Precipitation in Antarctica:

1
Precipitation in Antarctica results from a
regional atmospheric model
Nicole van Lipzig
2
Surface mass balance precipitation -
sublimation snowdrift - melt
Methods used at BAS to estimate the surface mass
balance In-situ stakes, snow pits, ice
cores Radiosondes Satellites Atmospheric models
3
In-situ stakes, snow pits, ice cores
_at_ Rob Mulvany
4
In-situ stakes, snow pits, ice cores
Bryan coast
Elevation
Accumulation
_at_ Tom Lachlan-Cope
5
Satellites (a similar method is presently tested
for the Antarctic region)
D.P. Winebrenne, R.J. Arthern, C.A. Shuman
_at_ Rob Arthern
6
Compilation of Observations
ECMWF Re-Analyses (15) (Turner et al., 2002)
Antarctic Peninsula
_at_ John Turner
7

• RACMO
• grid spacing 55 km
• relaxation at lateral boundaries from ECMWF
  Re-Analyses (ERA-15)
• Sea surface temperature and sea ice extent
  prescribed from observations

8
14-year mean RACMO precipitation in the Peninsula
area
9
Compilation of Observations RACMO
output
14 year mean
10
Surface mass balance
Compilation of measurements Vaughan et al.
14-year mean RACMO output
11
Surface mass balance
Compilation of measurements Vaughan et al.
14-year mean RACMO output
RACMO-measurements
12
Compilation of Observations
14-year mean RACMO output Schwerdtfeger (1984)
Ross Ice Shelf
13
Surface mass balance at Neumayer during 1987
14
Parameterisation of snowdrift at Neumayer during
1987
10
mm w.e. per day
0
OBS RACMO Snowdrift convergence
10
(Takahashi, 1985, 1988)
15
Monthly mean surface pressure
16
14-year mean seasonality of the 2m temperature
Obs
RACMO
ERA-15
17
Conclusions - recommendations A regional model,
realistically forced from the lateral boundaries,
is a suitable tool to study precipitation in
Antarctica Measurements AND parameterisations in
models on the seperate components of the surface
mass balance have to be improved