Arctic Sea Ice

Through the eyes of Healy

This is a translation of a blog post on the excellent Spanish blog on Arctic sea ice called Diablobanquisa:

Towards the North Pole aboard the Healy

We go aboard the icebreaker USCGC Healy again...

...to travel from the Alaskan coast almost all the way to the North Pole.

Its position and route can be seen on this map, which is updated here [I have overlaid the image with a sea ice concentration map to give an idea, N.]:

On this web page we find all the images that are shot on an hourly basis by a webcam aboard the icebreaker Healy. It's a great opportunity to travel, almost live, across the Arctic Ocean to the North Pole, and have a look at the actual state of the Arctic sea ice pack, that is only a few days away from this summer's minimum extent.

On August 21st the USCGC Healy leaves the Alaskan coast behind and sails off into a Beaufort Sea (at 71ºN) that is entirely free of ice:

2011 End Zone

Last year I wrote a series of five posts called End Zone, comparing different aspects of the final phase of the Arctic melting season in different years, to be able to predict a bit what those last weeks of the 2010 melting season could be holding in store. A lot of that ground work still stands, so I don't have to repeat it this year. In this post I'll be looking at sea ice concentration and sea surface temperatures mainly, as these are most interesting right now. I basically said everything there is to say about atmospheric pressure, air temperature and ice displacement (no more PIPS, sniff) last year.

Sea ice concentration

I'm trying out something new here, which I hope you'll like. I'm comparing the years of the new Arctic era with 2011 on August 29th by fading the images:

2011 looks quite a bit like 2007, except that the large protuberance is sticking out in the East Siberian Sea instead of the Laptev Sea. That protuberance blocked the Northern Sea Route right till the end of the 2007 melting season. This year it's been wide open since very early on.

IJIS SIE: 5 million km2 mark passed

Seke Rob has been treating us with fantastic graphs for many weeks now, and it's high time I picked one out for a highlight. IJIS sea ice extent broke through the 5 million km² barrier yesterday. This graph shows how many days it has taken to drop from one million to the next from the date of maximum extent onwards (click on the link above for a larger version):

Thanks, Seke Rob!

SIE 2011 update 18: ten yard line

During the melting season I'm regularly writing updates on the current sea ice extent (SIE) as reported by IJIS (a joint effort of the International Arctic Research Center and the Japan Aerospace Exploration Agency) and compare it to the sea ice extents in the period 2005-2010. NSIDC has a good explanation of what sea ice extent is in their FAQ. I also look at other things like sea ice area, concentration, volume, 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.

August 27th 2011

We have an exciting week behind us. And that's putting it mildly.

In the last SIE update I referred several times to the unfulfilled potential the ice pack is showing this melting season, even making it the title of the update. A coupe of days later we saw some of that potential being put to use when a big cyclone ripped through the Beaufort and Chukchi regions, causing an unprecedented (I think) case of flash melting in a huge area of the ice pack. Normally you get a bit of ice melt/compaction everywhere at the edges of the ice pack, but this week we saw a massive amount of ice just disappearing from the radar one day to the next. Stunning stuff.

Of course, it is impossible for so much ice to disappear in just 24 hours, but the cyclone managed to disperse the floes, which probably got washed by water in the process, in such a way that concentration fell below the 15% threshold combined with some other factors (there has been much speculation regarding this matter in the Flash melting post). Some of the ice could show up again in the coming days if the winds push it together.

The cyclone was as short-lived as it was big, which means there still is a lot of untapped potential out there. The satellite images and sea ice concentration maps don't lie and show us how weak the ice is at the edges. We even see the water that has been warmed up to the brim in the Laptev Sea starting to eat its way into the ice pack, towards the North Pole.

As usual, weather patterns in these last 2-4 weeks of the melting season will determine the final outcome. But what makes this year so interesting is that this dominant influence is being superseded by the state of the ice. In other words, the ice determines how much influence weather patterns are allowed to have. This week's cyclone, for instance, would have actually made sea ice extent jump up only ten years ago because of its diverging power. But you can't diverge what you disintegrate.

Barring some really strong weather patterns that keep the ice in place and freeze the water over at the edges, we are in for a final phase of the melting season where everything is possible.

Sea ice extent (SIE)

Here's the current IJIS SIE graph:

IJIS extent is about to break through the 5 million square km barrier, for the fourth time in the satellite record, after 2007, 2008 and 2010. This year has managed to nibble off some more of 2007's lead (with the help of a very late century break due to the 'flash melting'), but a difference of 191K square km is still quite significant at this stage of the melting season. 2007 is having some very slow days at the end of the week, so maybe 2011 can get closer still. In the meantime, it seems to be fending off 2008's massive attack quite well, still leading by almost 300K square km.

The current difference between 2011 and the other years is as follows:

Oh, and BTW, the Passages are open

It's crazy when you think about it. Just a few years back everyone was stunned to see the Northwest Passage and the Northern Sea Route (also known as the Northeast Passage) open at the same time. Last year we saw the first boats making it through both passages in one season. Some people might try to downplay the significance of this fact by referring to Amundsen or the St. Roch, but we have a guy this year who did the Northwest Passage solo. I'm certain the ghost of poor Sir John Franklin is howling with envy.

But still, for most people it has become more or less normal now for the Northwest Passage and Northern Sea Route to open up towards the end of the melting season. Such is human nature, I guess. We might look up briefly with a bored look if someone tells us that those Passages open up a bit earlier every year, but that's it. The new normal is not so new and very normal. I'm covering it anyway, just to let you know.

There's some white stuff left in the Northwest Passage, but I think it's safe to say it's open. The Northern Sea Route has been open for a while now, with proper Suez-size tankers apparently going through it. Here it is:

People who like to have more details can read this recent paper by Shibata et al: Interannual changes in sea-ice conditions on the Arctic Sea Route obtained by satellite microwave data (hat-tip to Angela Marchbank)

Area graphs: 3 million km2 mark passed

We are getting closer to the minimum sea ice area, which comes a bit earlier towards the end of the melting season than sea ice extent because of the simple fact that low air temps start to make melt ponds and even water between ice floes freeze over. This effect shows up immediately in sea ice area data, but a bit later in sea ice extent data, due to the different ways they are calculated.

The Cryosphere Today minimum SIA was recorded quite early in 2005 (August 31st) and quite late in 2006 (September 16th), but in the last few years minimum sea ice area occurred between September 7th and 9th. Even though we still have about two weeks to go, it's interesting to have a preliminary look today at what the different sea ice area graphs are showing us.

The main reason is that the Cryosphere Today SIA has passed the 3 million square km for the second time in recorded history, the other time this happened, was in 2007 (graph courtesy of Piotr Djaków):

The 3 million mark has been passed 10 days earlier than 2007 and only a drop of about 68K square km is needed to break the minimum SIA record, but it might take the full two weeks to happen. Area can now go up and down very arbitrarily, depending on weather conditions. If things turn really bad up there, we might even see an early minimum SIA like in 2005, with no record broken. But chances of this happening are slim.

Larry Hamilton's bar chart gives an excellent impression of how this year stacks up so far, compared to minima in other years:

There are some other SIA graphs that are updated on a daily basis, such as the one by Arctic ROOS which uses SSM/I data provided by NERSC:

Flash melting

I introduced the term 'flash melting' in a recent SIE update. It was a pun on the term 'flash flooding' where lots of rain falls out of the sky in a short amount of time, causing creeks and rivers to flood very fast. I based the concept on the state of large parts of the ice pack in the Beaufort, Chukchi and East Siberian Seas that looks like slush puppie on the satellite images. It seems so weak that one can't help but wonder if it will all "just melt away quite suddenly", to quote Professor Peter Wadhams from this 2007 BBC interview (as I did in the piece CAPIE hits record low).

In the last two days something weird has happened on the sea ice concentration maps of the University of Bremen, with large swathes of ice suddenly disappearing from the radar (the full animation from August 6th-22nd can be watched here) on the upper left of the image:

Update August 24th: Added yesterday's image. Could be the sensor is picking up ice again.

Update August 25th: Added yesterday's image. No more flash melting (thank God).

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This looks so spectacular that it could just be a fluke, a deceived satellite sensor. Flash melting is a nice term for fast melting, but it can never be as fast as flash flooding. It ought to occur more on a time scale of say one week (which is very fast in the Arctic). Because however weak the slush puppie ice may be, it still takes large amounts of energy to make it disappear completely.

On the other hand IJIS extent took a bit of a nosedive with a reported melt of 98K square km for yesterday's date, and there's a huge cyclone battering the ice as we speak:

How thick is your ice?

In honour of Horatio Algeranon, the climate poet, and today's intriguing news from the Alfred Wegener Institute that most of the ice they have measured at the Norh Pole is 0.9 meters thick, I have written an alternative version to a song people who have survived the 70's will appreciate:

 

How thick is your ice?

I see the ice in the morning sun
I feel it thinning in the pouring rain
And the moment that the graphs drop off a cliff
I wanna feel you in my arms again

And you come to me on a summer breeze
Warming up in the sun and then swiftly leave
And it's me you need to show...

How thick is your ice? (how thick is your ice, how-thick-is-your-ice?)
I really need to learn
'Cause we're living in a world of fools (didn't have to change that one)
Breaking us down
When they all should let us freeze
We belong to you and me

I believe in you
Without you there could be much harm
You're the thing that keeps the weather calm
My air conditioner when I warm
And you may not think
I care for you
When you know down inside
That I really do
And it's me you need to show...

How thick is your ice? (how thick is your ice, how-thick-is-your-ice?)
I really need to learn
'Cause we're living in a world of fools
Breaking us down
When they all should let us freeze
We belong to you and me

Polarstern reaches North Pole

According to this press release by the Alfred Wegener Institute, the polar icebreaker Polarstern has reached the North Pole this morning, 22nd August at 9:42 AM CET.

The 55 scientists and technicians from 6 different countries are there to investigate the changes in the Arctic. Hence the name of their expedition: TransArc - Trans-Arctic survey of the Arctic Ocean in Transition.

I have translated one part of the press release that I found of particular interest:

Schauer was in the central Arctic for the last time in 2007 and this time around has found an ice cover that is similar to the one in the year that went into the history books as the year with the lowest sea ice cover since satellite measurements in 1979 began. The first ice thickness measurements confirm this: in 2011 as well as in 2007 most of the ice has an ice thickness of 0.9 m. In comparison, most of the ice in 2001 was measured at 2 m. That year total sea ice extent at the end of the melting season corresponded to the long term average.

This is the third time the Polarstern reached the North Pole. On September 7th 1991 it did so with the Swedisch research icebreaker Oden. Almost exactly 10 years later, September 6th 2001, there was a joint expedition with the American USCGC Healy.

Alfred Wegener Institute press release

Analogies

I'm being a bit tongue in cheek here, but at the same time I'm sure there is something to be learned from this video in relation to the sea ice in the Beaufort, Chukchi and East Siberian Seas: