Arctic Sea Ice Collapse Threatens - Update 4
14
August, 2015
On
August 12, 2015, Arctic sea ice extent was 6.043 million square km.
For this date, the only years on record that sea ice extent was
smaller were 2007, 2011 and 2012, as illustrated by above image.
Similarly,
on August 11, 2015, Arctic sea ice area on August 11, 2015, was
3.67025 million square km (bottom end yellow line). For this date,
the only years on record that sea ice area was smaller were 2007,
2011 and 2012.
So,
will Arctic sea ice reach a record low this year? The situation is
actually a lot worse than it appears when just looking at sea ice
extent and area up until now.
In
fact, sea ice is in a horrible state. One indication of this is the
almost complete absence of thick sea ice on August 12, 2015, which
becomes even more clear when compared with the situation in 2012 for
the same date, as illustrated by the image below.
The
absence of thick sea ice means that, in terms of volume, there is
very little sea ice left to melt until the minimum volume will be
reached around half September. In other words, the remaining sea ice
could melt rather quickly.
Also
note the presence of water on the image below, from Web Cam 1, from
the North
Pole Environmental Observatory, National Science Foundation.
For a drift map of the buoys, also see this page.
The image below shows sea surface temperature anomalies in the Arctic on August 13, 2015.
As
discussed earlier, Greenland's dramatic losses of ice mass over the
past few years and the subsequent large volumes of meltwater have
affected sea surface temperatures in the North Atlantic and have
caused the sea ice to be larger than it would otherwise have been in
terms of extent and area.
Nonetheless, this has not halted the overall decline of the sea ice, as illustrated by the discussion further above on sea ice thickness. Thick sea ice is shattered if not absent altogether in many places.
Nonetheless, this has not halted the overall decline of the sea ice, as illustrated by the discussion further above on sea ice thickness. Thick sea ice is shattered if not absent altogether in many places.
Until
now, the thicker multi-year sea ice used to survive the melting
season, giving the sea ice strength for the next year, by acting as
a buffer to absorb heat that would otherwise melt away the thinner
ice. Without multi-year sea ice, the Arctic will be in a bad shape
in coming years. Absence of thick sea ice makes it more prone to
collapse, and this raises the question whether a collapse could
occur not merely some years from now, but even this year.
Meanwhile, ocean heat is at a record high and there's an El Nino that's still gaining strength. The image below illustrates that a huge amount of ocean heat has been piling up in the Atlantic Ocean, ready to be carried into the Arctic Ocean, while large amounts of heat are also entering the Arctic Ocean from the Pacific Ocean through the Bering Strait.
This ocean heat is likely to reach the Arctic Ocean in full strength by October 2015, at a time when sea ice may still be at its minimum. Absence of sea ice goes hand in hand with opportunities for storms to develop over the Arctic Ocean, which could mix surface heat all the way down to the seafloor, where methane could be contained in sediments.
The
methane situation is already very dangerous, given mean methane
levels that recently reached levels as high as 1840 ppb, while much
higher peak levels can occur locally, as illustrated by the image
below.
Methane
levels appear to be rising by over 10 parts per billion a year at
Barrow, Alaska. Worryingly, high peaks have been showing up there
recently.
In
conclusion, Arctic sea ice looks set to take a further battering
over the next few weeks and could end up at a record low around half
September 2015. If things get really bad, sea ice collapse could
occur and the remaining pieces of sea ice could be driven out of the
Arctic Ocean altogether by storms, resulting in a blue ocean event
as early as September this year.
The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan.
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