Arctic Sea Ice

If global warming continues unabated...

Here's a Discover magazine article I noticed a couple of days ago, containing a nice (but big) animation that shows how many days per year (parts of) the Arctic will be ice-free in the future if things keep going as they are:

If global warming continues unabated, humans are likely to completely remake the map of the Arctic in a few decades

Ice was in the news quite a lot last week. There was, for example, the news that Antarctica could be gaining, not losing, ice, at least for now.

Lest you were tempted to breathe a sigh of relief, critics pointed to contrary evidence. And there were also these unsettling findings about the gigantic West Antarctic Ice Sheet.

But far to the north, some equally important news unfortunately got less attention. For the long and short of it, see the animation above.

I created it to portray in visual form what a study published last week has revealed: Unless we start reining in greenhouse gas emissions, “our projected impact on the climate system will change the face of Arctic sea ice,” says Katy Barnhart, who led the study while she was at the University of Colorado’s Institute for Arctic and Alpine Research. (Full disclosure: I’m a professor at the University of Colorado.)

The animation shows computer model simulations of how Arctic sea ice is likely to respond to continued human-caused warming. More specifically, it models how the number of days of open water change each year from 1920 to 2100 under a “business-as-usual” scenario. By 2100, according to the study, much of the Arctic has greater than 150 additional days of open water as compared with the pre industrial period prior to 1850.

Read the rest of the article here. Of course, it's not about the open water per se, but about the consequences for ecosystems and climate, not just regionally, but for the entire Northern Hemisphere.

Minimum and MYI

The lowest point has been reached on all sea ice area and extent graphs, and so the melting season has ended. I'll have more on the details later this week, but here's a quick preview of one of the most important features of this melting season, and that's the decimation of multi-year ice (MYI) on the Pacific side of the Arctic.

Here's a nice video that shows how the melting season developed and ended, based on AMSR2 data. It's made by Felicia Brise of the University of Hamburg, and I've taken the liberty to upload it to YouTube:

There's a stunning contrast between the destruction on the Pacific side of the Arctic, and the relative stable and compact situation on the Atlantic side of the Arctic, even though the ice there was thinnest at the start of the melting season. In fact, this region of first-year ice was so large that it even covered the North Pole, perhaps for the first time on record. I even speculated in my 2014/2015 Winter analysis that under the right conditions the North Pole could become ice-free this year.

But the opposite happened, the first-year ice on the Atlantic side was spared (there was also remarkably little transport of ice through Fram Strait) and it was the multi-year ice on the Pacific side that took barrage after barrage of warm, sunny weather. Now that the ice age distribution maps (developed by J. Maslanik and C. Fowler, and currently produced by M. Tschudi of CCAR) have been updated, we can see how things have proceeded since my last blog post on the subject three weeks ago:

As expected, all of the 5+-year old ice on the Pacific side of the Arctic has disappeared in truly spectacular fashion. As there wasn't that much 4-year old ice to begin with, there will be less of the oldest class of ice next year. On the other hand a lot of the 3-year old ice (green) will become 1 year older, and as said, first-year ice (dark blue) got off lightly.

Nevertheless, it seems that part of the rebound in MYI that happened since 2012 has been wiped out (something I speculated about almost two months ago in this guest blog for the Guardian Environment page). We'll know how much exactly when the NSIDC puts up their monthly analysis two weeks from now. Of course, ice age doesn't necessarily tell us how thick the ice is - this isn't our (grand)fathers' Arctic anymore - but it gives us an idea of long-term changes in the Arctic.

Another indicator is sea ice volume, both modelled and observed. To know whether 2015 will dip below rebound years 2013 and 2014, we'll also have to wait a week or two for the PIOMAS model to be updated. Either way, yet another fascinating melting season is now behind us. Thanks for watching.

Beaufort and Northwest Passage videos

Over on the Arctic Sea Ice Forum commenter Jim Hunt from the Great White Con blog posted videos he made, showing developments since the start of the month in the Northwest Passage (where the blue ice is breaking up fast):

Events since April 1st in the Beaufort Sea have been even more spectacular. A late cracking event, heat waves and scattered multi-year ice floes, all of it in just one minute and a half. Enjoy:

Jim used data from the University of Hamburg for these animations, with an extremely low resolution of 3.125 km (edit: high resolution of course, for more technical info see this research paper).

Update July 19th:

Jim has added another animation showing the situation along the Northern Sea Route:

Shock news!

There is no shocking news, really. I'm just emulating a way of news reporting as seen in recent months by folks trying to play down the long-term shocking news of Arctic sea ice loss. You know, paid climate science disinformers like Benny Peiser who claimed that the poles aren't melting, twisting the words and work of a respected oceanographer and putting up a bunch of strawmen along the way, because global sea ice area is at a record high.

It's a neat trick, even though it's like saying that one billion people starving globally is not a problem, because there are one billion obese persons. We all know that Antarctic sea ice has been increasing in winter, most likely because of winds that push the ice further out, with the open water left behind freezing up again. So if you compare Antarctic winter anomalies with those of Arctic summer anomalies - especially during rebound years such as 2013 and 2014 - it looks as if not much is happening.

However, if you compare the numbers as they are, during the same season, the picture is, well, shocking:

That graph (found here, updated at the end of this blog post) shows the minimum in both Arctic and Antarctic, which never occur at the same time, of course. In the end it's all about the minimum and the period leading to it, because that's the time when most of the sunlight reaches either one of the poles. And there is hardly a trend in the Antarctic minimum, despite the spectacular winter increases, because most of it melts out anyway in summer. As can be seen on the small image at the top of this blog post, showing that the only Antarctic place with a substantial amount of sea ice left right now, is the Weddell Sea.

And it's like that every year, contrary to the entirely different Arctic. Not everyone knows this, and so this is what climate science disinformers use to fool people and thus delay meaningful climate mitigation policies that threaten either their wallets or their beliefs, and most of the time both.

Erase and rewind

I don't know what the most interesting forum thread on the planet was last week, but this week it's definitely the Nares Strait thread, over on the Arctic Sea Ice Forum.

All who regularly follow Arctic events, know that one of the coolest places in it is Nares Strait, the waterway between Ellesmere Island and Greenland that I write about every now and again.

Even though the strait is narrow, it transports ten times more water than the Amazon River (according to physical oceanographer Andreas Muenchow from the Icy Seas blog) and can flush out as much as 10% of the much larger Fram Strait sea ice export, like it did in 2007. Most of this ice is multi-year ice, sometimes mixed with Manhattan-sized icebergs from Petermann Glacier.

Almost every winter the strait gets closed off by so-called ice arches or bridges that can form at various spots in the strait. It happened relatively late this winter, around the end of last month, with an arch forming at the south end of Nares Strait, called Kane Basin (adapted from an animation made by Wipneus):

Normally that would've been the end of it, but not this year. Where normally the newly-formed arch would now become stronger because of thickening ice, and break up somewhere in June or July, some really intense weather the past couple of days, in the form of very strong winds from the South, has caused the arch to break up and retreat back up the strait again! As can be seen in this animation by commenter Espen:

Fram Strait 2014

Wipneus, creator of many graph and animations, has posted another gem over on the Forum.

The animation he uploaded to Youtube becomes really interesting after the end of May, when the transport through Fram Strait (one of the reasons that made the 2007 melting season so spectacular) almost completely stalls for much of the rest of the melting season:

Even though it's obvious that the lack of movement and transport was the defining theme of the 2014 melting season, it's still amazing to see it expressed so clearly in this animation. That trunk of ice that always protrudes through Fram Strait into the Greenland Sea, simply vanishes in July.

In October transport picks up again, and in the past few weeks it has been relatively strong. This is somewhat interesting because compared to 2013 a lot of the volume difference is situated close to Fram, as can be seen on this 2014-2013 thickness difference map produced by... wait for it... Wipneus:

If transport keeps up, the difference in volume (with 2013) might become smaller, but we'll have to wait and see what PIOMAS reports. In 2015.

And so, in advance, I wish everyone a happy, healthy, succesful and sustainable New Year!

Ice pack in full

Arctic Sea Ice Blog commenters come up with all kinds of ways to make sense of or visualize what's going on with the ice pack, tweaking satellite data, 'declouding' images or compiling animations. In this blog post I want to show a couple of those efforts.

Commenter Danp opened a thread on the ASIF a couple of days ago, showing a cleaned up compilation he made of LANCE-MODIS satellite images (like commenter dabize did last year). The result looks very nice indeed, giving us a clear view of the holes on the Atlantic side of the Arctic, near the North Pole:

You can go to Danp's Google Drive image and zoom in up to a 500m resolution.

Commenter A-Team, of course, keeps rocking hard with his infinite ways of tweaking images to squeeze info out of them. His latest creations can be admired in the recent Nares blog post, but here's one interesting example:

On the move

When A-Team is not improving masterpiece paintings, he makes great animations. Here's yet another one, showing the speed with which the cracked ice pack in the Beaufort Sea has been moving in past weeks:

The largest crack functions as a reference point. In the Arctic Sea Ice Forum I jokingly said Banks Island fits in there - okay, I acted as if it was a joke when it turned out I had it wrong -, but it's still pretty big. I'm very curious what will happen once the thin ice in that crack gets properly introduced to the Sun.

According to A-Team's calculations (which he probably does while painting):

The Beaufort ice pack is very much on the move. The fast-moving western tip of a recognizable central feature, traced for 41 days (23 Feb 13 to 02 Apr 13), has moved 479 km or 11.7 km per day at 0.49 km per hour. The angular velocity about the feature's Euler pole at 82.5ºN 140ºW is quite rapid, about 1.2º per day.

As evidenced by the 60-day drift track of the IABP buoys in the Beaufort area:

Peeking through the clouds 6

It's been very cloudy in the Arctic this year. Luckily commenter dabize kept on sending me his 'declouded' version of the False-Colour Composite images Environment Canada makes of the LANCE-MODIS satellite images. These give us a good indication of what's going on. Hopefully he'll have the time for a couple more now that the freezing season is starting. Thanks for the great work so far, dabize!

Here is the latest animation:

Peeking through the clouds 4

Commenter dabize has sent me the latest 'declouded' version of the False-Colour Composite images Environment Canada makes of the LANCE-MODIS satellite images. They give us an excellent view of week to week changes. Due to some resolution incompatibilities I had to exclude last week's image (it's in the 3rd instalment of this Peeking through the clouds series), which makes the changes caused by the Arctic summer storm even more pronounced: