GREENLAND PRECIPITATION ESTIMATES FROM THE ATMOSPHERIC MOISTURE BUDGET

Eight radiosonde stations surrounding Greenland at an average separation of 750 km are used to compute the atmospheric moisture budget. Radiosonde data were available from 1963-89, but were not used for 1963-79 due to insufficient data coverage which likely resulted in a major underestimation of large moisture inflow events. There is a mean annual inflow of moisture to the atmospheric volume over Greenland through its southeast and southwest sectors, and outflow to the northeast. Moisture convergences, equivalent to precipitation minus evaporation, yield an areal average of 32 cm yr-1 of water equivalent; they also show high inter- and intra-annual agreement with earlier modeled precipitation estimates found by the authors and serve as further confirmation of their modeling results. The time-averaged eddy component accounts for 90% of the total moisture convergence, reflecting the dominant contribution of precipitation from synoptic-scale cyclones.