Description: Oceanographic studies during IPY 2007/2009 provided new information on spatial variability of hydrographic parameters. Detailed pattern of irregularities in the Atlantic Water (AW) layer was documented in the Nansen Basin. Spatial scales of temperature distribution and the depth of the upper boundary of AW were estimated. In the Canadian Basin spatial variations of temperature were less pronounced. During IPY 2007/2008 the area occupied by AW has increased. According to our estimations the positive temperature anomaly in some regions was as high as 1,5°C, which is about 70% of temperature maximum in 1950-1959. The upper boundary of AW (zero degree isotherm) rose by 40-120 m around the Mendeleyev Ridge and in the Amundsen Basin. At the same time, in the Canada Basin and in the western Fram Strait the AW thickness decreased by similar value. Heat content of the AW layer around the major part of the Arctic Ocean exceeded mean climatic value, except for the compact area north of Franz Josef Land, where small negative anomaly was observed. Throughout 2008 mean temperature and maximum temperature in the AW layer were higher than mean climatic values. At the same time, the state of AW layer in the inflow region, east of Fram Strait along the continental margin to the Laptev Sea, substantially changed in comparison with 2007. Mean and maximum temperature of AW dropped by 0,25/0,5°C. Heat content and the Thickness of AW layer have also decreased. Basing on the obtained results, we conclude that during 2008/2009 there was a neneral reverse trend in AW parameters towards mean climatic results.