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Arctic Sea Ice Rallies a Bit
radioweather writes "Like the recent stock market rebound, Arctic sea ice is making a big rally over the record low set last year. According to the Alaskan
IARC-JAXA website, satellite data which shows sea
ice extent as of 10/14/08 was 7,064,219 square kilometers, when compared
to a year ago 10/14/08 it was 5,487,656 square kilometers. The one-day gain between 10/13/08 and 10/14/08 of 3.8% is also
quite impressive. On May 5th, The National Snow and Ice Data Center suggested
the possibility of an ice-free north pole
in 2008, but so far, this year has been a banner year for sea ice recovery."
No, and they're being *deliberately* misleading. Arctic sea ice this year hit the second lowest level in recorded history. Last year was the lowest.
Arctic sea ice extent during the 2008 melt season dropped to the second-lowest level since satellite measurements began in 1979, reaching the lowest point in its annual cycle of melt and growth on September 14, 2008. Average sea ice extent over the month of September, a standard measure in the scientific study of Arctic sea ice, was 4.67 million square kilometers (1.80 million square miles) (Figure 1). The record monthly low, set in 2007, was 4.28 million square kilometers (1.65 million square miles); the now-third-lowest monthly value, set in 2005, was 5.57 million square kilometers (2.15 million square miles)./I.
To report values now, from *October*, during the refreeze is just bloody ridiculous. Yes, different years melt and refreeze at different times; there's a lot of spring and fall fluctuation. What matters are the maximum and minimum extents.
FYI, arctic sea ice normally low in years after El Nino winters and high in years after La Nina winters. Winter of 2006-2007 was in El Nino conditions, leading to the record 2007 melt. But winter of 2007-2008 was in a strong La Nina. The fact that we got the second lowest ice extends on record despite this is incredibly disturbing.
If I ever become wealthy and mad, I'll leave Companion Cubes on desert islands for shipwreck survivors.
Once again, this is why people who don't know anything about a topic shouldn't comment on it.
Earth's oceans, especially the Pacific, are truly massive heat reservoirs, and changing how they interact with the atmosphere can strongly affect the atmosphere's temperature in the *short term*. In the long term, the planet is still dominated by its radiation balance, of course.
The linked article was describing, quite accurately, how the early part of this year was in La Nina conditions. El Nino is caused by the weakening or reversal of the Walker circulation (an atmospheric flow around the Equator). The Walker circulation helps encourage the upwelling of cold waters in the eastern Pacific, so El Nino conditions prevent more of this cool water from reaching the surface. As a net change, the equatorial Pacific ends up much warmer on the surface, raising atmospheric temperatures. In La Nina conditions, the situation is reversed; a stronger Walker circulation encourages more upwelling, and thus colder surface (and hence atmospheric) temperatures.
This has *absolutely nothing* to do with the planet's long-term temperature, which even a six year old looking at a graph could recognize through the year-to-year noise.
Now, if you *really* want a breakdown of how it ranked (records since 1880), here you go (remember that the first half of this year was in strong La Nina conditions!):
January: 31st warmest
February: 15th warmest
March: Warmest for land on record, 13th warmest for ocean
April: 13th warmest
May: 8th warmest
June: 8th warmest
July: Tied for 5th warmest
August: 10th warmest
September: Tied for 9th warmest
Spring: 7th warmest
Summer: 9th warmest
January to July: 9th warmest
If I ever become wealthy and mad, I'll leave Companion Cubes on desert islands for shipwreck survivors.
Seriously, I wish people would stop getting so shocked about this.
Climatologists are not unaware that the climate has changed in the past. The issue is that climate is currently changing faster than it would have without human input, and that larger and faster changes are likely if we continue to increase our input to the climate system.