Accumulation over the Greenland Ice Sheet as Represented in Reanalysis Data

Annual precipitation, evaporation, and calculated accumulation from reanalysis model outputs have been investigated for the Greenland Ice Sheet (GrIS), based on the common period of 1989--2001. The ERA-40 and ERA-interim reanalysis data showed better agreement with observations than do NCEP-1 and NCEP-2 reanalyses. Further, ERA-interim showed the closest spatial distribution of accumulation to the observation. Concerning temporal variations, ERA-interim showed the best correlation with precipitation observations at five synoptic stations, and the best correlation with in itu measurements of accumulation at nine ice core sites. The mean annual precipitation averaged over the whole GrIS from ERA-interim (363 mm yr^-1) and mean annual accumulation (319 mm yr^-1) are very close to the observations. The validation of accumulation calculated from reanalysis data against ice-core measurements suggests that further improvements to reanalysis models are needed.