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Piotr Djaków
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So, Kara Sea again... http://meteomodel.pl/klimat/gfsanom_np.png http://www.yr.no/sted/Russland/Krasnojarsk/Ostrov_Vize/langtidsvarsel.html http://pogoda.ru.net/monitor.php?id=20069
Problem solved: "Unfortunately, you cannot take the daily numbers from ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/NH_seaice_extent_nrt.csv and divide by 31 to get the monthly average extent. . It is confusing, but I will try to explain. First let me set up a data scenario for you in 4 hypothetical 25km grid cells for 3 days. Listed below is the concentration of sea ice in each grid cell. For extent calculations, if a data cell has less than 15% sea ice, it is considered "no-ice" and is not included*: If it has more than 15% it is considered "ice" CELL A B C D Day 1 10% 25% 40% 50% total extent would be 25sq km x 3 = 75sq km Day 2 5% 17% 20% 60% total extent would be 25sq km x 3 = 75sq km Day 3 35% 20% 30% 50% total extent would be 25sq km x 4 = 100sq km. This is what you are seeing in the near-real time data file for daily values. If we took the average of those numbers the average extent would be 83sq km. For the monthly average extent we are actually looking at the average for each cell over the period, then adding that up to reach the total average extent (TAE). If the average for a cell for the month passes the 15% threshold, it will be included (our "month" in this example is 3 days.) CELL A B C D Day 1 10% 25% 40% 50% total extent would be 25sq km x 3 = 75sq km Day 2 5% 17% 20% 60% total extent would be 25sq km x 3 = 75sq km Day 3 35% 20% 30% 50% total extent would be 25sq km x 4 = 100sq km. TAE 17% 21% 30% 57% total average extent would be 25sq km X 4 = 100sq km You can see CELL A with two days of low concentration, gets a bump into the averaging with it's last day of much higher concentration (10% + 5% + 35% /3 = 17%) Therefore what you are seeing is just like the difference between 100sq km and 83 sq km. This same principle would apply for the 1979-2000 values. Please note that we also do archive the values for area (being the grid cell size x % covered summed.) There are reasons why extent is reported in our blog. If you want me to explain that, just let me know. You may have already had your fill of information!"
Value 7.00 mln km^2 is obviously wrong. Look on the daily numbers and plots. From daily NSIDC data - 5.8 mln km^2.
@Jim Hunt " My interest in Polish meteorology is much more recent than yours, but I know snow is nothing unusual! I also know a week or so ago temperatures in Łódź were over 20. Is such a sudden decline common in October, particularly when accompanied by power cuts?" Very similar rapid temperature changes occured in october 1997. 2009: max. temperature in Lublin drop from 23 deg C at october 8th to 1 deg C at october 15th. http://news.bbc.co.uk/2/hi/europe/8307661.stm 1973 - In Lublin at october 13th temperature drop to +1 deg C from 22 deg C. at october 7th. In Siedlce temperature drop from 23 deg C to 0 deg C (7 - 13.10.1973).
Commented Oct 31, 2012 on Looking for winter weirdness 2 at Arctic Sea Ice
Snow in Poland in late october? Nothing unusual. 3 years ago it was 14th october. Conditions this year are very similar to those from 1997.
Commented Oct 29, 2012 on Looking for winter weirdness 2 at Arctic Sea Ice
NSIDC SIE drop to 4.45*10^6 km^2. http://meteomodel.pl/index.php/arcticice Third image on this page show what happens if SIE will follow 1979-2011 values.
There was some serious server problems. Now it seems to be ok.
Entire 2011 was very warm in the Kara Sea http://gfspl.rootnode.net/klimat/arctic/2011year.png Monthly anomalies > +15 deg. C. in February. http://gfspl.rootnode.net/klimat/arctic/201112.png http://gfspl.rootnode.net/klimat/arctic/201201.png http://gfspl.rootnode.net/klimat/arctic/201202.png Arctic temperature anomalies fro ERA INTERIM reanalisys: http://gfspl.rootnode.net/klimat/arctic/
Impressive: http://gfspl.rootnode.net/klimat/JAXA.png
Meanwhile there was very warm in Kara Sea during 2011. gfspl.rootnode.net/klimat/arctic/2011year.png Winter 2011/12 anomalies: http://gfspl.rootnode.net/klimat/arctic/201112.png http://gfspl.rootnode.net/klimat/arctic/201201.png http://gfspl.rootnode.net/klimat/arctic/201202.png
@Neven Unfortunetaly you showed not updated graph ;)
Commented Sep 8, 2011 on New area record at Arctic Sea Ice
Oh my... http://gfspl.rootnode.net/webcache/dmierror.png
http://gfspl.rootnode.net/klimat/globalice2.png http://gfspl.rootnode.net/klimat/globalice.png
Arctic temperatures from ERA-Interim dataset: http://gfspl.rootnode.net/klimat/arctic/index.php
Now it's up :) 07,14,2011,7525000 07,15,2011,7440781 07,16,2011,7346563
@neven ECMWF forecast map concentrated on Arctic only (MSLP+T850): http://gfspl.rootnode.net/ecmwfarct/T850/00 http://gfspl.rootnode.net/ecmwfarct/CIS/00
Does anyone know if the GRIB or NetCDF files from HYCOM/CICE available?
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Jul 15, 2011