Unexpectedly, the arctic sea ice is now racing ahead to catch up to last years melt. It makes sense. Last years old ice was greatly weakened and only replaced by the new winter ice now been eliminated. A satellite view of the arctic shows mostly well broken up ice floes that are certainly at the ambient sea temperature right now and are been attacked by the solar energy collected by the sea. They are all in a melt environment with dropping support from adjacent ice.
It is important to understand that the overall ice mass is continuing to drop season by season and the last report stated that we have lost fifty percent in the last five years. That was after we lost sixty percent between 1959 and 2000. (we have only the two data points and the loss likely took place in the late eighties and the nineties.)
So at the current melt rate now even less impeded and accelerated by expanded open water, it will all be gone in five years at the most. Again for those keeping score, that means 2012. It now appears even possible that we will be even a bit earlier.
At least everyone is watching this year. Last year at this time they were all keeping their heads in the sand. The main point is that this is the terminal collapse of the perennial Arctic sea ice sheet that we are now watching. The only question I had two and three years ago been as to when the collapse would kick off. It kicked off last year and continues in full swing today and can only end with an ice free summer sailing season by 2012.
The cold needed to reverse this situation is actually beyond what has been experienced in the Arctic for decades.
This also makes me revisit the subject of the little Ice Age and the Bronze Age. It is now very apparent to me that the natural state of the Northern Hemisphere is warm. This now clearly means no summer time sea ice left in the Arctic. In fact, with a restored Sahara, we can expect it to be warmer still and very resistant to volcanic cooling.
It is clear that a major agent of cooling brought the temperature down two full degrees at the beginning of the Little Ice age and held it there long enough to produce a very thick ice sheet in the Arctic. This likely took place over a full century.
We have two options. The first is the Maunder Minimum of which I am a bit skeptical and unconvinced. The second is a very active eruption sequence associated with the Aleutians and Kamchatka Peninsula. For that we need eruption and ash volume histories of all these volcanoes. We also need to differentiate those that are rich in volatiles.
Recall that the impact on temperature is magnified in the Arctic. A Mount Pinatuba in the Arctic could be expected to impact several degrees as compared to the degree or so experienced on the equator.
So we really need only an increase in normal volcanism to achieve the temperature changes and preferably in the form of a major eruption followed by several others over a number of years. This is an apt description of the region's behavior.
Arctic Sea Ice Decline Accelerates, Amundsen’s Northwest Passage Opens
12 August 2008
Just several weeks ago it seemed as though the loss of Arctic sea ice would not be as extreme as last year’s, which shattered previous records. (Earlier post.) However, the rate of sea ice loss has accelerated during the past ten days, triggered by a series of strong storms that broke up thin ice in the Beaufort and Chukchi Seas and brought warm southerly winds into the region, according to the National Snow and Ice Data Center (NSIDC).
Amundsen’s historic Northwest Passage is once again opening up; the wider and deeper route through Parry Channel is currently still clogged with ice. This route opened in mid-August last year; it may still open up before the end of this year’s melt season, according to NSIDC.
Arctic sea ice extent on 10 August was 6.54 million square kilometers (2.52 million square miles), according to NSIDC data, a decline of 1 million square kilometers (390,000 square miles) since the beginning of the month. Extent is now within 780,000 square kilometers (300,000 square miles) of last year’s value on the same date and is 1.50 million square kilometers (580,000 square miles) below the 1979 to 2000 average.
Ice extent has begun to decline sharply. The decline rate surged to -113,000 square kilometers per day on August 7 and as of August 10 was -103,000 square kilometers per day. This compares to the long-term average decline of -76,000 square kilometers per day for this time of year. Normally, the peak decline rate is in early July.
Many of the areas now seeing a rapid retreat saw an early melt onset (see July 2, 2008); this helped set the stage for rapid retreat (July 17 and April 7). However, the more fundamental issue is that these regions started the melt season covered with thin first-year ice, which is especially vulnerable to melting out completely. Thin ice is also vulnerable to breakup by winds; the last ten days have seen a windy, stormy pattern that has accelerated the ice loss.