Watts Up With That?
July 19, 2010
We are seeing a number of interesting polar ice milestones this month. First, WUWT now has a new permanent Sea Ice Page, where you can find all of the live graphs and images in one place. Details here.
Second, it has been the slowest July (1-17) Arctic melt in the eight year JAXA record.
Ice extent has declined at less than half the rate of 2007, and total ice loss has been more than 200,000 km² less than the previous low in 2004.
DMI now shows Arctic ice extent as second highest for the date, topped only by 2005.
Cryosphere Today shows that ice extent and concentration is about the same as it was 20 years ago.
The modified NSIDC map below shows in green, areas where ice is present in 2010 but was not present in 2007.
The modified NSIDC map below shows (in red) ice loss over the last week. Note that ice extent has increased slightly in the Chukchi and Beaufort Seas, while it has declined slightly in the East Siberian Sea.
The modified NSIDC map below shows the record low ice loss since the first of the month.
The modified NSIDC map below shows ice loss since early April.
The graph below shows PIPS ice thickness over the last five years. Average ice thickness in 2010 continues to track a little below 2006. It should bottom out in the next week or so between 2006 and 2009.
The low ice loss is consistent with the low Arctic temperatures we have seen this summer.
The video below shows ice movement since the start of June. Note that we are starting to see a clockwise circulation setting up again, which hints at increased ice loss over the rest of the month.
Another factor suggesting increased ice loss is the NCEP forecast, which projects warm temperatures over the East Siberian Sea and Arctic Basin for the next few days.
A third factor suggesting increased ice loss the rest of the month is that the the ice concentration has declined, due to winds exerting tensile stress on the ice. This allows more sunlight to reach the water and warm it. I expect to see the ice extent graphs showing steeper losses towards the end of the week, primarily in the East Siberian Sea.
This is primarily due to the fact that they have almost no coverage there, and that they make up numbers extrapolate across vast distances with no data.
Meanwhile down south, sea ice continues at a record high level for the date.
July has been typified by record low ice loss in the north, and record high ice gain in the south. Global sea ice is above normal.
If the current trends were to continue, there is a small possibility that we will see a record maximum global sea ice extent towards the end of September. One thing is for sure – no matter what happens, the press will continue to be fed reports that the poles are “melting down” due to “record heat.”
This article was posted: Monday, July 19, 2010 at 3:47 am