A new data set of daily atmospheric moisture budget quanities for the entire Arctic region has been created by coupling satellite-derived water vapor and temperature profiles with NCEP Reanalysis wind fields. The data set extends from 1985-1994, has a 100 km horizontal resolution, and spans the area north of 60 deg. north. Previous studies using in situ data (rawinsondes) have characterized the climatological yearly cycle of moisture transport and to an extent, moisture deposition. However, the high spatial and temporal resolution of this data set provides opportunities to examine the unknown temporal variability of moisture transport and deposition in the Arctic. These processes have implications for the mass balance of the Arctic sea ice as well as the radiation budget of the Arctic.
These new data reveal that annual net precipitation in the different Arctic sub-basins can vary significantly from year to year. We examine the relationship between this variability and known modes of variability in the Arctic. As reported by Thompson and Wallace (1998), temporal variation of sea-level pressure (SLP) over high-latitudes, as characterized by the leading empirical orthogonal function of wintertime SLP, have influenced the advection of heat over the Asian content. I examine the relationship between the time variation of this pattern (termed the "Arctic Oscillation") and satellite-derived moisture budget quantities. This approach of analyzing trends of spatial patterns as opposed to trends of retrieved atmospheric moisture quantites is particularly suited for satellite data since trends of retrieval quantities may suffer from uncertainties in inter-satellite calibration, sensor degredation, and satellite orbit variation.
The satellite data used in the study are contained in the NASA/NOAA TIROS Operational Vertical Sounder (TOVS) Polar Pathfinder data set. When completed in late 1998, this data set will extend from 1978 through 1996, allowing this study to be expanded to 18 years. Please see my other presentation, which discuss the methodology for calcuating the moisture balance fields and describes the new climatological fields and their dominant features.