科研之友
微信
新浪微博
Facebook
分享链接
摘要
The near-surface atmospheric elements including air temperature, pressure, relative humility, wind, precipitation and radiation are called forcing data to drive hydrological, land surface, and ecological models. However, the spatial resolution of general circulation models (GCMs) is too coarse to represent regional climate variations at the regional, basin, and local scale. Weather research and forecasting model (WRF) is a next generation, fully compressible, Euler non-hydrostatic mesoscale forecast model with a run-time hydrostatic option. This model is useful for downscaling weather and climate at the scales from one kilometer to thousands of kilometers, and is useful for deriving meteorological parameters required for hydrological simulation too. The Heihe River Basin (HRB) is the second largest inland river in China. It is located in the middle part of the Hexi Corridor in the arid regions of northwest China and covers an area of approximately 140, 000 km2. The HRB extends from the Qilian Mountain glaciers, passing through alpine meadows and forest areas (precipitation recharge area), through an arid region, In this paper, the near-surface atmospheric forcing data over the Heihe River Basin is introduced, which was produced by using WRF model from 2000 to 2016 at hourly, at 0. 05 deg. resolution, including the following variables: 2m temperature, surface pressure, 2m specific humidity, downward shortwave radiation, downward longwave radiation, 10m wind field and precipitation. The forcing data was validated against daily data collected at 15 automatic weather stations of Chinese Meteorological Administration (CMA), and hourly data at a few sites of Heihe River eco-hydrological process comprehensive remote sensing observation (WATER and HiWATER). The following conclusions were drawn: 2m surface temperature, surface pressure and 2m specific humidity are more reliable, especially the average errors of 2m surface temperature and surface pressure are very small and the correlation coefficients with observations are above 0. 96; correlation between downward shortwave radiation and WATER site observation data is more than 0. 9 either, and the correlation of downward longwave radiation is 0. 6; the error of 10 m wind speed from observational data is large, the correlation is relatively weak. The correlation coefficient between simulated and observed rainfall data at monthly and yearly time scales were up to 0. 94 and 0. 84, and the correlation coefficient reached 0. 53 at daily scale; the correlation between simulated and observed snowfall data at monthly scale reached 0. 78, the spatial distribution of snowfall agrees well with the snow fractional coverage rate of MODIS remote sensing product. So WRF model can be used for downscaling analysis in complex and arid terrain of Heihe River Basin, and the simulated data can meet the requirements of watershed scale hydrological modeling and water resources balance.
- 单位
