Abstract
JOURNAL OF GEOPHYSICAL RESEARCH,
VOL. 106, NO. D24,
PP. 33,891-33,908, 2001
doi:10.1029/2001JD900251
Modeled precipitation variability over the Greenland ice sheet
Polar Meteorology Group, Byrd Polar Research Center Ohio State University, Columbus, Ohio, USA
Polar Meteorology Group, Byrd Polar Research Center Ohio State University, Columbus, Ohio, USA
Polar Meteorology Group, Byrd Polar Research Center Ohio State University, Columbus, Ohio, USA
Polar Meteorology Group, Byrd Polar Research Center Ohio State University, Columbus, Ohio, USA
Polar Meteorology Group, Byrd Polar Research Center Ohio State University, Columbus, Ohio, USA
On the basis of the evaluation of recent Greenland precipitation studies, some of the deficiencies in the modeled precipitation
are probably related to the topographic data employed in modeling. In this paper the modern digital elevation data of Ekholm [1996] is used. If the horizontal pressure gradient force in σ coordinates is separated into its irrotational and rotational
parts, which are expressed by the equivalent geopotential and geo-stream-function, respectively, the topographic effect on
the precipitation can be accurately modeled. The equivalent geopotential and geo-stream-function are implemented in a fully
consistent manner in the generalized CD-equation in this paper. A simplified large-scale condensation without evaporation
of condensate is also used. These improvements are combined to yield an improved dynamic method. Two aspects of the precipitation
distribution are refined by the improved dynamic method. One is the 10 cm yr−1 contour near Summit, Greenland, and the other is a relative large precipitation area centered near the point (70°N, 49°W).
Extensive comparisons are made between the retrieved precipitation and the observed annual accumulation time series from 11
ice core sites on the ice sheet. The modeled precipitation from the original method must use sealers to have a high degree
of interannual correspondence between the measured accumulation and the retrieved precipitation, but the retrieved precipitation
from the improved method increases at all ice core sites and a good correspondence is obtained without any sealer being required.
The spatial average of multiyear mean error (
Received 28 August 2000; accepted 26 June 2001; .
Citation: (2001), Modeled precipitation variability over the Greenland ice sheet, J. Geophys. Res., 106, 33,891–33,908, doi:10.1029/2001JD900251.
Cited By
