Meteorological conditions in the Arctic Ocean in spring and summer 2007 as recorded on the drifting ice station Tara

[1] Meteorological observations were made at the drifting ice station Tara in the central Arctic Ocean from 23 March to 19 September 2007, constituting a unique data set from the season preceding the record-low sea ice extent. Comparisons of the Tara data with observations at the Russian drifting ice stations in 1937–1938 and 1950–1991 and at SHEBA in 1998 indicated that at Tara and SHEBA the atmospheric transmissivity for shortwave radiation was smaller than at the Russian stations, suggesting a higher cloud fraction or optical thickness. Compared to the mean conditions at the Russian stations, at Tara the melting season was twice as long and in April the 2-m air temperature was 7.0°C higher, but in July the 2-m temperature difference disappeared. The Tara tethersonde sounding data suggest that the air temperature at the altitudes of 200–1000 m was approximately 1°C higher than the mean of 1954–1985.