Saturday, 15 April 2017

An ice update - 04/14/2017


Under the Arctic Dome — Brutish High Pressure System is Wrecking the Already Thinned Sea Ice


14 Apri7, 2014

There’s a real atmospheric brute towering over the Arctic’s Beaufort Sea at this time. A high pressure system that would put shame to most other anti-cyclonic phenomena that bear the name. It is sending out a broad, clockwise pattern of winds. It is pulling up warm air from the Pacific to invade the Bering, Chukchi, East Siberian and Laptev Seas. And its torquing motion is shattering the already considerably thinned ice beneath it.

(A powerful high pressure system over the Beaufort Sea is predicted to further strengthen by late April 15. Image source: Earth Nullschool.)

Clocking in at 1046 mb of pressure, it makes typically strong 1030 mb high pressure systems seem weak by comparison. Over the next day it is expected to strengthen still — hitting 1048 mb by late April 15th (coming very close to an extraordinary 1050 mb system).
Shattered Sea Ice

This powerful and strengthening system has already been in place for about two weeks — slowly gaining momentum as its circulation has moved in mirror to the waters of theBeaufort Gyre that swirl beneath it. Masked only by a veil of sea ice considerably thinned by human-forced climate change, the waters of the Beaufort are now breaking through. Streaks of dark blue on white in an early break-up enabled both by a terrible Arctic warming and by this powerful spring weather system.
(Side-by-side images of Beaufort sea ice from April 4 [left frame] to April 13 [right frame]. Note the considerable and rapid advance of fracturing in a relatively short period. For reference, bottom edge of frame in both images is 500 miles. Image source: LANCE MODIS.)

Warm Storms

On the Siberian side of the Arctic, this massive high pressure dome is drawing in warm winds from the Pacific Ocean. Gust by gust and front by front, they come in the form of squalls that deliver above freezing temperatures and rains that blanket this thawing section of the Arctic. On Thursday, April 13, these warm winds had driven northward over 2,500 miles of Pacific waters to be drawn into storms that unleashed their fury — driving rains and gales through the already dispersed ice in the Bering Sea and shattering ice floes through the Chukchi. Today, April 14, these winds and rains drove northward to assault the ice of the East Siberian and Laptev seas.

(On April 13, above freezing temperatures, rains, and gale force winds ripped through the sea ice near Wrangle Island in the Chukchi Sea. Image source: Earth Nullschool.)

A Great Atmospheric Stack Drawing Heat into the Arctic

In the past, meteorologists like Stu Ostro envisioned that climate change would tend to produce towering high pressure systems — featuring increasingly strong storms roaring about their fierce outer boundaries. And the massive high lurking over the Arctic at this time is a good example of Ostro’s predictions coming to light in a region that is very sensitive to human-forced warming.

This great atmospheric stack appears to have had a considerable impact on the ice already —helping to push extent measures back into record low ranges by accelerating the melt trend. But these impacts are likely to spike over the coming week as this powerful high expected to remain in place through the next five days — continuing to draw warm air into the region. 
(Global Forecast System models predict extreme warming over the Arctic Ocean throughout the next week resulting from the influence of a powerful high pressure system and very strong associated ridge in the Jet Stream. Image source: NCEP Global Forecast System Reanalysis.)

GFS model runs indicate that average temperatures over the Arctic Ocean region will hit a peak as high as 4 degrees Celsius above average by late next week. Meanwhile, the warmest zones are expected to be as much as 18-20 degrees Celsius above average. Such abnormal warmth at this time of year, if it emerges, will put a considerable damper on a freeze that should now be continuing in the High Arctic even as edge melt ramps up with the progression of spring.
This is particularly concerning due to the fact that temperature anomalies in the Arctic tend to fall off during spring and summer. In other words, such a powerful warming trend for the Arctic Ocean would be bad enough during winter — but it is an even more unusual event for spring. An ominous start to a melt season that could produce far-reaching regional and global consequences.
Links:
Hat tip to Colorado Bob
Hat tip to Andy in San Dieg


The Permafrost is Thawing 20 Percent Faster Than Previously Thought


14 April, 2017

Even in a world at 1 to 1.2 C warmer than 19th Century averages the permafrost is in trouble.

Already, vast thawed lands are starting to release carbon dioxide and methane. Thermokarst lakes bubble with the stuff. And pingos are now starting to erupt as the ice relinquishes the soils of Siberia. Russians, ironically concerned about the safety of an oil and gas infrastructure that helped to precipitate the warming in the first place, are starting to install seismographs to detect these new warming-induced eruptions from the thawed lands. Meanwhile, each new summer brings with it ridiculously warm temperatures, never before seen Arctic thunderstorms, and epic wildfires that rage over these growing piles of peat-like carbon laid down during the course of millions of years of glaciation — but now unlocked in just years and decades by an unnatural thaw.

Permafrost Thawing at 20 Percent Faster Rate Than We Previously Thought

Back in the late 1800s, permafrost covered about 17 million square kilometers of the Northern Hemisphere. In less than 150 years, that extent has been reduced by 2 million square kilometers due to the warming that has, to date, been produced by fossil fuel burning and related carbon emissions. Even worse, according to the new research, present temperatures alone are enough to, this Century, push permafrost coverage back to 12.5 million square kilometers.
That’s about 1/4 of the world’s permafrost gone due to just 1 to 1.2 degrees Celsius of global warming.
(A new study shows that 2 C worth of warming nearly cuts preindustrial permafrost extent in half to around 9 million square kilometers. Warming to 6 C above 1880s averages, which will occur so long as fossil fuel burning continues, will wipe out nearly all of the Northern Hemisphere’s permafrost. These thaw rates are about 20 percent more than previously estimated. Image source: An observation-based constraint on permafrost loss as a function of global warming.)

Warm the world by just another degree Celsius to 2 C above 1880s averages and, according to the new research, we’ll end up thawing another 3.5 million square kilometers of frozen ground to an ultimately reduced area of around 9 million square kilometers — cutting the Northern Hemisphere’s original permafrost coverage nearly in half.

Still More Urgency For Rapid Cuts to Fossil Fuel Burning

This newly identified permafrost thaw rate in response to human-forced warming is much faster than previously expected — representing a 20 percent acceleration compared to past permafrost thaw model estimates. And since the frozen ground of the world contains 1.2 to 1.4 trillion tons of carbon locked away over the course of millions of years, so rapid a thaw has big implications in a world warmed by fossil fuel burning.

(Wildfires burn through Siberia during August of 2014. Thawing permafrost lays bare billions of tons of carbon that can then be subject to release by microbes and the warming elements. Bacteria can break down the carbon — releasing methane and CO2. Thawed permafrost also forms a peat-like layer that can burn as more extensive fires rage across the heating Arctic. Image source: LANCE-MODIS.)

Back in 2015, scientists estimated that about 100 billion tons of permafrost carbon would hit the atmosphere over the course of the 21st Century due to human-forced warming. This warming feedback is equivalent to about 10 years of present fossil fuel emissions. Add an estimated 20 percent extrapolated from a faster than expected thaw to that rate and you end up with roughly 120 billion tons of carbon — or 12 years of present emissions bubbling and bursting up out of that previously frozen ground (approximately 40 ppm of CO2e heat forcing as feedback to the present warming).

It’s just another scientific finding of warming-related geophysical impacts occurring on timescales that were faster than previously expected. Still more added proof, as if we required any, that the need for cutting human fossil fuel emissions couldn’t be greater or more urgent. And when seismographs are now being constructed to detect permafrost methane bursts due to pingo detonations, it’s becoming more and more clear that we do not want to precipitate any more volatile Arctic thaw than we’ve already locked in.

Links:

Hat tip to Ryan in New England
Hat tip to Wili
Hat tip to Unnaturalfx






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