Journal of Arid Meteorology

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Comparison of Atmospheric Boundary Layer Simulation by
 Multiple Models over Grassland in Central USA

HUANG Wenyan, WU Jianqiu, WU Jinglu, CHEN Boli, LEI Zhengcui   

  1. Changzhou Meteorological Bureau of Jiangsu Province, Changzhou 213022, China
  • Online:2016-08-31 Published:2016-08-31

多模式对美国中部草原大气边界层模拟的对比分析

黄文彦吴建秋吴晶璐陈渤黎雷正翠   

  1. 江苏省常州市气象局,江苏常州213022
  • 作者简介:黄文彦(1989- ),男,硕士,助理工程师,主要从事气溶胶气候效应和边界层气象等研究. E-mail:h_wenyan@yahoo.com
  • 基金资助:

    常州市科技局科技支撑计划社会发展类项目(CE20145047、CE20135047)和江苏省气象科研开放基金项目(201206)共同资助

Abstract:

Based on the results simulated by four atmospheric models (UM, GEM, LMD and WRF) in DICE and sounding data, the effects of simulation on convective boundary layer in the daytime and stable boundary layer at night over grassland in central USA from 23 to 26 October 1999 were comparatively analyzed. The results showed that the vertical distributions of meteorological elements in the convective boundary layer over grassland in central USA in the daytime from 23 to 26 October 1999 simulated by four atmospheric models were significantly different, which were related with their parameterization schemes. The turbulent mixing was stronger due to entrainment action between the boundary layer and free atmosphere, which resulted in the higher height of mixture layer simulated by UM and LMD models than the observed. However the simulated turbulent mixing by GEM model was weaker, the atmospheric stratification in boundary layer was unstable, and the simulated wind speed generally increased with height, which differed greatly from observation. The simulated effects by WRF were the best in all models, the WRF model could successfully simulate the area of low wind speed and dry layer of water vapour between boundary layer and free atmosphere on 24 October 1999. For the stable boundary layer during the nighttime, there were small simulated differences in all models. The simulated low-level jets by UM and GEM models during the nighttime were weak, while those simulated by WRF and LMD models were close to observation on 24 and 25 October 1999.

Key words: multiple models comparison, atmospheric boundary layer, turbulent mixing, entrainment action, low-level jet at night

摘要:

利用DICE试验的4个大气模式(UM、GEM、LMD和WRF)模拟结果,结合探空资料,对比分析了不同模式对1999年10月23—26日美国中部草原白天对流边界层和夜间稳定边界层的模拟效果。结果表明:对于白天对流边界层,不同模式之间存在明显差异,这与各自的边界层参数化方案密切相关。其中,UM和LMD模式中,边界层和自由大气之间强的卷夹作用导致了偏强的湍流混合,进而使模拟的混合层高度高于观测值;GEM模式模拟的白天湍流混合偏弱,边界层为不稳定的大气层结,且模拟的风速在边界层中随高度基本呈递增趋势,但与观测值差异较大;所有模式中WRF模式模拟效果最佳,成功模拟出24日边界层与自由大气之间的水汽干层和低风速区。对于夜间稳定边界层,不同模式之间差异较小。其中,UM和GEM模式模拟的24、25日夜间低空急流偏弱,而LMD和WRF模式模拟的夜间低空急流更接近实况。

关键词: 边界层, 湍流混合, 卷夹作用, 夜间低空急流, 多模式对比

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