摘要
利用中尺度数值预报模式(WRF)对兰州市区和兰州大学半干旱气候与环境观测站(SACOL)山谷地区典型日山谷风环流特征进行模拟研究,比较分析了不同构造的山谷对山谷风环流日变化特征的影响。结果表明,封闭型和开放型山谷谷风环流起止时间分别为13:00/18:00和16:00/18:00,封闭型谷风起始时间比开放型早3 h且持续时间长3 h,表明封闭型山谷的典型地形条件会加强由热力因素强迫产生的热力环流并能长时间维持此环流;16:00封闭型和开放型山谷中边界层高度分别为500 m和900 m,山坡上边界层高度分别为3 500 m和3 300 m,表明吹向山坡的谷风使山坡上对流边界层高度升高,而山谷上空的下沉气流使山谷中边界层高度降低。从边界层发展高度可知封闭型山谷形成的谷风环流比开放型山谷的环流发展厚度大且特征显著。
The characteristics of local circulation in the urban area of Lanzhou and the Semi - Arid Climate and Environment Observatory of Lanzhou University （SACOL） was simulated by using weather research and forecasting （WRF） model, and the effects of different valley types on diurnal variations of local circulation on May 1, 2010 were analyzed. Simulation results show that the starting/ending time of the typical closing valley and open valley wind is 13：00/18：00 and 16：00/18：00, respectively, the starting time of the closing valley wind is 3 hours earlier than that of the open valley, which demonstrated that the typical terrain of the closing valley could strengthen the thermodynamic circulation and maintain it. At 16：00, boundary layer height over the bottom of the closing valley and open valley is 500 m and 900 m, and that over the slope is 3 500 m and 3 300 m, respectively. The data show that valley wind increases the convective boundary layer height over the slope and the subsidence flow over valley sinks the boundary layer height over the bot- tom of the valley. The feature of the starting/ending time and the development of boundary layer height indicate that the depth of closing valley wind is deeper than the open valley wind and the closing valley wind is more significant.
出处
《干旱气象》
2012年第2期169-177,共9页
Journal of Arid Meteorology
基金
国家重点基础研究发展规划项目(2010CB428604)
国家自然科学基金资助项目(41075104)共同资助
关键词
典型日环流
封闭型与开放型山谷
WRF模拟
对比分析
半干旱区兰州附近
mountain - valley wind of typical date
closing and open valley
WRF simulation
comparative analysis
semi - arid areasnearby Lanzhou
