文章基本信息

标题：Comparison of two double-moment microphysics schemes in aspects of warm-rain droplet spectra and raindrop budget
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作者：Hengchi LEI ; Jiaxu GUO ; Di CHEN 等
期刊名称：Atmospheric and Oceanic Science Letters
印刷版ISSN：1674-2834
电子版ISSN：2376-6123
出版年度：2019
卷号：12
期号：6
页码：424-433
DOI：10.1080/16742834.2019.1664882
语种：English
出版社：Taylor and Francis Ltd
摘要：Simulation results of the WDM6 scheme and the Thompson scheme, both of which are commonly-used double-moment bulk microphysics schemes, are compared within the Weather Research and Forecasting model. The purpose of the comparison is to study the difference in the aspects of the warm-rain hydrometeor number concentrations, the droplet size distributions, and the budgets of the rain mixing ratio and number concentration. It is found that the WDM6 scheme overestimates the ratio and the amount of large precipitation, and underestimates those of small precipitation, compared to the Thompson scheme. The cloud number concentration (CNC) predicted in the WDM6 scheme is one to three orders of magnitude smaller than that of the Thompson scheme, which is set to the specific value of CNC. The cloud droplet spectra of the WDM6 scheme are broader. The WDM6 scheme produces a larger rain number concentration and smaller mass mean diameter of raindrops under the influence of both warm and cold rain processes— specifically, autoconversion and melting of snow and graupel. The WDM6 scheme produces a larger autoconversion rate and smaller total melting rate of snow and graupel than the Thompson scheme in the rain mixing ratio budget. The sign of the difference in the rain-cloud collection varies with region, and the rain-cloud collection process together with evaporation of rain have a major influence on the sign of the surface precipitation difference between the two schemes.
其他摘要：本文对WRF模式中两种常用的雨滴双参数微物理方案，即Thompson方案和WDM6方案在华北地区‘7.20’暴雨中暖云粒子谱和雨滴源汇项的模拟差异，以及上述差异如何影响降水模拟进行了详细的分析.结果表明：WDM6方案模拟的云滴数浓度比Thompson方案中给定的云滴数浓度概量小1-3个量级，云滴谱较宽.云雨自动转换过程和雪、霰融化过程的共同导致WDM6方案雨滴粒子数浓度较大，平均尺度较小.本文着眼于微物理方案间的暖云粒子谱模拟差异，是以往研究关注较少的领域，有助于更好地理解微物理方案的模拟特征.
关键词：WDM6 scheme;Thompson scheme;droplet number concentration;droplet size distribution;raindrop budget analysis
其他关键词：WDM6方案##Thompson方案##粒子数浓度##粒子谱分布##雨滴源汇项分析