Tag Archives: sea ice extent

Arctic Sea Ice Extent: In October 2008, Fastest Ever Growth

As expected a few days ago: October 2008 has seen the fastest Arctic sea ice extent growth ever recorded. According to the data published by IARC-JAXA, the amount of growth has reached 3,481,575 square kilometers for the month, or 112,319 sq km per day on average.

The previous maximum was October 2007, with 3,330,937 sq km for the month and 107,450 sq km per day on average. Record shrinkage remains July 2007, with 2,913,593 sq km lost and 93,987 sq km per day on average.

Growth should be starting levelling off now. November values could be as high as 2,179,844 sq km (2002) or as low as 964,688 sq km (2006).

UPDATE NOV 6: I should have known it. OF COURSE the above is an indication that Climate Change is upon us. Read this comment by Georg Hoffman at Tamino’s:

So I would make the specific prevision that 1) a seasonal cycle will show up in sea ice data and 2) due to 1) the october/november increase and the may/june decrease of seaice will become bigger and faster. I might check that with CMIP model data but I am pretty sure that this is what the model show

Here’s a link for the “CMIP model“. It never ceases to amaze me how elastic AGW theory truly is.

October 2008 Possibly Set for Record Sea Ice Extent Increase Rate

UPDATE NOV 10: October 2008 did show the fastest ever growth in sea ice extent

What is the reason behind the fact that “[Arctic] sea ice area [is] approaching the edge of normal standard deviation“?

It’s because October 2008 is set to break all records in the daily rate of increase in sea ice extent in the Arctic, that’s why.

Just look at the graph below, extracted from the values available at the IARC-JAXA website.

Daily Change Rate (Sea Ice Extent) (sq km, by month)
Daily Change Rate (Sea Ice Extent) (sq km, by month)

(The Y values are the daily rates of change in sea ice extent in the Arctic, averaged across each month. Note that for October I have only computed and plotted the rates between the 1st and the 23rd day of the month).

Some considerations:

(a) The October 2008 average daily rate so far is the largest overall, both in actual value (around 122,400 sq km of increase per day, previous record 100,500 in 2005) and in absolute terms (the overall minimum is around 94,000 sq km of decrease per day, in July 2007)

(b) If confirmed in a week’s time, the above will become the fifth record set in 2008:

largest January daily increase rate (44,000, previous record 39.800 in 2003)
largest February daily increase rate (27.500, previous record 25,400 in 2005)
largest May daily decrease rate (47,100, previous record 46,000 in 2005)
largest August daily decrease rate (66,800, previous record in 62,600 in 2004)

(c) Compared to 2007, the current year 2008 has so far shown

larger daily rates of increase in January (44,000 vs 35,400), February (27,500 vs 12,100), September (8,800 vs -600) and October (122,400 vs 93,500)
larger daily rates of decrease in April (39,800 vs 27,100), May (47,100 vs 44,200) and August (66,800 vs 55,400)
smaller daily rates of decrease in March (11,900 vs 12,200), June (57,900 vs 63,000) and July (78,800 vs 94,000)

========

Let’s see what happens during the upcoming week.

Past values suggest that the final average daily rate of increase for October may be slightly less than today’s. Still, as the current rate is some 20% larger than the previous record in October 2005, it would surprise nobody if October 2008 will remain the month with the largest value ever recorded by JAXA.

ps Who knows what NASA will have to say?