摘要
[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.
[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.
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)
