« Get your desktop wallpaper now | Main | Polar ice caps can recover »

Comments

Feed You can follow this conversation by subscribing to the comment feed for this post.

Rich and Mike Island

I noticed that ice extent only fell by 40,000 square km today. 2007 increased its lead by 469 square km. One day aberration or a trend?

Neven

Rich and Mike Island, my guess is that it will stay like this for a few days at least, unless the flash melting continues without favourable weather conditions.

Rich and Mike Island

Thanks for answering Neven! I wonder how fast melting can happen later in August with the lower sun angle. Even with favorable weather conditions, century breaks will be hard to come by.

Seke Rob

Re: Rich and Mike Island | August 16, 2011 at 05:50

Me day on day comparer makes it 277,031 kmsq total lead by 2007 ATM...there's this ladder the 2011 ice is on, descending down and somewhere in there a few broken sports (Got a cheat sheet [many will have I'm sure] that pulls a lot of comparative numbers in for JAXA.

idunno

Hi Neven,

(Good luck with the new farm.)

Shame that the DMI North Atlantic and Equatorial NA charts are still down...

Rob Dekker

Thanks Neven, I really missed the DMI SST graphs.
Interesting to note how much heat seemed to have built up in the Kara sea and north, and how (relatively) little in the Beaufort.

This suggests that bottom ice melt north of the Kara will continue for a while, while the Beaufort may run out of steam next month.

fred

Just a quick question: if we know the SSTs nowand we know the ice volume now, can't we calculate what the final volume would be based on the assumption that the ice absorbs the heat? (This goes back to the post on the correlation between ice temperatures in July and final ice extent, which I thought was pretty interesting.)

That is a basic high school physics problem for a glass of water with ice. I realize for a glass of water, the question has infinitly less environmental factors... but wouldn't there be some correlation still?

Thinking about this question, as the coffee slowly sinks in, I realize this question shows the shallowness of my knowledge about seaice methods with respect to the knowledge of the people on here who range from passionate amateurs to professionals, so please let me rephrase my question: since this is an obvious and basic method, to what extent does this calculation work? Is there any correlation at all?

Rich and Mike Island

40K decrease in arctic sea ice extent on August 16, 58K decrease on August 17, and 77K decrease on Aug 18. A 34K closing of the gap in the past 3 days. Today's 77K drop was very respectable, especially for this time of year! I'm not an expert, but eyballing IJIS it looks like a drop of 77K this late is quite rare.

Artful Dodger

Yeah RnMI, the 7-day moving avg -SIE is -70,179 km^2 / day right now, and the 15-day is -73,573.

So with just 15 days to Sep 2nd, 2011 needs to average just -53,073 km^2 / day to catch 2007 for SIE.

Similarly, 2011 is on track to tie the 2007 all-time low SIA on about Aug 26 or so. Keep in mind, 2007 date of min SIA was Sep 7, so 2011 has 12 days in hand over 2007 for Area.

There has been some discussion about snow cover on the sea ice recently. Here is the latest AMSR-E 5-day snow cover on ice chart (Aug 12-16, 2011):

Aqua AMSR-E NH 12.5 km Snow Depth over Ice

In this image, black is the domain of ocean that contains any detectable sea ice concentration. The color bar on the right of the image indicates snow depth.

Steve Bloom

Lodger, I'm seeing an awful lot of artifacts in the black. Is this map reliable?

Artful Dodger

Yes.

D

Is not. Since late May, there's been absolutely no ice in the Northern end of the Gulf of Bothnia, and no ice since April I think in Lake Ladoga or in the waters near St Petersburg either.


Artful Dodger

Is too. This is a snow depth map. The algorithm has been extensively validated. See here:

Sea ice concentration, ice temperature, and snow depth using AMSR-E data. Comiso, J.C. | Cavalieri, D.J. | Markus, T. IEEE Transactions on Geoscience and Remote Sensing. Vol. 41, no. 2, pp. 243-252. Feb. 2003

A summary of the theoretical basis and initial performance of the algorithms that are used to derive sea ice concentration, ice temperature, and snow depth on sea ice from newly acquired Earth Observing System-Aqua/Advanced Microwave Scanning RadiometerEOS (AMSR-E) radiances is presented. The algorithms have been developed and tested using historical satellite passive microwave data and are expected to provide more accurate products, since they are designed to take advantage of the wider range of frequencies and higher spatial resolution of the AMSR-E microwave instrument. Validation programs involving coordinated satellite, aircraft, and surface measurements to determine the accuracies of these sea ice products and to improve further our capability to monitor global sea ice are currently underway.


Bfraser

I'm confused by the PIPS "Ice speed and Drift" and DMI "Surface Pressure" maps.

It looks to me as though we have a high near Svalbard and a ridge of low pressure over Greenland and Iceland (which is a negative arctic dipole, right), but the Fram is running the "usual" direction anyway.

Can anyone explain? Or am I just wrong....

crandles

Seems to have changed back to the old colour scheme. The pink is back on the anomaly map.

D

"Is too. This is a snow depth map. The algorithm has been extensively validated. See here:"

Artful Dodger, I don't care or know if the algorithm has been validated or not and by whom, but when and if it shows there's either snow or ice in Finland anywhere this time of the year -- it's positively not working correctly throughout the latitudes, if at all.



The comments to this entry are closed.