By Steve Goddard
I generated an animation of 2007 sea ice thickness from the US Navy’s PIP database, and noticed something remarkable. Watch the video below, particularly inside the red square – the animation runs from May through October, 2007. The color scale on the left indicates the thickness of the ice. Watch:
At the beginning of May, ice thickness was about three metres in the center of the red square. By mid-June it was getting thicker, and by early September it was close to five metres thick! During the notorious summer of “record melt” which we have been told about ad nauseum, the ice thickness near the most affected area increased by 60%. What could have caused this? Simple – the ice was compacting to the north as it was pushed by southerly winds. It lost area – while it gained thickness.
The NSIDC news from September, 2007 touched peripherally on this idea, without actually mentioning the critical point.
The region over Siberia experienced fairly low pressure during the same time period. Winds blow clockwise around high-pressure areas and anticlockwise around low-pressure areas. The combination of high- and low-pressure areas thus fostered fairly strong winds over coastal Siberia that were partly from the south, pumping warm air into the region and also contributing to a warming Arctic. At the same time, these winds from the south acted to push ice away from the coast and into the central Arctic Ocean, further reducing ice extent in the coastal areas
Ice thickness in May 2007 was ~3 metres
Ice thickness in September, 2007 was ~5 metres
Exaggerated animation of thickness gain from compression. For effect only.
A good analogy would be shoveling the snow off your driveway. As you push the shovel forwards, the area of snow decreases – but the thickness of the snow increases in front of the shovel.
Now on to 2010. Note in the images below that ice in the Chukchi and East Siberian seas is thicker this year than it was on this date in 2007. In some locations it is as much as 5 metres thick in 2010.
May 27, 2007 Ice inside the vulnerable square (where much of the anomalous 2007 “melt” occurred) was 0.5 to 3 metres thick
May 27, 2010 Ice inside the vulnerable square is 0.5 to 5 metres thick
The AGW chameleon changes it’s colours constantly. It complains about area and extent when convenient, and about thickness when convenient. I am coming to the conclusion that the 2007 melt was more of a marketing event than a climatological event. The graph below gives a feel for just how much of a non-event it was. 2007 was 1.5 standard deviations off the 30 year extent trend, but apparently a lot of the supposedly “melted” ice just crumpled up into more survivable thick ice.
One of the ice experts must have known this. Surprising that it took the “breathtakingly ignorant” WUWT to point it out.
ADDENDUM for clarity:
Currently the NIC uses the Polar Ice Prediction System (PIPS) version 2.0 as the basis for its “operational” short-term (24–120 h) sea ice forecasts. These forecasts are evaluated daily and amended by skilled analysts using reconnaissance data (if available), the most recent weather charts and data, and historical knowledge of the conditions in the area to provide the highest quality forecasts possible out to 120 h. Special emphasis in these forecasts is placed on the location of the ice edge and the conditions in the marginal ice zone (MIZ), as these are the most critical operational areas for marine transportation and safety.