Lin, Chin-Fang, Fang-Yi Cheng, Chih-Hsiang Wu,
Jeng-Lin Tsai, National Central University, Taiwan.
The accurate
determination of the surface momentum, heat and moisture fluxes is strongly
dependent on the accuracy of the land surface parameters. In this study, the
mesoscale meteorological simulation using WRF is performed for the area in
Taiwan by using the updated land use (LU) type, terrain height and roughness
length (Z0). The updated LU data were reclassified using the 2007 MODIS
satellite image. The new LU data correctly represents Taiwan as mixtures of
cropland, urban, and forestlands as well as the other land types. The elevation
data is provided from NASA Shuttle Radar Topographic Mission (SRTM) satellite
image. The Z0 is recalculated using the arithmetic mean of the fraction of each
LU type and the corresponded Z0. Several WRF sensitivities are performed using
the updated land surface parameters. The simulation using the updated LU data
shows higher temperature and lower wind speed than the run using the default
setup due to the increasement of the urban and forest areas. The simulation
using the SRTM data improves the temperature biases particularly in the
mountain area. The newer roughness length data was about an order higher than
the default setup and the simulation result shows the enhancement of the
temperature diurnal variation and improves the wind speed.