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I have cut back a little on coverage of climate change stories unless they are news or new contributions to out understanding.
This falls into that category
This falls into that category
Bering
goes extreme
28 March, 2018
The melting season hasn't
started in earnest yet, but it seems the Bering Sea hasn't received
the memo. For almost the entire winter, sea ice has been reluctant to
form there, and now that the Sun has returned, the ice edge has
started to retreat to record high latitudes, past the Bering Strait
all the way up into the Chukchi Sea. Here's how that looks on
Wipneus' regional graph:
Bering Chukchi 20180325
To emphasize how truly
exceptional this is, here's a comparison with the situation in all
other years from the 2006-2018 period (images retrieved from the
University Bremen sea ice concentration maps page on the ASIG, click
for a larger version):
Bering Chukchi 20180325
Now, if this was it,
other years would maybe catch up in the next few weeks, but this
isn't it. The coupled HYCOM-CICE model from the Naval Research
Laboratory forecasts the sea ice to continue to drift northwards,
until the end of the month at least:
ACNFS sea ice drift
forecast 0325-31
This ice drift is caused
by winds, of course. These winds have already brought some anomalous
heat with them, right past Bering Strait, as can be seen on this DMI
temperature map:
DMI temp 20180326
According to the GFS
weather model, these winds will continue to bring in mild air well
into April(images provided by Climate Reanalyzer):
CR GFS T2 anom 0328-0406
The winds are probably
pushing in warmer water from the North Pacific as well. Here's how
sea surface temperature anomalies in the Bering area compare to those
of 25 March last year, when SSTs were already relatively high:
DMI SSTa 20180325
These images from the
VIIRS instrument aboard the joint NASA/NOAA Suomi National
Polar-orbiting Partnership (Suomi-NPP) satellite show how the ice has
already been retreating from the Alaskan coast during the past few
days (hat-tip to JayW over on the ASIF, who created the original
animation):
VIIRS
This is going to continue
for a couple of days, and we'll have to see what happens to the open
water that the ice is inevitably going to leave behind. I don't know
whether there will be enough cold to let it freeze over again, or
whether the ice gets shoved back towards the coast when the winds
turn (if they turn any time soon). Either way, this can't be good for
the ice, even though the winds cause ridging further into the pack.
At the same time, even further away, the ice gets pushed towards Fram
Strait, which may increase sea ice area/extent in the Atlantic
regions for a while, but isn't good for the ice pack in the
long-term. I'll look closer into this next week.
One thing we do know, and
that is that what we are witnessing in the Bering Sea, is
unprecedented in the satellite era. This will make the Pacific side
of the Arctic extremely vulnerable to further, rapid melt-out, if
weather conditions wish it so. We'll see.
A couple of the comments:
A couple of the comments:
Over on the ASIF commenter Romett1 posted this table showing Bering sea icea area numbers according to NSIDC:
Hi Neven
I have rarely seen the Bering area, in particular Alaska being so warm all winter, Bering Russian side area apparently has no stations for good data.
I can recall only 2 small periods of normal cooling. This was largely due to near static circulation associated with weak polar vortices, as reported in January,
http://eh2r.blogspot.ca/2018/01/very-weak-tropospheric-polar-vortex.html
I can recall only 2 small periods of normal cooling. This was largely due to near static circulation associated with weak polar vortices, as reported in January,
http://eh2r.blogspot.ca/2018/01/very-weak-tropospheric-polar-vortex.html
At least the equally warmer Novaya Zemlya region finally got cold about a week or 2 ago, but Alaska remained above normal all winter , and true enough, its ice footprint or lack of ice, describes this quite well.
