利用美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)再分析资料和中尺度数值模式(Weather Research Forcast,WRF)输出的高分辨率资料,分析了2014年7月20—21日辽宁地区一次短时暴雨过程的环流形势、中尺度...利用美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)再分析资料和中尺度数值模式(Weather Research Forcast,WRF)输出的高分辨率资料,分析了2014年7月20—21日辽宁地区一次短时暴雨过程的环流形势、中尺度特征和云物理降水机制。结果表明:2014年辽宁地区此次短时暴雨天气过程发生在500 h Pa槽前、850 h Pa切变线前和低空急流左侧的辐合区中,高空急流的"抽吸作用"加强了上升运动,并有远距离热带气旋通过西太平洋副热带高压间接的向辽宁地区输送水汽。地面中β尺度气旋性环流触发了暴雨中心的降水,冷空气的侵入对降水强度影响较大。最大降水由下沉运动向南的冷出流与偏南暖湿入流的低层辐合及中层偏北入流和偏南入流的辐合引发,中γ尺度次级环流的存在加强了上升运动。另外,不同时段的云物理降水机制不同,降水最强时雨水含量随着霰粒子的增多而迅速增加,主要表现为冰相粒子的冷云降水,霰粒子的融化起主导作用;冷云降水的效率明显高于暖云降水,易造成强度较大的短时强降水。展开更多
[Objective] The research aimed to study the influences of GWDO parameterization scheme and terrain on a rainstorm in Dabie Mountain.[Method] By using NCEP/NCAR 1°×1° analytical data,the conventional and...[Objective] The research aimed to study the influences of GWDO parameterization scheme and terrain on a rainstorm in Dabie Mountain.[Method] By using NCEP/NCAR 1°×1° analytical data,the conventional and unconventional ground observation data,WRFV3.1.1 version of non-hydrostatic balance meso-scale mode,a meso-scale shear line rainstorm process which happened in Dabie Mountain zone during 05:00-14:00 on June 21,2008 was carried out the diagnostic analysis and numerical test.In the control experiment,the gravity wave drag by orography(GWDO) parameterization scheme was added.The influences of GWDO parameterization scheme and terrain on the rainstorm process were discussed respectively by the sensitivity test.[Result] The orography dragging coefficient had the good improvement role on the rainstorm intensity or falling zone.The result had the very big difference when considering or non-considering the orography dragging coefficient.After the parameterization scheme was added,the rainstorm intensity or falling zone was better than that of non-addition.When there was no dragging coefficient,the shear line disturbance was strong,and the gravity wave activity was obvious.The precipitation was stronger in the zone where the gravity wave was obvious.The terrain in Dabie Mountain and the surrounding place also had the important effect on the shear line precipitation.When the terrain in Dabie Mountain was removed,the precipitation intensity on the shear line increased significantly,and the strengthening of rain belt in the west was the most obvious.When the terrain in the southeast of Dabie Mountain was removed,the precipitation in the east had the obvious increasing effect.The terrain wasn’t favorable for the rainstorm strengthening.The intensity variation of rain belt not only related to the terrain,but also related to the disturbance variation on the shear line.[Conclusion] The research provided the theory basis for the prediction and forecast of rainstorm.展开更多
文摘利用美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)再分析资料和中尺度数值模式(Weather Research Forcast,WRF)输出的高分辨率资料,分析了2014年7月20—21日辽宁地区一次短时暴雨过程的环流形势、中尺度特征和云物理降水机制。结果表明:2014年辽宁地区此次短时暴雨天气过程发生在500 h Pa槽前、850 h Pa切变线前和低空急流左侧的辐合区中,高空急流的"抽吸作用"加强了上升运动,并有远距离热带气旋通过西太平洋副热带高压间接的向辽宁地区输送水汽。地面中β尺度气旋性环流触发了暴雨中心的降水,冷空气的侵入对降水强度影响较大。最大降水由下沉运动向南的冷出流与偏南暖湿入流的低层辐合及中层偏北入流和偏南入流的辐合引发,中γ尺度次级环流的存在加强了上升运动。另外,不同时段的云物理降水机制不同,降水最强时雨水含量随着霰粒子的增多而迅速增加,主要表现为冰相粒子的冷云降水,霰粒子的融化起主导作用;冷云降水的效率明显高于暖云降水,易造成强度较大的短时强降水。
基金Supported by National Key Basic Research Development Project Planning "973"(2009CB421503)National Natural Science Fund(40975037)Public Welfare Industry (Meteorology) Science Research Specific Item(GYHY200806009)
文摘[Objective] The research aimed to study the influences of GWDO parameterization scheme and terrain on a rainstorm in Dabie Mountain.[Method] By using NCEP/NCAR 1°×1° analytical data,the conventional and unconventional ground observation data,WRFV3.1.1 version of non-hydrostatic balance meso-scale mode,a meso-scale shear line rainstorm process which happened in Dabie Mountain zone during 05:00-14:00 on June 21,2008 was carried out the diagnostic analysis and numerical test.In the control experiment,the gravity wave drag by orography(GWDO) parameterization scheme was added.The influences of GWDO parameterization scheme and terrain on the rainstorm process were discussed respectively by the sensitivity test.[Result] The orography dragging coefficient had the good improvement role on the rainstorm intensity or falling zone.The result had the very big difference when considering or non-considering the orography dragging coefficient.After the parameterization scheme was added,the rainstorm intensity or falling zone was better than that of non-addition.When there was no dragging coefficient,the shear line disturbance was strong,and the gravity wave activity was obvious.The precipitation was stronger in the zone where the gravity wave was obvious.The terrain in Dabie Mountain and the surrounding place also had the important effect on the shear line precipitation.When the terrain in Dabie Mountain was removed,the precipitation intensity on the shear line increased significantly,and the strengthening of rain belt in the west was the most obvious.When the terrain in the southeast of Dabie Mountain was removed,the precipitation in the east had the obvious increasing effect.The terrain wasn’t favorable for the rainstorm strengthening.The intensity variation of rain belt not only related to the terrain,but also related to the disturbance variation on the shear line.[Conclusion] The research provided the theory basis for the prediction and forecast of rainstorm.