Arctic Sea Ice

ASI 2012 update 3: international daily data day

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily IJIS sea ice extent (SIE) and Cryosphere Today sea ice area (SIA) numbers, which I compare to data from the 2005-2011 period (NSIDC has a good explanation of sea ice extent and area in their FAQ). I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything that can be of particular interest. Check out the Arctic sea ice graphs webpage for daily updated graphs, maps and live webcam images.

May 21st 2012

Be careful what you wish for, because you just might get it, as the saying goes.

After complaining that everything was going to pieces for us avid Arctic watchers, with malfunctioning sensors, satellites and servers, suddenly out of the blue a cascade of data came online. First the NSIDC with thickness data from the NASA IceBridge Mission (check out the excellent graph in this blog post), followed by a resumption of IJIS sea ice extent data, and Cryosphere Today sea ice area came back online not long after that. To top it all off, JAXA announced that the satellite that carries the AMSR-2 sensor was succesfully launched and brought into orbit. So from now on May 15th will be known as International Daily Data Day on this blog. I guess that now I will have to give IJIS SIE and CT SIA equal space in these ASI updates. A double amount of work, but hey, I asked for it!

And what's going on with the ice, you may ask. Well, nothing that wasn't expected. There was a slight negative temperature anomaly over the Arctic, but the 2012 trend line has nevertheless come down from its lofty abode and seems to be ready for another clash of the trend lines.

Sea Ice Extent (SIE)

IJIS has altered its graph and instead of some of the most recent years is now showing averages for the 80's, 90's and 2000's (edit: the 'old style plot' is here). This is of course fine, but I like to compare this year with the other years in the 2005-2011 period, so I've decided to make my own graphs (still fiddling around though, so these might change). Here's the IJIS SIE graph for May, for the full thing go to IJIS:

I have left off the last data point, because it goes very low every day (around 200K), but is revised just as much upwards the next day. So this graphs runs up to May 20th.

The current difference between 2012 and the other years is as follows:

ASI 2012 update 2: no daily data

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Because of the demise of AMSR-E the IJIS sea ice extent (SIE) numbers are no longer central to these updates. Instead I now use Cryosphere Today sea ice area (SIA) numbers and compare them to the SIA numbers in the 2005-2011 period. NSIDC has a good explanation of sea ice extent and area in their FAQ. I also look at other things like regional sea ice area, sea ice extent, temperature and weather forecasts, anything that can be of particular interest. Check out the Arctic sea ice graphs webpage for daily updated graphs, maps and live webcam images.

May 13th 2012

How depressing (image courtesy of Terrible Taxidermy). First we lost the great day-to-day extent data provided by IJIS. A couple of weeks ago ENVISAT stopped transmitting data, which means we no longer have these great radar images to check out the ice plug in Nares Strait. And since April 28th the good people over at the University of Illinois at Urbana-Champaign are having some server problems, which means their excellent Cryosphere Today page hasn't been updated since. So no daily sea ice area data either.

Apart from Larry Hamilton keeping us up-to-date every couple of days on the DMI SIE numbers, and Dr.Tskoul keeping an eye on MASIE numbers, there is nothing there to satisfy my curiosity and obsession with Arctic sea ice. And the basis on which these ASI updates are written is swept right from under my feet...

But let's stay positive, okay! At least it isn't September! And as long as we have eyes to see, we can still gaze at various graphs. So that's exactly what we're going to do in this ASI update.

The NSIDC SIE chart had SIE dropping fast, but it has leveled off again in the past week or so:

Long-term regional graphs

The good people of the Polar Research Group at the University of Illinois at Urbana-Champaign that produce the Cryosphere Today webpage, a monolith in the collective consciousness of Arctic aficionados, have yet again done something great by adding long-term SIA anomaly graphs - spanning the 1979-present period - to their regional graphs. This will make it so much easier to put events into perspective.

Here for instance is the graph for the largest region, the Arctic Basin:And the graphs for this year's mega-extremes, the Bering and Barentsz Seas:

PIOMAS April 2012

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

Still on a par with last year.

Wipneus produces many excellent PIOMAS graphs. I'll start with his latest creation, the graph for which he calculated the "expected" 2012 values, based on the same date values of 1979-2011 and an exponential trend. A caveat from Wipneus: "Note that the (not indicated) statistical error bars are quite large."

As a bonus I have finally come round to making a new graph, one that very crudely shows average ice thickness across the Arctic, by simply dividing the PIOMAS volume numbers (km3) by the Cryosphere Today area numbers (km2), and multiplying them by 1000 to get the average thickness in meters:

CT SIA: maximum reached (this time for real)

Update March 31st: It looks like the maximum has arrived even later. The peak from 11 days ago has been beaten by almost 8K square km. This isn't much, but those 11 days extra make it a super late maximum. And the Lord only knows if this is the final maximum. I'm not calling this one anymore, ever!

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Do you remember last week when I said that Cryosphere Today sea ice area had reached its maximum? Well, it didn't. The Arctic sea ice has this amazing propensity for turnabouts, even in just one week time.

image source: Pogoda i Klimat

I waited extra long to call the maximum, even though I announced at the end of February that it could well come about around March 5th. On March 6th a first peak was reached and a week later I felt confident to call the maximum:

Looking at various weather forecast maps, and considering the fact that most regions have an anomalously high area, I think it's safe to say the CT maximum SIA has been reached on March 6th.

Those weather forecast maps started changing soon afterwards, but with a couple of drops amounting to 236K km2 less than the peak, I was still confident the max would hold up, if only for the fact it was March 15th already, and in the last 7 years all the maxes were reached before March 11th. Enter Arctic sea ice.

Cryosphere Today sea ice area: maximum reached

I finally feel confident enough to call the maximum for the Cryosphere Today sea ice area dataset*:

graph comes from the Pogoda i Klimat blog

More than two weeks have passed since I wrote the following:

ECMWF is showing a big high taking over the Barents/Kara regions 5 from days from now, with a big low doing its thing in the Bering/Okhotsk region. If this forecast comes about I think we will have our CT SIA maximum around March 5th.

It came about, but didn't last, and so I decided to hold on to my horses:

2012 minimum global sea ice area

After recent records in the Cryosphere Today global sea ice area dataset - such as lowest maximum on record and longest negative anomaly streak - it is my pleasure to announce that a new record minimum global sea ice area hasn't been hit this year. The Arctic SIA is relatively low for the time of year, but the Antarctic SIA is on the high side, and about to reach its minimum. So unless something crazy happens in the Arctic, like the maximum being hit extremely early and an extremely fast start to the melting season, this year's minimum global SIA could go lower still. But it doesn't look like the weather up North is going to allow that, and besides, we haven't reached that stage yet where things like that could happen (I think).

Here's the graph from the Polish Pogoda i Klimat blog:

As you can see there was a dip about 10 days ago. The trend has been stable since, but needs to dip again quite fiercely to threaten the current minimum (at least 250K). There was a second dip last year almost reaching a lower low, but personally I'm not seeing that happen this year.

Here's one of Larry Hamilton's bar graphs showing the minimum in relation to previous years:

Bering the load

After last year's corny title (Bering in mind) I naturally had to continue the tradition. But this year the pun is quite appropriate, as it seems that the Bering Sea is indeed bearing the load of anomalous ice cover that offers a counterweight to what's happening on the Atlantic side of the Arctic, and thus keeps total sea ice extent and area figures in balance. If it weren't for this chances of a new winter maximum ice cover would be very great indeed.

On the Cryosphere Today sea ice area map for the Bering Sea region figure we can see how anomalously high sea ice over is at the moment (red line):

The NASA Blue Marble on the NSIDC Sea Ice Index confirms:

2012 Maximum Area Pool

EDIT Neven: There's a poll in the right hand bar running until February 8th for predicting the Cryosphere Today maximum sea ice area number. See details below. Don't be afraid to share your prediction in the comments. :-)

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Post by guest author crandles:

It doesn't look like the area maximum will be under 13 million km^2 based on past 10 years all increasing by at least 0.6m km^2 and sometimes over 1m km^2 from this time of year. We are currently at 12.414m km^2.

Also, you could argue that the recent trend has been unusually in that amount is less now than 15 days so perhaps a spike upwards is imminent.

On the other hand, area is high outside Bering strait and by Baffin Bay so maybe these won't increase area much further. Where the area is low, Barents and Kara seas, the water is warm and set to stay that way at least this week with strong winds blowing from Atlantic. Then maybe the sun is getting high enough for Southern Barents to receive more solar energy than usual because of low ice and therefore albedo.

This might suggest the increase in area could continue to be slow a little longer.

Or you might completely disagree with above assessment.

So how about a pool of guesses on the area maximumper Cryosphere today? Not much time left so I suggest guesses should be submitted before end of January.

Neven commented:

On the other hand: that huge high over Northern Siberia means clear skies and thus a lot of radiation escaping to space.

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EDIT Neven: 

To add to the fun I have opened a poll and added it to the right hand bar. You can vote on what you think the SIA maximum will be until February 8th.

Here are the Cryosphere Today SIA maximums in the period 2005-2011 with the date of maximum (from this daily updated data file):

• 2005: 13.46 million km2 (March 6th)
• 2006: 13.36 million km2 (March 11th)
• 2007: 13.32 million km2 (February 26th)
• 2008: 13.89 million km2 (March 11th)
• 2009: 13.85 million km2 (March 2nd)
• 2010: 13.81 million km2 (March 7th)
• 2011: 13.14 million km2 (March 8th)

A negative year

I keep coming back to the Cryosphere Today global sea ice area anomaly graph, as it keeps on delivering records and/or trivial tidbits.

We had to wait a relatively long time for the anomaly trend to go above zero, but Arctic SIA as well as Antarctic SIA are currently both higher than for instance last year, so here it is:

This was the longest period on record of a negative global SIA anomaly. According to my calculations based on the CT SIA data the previous longest period lasted 444 days and ended just before the end of 2007. Another period of 333 days took place from mid-2009 to mid-2010, not much later followed by this new record period of 502 days. As the period ended at the beginning of this year we also just witnessed the first full calendar year on record without a positive anomaly.

In the coming few weeks the global sea ice area minimum will be hit. I don't expect a new record.