Monthly Mean Greenland Climate Data, 1988-2004
The Pennsylvania State University-National Center for Atmospheric Research (NCAR) Fifth-Generation Mesoscale Model (MM5) has been modified for use in polar regions
(Bromwich et al. 2001, Cassano et al. 2001) and is known as Polar MM5. The major polar-specific modifications are as follows: explicit ice phase cloud microphysics, polar physical parameterizations for cloud-radiation interactions, optimal stable boundary layer turbulence parameterization selected, improved treatment of heat transfer through snow and ice surfaces, and implementation of a sea ice surface type. The model domains configured for this study of the climate and surface mass balance of the Greenland ice sheet (Box et al. 2006) are shown in the figure. Each domain has 28 vertical sigma levels. The lowest two model levels correspond to roughly 14 m and 0 m. The model is run in non-hydrostatic mode with a sixth-order finite-difference scheme after Chu and Fan (1997) implemented to improve estimation of vertical motion that determines precipitation formation, particularly along steep slopes.
The Polar MM5 was initialized at the surface and updated every 12 hours at the lateral boundaries with the 2.5 degree horizontal resolution ECMWF operational (TOGA) analyses. It was run at 24-km horizontal resolution in a series of 30-hour forecasts. The first 6 hours were discarded for model equilibration, and the remaining 24 hours were concatenated into a 6-hourly output time series spanning 1988-2004. Output data are available for 0600, 1200, 1800, and 2400 UTC (or 0400, 1000, 1600, and 2200 west Greenland standard time). The 6-hourly data are averaged to produce monthly means for 2-m temperature (°C), 2-m specific humidity (g/kg), zonal wind at 10 m (m/s) , meridional wind at 10 m (m/s), wind speed at 10 m (m/s), and precipitation (monthly total in mm).
This work was supported by NASA grant NNG04GH70G and NSF grants 0112486 and 0321053.
Box, J.E., D.H. Bromwich, B.A. Veenhuis, L-S Bai, J.C. Stroeve, J.C. Rogers, K. Steffen, T. Haran, S-H Wang, 2006: Greenland
ice sheet surface mass balance variability (1988-2004) from calibrated Polar MM5 output, J. Climate, accepted, Sept 27 2005. Full Text (PDF)
Bromwich, D.H., J.J. Cassano, T. Klein, G. Heinemann, K.M. Hines, K. Steffen, and J.E. Box, 2001: Mesoscale modeling of katabatic winds over Greenland with the Polar MM5. Mon. Wea. Rev., 129, 2290-2309.
Cassano, J.J., J.E. Box, D.H. Bromwich, L. Li, and K. Steffen, 2001: Evaluation of Polar MM5 simulations of Greenland's atmospheric circulation. J. Geophys. Res., 106, 33,867-33,890.
Chu, P. C., and C. Fan, 1997: Sixth-order difference scheme for sigma coordinate ocean models. J. Phys. Ocean., 27, 2064- 2071.
David Bromwich, P.I. (email@example.com)
SOFTWARE (FORTRAN 77)