 11:39:52 AM »
https://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/

As at 31 August 2018

On schedule without drama the Greenland melting season finishes.  The SMB gain for the year is 150 gt above average.

The last two days did give a bit of drama as S. Greenland got a good bit of rain and snow from a low which is now zooming up the East Greenland coast.

GFS suggests that S Greenland will get another dose of precipitation in about a weeks time - but this time from way down south.
_____________________________________________________________
SMB = Surface Mass Balance which excludes mass loss from calving, that on average is greater than SMB gain in the year. i.e. usually Greenland loses mass every year.

23
Consequences / Re: 2018 ENSO
« on: September 01, 2018, 03:31:08 AM »
Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to -6.9:

24
Science / Comparison: forcings from CO2, CH4, N2O
« on: August 20, 2018, 02:57:23 PM »
From time to time on ASIF (e.g. here) there seems to be some mistaken ideas about the relative importance of CO2 vs methane.

Over the past three-plus decades, the annual change in forcing from CO2 has consistently been much larger than from methane (or N2O, for that matter):



In fact, the gap between them is growing, not shrinking.  The trend in this gap (dF_CO2 minus dF_CH4) is statistically significant.  From 1985 to 2017 it increased by approximately 77%. 

At this point in time, the increase in the methane forcing is simply not very important compared to the increase in the CO2 forcing.

The fine print:  Data from here, here, and here.  All forcings calculated using the updated models from Etminan et al. (2016)

25
Arctic sea ice / Re: The 2018 melting season
« on: August 11, 2018, 04:29:28 PM »
Quote
is there a warm current sneaking it's way along the coast?
FishOwater has been on a roll lately with some great posts, calling our attention to the SSW (sudden stratospheric warming) event of 12 Feb 18 aka day 43 and its consequences for subsequent weather patterns. I looked to see whether that date showed up as a breakpoint on Ascat sea ice motion, UH AMSR2 sea ice concentration, GFS winds, or OSI-SAF sea ice motion.

Sure enough, day 43 was the start of the remarkable North Greenland retro-event that backed already exported Fram ice up across the flux gate, along with creating a major lift-off and associated open water.

Ice export eventually returned to its previous pattern until early June when the semi circumpolar drift weather pattern drifted into the indeterminacy that continues until today. Note no transpolar drift has occurred in recent years, ie don't trust old textbooks, look at actual ice motion, read current journals:

Collapse of the 2017 Winter Beaufort High: A Response to Thinning Sea Ice?
March 2018 Geophysical Research Letters 45(6)
DOI: 10.1002/2017GL076446

Now this was one of these low pressure systems that not infrequently barrel up into the Arctic Ocean between Svalbard and Greenland. So in terms of SSW, was this coincidental, correlated, or causal?

Oceanographic work by A Muenchow and others has indicated a returning path for Atlantic Waters along the Lomonosov Ridge and out the Nares year-round at depth. This route takes several years to complete so even if somehow now affecting north Greenland surface waters, it wouldn't be tied to the current intrusion.

Thus FishOwater's proposal for unprecedented Atlantic Water upwelling and westward dispersal to this region, despite its dire implications for the future of the CAB, is more attractive, though it remains to be seen how it will play out over coming weeks.

Some forums are still claiming that the SV-FJL-SZ retreat is eating into MYI CAB ice. Wrong. I've explained 40-50 times this year that this is not the case. Even now, retreat is only processing the long tongue of FYI that was extruded from the Kara (and Laptev), see the Ascat mp4 below.

It is more accurate to say, as Rox and others do up-forum, the melt season mostly just undoes freeze season, with both operate primarily on ice peripheral to the core CAB. The CAB surely undergoes thickening and thinning over the year but mostly we cannot observe it. Hence the immense interest in the still-unfolding west Lincoln Sea event.

Note too not one snowflake from the Arctic basin has exited via the CAA garlic press this season. The aforementioned summer weather is not up to the job.

As shown earlier, a huge thick floe of MYI pushed down one of the minor channels last summer completely blocked the NW Passage above the Lougheed Island pinch-point.The Northwest Passages are mostly melting in situ, with more southerly ice breaking off and being brought by currents into Baffin Bay as in past years. The M'Clure Strait cork has quieted down and been replaced by lift-off (tracked in recent uniquorm posts).

Quote
We have had an atmospheric circulation vortex around Greenland for over 3 months that was brought on by the major stratospheric warming in February. That stratospheric warming was caused by the strongest wave driving event, which drove energy upwards from the troposphere to the top of the stratosphere, on record.

There's more warm salty Atlantic water spinning around the N coast of Greenland that's moving into the waters of the CAA. Brief events where the ice blows off N Greenland cause an increase in surface salinity. Longer events of clockwise winds may well up relatively warm salty water from the 300m Atlantic water layer along the continental shelf. This is serious stuff.

Many of the models we have seen over the years pile up ice along the N shore of Greenland and the CAA as a last resort as the Arctic heads towards blue water, but we are seeing right now the beginning of the collapse of that last resort. The remaining ice is thin and shattered north of Greenland and into the Lincoln sea. The shattered ice is floating in a matrix of open water.

26
Arctic sea ice / Re: The 2018 melting season
« on: August 11, 2018, 03:17:04 PM »
There are weather stations at Morris Jesup, Alert, Nord and Svalbard that report online. Forums here don't follow them very closely, preferring computer theories. These would be 2m temperatures at MJ; it reports hourly to DMI. The station is located on the coastal plain a few hundred meters from the ocean at 83°37′59″N, 32°31′00″W.

Temperatures have been unremarkable though above freezing with a fair amount of insolation. Upward and downward short and long wave radiative fluxes could be quantitated but I don't believe they are at this station. It could have been located on fixed ice say off Kaffeklubben but isn't because of servicing issues.

Svalbard has daily soundings, a much longer historical record and more advanced statistical offerings. These too are not often consulted on the forums but more likely to be baked into planetary-scale weather presentations. The DMI 80ºN would include MJ and station data on FJL and SZ islands. There is currently no instrumentation reporting from the Arctic Ocean itself.

The Polarstern has been down in the Fram recording weather and water properties. "On July 28, the research icebreaker Polarstern arrived in the Northeast Water Polynya, an area of open water on the northeast Greenland shelf. A large part of the landfast sea ice south of Polarstern's current position at 80°N just  broke off." See https://twitter.com/seaice_de?lang=en

27
Arctic sea ice / Re: The 2018 melting season
« on: May 15, 2018, 01:06:41 PM »
Here is another model-view on the things that might come to the Arctic. The first pic compares ESRL & GFS forecasts for temps and SLP.
In agreement with the ECMWF-forecast posted by Neven above they show the high pulling back to the Beaufort. That could make room for a little heat intrusion over the ESS and Laptev. The forecasted SLP is in good agreement, the surface temps differ slightly  ;)

The two other pics show the predicted melt pond fraction. First pic from today has some ponds in the Chukchi/Beaufort. The second shows the possible consequences of the predicted little heat wave: widespread meltponding in the ESS/Laptev.

Bad news for the ice? Who knows. Fortunately the SPIE of the great late professor Slater is back online (maintained now by Andrew Barret's team at NSIDC as I gather from this guest post at the ASIB).
Will be interesting to see if this forecast materializes and how this will effect Slaters model.

PS: A late thanks to Dryland for the effort and the link to his site, wehre he has put together the most interesting ESRL model outputs

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