摘要
随着数值天气预报模式的水平分辨率不断提高,在对流参数化方案的“灰色区域”(1~10 km)内,积云不足以被模式网格尺度显示分辨,以至传统的积云对流参数化方案难以较好地适用不同分辨率下对降水的模拟,因此发展尺度适应(Scale-Aware)积云参数化方案是数值模式精细化发展趋势之一。通过在中国气象局中尺度天气数值预报系统(China Meteorological Administration Mesoscale model, CMA-MESO)模式中引入尺度适应的KFeta(Kain-Fritsch eta)积云对流参数化方案,组合3种分辨率(1 km、3 km、10 km)对中国西南山地地区2023年7月11—12日的一次降水过程进行数值模拟试验,并就2023年6月17—23日的降水过程开展为期7 d的批量试验。结果表明:(1)在个例试验中,尺度适应方案对于降水雨带和降水强度模拟较好,强降水中心的模拟有一定优势,随分辨率提高尺度适应组的降水强度和落区更接近实况,极大程度减少了由积云引起的虚假性降水,提高了网格降水量。(2)应用尺度适应方案后的模拟结果显示强对流区域的组合反射率因子、垂直速度模拟结果更优。(3)批量试验中,在西南山地地区尺度适应方案的降水模拟结果较稳定,尤其在中雨及以上量级模拟结果优势较强,相比原方案其降水TS评分整体提高了4%。总体而言,尺度适应方案对西南山地地区强降水预报性能较好,为改进现行数值模式强降水预报提供了一定依据。
With the continuous improvement of the horizontal resolution of the numerical weather prediction model,cumulus clouds are not distinguishable by the grid scale in the“grey area”(1-10 km)of the convective parameterisation scheme,making the traditional cumulus convective parameterisation scheme difficult to apply to the simulation of precipitation at different resolutions.Therefore,the development of scale-aware cumulus cloud parameterisation schemes is one of the development trends of numerical model refinement.By introducing the scale-aware KFeta(Kain-Fritsch eta)convective parameterisation scheme into the CMA-MESO(China Meteorological Administration Mesoscale model)model,the paper combines three resolutions(1 km,3 km,and 10 km)and designs three sets of experiments so that a numerical simulation test is carried out on a precipitation process on 11-12 July 2023,in the mountainous area of southwest China,and a 7-day batch test is carried out on the precipitation process on 17-23 June 2023.This is done to test and evaluate the effect of the scale adaptation scheme on precipitation simulation in the southwest mountainous area.The results show that:(1)In the case experiment,the scale adaptation scheme has a good grasp of the precipitation rain band and precipitation intensity,and the simulation of the heavy precipitation centre has certain advantages.With the increase in resolution,the precipitation intensity and falling area of the scale adaptation group are closer to reality,which greatly reduces the false precipitation caused by cumulus clouds and increases the grid precipitation.(2)The combined reflectance factor and vertical velocity simulation results in the strong convection region of the scale adaptation scheme are better.(3)In the batch test,the scale adaptation scheme has a good and stable simulation ability for precipitation in the southwest mountain area,especially the simulation results of the scale adaptation scheme for moderate rain and above,which are more advantageous,and the precipitation TS score of the original scheme improves by 4%overall.In general,the scale adaptation scheme performs well in the forecast of heavy precipitation in the southwest mountainous area,providing a basis for improving the current numerical model of heavy precipitation forecasts.
作者
马怡轩
于翡
徐国强
MA Yixuan;YU Fei;XU Guoqiang(Shaanxi Provincial Meteorological Bureau,Xi’an 710014;CMA Earth System Modelling and Prediction Centre,Beijing 100081)
出处
《气象科技》
2025年第4期508-519,共12页
Meteorological Science and Technology
基金
国家自然科学基金项目(U2142213,42175167)
中国气象局能力提升联合研究专项(22NLTSZ006)
中国气象局青年创新团队(CMA2023QN06)共同资助
中国沙漠气象科学研究基金(Sqj2023022)。
