为了进一步研究下垫面对西南地区暴雨的影响,本文采用非静力中尺度数值模式WRF-ARW (V3.9.1版),利用WRF自带的MODIS陆面数据和全球30米精细地表覆盖产品(GLC_FCS30-2020)数据,对发生在四川盆地的一次暴雨过程进行数值敏感性试验,通过天...为了进一步研究下垫面对西南地区暴雨的影响,本文采用非静力中尺度数值模式WRF-ARW (V3.9.1版),利用WRF自带的MODIS陆面数据和全球30米精细地表覆盖产品(GLC_FCS30-2020)数据,对发生在四川盆地的一次暴雨过程进行数值敏感性试验,通过天气学诊断分析方法,从动力作用和水汽条件等方面分析不同陆面数据对此次降水过程的模拟,结果表明:1) 此次降水过程是在槽前西南气流、西南低涡以及低空急流加强的共同影响下产生的。强降水主要出现在大巴山地区,降水带呈东北–西南走向,降水强中心出现在四川东北部。2) 两个实验均较好地模拟了此次降水过程。两个模拟的结果在降水水平分布上均偏强、偏西,在时间演变上降水量级更强,峰值持续时间也更长。GLC的模拟结果更加接近观测数据,优化了降水模拟。3) 动力场上,GLC数据模拟出了更弱的辐合,导致了更小垂直速度,在动力抬升方面优化了降水模拟。4) 水汽条件上,近地面水汽含量分布与下垫面类型分布有一定的对应关系,在降水区附近,GLC数据集模拟出更少的水汽含量、更弱的水汽通量和水汽通量辐合,减小了模拟的降水量,在水汽条件方面优化了降水模拟。In order to further study the impact of the underlying surface on heavy rainfall in the southwestern region, this paper uses the non-hydrostatic mesoscale numerical model WRF-ARW (version 3.9.1). Using MODIS land surface data provided by WRF and the global 30-meter refined land cover product (GLC_FCS30-2020), a numerical sensitivity experiment was conducted on a heavy rainfall event that occurred in the Sichuan Basin. Through meteorological diagnostic analysis, the simulation of this rainfall process using different land surface data was analyzed from the aspects of dynamic effects and moisture conditions, and the results show that: 1) This precipitation process is caused by the combined influence of the southwest airflow in front of the trough, the southwest vortex, and the strengthening of the low-level jet stream. Heavy precipitation mainly occurs in the Daba Mountain area, with the precipitation belt trending from northeast to southwest, and the center of intense precipitation appears in northeastern Sichuan. 2) Both experiments simulated the precipitation process well. The results of both simulations are stronger and more westward in the distribution of precipitation levels. In terms of time evolution, the precipitation magnitude is stronger and the peak duration is longer. The simulation results of GLC are closer to the observation data and optimize the precipitation simulation. 3) In the dynamic field, the GLC data simulates weaker convergence, resulting in smaller vertical velocity, and optimizes the precipitation simulation in terms of dynamic lift. 4) In terms of water vapor conditions, there is a certain correspondence between the distribution of water vapor content near the surface and the distribution of underlying surface types. Near the precipitation area, the GLC data set simulates less water vapor content, weaker water vapor flux, and water vapor flux. Convergence reduces the amount of simulated precipitation and optimizes the precipitation simulation in terms of water vapor conditions.展开更多
为了研究同化风云三号B星(FY-3B)和C星(FY-3C)的微波湿度计(MWHS及MWHS-2)观测资料在四川暴雨数值预报中的影响,本文基于Weather Research and Forecasting Model(WRF)及其三维变分同化系统Weather Research Forecast Variatinal Data A...为了研究同化风云三号B星(FY-3B)和C星(FY-3C)的微波湿度计(MWHS及MWHS-2)观测资料在四川暴雨数值预报中的影响,本文基于Weather Research and Forecasting Model(WRF)及其三维变分同化系统Weather Research Forecast Variatinal Data Assimilation System(WRFDA),实现了对MWHS/FY-3B和MWHS-2/FY-3C观测资料的直接同化。针对2018年7月的一次四川盆地区域性暴雨过程的同化试验结果表明:同化风云三号系列卫星的微波湿度计观测资料对试验开始时刻均有改善,对相对湿度和矢量风场等物理量场有一定的正向调整作用,尤其是同化MWHS-2/FY-3C资料对风场的调整较为明显。同化试验对龙门山北部降水有较明显的改善作用,改善了降水的分布与落区,其中同化MWHS/FY-3B对盆地中部到东北部的降水量级的预报更接近实况,雨区更为连续。同化试验证明了同化风云三号系列卫星的微波湿度计观测资料对于四川盆地暴雨数值预报有一定的业务应用价值。展开更多
利用常规地面和探空气象观测资料、自动气象站资料、卫星和雷达拼图资料以及NCEP FNL分析资料对2013年7月3-5日四川盆地强降水过程的中尺度对流系统及其环境场特征进行了分析。结果表明:此次降水过程分为三个阶段,分别对应三次中尺度对...利用常规地面和探空气象观测资料、自动气象站资料、卫星和雷达拼图资料以及NCEP FNL分析资料对2013年7月3-5日四川盆地强降水过程的中尺度对流系统及其环境场特征进行了分析。结果表明:此次降水过程分为三个阶段,分别对应三次中尺度对流系统的发生、发展;700 h Pa切变线和850h Pa低涡为中尺度对流系统的产生提供了有利的动力条件,中尺度对流系统沿700 h Pa切变线以及850h Pa低涡中心附近发生、发展,三个阶段的中尺度对流活动均与低层切变系统的发展、演变相吻合。冷空气对中尺度对流系统的发生发展具有重要影响,强降水的产生时间和空间分布均与冷空气入侵密切相关。四川盆地地形对强降水的产生有两方面的作用,一是使气流在山前辐合抬升,二是使冷空气堆积造成强的冷暖空气对峙,导致锋生作用加强。展开更多
文摘为了进一步研究下垫面对西南地区暴雨的影响,本文采用非静力中尺度数值模式WRF-ARW (V3.9.1版),利用WRF自带的MODIS陆面数据和全球30米精细地表覆盖产品(GLC_FCS30-2020)数据,对发生在四川盆地的一次暴雨过程进行数值敏感性试验,通过天气学诊断分析方法,从动力作用和水汽条件等方面分析不同陆面数据对此次降水过程的模拟,结果表明:1) 此次降水过程是在槽前西南气流、西南低涡以及低空急流加强的共同影响下产生的。强降水主要出现在大巴山地区,降水带呈东北–西南走向,降水强中心出现在四川东北部。2) 两个实验均较好地模拟了此次降水过程。两个模拟的结果在降水水平分布上均偏强、偏西,在时间演变上降水量级更强,峰值持续时间也更长。GLC的模拟结果更加接近观测数据,优化了降水模拟。3) 动力场上,GLC数据模拟出了更弱的辐合,导致了更小垂直速度,在动力抬升方面优化了降水模拟。4) 水汽条件上,近地面水汽含量分布与下垫面类型分布有一定的对应关系,在降水区附近,GLC数据集模拟出更少的水汽含量、更弱的水汽通量和水汽通量辐合,减小了模拟的降水量,在水汽条件方面优化了降水模拟。In order to further study the impact of the underlying surface on heavy rainfall in the southwestern region, this paper uses the non-hydrostatic mesoscale numerical model WRF-ARW (version 3.9.1). Using MODIS land surface data provided by WRF and the global 30-meter refined land cover product (GLC_FCS30-2020), a numerical sensitivity experiment was conducted on a heavy rainfall event that occurred in the Sichuan Basin. Through meteorological diagnostic analysis, the simulation of this rainfall process using different land surface data was analyzed from the aspects of dynamic effects and moisture conditions, and the results show that: 1) This precipitation process is caused by the combined influence of the southwest airflow in front of the trough, the southwest vortex, and the strengthening of the low-level jet stream. Heavy precipitation mainly occurs in the Daba Mountain area, with the precipitation belt trending from northeast to southwest, and the center of intense precipitation appears in northeastern Sichuan. 2) Both experiments simulated the precipitation process well. The results of both simulations are stronger and more westward in the distribution of precipitation levels. In terms of time evolution, the precipitation magnitude is stronger and the peak duration is longer. The simulation results of GLC are closer to the observation data and optimize the precipitation simulation. 3) In the dynamic field, the GLC data simulates weaker convergence, resulting in smaller vertical velocity, and optimizes the precipitation simulation in terms of dynamic lift. 4) In terms of water vapor conditions, there is a certain correspondence between the distribution of water vapor content near the surface and the distribution of underlying surface types. Near the precipitation area, the GLC data set simulates less water vapor content, weaker water vapor flux, and water vapor flux. Convergence reduces the amount of simulated precipitation and optimizes the precipitation simulation in terms of water vapor conditions.
文摘为了研究同化风云三号B星(FY-3B)和C星(FY-3C)的微波湿度计(MWHS及MWHS-2)观测资料在四川暴雨数值预报中的影响,本文基于Weather Research and Forecasting Model(WRF)及其三维变分同化系统Weather Research Forecast Variatinal Data Assimilation System(WRFDA),实现了对MWHS/FY-3B和MWHS-2/FY-3C观测资料的直接同化。针对2018年7月的一次四川盆地区域性暴雨过程的同化试验结果表明:同化风云三号系列卫星的微波湿度计观测资料对试验开始时刻均有改善,对相对湿度和矢量风场等物理量场有一定的正向调整作用,尤其是同化MWHS-2/FY-3C资料对风场的调整较为明显。同化试验对龙门山北部降水有较明显的改善作用,改善了降水的分布与落区,其中同化MWHS/FY-3B对盆地中部到东北部的降水量级的预报更接近实况,雨区更为连续。同化试验证明了同化风云三号系列卫星的微波湿度计观测资料对于四川盆地暴雨数值预报有一定的业务应用价值。
文摘利用常规地面和探空气象观测资料、自动气象站资料、卫星和雷达拼图资料以及NCEP FNL分析资料对2013年7月3-5日四川盆地强降水过程的中尺度对流系统及其环境场特征进行了分析。结果表明:此次降水过程分为三个阶段,分别对应三次中尺度对流系统的发生、发展;700 h Pa切变线和850h Pa低涡为中尺度对流系统的产生提供了有利的动力条件,中尺度对流系统沿700 h Pa切变线以及850h Pa低涡中心附近发生、发展,三个阶段的中尺度对流活动均与低层切变系统的发展、演变相吻合。冷空气对中尺度对流系统的发生发展具有重要影响,强降水的产生时间和空间分布均与冷空气入侵密切相关。四川盆地地形对强降水的产生有两方面的作用,一是使气流在山前辐合抬升,二是使冷空气堆积造成强的冷暖空气对峙,导致锋生作用加强。
