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"A simplified way to think of extent versus area is to imagine a slice of swiss cheese. Extent would be a measure of the edges of the slice of cheese and all of the space inside it. Area would be the measure of where there is cheese only, not including the holes. That is why if you compare extent and area in the same time period, extent is always bigger." -- National Snow and Ice Data Center FAQ

Read more... )
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What's happening in the Arctic right now will effect the future of all humans -- as in, if we're going to make it out of this century alive.

Here are the Cliff Notes to the new study Arctic Resilience Report. There is a very good graphic on page 80, Fig 3.3.
Read more... )
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-- Burning Earth Radio, November 2016 youtube

"There's three cyclone activity areas in the arctic; you have one off the north coast of Iceland, one strong one off the north coast of Norway, and another one up here at the north pole. There's a lot of strong winds associated with these cyclones.

We have a lot of wind activity at the surface associated with these cyclones. We can see why we're getting these winds -- we have all of this warm water coming up in the gulf stream coming up and pooling in the arctic. We have extremely warm waters here, hot spots up to 9.9C warmer than normal and very large warm pools 1.1C-2C above average. And what it's doing is bringing a lot of warm air with it, up into the arctic.

What's happening is that these low pressure areas are pulling cold air down off the arctic. Now you have the cold air pulled off the Greenland ice sheet, drained off Siberia...You can see this going back to the temperature map, you have the cold air extending into the southern latitudes here, and warm air extending very high into the arctic.

With a lot of these strong winds, you're going to get a lot of breaking up of the sea ice. You can see that a lot of this air is carrying a lot of moisture. What this is doing is that this is creating a lot of strange rain events in the arctic... We can see that there's this jet of precipitable water in the air that's coming up over Europe and getting pulled into the arctic, bringing rain.

With these high winds, these storms, we have a lot of wave action. For example, 4.5 meter waves off these Russian arctic islands, 9.9 meter waves off the coast of Norway, 3.9 meters near the north pole -- these are very big waves.

These waves are causing a lot of problems for the sea ice in the arctic. We have the warm water, a lot of wave activity -- the sea ice just doesn't have a chance. Looking at the sea ice graph, we can see is that the sea ice isn't doing too well this year. The sea ice is basically crashing, running into this brick wall of cyclone activity and warm air that's being pulled up into the arctic.

A lot of the air in the arctic this November is 20C warmer than average. Don't be fooled that 1C or 2C average warming doesn't make a difference.

These cyclones in the arctic -- we're only going to see more of this as the Earth warms. Eventually, this whole warm anomaly is going to connect across the arctic basin, and we'll see a lot of these storms raging around the arctic."
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It's the beginning of the freezing season. Here are three posters on Neven's Arctic Sea Ice blog forum:

Tigertown wrote: The fast freeze seems to have hit a bit of a stall. Any guesses as to why?

I thought the one idea(above) about all the fresh water from prior melting and that puddled near the ice and then refreezing quickly, made some sense. That would explain a pause when the salt water was reached. But how much melt water would stay through storms and rough seas?

What about the slightly warmer peripheral waters and the less than ideal air temps?

magnamentis wrote: just look at seawater temps and wind/wave patterns and you got your answer, i mentioned this will happen a few days ago and the stall (with ups and downs) could continue for quite a while.

water temps are not slightly warmer, they are a lot warmer and a lot above average in peripheral seas. further air temps are way warmer above 80N than any previous year, including 2012. the energy/heat that has been there now for quite some time finally start to show it's effect. if the stormy conditions continue it will be a very late "real" refreeze because current temps do not explain the fast refreeze, must be a lot of freshwater and smaller floes floating around that held freshwater temps close to freezing temps.


jdallen wrote: (...) The further problem we now have is, all that moisture falling now as snow will be piling onto that new ice, and reducing heat flow *out* of the water, all the while replacing/displacing heat flow out of the ice through the top of the atmosphere. I'm pessimistic about the coming refreeze and the condition the ice will be in at max.
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"Some of the models suggest that there is a 75 percent chance that the entire north polar ice cap during some of the summer months will be completely ice-free within the next five to seven years." Al Gore, U.N. Climate Summit, Copenhagen, 2009

Well, we'll end up at about 4000 km3 for the 2017 minimum, compared to the historic (1950-1990) value of about 7500 km3. So it's going slower than we worried it might.

However, this year, we have an ice-free north pole:

From the Canadian Cost Guard twitter feed, the scientific ship and ice-breaker, Odin, at the geographical North Pole, August 28, 2016.

I am thankful that we aren't yet ice-fee. But I don't think it will be long now.
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The "Wrangel Arm" in the arctic ocean, from Aug 2 to Sept 2, 2016:




"First, since the summer sea ice was also shrinking, this meant that the summer ice cover had lost something like 60 per cent of its volume between the 1970s and the 1990s, a far more drastic and dramatic loss than one would have suspected without taking account of the ice thickness. At this rate the summer ice would disappear fairly early in the coming twenty-first century. The world needed to be warned, and we did our best to warn it. But not only did the politicians and industrialists not want to know, neither did the scientific modelers. They continued to run unrealistic models which forecast that sea ice would remain substantially undiminished right up to the end of the twenty-first century. The UK Meteorological Office still clings to these impossible predictions. Nature would soon prove them wrong."

A Farewell To Ice, p. 69, Wadhams 2016


"A mild winter, early opening up, extreme low snow cover, probably caused the Arctic to soak up enough heat to not care about the June and July sun. And who knows, maybe a pulse of warm water - extremely difficult to measure - from the Atlantic and Pacific continued the long-term process of complete Arctic sea ice loss.

The world hasn't experienced the warmest average global temperatures on record for three years in a row for nothing. This heat eventually ends up in the Arctic."

-- Neven Acropolis, Sea Ice Blog, PIOMAS September 2016
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There's a chance that this year we'll see our first ice-free north pole in recorded history.
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From A guest article by Florence Fetterer, principal investigator at the National Snow and Ice Data Centre (NSIDC) in the US.

"Most fundamentally of all, the new dataset allows us to answer the three questions we posed at the beginning of this article.

First, there is no point in the past 150 years where sea ice extent is as small as it has been in recent years. Second, the rate of sea ice retreat in recent years is also unprecedented in the historical record. And, third, the natural fluctuations in sea ice over multiple decades are generally smaller than the year-to-year variability."


Sea ice cover maps for the annual minimum in September, for the periods 1850-1900, 1901-1950, 1951-2000, and 2001-2013. The maps show the sea ice extent in the lowest minimum during each period, which are in years: 1879, 1943, 1995, and 2012.

Walsh, J. E., Fetterer, F., Stewart, J. S. and Chapman, W. L. (2016) A database for depicting Arctic sea ice variations back to 1850. Geographical Review, doi:10.1111/j.1931-0846.2016.12195.x
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from Tenney Naumer's climate change blog:


and from the a post on the Arctic Ice Forum:

Ten day forecast for 10mb, this time from ECMWF.
Click to animate:


And we're currently at the lowest measured extent:

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HLY1502 LETTER 05 FROM JIM SWIFT Monday, 07 September 2015, 7:00 pm, local date and time (2100 07 September UTC)
90°N (in the Amundsen Basin of the Arctic Ocean)
air -3.8 degC / 25 degF
water -1.4 degC / 29 degF
wind 16 knots from N (not certain what the “N” on the meteorological display means, considering our location!)
on station 34, at the North Pole

Dear Family, Friends, and Colleagues,

At 7:47 am ship’s time Saturday, September 5th, USCGC Healy became the first US ship to reach the North Pole unaccompanied by another icebreaker. I am not certain of this, but Healy may also be the first ship of any nation to reach the pole from Bering Strait unaccompanied. It was also a milestone of sorts for me, because there have been three scientific crossings by surface ship from Bering Strait to the Pole – 1994, 2005, and 2015 – and I was on all three, doing similar work each cruise (and thus learning about ocean change in this remote part of the World Ocean).

My informal observations of the Arctic Ocean sea ice we have been traversing continue in the same vein as during the past two weeks: much of the ice appears to be first-year ice and passage through it has mostly not been difficult. Yes, there are larger, tougher floes and some pressure ridges. [Pressure ridges form when floes and sheets are pushed together and pile up high (and well below the surface) and can be very tough to pass through.] But these can usually be avoided and even the ones we have crossed have not yet been significant impediments to our progress. Extra power (provided by bringing more engines on line) has been required remarkably few times for an expedition working in the central Arctic Ocean. This is very different from the experiences we had with the ice 10 and 21 years ago.

There was a seal near the ship at the Pole and people saw bear tracks on the way here, so the ecosystem we associate with the Arctic Ocean – a simple food chain from phytoplankton & algae, to zooplankton, to Arctic cod (a small fish that lives under the ice), to seals, and finally to bears – is active even at the Pole.

(...)


On Neven Acropolis' Arctic Ice blog, Kris commented:

(...) For sure Jim Swift ia a man of science, nevertheless he (and his fellow companions) missed the scoop as well as the most worrying important:

There was a seal near the ship at the Pole and people saw bear tracks on the way here, so the ecosystem we associate with the Arctic Ocean – a simple food chain from phytoplankton & algae, to zooplankton, to Arctic cod (a small fish that lives under the ice), to seals, and finally to bears – is active even at the Pole.

Seals and their Icebear predators shouldn't have any business in the center Arctic, at more as 1500 km from their natural habitats. Because the ice field is too dense thus the distance from one air hole to the next one is too long to allow seals to breath and evolve. And of course, where no seals are there won't be icebears either.

So, if seals are appearing in the center Arctic, even at the Pole, it means the ice has been fragmented that much already that seals are able to live and feed there. And icebears have been forced to follow their dinners into a rather icebear unfriendly environment - over 1500 km away from their natural habitat.

Making me repeating myself in saying 2015 even has been even worse as 2012.

It won't be a good nighty night sleep for me...
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A weather driven ice free September is now possible in any given year. A climate driven ice free September is not likely until 2030 to 2050, and I would trend toward the later part of that period. As climate warms weather should become less predictable, a somewhat balanced system becomes disturbed and more chaotic until a new equilibrium is reached, which will be a long time coming. -- Carex on the Arctic Sea Ice Forum
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The arctic ice may have reached its 2015 maximum a month early. The arctic is a chaotic place, but here's the graph:
ijis_extent

Northern Pacific waters are flowing into the Bering Sea, and warming there is persistent. On the eastern side, the wonky jetstream is pushing surface warmth up the east coast from the gulf, and tidal forces are pushing deep water warmth, for an Atlantic double-whammy.
na-moc_en_100546

This pic is from last September:
map

This is what the collapse of the polar cell looks like:
polar

Check out the animation of the crazy polar collapse here.

GAC-2012

Sep. 1st, 2012 11:07 am
ljgeoff: (Default)
I still like the name Gaagii. Hmph. Anyways, this is a pretty succinct explanation of the Great Arctic Cyclone of 2012. From Artful Dodger on the post Record dominoes 9: PIOMAS sea ice volume at Nevin's Arctic Sea Ice Blog:

GAC-2012 was NOT a tropical cyclone, it was a cold-core (extra-tropical) cyclone. Certainly it was very large, powerful and long-lived, with exceptionally low central pressure and strong winds but none-the-less, not a tropical cyclone.

All cyclones are heat difference engines, propelling moist air into a rotating vortex which transfers heat from the warm side to the cold side. With GAC-2012, the warm side was the airmass over Siberia, and the cold side was the pack ice in the Central Arctic Basin.

The jetstream added further rotation to the gathering depression, reinforced by the Coriolis effect. Voilà, a massive storm was the result, one even more powerful than hurricane Issac which just devastated Louisiana (964 mb vs 970 mb central pressure).

Note that a cold-core cyclone is the WORSE possible scenario for sea ice survival, since it moves heat from the South over the continent into the midst of the pack ice. And scientific studies show these storms are getting more frequent and more powerful since 2007.

But remember this take-away point (when engaging deniers): the loss of sea ice caused this storm, NOT the other way around. This cyclone simply could not have occurred without vast areas of melt-out in the Arctic ocean, and the vast snow cover retreat in Siberia.

When these conditions reoccur, it will happen again. The next big Summer cyclone could finish the Arctic sea ice.

"Shaken AND stirred, with crushed ice."

Here's a visual that puts the current ice volume in context. n Click on the image to see the whole graph if it's cut off.

ljgeoff: (Default)
arctic cyclone Aug 6, 2012

Aug 6, 2012

From the National Weather Service:

UPPER AIR...A DEEP LOW NEAR 78N 160E EAST WILL CONTINUE TO DEEPEN
TO OVER THE NEXT 48 HOURS AS IT TRACKS TO THE NORTHEAST AND JUST
SOUTH OF THE POLE. ALL OF THE MODELS ALL HAVE AN ANOMALOUSLY DEEP
SUB 510 DM LOW AT 500 MILLIBARS BY 12Z TUE. A LOW THIS DEEP IN
AUGUST IS INDEED A RARE EVENT.

Neven is live-blogging it.

Gaagii is Navajo for Raven.

From Paul Klemencic:
"Currently, the LP center of Gaagii is located at 170W and 80N. The ice pack around this location is likely getting ripped apart, particularly between the 170W and 165E longitudes.

The Bremen map tonight, should show a big hole of lower concentration ice opening up at this location (if the sensors can see the ice)."

This puts the storm about 700 miles from the north pole.
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This is very big news.

DMISLP20120805_12

It's expected that this storm will cause a flash melt in the arctic. From Neven's blog:

Paul Klemenic: If we wanted to design a storm to destroy ice pack, I don't think we could do it any better than the current reality.

This storm will pick up moisture from Siberia and the Laptev, it already has picked up moisture from the Kara, and it will move all this thermal energy into the E. Siberian and Chukchi. Furthermore, it will churn things up big time and bring up warmer saltier water. The ice pack is weak and fractured at this point in the season, so wave action won't be quashed, as it would normally.

And the storm will push ice toward the Beaufort with its relative warmth, then even pick up more moisture and warmth to carry back over the Central Arctic.

As the wind rotates around the low, it will push the fractured edges of the CAB ice pack away from the pack and toward the Laptev, which also has plenty of warm water. And churn things up along the way.

The storm will keep this up for 6-8 days, although the peak will last 3-4 days. This is plenty of time to do lots of damage.

And finally, the storm hits right after the peak solar period ends, but before the surrounding seas and atmosphere begins cooling down into autumn.

This really is "A Perfect Storm".

(and later, down thread)

OK, the new Bremen map is up, and I have really underestimated the impact of this storm. The damage is huge in the Chukchi and the E. Siberian, and elsewhere (notably the Beaufort and Laptev regions) the ice pack is coming apart.

And the storm hasn't even hit yet.

Steve Bloom: Hmm, some sea ice expert, can't recall who, said several years ago that the first ice-free event would be quite sudden. Perhaps this was the anticipated mechanism.

Not that it's important, but present conditions seem to make it likely that the pack will lose contact with all of the small archipelagos, leaving contact with only the QEI and Greenland.


The US Navy projects "what this growing cyclonic monster in the Arctic might be doing to the ice by Friday, August 10th

And here is a graphic showing arctic ice changes over a 48 hour period, Aug 4-Aug5.

Why is this important?

new lows

Aug. 2nd, 2012 10:08 pm
ljgeoff: (Default)
graph - arctic sea ice extent )

Neven has a good graphic up on the Arctic Sea Ice Blog.

I'm trying to picture what it will be like when we have a worse year next year; hotter, drier/wetter and more crops failing. And another year. And another. I wonder how long we can keep going.

Lake Mead is below projections, currently at 1,116 ft, which is 113 ft below full pool of 1,229 ft. This is not it's lowest level; it's lowest level was in Oct of '10. It will be interesting to see what happens there over the next couple of months.

The Ogallala Aquifer had an annual rate of ground water decline of approximately 1.4 feet per year from 1969 to 1979 to just over 0.5 feet per year from 1989 to 1999. (report) Last year it declined 2.56 ft. -- the third largest single year decline that has been measured.

Here's the current drought picture of the US:
drmon

I'm hoping that with the coming El Nino, we'll have some relief. But I keep thinking of that .89 °C per decade estimate. I can't get my head around it.

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