Johnny Rook's Climaticide Chronicles

NOTE: crossposted at Daily Kos.

This week, the camera direction at NOAA webcam #1 was moved once again to a position similar to when I started doing these diaries in early July. There was no still image from the camera today; the last one was from 22:25 UTC yesterday, 16 August 2008. Temperature at that time was -2°C, and it appeared there was some ground fog beneath a generally clear sky.

I’ve also included an image from today from the “fisheye” lens webcam #3, taken 20:16 UTC, below.

Note the hoarfrost on the pole to the right and the precipitation gauge to the left. It’s been colder this past week in the Arctic, at least the part where these webcams are located.

Colder weather notwithstanding, Arctic sea ice loss continues at the same pace as last season, though the amount of coverage is still greater than in 2007. This can be seen in the graphic below:

Eyeballing the figure shows that coverage is at about 6 million km²; last year that level was reach about 5 August, so we’re about 12 days behind that season. If the ice melt rate reverted back to the normal rate (bold gray line), coverage would bottom out at about 5.5 million km², which would put the 2008 minimum at third lowest behind 2005 and 2007. That might be considered the best case scenario. If ice melt goes at the same rate as last year, on the other hand, minimum sea ice extent will probably reach about 5 million km², which would result in a second-least ranking behind last year.

Large areas of the Arctic Ocean have relatively low concentrations of sea ice (50% or less) as can be seen in the upper left graphic in the table below (yellow-green to red).

17 Aug 2008	Color legend	17 Aug 2007
10 Aug 2008	Color legend	10 Aug 2007

The Arctic sea ice climatology for 17 August, taken from the period 1953-1991 is shown below, for perspective. The degree to which the sea ice climate has changed from that period is crystal clear.

What’s the future hold? Normally, the ice melt season ends in early September, as we see the average minimum appears at that time. With an extended ice melt season as has been seen in recent years, ice melt probably won’t end until mid-to-late September. How that will evolve, and how low we will go in 2998, will depend on the weather over the next month. What did the full Arctic look like today? Here’s a graphic from the University of Cologne (Germany) showing air temperatures at the crosses over the Arctic Ocean (not bad coverage considering):

Temperature are in °C. Most are within a degree or two either side of 0°C, with darker blue from 0 to -2°C, lighter blue from 0 to +2 or so °C.

Finally, here are the western hemisphere sea surface temperature anomalies as of today, 17 August 2008. Note how warm the Arctic Ocean is north of AK and how warm Hudson’s Bay is (as much as +5°C above normal). The colder-than-normal water around Greenland is the result of fresh water ice melt from the Greenland ice sheet; it’s been a prominent feature now for a number of years in boreal summer.