Winter is finally here, Kotolny Island is really cold!
No it isn't. The quite moderate 10 day forecast is attached below. The icons indicate extent of cloud cover which affect radiative balance. The weather station reports 2m temperatures but those are relative to its elevation of 8m above sea level.
http://www.aps-polar.org/mv_html/j00001/2015-02/20150206_APS.htm congelation land-fast ice
While ECMWF and GFS assimilate this station in their regional forecasts (and CR in turn), it's not at all clear which hPa over the Laptev (925? boundary layer?) is most relevant to the cold experienced by open water (near-surface air is somewhat clamped to surface water temperature).
GFS is currently reporting air temperatures of -4.5, -4.7, -15.9 at the surface, 1000 hPa, 850 hPa respectively at UTC noon today. These bear no immediate relationship to highs or lows at Kotolny (-12. -7).
Can buoys in Laptev validate or improve on SST measurement
That 204672 buoy is in a good location but it does not currently appear in IADP's table!
https://iabp.apl.uw.edu/TABLES/ArcticTable.phpHowever 204761 and 204762 do: these are global drifters of type SVP-B, placed by AARI-USIABP (Russian Arctic and Antarctic Research Institute joint US Interagency Arctic Buoy Program). The former is at 75.23 114.88 on 10/25/2020 measuring water temperature at the bottom of the buoy at 0.96ºC. The latter is at 76.78 118.34 showing 1.68ºC.
It seems like 204763 and 204764 are also worthy of consideration. These are at 76.70 111.48 showing -1.68ºC and 79.90 121.38 seeing -0.80ºC. Uniq has picked these up in #538 below.
"These SVP (surface velocity drifters) were standardized in 1991 with small spherical hull, floats and large Holey-Sock drogues 15m below the surface. In 1993, drifters with barometer ports, called SVPB drifters measure sea surface currents, sea surface temperature baryometric pressure and lat/lon."
The hourly data is in .dat format which opens as tab-ready row & column in any text editor. It uses day number instead of dates: 299 is today Oct 25th. The most recent 557 readings from 204761 average 1.36ºC with a range of 0.58 to 4.08 ºC and stdev of 0.97, that is, the buoy has not seen any temperatures below zero and has mostly been around 1.4±1.0 ºC during its drift.
Do direct buoy measurements provide an independent check on the daily SST product from GHRSST?
More likely, the buoy data is assimilated into the product but that's unconfirmed.
Can radiative heat loss be determined from Worldview?
No. Clear weather allows that dramatic definition of heat loss leads via band 15 of Suomi VIIRS along the upper CAA. Note this is calculated from top-of-atmosphere in kelvin and is
not suitable for determining overall blackbody heat loss:
"It does not provide an accurate temperature of either clouds nor the land surface, but it does show relative temperature differences which can be used to distinguish features both in clouds and in sea ice and open water over the polar regions during winter (in cloudless areas).... The sensor resolution is 375m, the imagery resolution is 250m, and the temporal resolution is daily."
How unusual is the current pattern of open water?
The image below calculates the frequency of open water at each position on Nov 1st for the seven years 2013-19 (this date in 2012 is not available from AMSR2_UHH). This gives the lightest gray for open water in all seven years, a slightly darker gray for open water in six of seven years and so on. The progression is fairly orderly Chukchi; the Laptev has mostly been frozen over. The pink shows areas that have never before been open on Nov 1st.
The base image is Smos-Smap ice thinness for Oct 23rd. It has an interesting green fringe of presumably nascent ice in the 2-3 cm thinness range. The interior ice thicker than 0.5m has been replaced with OsiSaf ice motion for the same date; the exterior open water has been removed to reveal the historical open water probabilities.