Arctic Sea Ice

ASI 2016 update 5: big cyclone

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Because of issues with data based on the SSMIS sensor aboard DMSP satellites, I mainly focus on higher-resolution AMSR2 data from the Japan Aerospace Exploration Agency (JAXA), as reported on the Arctic Data archive System website. I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything of particular interest.

The animation on the right consists of NSIDC
sea ice concentration maps, one for each ASI update.

Check out the Arctic Sea Ice Graphs website (ASIG)
for daily updated graphs, maps, live webcam images, and
the Arctic Sea Ice Forum (ASIF) for detailed discussions.

August 13th 2016

In the previous update I wrote with regards to the 2016 trend line on the JAXA sea ice extent graph:

If it now somehow manages to end the month between 2011 and 2015, there's still room for August weather to keep the race exciting.

The 2016 trend line managed to end July right between 2011 and 2015, it is still in 3rd position as we speak, and now August weather is going to keep the race exciting. Another big cyclone is on its way and will hit the ice pack the day after tomorrow (no pun intended). This storm will not be as intense as the Great Arctic Cyclone of 2012, but it will be almost as big, and linger for a few days. I think it's the second biggest storm I have seen since starting this blog, back in 2010.

It's difficult to tell whether this storm will have as much of an effect as GAC-2012 had. The ice pack was much weaker back then due to plenty of periods that were conducive to melting, in other words melting momentum. There hasn't been much melting momentum to speak of this year, as there has been little preconditioning of the ice pack during May and June, and cloudy conditions kept dominating the Arctic up till last week.

There has been a second kind of momentum, though, caused by the preceding mild winter and the spectacular retreat at the very start of the melting season. Snow cover melted out really fast and sea surface temperatures have been as high as they've ever been. A handful of cyclones so far have helped disperse the ice pack, with quite a large zone of ice, jutting out from the Central Arctic towards the East Siberian Sea, about to bear the brunt of the big storm (source: Uni Bremen):

When the Great Arctic Cyclone hit in 2012 all of the weak ice in this zone detached from the main pack and was annihilated. We'll have to wait and see if something similar can happen this time around.

Sea ice extent (SIE)

As said, the 2016 trend line on the JAXA SIE graph keeps moving downwards steadily:

ASI 2016 update 4: breaking point

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Because of issues with data based on the SSMIS sensor aboard DMSP satellites, I mainly focus on higher-resolution AMSR2 data from the Japan Aerospace Exploration Agency (JAXA), as reported on the Arctic Data archive System website. I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything of particular interest.

The animation on the right consists of NSIDC
sea ice concentration maps, one for each ASI update.

Check out the Arctic Sea Ice Graphs website (ASIG)
for daily updated graphs, maps, live webcam images, and
the Arctic Sea Ice Forum (ASIF) for detailed discussions.

July 20th 2016

Three weeks have passed since the previous ASI update, but I must say that I haven't become much wiser since then. I was expecting this year to start falling behind on the extent and area graphs, as weather conditions that aren't really conducive to melting, have continued to dominate the Arctic.

More than one month and a half of cloudy weather, not exceptional warm, little compaction, hardly any Fram Strait export, but this year somehow still manages to stay among the lowest on record. Such circumstances would have inevitably led to a major stalling on the graphs in previous years, but not this year. It would seem the lack of melting momentum is being compensated by another kind of momentum, brought on by the mild winter, early melt onset/opening up, extreme low snow cover and anomalously high sea surface temperatures.

The question still is whether this year has the oomph to end up in the top 3 September minimums, but whereas three weeks ago I thought it probably wouldn't, I'm not so sure anymore.

ASI 2016 update 3: crunch time

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Because of issues with data based on the SSMIS sensor aboard DMSP satellites, I mainly focus on higher-resolution AMSR2 data from the Japan Aerospace Exploration Agency (JAXA), as reported on the Arctic Data archive System website. I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything of particular interest.

The animation on the right consists of NSIDC
sea ice concentration maps, one for each ASI update.

Check out the Arctic Sea Ice Graphs website (ASIG)
for daily updated graphs, maps, live webcam images, and
the Arctic Sea Ice Forum (ASIF) for detailed discussions.

June 29th 2016

The run-up to this melting season was really special, with an unprecedentedly warm winter season and early opening of the Beaufort Sea. Sea ice extent and area numbers went extremely low for the time of year, and sea ice volume reached the depths it was at before the 2013-2015 post-record rebound. But events in the Arctic don't behave like a straight arrow. Not in the short term, at least.

Weather conditions switched around the start of this month (see previous update) and prevented a large-scale soaking up of solar radiation through leads and melt ponds that would've increased the chances of a new record low September minimum even more. The lack of melting momentum has in fact decreased the chances to the point that I'd bet against it. If you want more details, read these two posts, or this blog post by Chris Reynolds that is hot off the press.

Mind you, this is not a melting season like 2013 or 2014 where persistent cloudiness and low temperatures caused relatively high September minimums (compared to top 3 years like 2007, 2011 and 2012, of course; they were well below the long-term average). 2016 still has many aspects going for it, like all that open water in the Beaufort Sea, low volume and snow cover that vanished at record speed. But it will take more to beat 2012, or 2007 and 2011 for that matter.

So, that's the question I will focus on in weeks to come: Can 2016 still make the top 3?

2016 melting momentum, part 1

Melting momentum, it's what I call the absorption of heat and solar radiation during May and June that does not directly lead to melt and a reduction in ice cover, but rather comes into play during July and August (I had a more wordy explanation last year).

As important as it seems to be for the final outcome of the melting season, it is one of those aspects of Arctic sea ice that has proven to be really difficult to measure. Observations based on satellite images have been developed in the recent past, but for some strange reason, this research didn't receive further funding.

I will discuss some indirect and experimental measurements further below, but start off with the best tool we have by far to get a feel for how much melting momentum is being built up during this crucial period in the melting season: the melt pond fraction simulation model developed by CPOM researchers at the University of Reading (more info).

Again this year, Dr David Schröder has been so kind as to send me the May melt pond fraction maps he uses for his SIPN 2016 Sea Ice Outlook prediction, showing melt pond anomalies for the years 2012, 2014, 2015 and 2016 compared to the average for the last 10 years:

Caveat: This is a model result, and so the distribution of melt ponds doesn't necessarily reflect reality.

This past May has been similar to last year's, but nowhere near May 2012. Here are two more maps that show the difference in melt pond fraction with May 2012 and 2015 (red = more melt ponds now, blue = less melt ponds now):

ASI 2016 update 2: closing the gap

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Because of issues with data based on the SSMIS sensor aboard DMSP satellites, I mainly focus on higher-resolution AMSR2 data from the Japan Aerospace Exploration Agency (JAXA), as reported on the Arctic Data archive System website. I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything of particular interest.

The animation on the right consists of NSIDC
sea ice concentration maps, one for each ASI update.

Check out the Arctic Sea Ice Graphs website (ASIG)
for daily updated graphs, maps, live webcam images, and
the Arctic Sea Ice Forum (ASIF) for detailed discussions.

June 11th 2016

This update could have easily borne the same title as update 1: Both sides. Two weeks ago the ice pack was shrinking on both sides of the Arctic, causing sea ice extent to drop to unprecedented daily lows. In the meantime, weather patterns have switched and the ice pack is now expanding on both sides!

Of course, a dispersing ice pack will cause extent loss to slow down, or even stall completely for a while. Especially if extent was extremely low to begin with. And so that enormous gap between this year and 2012 is getting smaller every day, fast. 2012 had perfect weather for melting during the first two weeks of June, and there was a large amount of thin ice that kept extent artificially high.

More importantly, these weather conditions set the tone for the rest of the 2012 melting season, as a large amount of melt ponds preconditioned the ice for big melts during July and August. This is where 2016 is falling behind now, even though it has been and still is lowest in many respects (extent, volume, snow cover).

2012 is punching hard in this round. Will it be enough to knock 2016 out?

ASI 2016 update 1: both sides

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Because of issues with data based on the SSMIS sensor aboard DMSP satellites, I mainly focus on higher-resolution AMSR2 data from the Japan Aerospace Exploration Agency (JAXA), as reported on the Arctic Data archive System website. I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything of particular interest.

The animation on the right consists of NSIDC
sea ice concentration maps, one for each ASI update.

Check out the Arctic Sea Ice Graphs website (ASIG)
for daily updated graphs, maps, live webcam images, and
the Arctic Sea Ice Forum (ASIF) for detailed discussions.

May 27th 2016

After an unprecedented warm winter and an unprecedented early opening of the Beaufort Sea, the 2016 melting season isn't showing any signs of shrugging off the 'unprecedented' label. What has struck me most so far, is that unprecedented things have been happening on both the Pacific and Atlantic side of the Arctic.

I've been closely observing events in the Arctic for almost a decade now, and have been writing about them since 2010, and during that time I have gotten used to this sort of see-saw, where fast melting on one side of the Arctic would be compensated by events unfolding slowly on the other side of the Arctic. But this year is different. This year the ice pack is under attack on both sides of the Arctic.

I have written separate blog posts to describe these events (see here and here), and in weeks to come these ASI updates will provide a comprehensive overview on what is happening to the sea ice in the Arctic, and how this melting season is unfolding.

Sea ice extent (SIE)

Let's jump right into it. Here's the latest JAXA SIE graph:That gap is pretty intense. I wasn't kidding when I said 'unprecedented'. Last year - orange line - was already quite spectacular, but this year is crazy.

As commenter Jim Pettit wrote on the Arctic Sea Ice Forum earlier today:

Beaufort final update

This isn't a final update as such, because I will certainly be mentioning events in the Beaufort Sea in upcoming ASI updates. But it is the last in a series of blog posts I have written (one, two and three) about this unprecedented event that started over 6 weeks ago and has led to a heavily cracked ice pack and a huge amount of open water on the American side of the Arctic.

The event has received some attention on other blogs and in the mainstream media. Just yesterday this image was posted on NASA's Visible Earth website, comparing this year to 2015 and 2014 (mind you, the Beaufort Sea opened up early last year as well):

The image is accompanied by a text, quoting Walt Meier:

“It really is quite remarkable,” noted Walter Meier, an ice specialist at NASA’s Goddard Space Flight Center. “There is always fracturing of the ice, but it seems to have become more prevalent and more widespread in recent years. This region used to be mostly multi-year ice, which is quite a bit thicker. Now, most of the Beaufort is seasonal, first-year ice. The thinner ice is weaker and more easily broken up by the winds.”

There are some links to other articles at the end of the Visible Earth article.

As I mentioned two weeks ago it looked as if that persistent high-pressure area was shifting away from the Beaufort, which would probably put "an (temporary) end to the massive cracking and ice movement". The animation below shows there has been some movement, but not as much as in prior weeks. Cloudiness makes it difficult to perceive, but if you focus on one of the two larger ice floes in the red circles, you can get an idea of the scale of movement/change:

Beaufort under relentless (high) pressure

When I wrote the Beaufort under early pressure blog post last month, I didn't quite expect this unprecedented pressure (timing and magnitude) to keep up for so long. High pressure areas tend to be short-lived in the Arctic, but this one was still going strong when the Beaufort quick update was published. Now, almost three weeks later, things still haven't completely calmed down, and this animation of satellite images showing weekly changes from March 30th to May 4th provides an astonishing sight:

Astonishing, mindblowing, frightening even. May is the month when melt ponds start to form on the ice, pools of water that lower the albedo and cause the ice to melt faster, leading to open water that absorbs solar radiation and warms up. The open water is already there in the Beaufort Sea. Look at all that open water!

No other year comes even close to it, as can be seen on the ASIG comparison of sea ice concentration maps, or on this sea ice extent graph (based on AMSR2 data, provided by Wipneus):

Jim Hunt provides this close-up view on the resources page of his Great White Con website (also be sure to read his latest blog post on early wave activity in all this open water):

Meanwhile, on the other side

Lately the focus has been on the Beaufort Sea where a high-pressure area has caused the ice pack to crack on a massive scale, even earlier than in previous years, with ice being transported away from the North American coast (see here). But such a large and persistent high-pressure system is bound to have an impact elsewhere in the Arctic as well, so here's an overview of what's been happening on the Atlantic side of the Arctic (and a bit of Siberia as well).

As we saw in the recent 2015/2016 Winter analysis blog post, the Arctic experienced an incredibly warm/non-cold winter:

On top of that, a string of cyclones crossed the Atlantic and veered off to the Arctic, causing increased ocean heat flux on the Atlantic side of the Arctic, which explains why the Barentsz Sea and Greenland Sea have been anomalously low in sea ice extent all winter. They're still extremely low:

In fact, Svalbard could almost be circumnavigated several times, with at one point very close to ice-free conditions from Svalbard all the way to Franz Josef Land.This graph from the PolarView website shows how anomalously low sea ice levels have been in the Svalbard region:

Beaufort quick update

It's been a week since I announced that the ice in the Beaufort Sea was going to come under early pressure. Here's a quick update on what has happened so far, how the forecast played out, and what the short-term conditions for this part of the Arctic will be.

As expected, the Beaufort Gyre kicked into action, big time, with winds causing large cracks in the ice pack, moving it westwards and away from the Alaskan and Canadian coasts. The massive polynyas that are left behind, get partially covered with a thin veneer of ice.

Here's an animation showing the difference between LANCE-MODIS satellite images on the first of the month and two weeks later:

Quite impressive, isn't it? As if someone threw a giant brick into it.

Here's an animation showing all days between April 1st and 14th (the file is somewhat large, apologies if it loads slowly):