Over the past few days, Arctic sea ice extent has braked dramatically in the daily loss rate and now has made a sharp right turn, which is rather unusual. Here’s the JAXA extent:
And here is a close up view, note the 2011 red line:
That turn is unique to the record since 2002. Note that in 2007, there was also a turn, though brief, and then melt accelerated.
It is also showing up in the NSIDC plot:
But what is really most interesting is the plot from DMI, which show not only a turn, but a reversal:
What does this mean? The short answer is, probably nothing. When we approach the minimum, and the ice pack becomes more fractured and scattered, it also becomes more susceptible to the vagaries of local and regional wind and weather.
WUWT regular and contributor “Just the facts” suggested in comments that:
One factor appears to be the Greenland Sea, where sea ice began to grow on July 15th and has been trending above average since then.
On the other hand, looking at the most recent comparison with 2007, the Arctic ice cover looks a bit more soupy in 2011:
Air temperature is above freezing throughout the Arctic….
…as is fairly normal for this time of year:
Clearly, at present, air temperature in the Arctic is not in any way climatologically abnormal, so the reasons for the current extent being low and making erratic turns must lie elsewhere. Wind, soot deposition/albedo, ocean currents, etc. all factor in.
So, while we may have temporarily avoided a new record minimum (as many in the “Serreze death spiral” camp said we are headed to) there’s still the possibility that the plots will turn to the left again, and resume or even accelerate. It all depends on the weather, and the outcome could go either way at this point. Historically, we have about 7 more weeks before the turn upwards as the Arctic begins the slow re-freeze.
Still, it makes for interesting observation and discussion. The WUWT sea ice page has all the latest stats, updated as soon as they are made available.
UPDATE: Bill Illis runs his own database, and offers this interesting view in comments.
The last 21 days are the lowest melt since 1973 in my database over the same period. The total ice extent is still well-below average but there are very few periods in the record where the trend is so different than normal for an extended period of time like the current period is.
Matching up a few different datasets back to 1972.
UPDATE2: In the meantime, while extent loss slows, the NSIDC “death spiral team” tries to make a case for a record low average for July, while at the same time admitting that On July 31, 2011 Arctic sea ice extent was 6.79 million square kilometers (2.62 million square miles). This was slightly higher than the previous record low for the same day of the year, set in 2007.
Arctic sea ice extent averaged for July 2011 reached the lowest level for the month in the 1979 to 2011 satellite record, even though the pace of ice loss slowed substantially during the last two weeks of July. Shipping routes in the Arctic have less ice than usual for this time of year, and new data indicate that more of the Arctic’s store of its oldest ice disappeared.
Figure 1. Arctic sea ice extent for July 2011 was 7.92 million square kilometers (3.06 million square miles). The magenta line shows the 1979 to 2000 median extent for that month. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data.
—Credit: National Snow and Ice Data CenterHigh-resolution image
Overview of conditions
Average ice extent for July 2011 was 7.92 million square kilometers (3.06 million square miles). This is 210,000 square kilometers (81,000 square miles) below the previous record low for the month, set in July 2007, and 2.18 million square kilometers (842,000 square miles) below the average for 1979 to 2000.
On July 31, 2011 Arctic sea ice extent was 6.79 million square kilometers (2.62 million square miles). This was slightly higher than the previous record low for the same day of the year, set in 2007. Sea ice coverage remained below normal everywhere except the East Greenland Sea.