Reflections
on Arctic sea ice surprises...
Paul
Beckwith
Via
Facebook,
29
July, 2013
1)
The cyclone that just passed through the Arctic was much weaker than
the US navy sea ice motion projections and GFSx/ECMWF forecasted.
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrf_nowcast_anim30d.gif
2)
Although sea ice volume must still be dropping, the cyclone pushed
the ice apart.
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictn_nowcast_anim30d.gif
When highly ridged, thick ice is pushed apart, the sea ice area
(defined as the region with 100% concentration) can actually flatten
or even increase. This flattening can be observed in the Japan
satellite date:
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
3)
Sea ice extent (defined as regions with ice concentration >15%)
still decreased according to NSIDC
http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
but was shown to flatten and even INCREASE according to DMI.
http://ocean.dmi.dk/arctic/plots/icecover/icecover_current_new.png
(image shown below).
4)
The sea ice seems to be dictating the local weather above the Arctic
more than the atmosphere. The larger surface area of ice (from all
the fractured chunks) is undergoing rapid melt but the whole blob of
ice is perhaps suppressing large cyclones.
5)
The ice behavior this whole melt season is turning out to be very
different from what we have seen in the past. Namely, the massive
cracking and fracturing back in March, the persistent cyclones in May
and June gouging out greatly thinned ice regions around the north
pole, and now the resilience of the ice during the latest cyclone
(and perhaps suppression of a large cyclone like last year)
6)
Bottom line. Greatly fractured ice seems to be more durable to
cyclones than expected, or even changing the ocean/atmosphere/ice
system to suppress such cyclones. It appears that the ridged ice just
north of the Canadian Arctic archipelago (that people mislabel as
multi-year ice (MYI)) is spreading out in an effort to save the rest
of the pack. I appears that my prediction of zero sea ice at the end
of this season may be a spectacular fail!!! Still another 6 weeks of
melt left to go, so we continue to observe in awe:) Fascinating
stuff...
From
Sam Carana:
Also
have a look at the animation I added at the bottom of the post at
http://arctic-news.blogspot.com/2013/07/arctic-cyclone-july-2013.html
(shown below)
showing the cyclone's huge impact on sea ice concentration.
Also,
have a look at
http://arctic-news.blogspot.com.au/2013/07/open-water-at-north-pole.html
which concludes that, while satellite images may indicate that the
sea ice is still several meters thick in many locations, huge amounts
of surface water may be present on top.
The albedo of water is far
lower than ice, so less sunlight is reflected back into space and a
lot more heat is absorbed by the water, further accelerating the sea
ice melt.
This spells bad news for the remaining sea ice, since the
melting season still has quite a bit of time to go.
Tornado in Italy / climate change in action
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