Performance of the fifth-generation Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model（MM5） over the Lake Nam Co region of the Tibetan Plateau was evaluated based on the data from...Performance of the fifth-generation Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model（MM5） over the Lake Nam Co region of the Tibetan Plateau was evaluated based on the data from five surface observation sites in 2006. The interaction between two thermally-induced circulations（lake breezes and mountain-valley winds） was also investigated. The results show that MM5 could be used to simulate 2-m air temperature; however, MM5 needs improvement in wind field simulation.Two numerical simulations were conducted to study the effect of the lake on the local weather and wind system. The original land cover of the model was used in the control experiment, and the lake was replaced with grassland resembling the area surrounding the lake in the sensitive experiment. The results of the simulations indicate that the lake enhanced the north slope mountain-valley wind and the mountain changed the offshore flow direction at the north shore. During the day, a clear convergent zone and a strong upflow were observed over the north slope of the Nyainq？entanglha Range, which may cause frequent precipitation over the north slope. During the night, the entire area was controlled by a south flow.展开更多
基金Supported by the National(Key)Basic Research and Development(973)Program of China(2010CB951700)National Natural Science Foundation of China(41175027,91337212,and 41375022)Key Research Program of the Chinese Academy of Sciences(KZCX2-YW-Q1-02)
文摘Performance of the fifth-generation Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model（MM5） over the Lake Nam Co region of the Tibetan Plateau was evaluated based on the data from five surface observation sites in 2006. The interaction between two thermally-induced circulations（lake breezes and mountain-valley winds） was also investigated. The results show that MM5 could be used to simulate 2-m air temperature; however, MM5 needs improvement in wind field simulation.Two numerical simulations were conducted to study the effect of the lake on the local weather and wind system. The original land cover of the model was used in the control experiment, and the lake was replaced with grassland resembling the area surrounding the lake in the sensitive experiment. The results of the simulations indicate that the lake enhanced the north slope mountain-valley wind and the mountain changed the offshore flow direction at the north shore. During the day, a clear convergent zone and a strong upflow were observed over the north slope of the Nyainq？entanglha Range, which may cause frequent precipitation over the north slope. During the night, the entire area was controlled by a south flow.
