Diagnostic Precipitation Data of Antarctica

In this gridded dataset, the precipitation for Antarctica from 1979-99
has been retrieved by a vertical motion calculation using ECMWF
operational analyses (ECT, 1985-1999; twice daily) and reanalysis
(ERA-15, 1979-1993; 4 times daily). The use of the dynamic retrieval
method to calculate precipitation has been developed and verified for
the Greenland ice sheet. Most major features in the spatial
distribution of Antarctic accumulation are well captured by the
dynamic retrieval results. In comparison with predicted precipitation
amounts from ERA-15 (1979-1993), ECT (1991-1999), and National Centers
for Environmental Prediction (NCEP) / Department of Energy,
Atmospheric Model Intercomparison Project Version 2 reanalysis
(1979-1999), dynamic retrieval calculations capture more mesoscale
features of the precipitation distribution over Antarctica. In
comparison to available glaciological measurements, the interannual
variability of the Antarctic precipitation is well represented by the
dynamic retrieval results at those measurement sites. A significant
upward trend of +1.2 to +1.7 mm yr-2 is found from retrieved and
forecast precipitation amounts for Antarctica that is consistent with
results reported by other investigators.

Twenty-two sigma levels are used in the vertical, and a 40-km grid
size is used in the horizontal. The square model domain used in this
study consists of 181 grid points in each orthogonal direction,
centered at the South Pole, with a horizontal polar stereographic
projection resolution of 40 km. The model topography data over the
Antarctic continent are also interpolated from a 5-km resolution
digital elevation model using bi-linear interpolation from the nearest
points. This dataset, as well as references to methodology and
validation, are currently available upon request from the Polar
Meteorology Group, Byrd Polar Research Center, Columbus, OH. Email
David Bromwich ([e-mail]).