Heavy, Early-Season Blow to Arctic Ice Cap: Powerful, Warm Storm Disintegrates Barents Sea Ice
18
April, 2014
A
vast swath of sea ice that painstakingly formed as somewhat cooler
conditions had finally settled in near Svalbard and Frans Joseph Land
in the Barents Sea was shattered yesterday as a powerful, heat-laden
Arctic cyclone screamed up out of a rapidly warming extreme North
Atlantic.
The
storm originated west of the Norway coastline where, in recent years,
a repository of exceptionally warm water has collected. This
near-Arctic and Barents Sea warm pool has resulted in numerous
effects including a forced recession of sea ice by hundreds of miles
during winter time as well as providing impetus for various anomalous
heat waves in Scandinavia in recent years.
This
time, the heat pool was the genesis for a powerful storm that
delivered an intense package of early season warmth to a section of
sea ice drifting in the North Barents Sea region.
Warm
Storm Impacts
In
the above image, provided by NASA’s LANCE-MODIS sensor,
we can see a 250 mile section of sea ice that had extended out into
the Barents Sea over the past few weeks during a cooler period as
warmer conditions shifted to the Laptev, East Siberian, and Beaufort
Seas. The date of this shot is April 16. To the lower left is the tip
of Svalbard. Upper left is the far edge of Frans Joseph Land. Another
few hundred miles to the right of far right frame is Northern Norway.
The
storm, for now is off frame.
Now
on April 17, we can see the storm center in the far left frame near
the tip of Svalbard. At this point, the storm has bombed out to an
extraordinarily powerful 950 mb low, packing 60+ mph winds. In its
upper quadrant, it carried with it temperatures ranging from 10 to 20
C above typical seasonal averages. Perhaps more importantly, through
cyclonic forces it pumped waters that were up to 5 C above average
temperature up from the depths and into the ice pack. This kind of
cyclonic Ekman Pumping, in recent years, has had an increased
potential to rapidly reduce sea ice due to warmer surrounding water
conditions and warmer waters at depth.
Note
that rapid sea ice disintegration is already involved in the wake of
this severe Arctic Cyclone.
Now,
today, on April 18, we can see that in the aftermath of this powerful
Arctic Cyclone there is very little contiguous sea ice left. What
remains is what in sea ice parlance can be termed nilas — very thin
and diffuse ice of 0-10 centimeters in thickness. Note that the
entire 250 mile zone is completely involved in this very visible ice
loss and that such losses continue on past Frans Joseph Land and into
the Kara Sea.
Further
Implications for the 2014 Melt Season
Melt
season in the Arctic is now well involved. In addition, we have
numerous weaknesses in the Northern Hemisphere Jet Stream that
continue to funnel much warmer than average air over the Arctic Sea
Ice. Alaska, Siberia and the Barents all continue to see strong warm
air impulses that progress well into the zone covered by sea ice.
Today,
according to GFS model measures for the zero hour, average Arctic
temperatures are 2.24 C above the, already warmer than normal, 1979
to 2000 average. This is a rather high spike for spring, when Arctic
temperatures typically start to settle back down after seeing high
levels of global warming associated heat amplification during winter
time.
The
excess heat had already pushed Arctic sea ice extent measures down to
near record lows as of April 17. According to NSIDC, extent measures
had fallen to 13.9 million square kilometers yesterday, the second
lowest level in the measure. With full effect from the recent intense
storm not yet fully realized, it is possible that impacts in this
region alone could reduce total values by at least 100,000 square
kilometers.
(Arctic
Sea Ice Extent Second Lowest on Record for April 17. Data Source:
NSIDC. Image Source: Pogoda
i Klimat.)
Yet
one more major blow to sea ice from a powerful warm storm type
system. And, in this case, with melt season progressing rapidly and
with so much heat already shifting into the Arctic, it is highly
unlikely that this zone of newly dispersed ice will see much in the
way of recovery over the coming weeks.
Links:
Arctic
Sea Ice in Steep Descent
22
April, 2014
Arctic
sea ice area is in steep descent, as illustrated by the image below.
Sea ice area was only smaller at this time of the year in 2007, for
all years for which satellite data are available.
|
|
Earlier
this year, on March 9, 2014, Arctic sea ice area was at a record
low
for the time of the year. Since then, area did show some growth for a
while, to the north of Scandinavia. This growth could be attributed
largely to strong winds that made the sea ice spread with little or
no growth in volume. The 30-day Naval Research Laboratory animation
below shows recent sea ice speed and drift.
Indeed,
sea ice volume in March 2014 was the 2nd lowest on record. Only March
2011 had a lower volume as discussed in a recent
post. The
30-day Naval Research Laboratory animation below shows recent sea ice
thickness.
Low
sea ice volume and area jointly suggest there could be a total
collapse of the sea ice later this year, in line with
observation-based non-linear trends. For years, this blog
has warned that
observation-based projections point at Arctic sea ice disappearance
within years, with dire consequences for the Arctic and for the world
at large.
As
said, winds are responsible for much of sea ice variability, and
winds could either slow down or speed up such a collapse. On this
point, it's good to remember what Prof. Peter Wadhams said
in 2012:
".
. apart from melting, strong winds can also influence sea ice extent,
as happened in 2007 when much ice was driven across the Arctic Ocean
by southerly winds. The fact that this occurred can only lead us to
conclude that this could happen again. Natural variability offers no
reason to rule out such a collapse, since natural variability works
both ways, it could bring about such a collapse either earlier or
later than models indicate.
In
fact, the thinner the sea ice gets, the more likely an early collapse
is to occur. It is accepted science that global warming will increase
the intensity of extreme weather events, so more heavy winds and more
intense storms can be expected to increasingly break up the remaining
ice, both mechanically and by enhancing ocean heat transfer to the
under-ice surface."
The
image on the right, produced with NOAA
data, shows mean coastal sea surface temperatures of over 10°C
(50°F) in some areas in the Arctic on August 22, 2007.
In
shallow waters, heat can more easily reach the bottom of the sea. In
2007, strong polynya activity caused more summertime open water in
the Laptev Sea, in turn causing more vertical mixing of the water
column during storms in late 2007, found
a 2011 study,
and bottom water temperatures on the mid-shelf increased by more than
3°C (5.4°F) compared to the long-term mean.
Another
study
found that drastic sea ice shrinkage causes increase in storm
activities and deepening of the wind-wave-mixing layer down to depth
~50 m (164 ft) that enhance methane release from the water column to
the atmosphere. Indeed, the danger is that heat will warm up
sediments under the sea, containing methane in hydrates and as free
gas, causing large amounts of this methane to escape rather abruptly
into the atmosphere.
Such
warming would come on top of ever-warmer water that is carried by the
Gulf Stream into the Arctic Ocean and that has already been blamed
for large methane releases from the seafloor of the Arctic Ocean last
year.
The
prospect of an El NiƱo event, as discussed in an earlier
post,
makes the situation even more dire.
The
consequences of sea ice collapse will be devastating, as all the heat
that previously went into transforming ice into water will be
asbsorbed by even darker water, from where less sunlight will be
reflected back into space. The danger is that further warming of the
Arctic Ocean will trigger massive methane releases that could lead to
extinction at massive sclae, including extinction
of humans.
Hopefully,
more people will realize the urgency of the situation and support
calls for comprehensive and effective action as discussed at
the Climate
Plan blog.
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