Siberian Heat Wave that began last week continues apace today. Far
warmer than normal southerly winds continue to blow over a large
region of Siberia bringing with them near freezing and occasionally
above freezing temperatures. The combined influence of this off-shore
flow and, what is for the Arctic, late spring and early summer-like
weather is having a profound effect on Arctic sea ice in the regions
of the Kara, Laptev, and East Siberian Seas.
week, we reported that an early break-up of sea ice was ongoing in
the Kara Sea. Now, with the warm, off-shore flow shifting west, this
break-up zone has expanded well into the Laptev and East Siberian.
Satellite observations indicate that a very large section of ice
pack, stretching from Severnaya Zemlya past the New Siberian Islands
and on into the East Siberian Sea has been shoved northward by the
strong south-north wind flow. The result is large gaps, ranging from
50-100 miles in width, forming along the boundary of the land fast
ice and spreading through a zone of high impact for about 2,000
kilometers through the Kara and Laptev Seas before extending along a
less involved fault zone another 1,000 kilometers into the East
from west to east around the Arctic Basin, below is a summary of the
ongoing break-up. Please note that some sections of these images are
obscured by cloud cover:
sea before large scale breakup on March 9 in the top frame and after
large-scale break up on March 24 in the lower frame. Image
we have a continuation of the Kara Sea ice breakup we reported last
week. Note that the break-up now extends all the way through sections
of the land-fast ice to shore. Motion of the floe is still mostly
south to north with sections of open water here ranging from 5-30
kilometers in width.
east, we find that the eastward drift of the off-shore wind pattern
and associated warm air temperatures that are closer to May and June
norms have had a dramatic impact on Laptev sea ice as well:
sea ice on March 9 with some large polynas prior to large scale
break-up and extending of polynas on March 24. Image
we find the section of large openings and polynas spreading east from
Severnaya Zemlya through the Laptev and on past the New Siberian
Islands. Ice crack sizes are quite large with gaps stretching between
30-50 kilometers in width. Sea ice toward the central pack shows much
more extensive cracks (leads) and breakage.
further east, the warm southerly winds have also widened and extended
large cracks running through the East Siberian Sea, the region of
water covering the shallow and sensitive East Siberian Arctic Shelf
Siberian Sea ice on March 9 in the top frame and March 24 in the
bottom frame. Image source: Lance-Modis.)
crack structure appears to have shifted north, extended and widened
even as the ice system became more crack-riddled.
Heat Wave Continues
in the region continue to range between 5 and 20 or more degrees
Celsius (9 to 36 F) above average for this time of year. This
abnormal ‘heat’ translates into average temperatures ranging from
-14 to 0 C (8 to 32 Fahrenheit). It is worth noting that salt water
freezes at around -2 C (28 F, depending on salinity). So average
temperatures in this range are enough to retard refreeze after
breakage, to keep sea ice more disassociated and brittle, and to
result in some areas where sporadic melt occurs.
spring continues, warmer water beneath the ice pack, waters warmed by
solar insolation, ice warmed by solar insolation, and warm water
outflows from the Continents may well become involved to enhance
early season sea ice break up and melt.
the Arctic is now experiencing an extraordinarily high temperature
anomaly of +4.21 above the 1979-2000 average or about 5.7 C above the
1880s average. These excessive above average temperatures are high
enough to initiate early melt, fragility and break-up in some zones
(as observed above).
particular heat wave is in association with a very large Asian system
in which much warmer than average temperatures extend south to north
from Northern China, Mongolia, through the Yakutia region of Russia
and on up into the Kara, Laptev, East Siberian, and Beaufort Seas of
the Arctic Ocean. It is also worth noting the rather impressive hot
pool forming over the Balkan States of Eastern Europe and the Ukraine
which is, perhaps, a pattern settling in with the potentially
oncoming El Nino.
model runs show the current Arctic pulse spiking to around +5 C above
1979 to 2000 averages over the next 48 hours and then slowly fading
through March 31 as anomalies return to a range of about +2-3 C above
average. Hot zones continue to linger over China, Mongolia, Siberia
and Eastern Europe as a somewhat troubling heat pulse develops over a
large swath of western Greenland before riding up over Svalbard
potentially bringing 30-40 degree (F) temperatures to both Western
Greenland and this Arctic island by late in the forecast period.