As some of you may already be aware, the loss of arctic sea ice this summer has been extraordinary. According to the NSIDC, the amount of ice that melted this year that had never melted since recording began is about the size of the State of Florida.
The NSIDC website is updated a couple of times a week with the latest sea ice extent measurements and I watch the numbers with horror because I am one of those who think we have gone past the tipping point already and news like this just further validates my opinion.
Well in todays update there was a very scary section I want to share with you related to the BIG tipping point for climate change: changes to ocean circulation patterns.
I was concerned back in May that there was evidence out there indicating that the ocean circulation patterns may have already changed. You can read that diary here in case you missed it: Have the ocean’s circulation patterns ALREADY been altered?
Today's update at NSIDC has confirmed that ocean circulation patterns have changed on both the Atlantic and Pacific sides of the Arctic Ocean.
In the August 22 report, we explained that another part of the 2007 story is "memory" of the sea ice to changes that have been unfolding over the past few decades. Our focus there was on the apparent transition to younger, thinner ice since the late 1970. As discussed, factors contributing to this thinning involve a general rise in air temperatures, and changing winds that have transported fairly thick ice out of the Arctic Ocean into the North Atlantic. An issue that we haven't addressed, yet, is changes in ocean circulation.
One prominent researcher, Igor Polyakov at the University of Fairbanks, Alaska, points out that pulses of unusually warm water have been entering the Arctic Ocean from the Atlantic, which several years la(t)er are seen in the ocean north of Siberia. These pulses of water are helping to heat the upper Arctic Ocean, contributing to summer ice melt and helping to reduce winter ice growth. Another scientist, Koji Shimada of the Japan Agency for Marine–Earth Science and Technology, reports evidence of changes in ocean circulation in the Pacific side of the Arctic Ocean. Through a complex interaction with declining sea ice, warm water entering the Arctic Ocean through Bering Strait in summer is being shunted from the Alaskan coast into the Arctic Ocean, where it fosters further ice loss.
So it seems as though scientists are now confirming changes to ocean circulation patterns, at least in the northern parts of the oceans. I have to assume then that changes are also taking place elsewhere, even in the North Atlantic. If you look at temperature anomolies (see picture on NSDIC page), it is startling to see how Siberia is about 7 degrees celcius hotter than average over the past couple of weeks (permafrost melt anyone???) and England is about 5 degrees celcius colder than average.
And then you read something like this:
Scientists fear ice caps melting faster than predicted
The Greenland ice cap is melting so quickly that it is triggering earthquakes as pieces of ice several cubic kilometres in size break off.
...
Robert Correll, chairman of the Arctic Climate Impact Assessment, said in Ilulissat today: "We have seen a massive acceleration of the speed with which these glaciers are moving into the sea. The ice is moving at two metres an hour on a front 5km [3 miles] long and 1,500 metres deep. That means that this one glacier puts enough fresh water into the sea in one year to provide drinking water for a city the size of London for a year."
...
He had flown over the Ilulissat glacier and "seen gigantic holes in it through which swirling masses of melt water were falling. I first looked at this glacier in the 1960s and there were no holes. These so-called moulins, 10 to 15 metres across, have opened up all over the place. There are hundreds of them."
Yikes.