Sensitivity of simulated summer monsoonal precipitation in Langtang Valley, Himalaya, to cloud microphysics schemes in WRF
Sensitivity of simulated summer monsoonal precipitation in Langtang Valley, Himalaya, to cloud microphysics schemes in WRF
复制标题
DOI：
10.1002/2016jd025801
复制
发表时间：
2017-06
期刊：
影响因子：
--
通讯作者：
A. Orr;C. Listowski;M. Couttet;E. Collier;W. Immerzeel;P. Deb;D. Bannister
中科院分区：
文献类型：
--
作者：
A. Orr;C. Listowski;M. Couttet;E. Collier;W. Immerzeel;P. Deb;D. Bannister
需要更好地了解喜马拉雅地区的区域尺度降水模式，以增加我们对气候变化对下游水资源可用性影响的了解。本研究检验了四种云微物理方案（Thompson、莫里森、天气研究与预报（WRF）单矩5级和WRF双矩6级）对尼泊尔喜马拉雅山脉中部朗唐河谷夏季风降水的影响，并在2012年7月采用WRF模式以1 km网格间距模拟了10天。通过与两个观测点的地面降水和辐射测量结果进行比较，对模型结果进行了评价。额外的理解是从每个方案，这是比较使用星载雷达/激光雷达云产品的测量模拟的微物理特性的详细检查。还研究了大尺度和小尺度强迫的作用。总体而言，该方案能够捕捉到的地表降水的时间比在浪塘流域，这主要是低估了，与莫里森方案显示出最好的协议与实测值的实际量。所有的计划都显示出一个大的正偏置入射辐射。对每个方案的雷达/激光雷达云产品和水凝物的分析表明，“冷雨”过程是一个关键的降水形成机制，这也很好地代表了莫里森方案。除了微物理结构外，大尺度和局部强迫对确定地面降水也很重要。
A better understanding of regional‐scale precipitation patterns in the Himalayan region is required to increase our knowledge of the impacts of climate change on downstream water availability. This study examines the impact of four cloud microphysical schemes (Thompson, Morrison, Weather Research and Forecasting (WRF) single‐moment 5‐class, and WRF double‐moment 6‐class) on summer monsoon precipitation in the Langtang Valley in the central Nepalese Himalayas, as simulated by the WRF model at 1 km grid spacing for a 10 day period in July 2012. The model results are evaluated through a comparison with surface precipitation and radiation measurements made at two observation sites. Additional understanding is gained from a detailed examination of the microphysical characteristics simulated by each scheme, which are compared with measurements using a spaceborne radar/lidar cloud product. Also examined are the roles of large‐ and small‐scale forcings. In general, the schemes are able to capture the timing of surface precipitation better than the actual amounts in the Langtang Valley, which are predominately underestimated, with the Morrison scheme showing the best agreement with the measured values. The schemes all show a large positive bias in incoming radiation. Analysis of the radar/lidar cloud product and hydrometeors from each of the schemes suggests that “cold‐rain” processes are a key precipitation formation mechanism, which is also well represented by the Morrison scheme. As well as microphysical structure, both large‐scale and localized forcings are also important for determining surface precipitation.