Associated with the changes of weather and climate,solar radiation is the most basic energy on the earth that drives the atmospheric circulation.Radiation process plays an important role in the mesoscale model.To make sure this model can accurately describe the radiation process in detail,it is necessary to take the variations of the atmospheric composition (water vapor,ozone,carbon dioxide,clouds and aerosols) and their effect on the radiation process fully into account.There exists different ways to deal with these atmospheric components in different radiation parameterization schemes,which can lead to great differences in simulation,and the results of suitable radiation parameterization scheme can be much closer to the actual situation.The WRF-ARW model (Version 3.7) coupled with the Noah land-surface process is used to simulate the sea breeze thunderstorm over the Hainan Island on July 20,2012.The characteristics of this thunderstorm in different radiation experiments are analyzed using radar and surface observation data.The structure and evolution of the thunderstorm as well as its trigger mechanism are also discussed.This paper is intended to study the impact of radiation parameterizations (Dudhia+RRTM and RRTMG+ RRTMG) on the simulated local sea breeze thunderstorm and its physical mechanism.Different radiation parameterization schemes have different ways of dealing with cloud,aerosol,and greenhouse gases in the radiative transfer process,resulting in different amounts of atmospheric absorption of heat.The energy near the ground simulated by the RAD experiment (RRTMG+RRTMG) is less than CNTL (Dudhia+ RRTM),causing the land-sea thermal contrast and pressure gradient of RAD to be relatively small.At the same time,the atmospheric stratification of RAD tends to be more stable.The land-sea breeze system is a wind pattern which is generated by the differences in the heat budgets of land and sea surfaces.In the two experiments,the land-sea thermal and pressure differences are mainly due to the variation of local sea breeze intensity and location.This variation is particularly evident in the sea breeze convergence zone,where the wind speed of CNTL experiment is greater than 3.0 m · s-1 while the RAD is only 1.0 m · s-1.The strength of sea breeze convergence can affect local divergence,characteristics of vortex and dynamical condition,so the sea breeze simulated by CNTL is more powerful,which can provide better lifting conditions and water vapor transportation for the sea breeze thunderstorm.Therefore,the intensity of the thunderstorm simulated by CNTL is stronger than the RAD experiment,so as the height of development and influence area.%本文利用高分辨率WRF模式探讨了两组短波、长波辐射参数化方案(Dudhia+RRTM、RRTMG+RRTMG)对海南岛一次海风雷暴模拟的影响及其可能的物理机制.结果表明,辐射参数化能影响大气的加热程度和近地面能量,决定海陆温差和气压差,改变海南岛的海风特征,最终影响海风雷暴的发生发展.Dudhia+ RRTM方案模拟的短波、长波综合加热率、感热通量以及潜热通量都大于RRTMG+ RRTMG方案,造成了前者模拟的近地面能量偏高,大气层结也表现得更加不稳定,进而使得该方案下的海陆温差和气压差相对较大,Dudhia+ RRTM方案模拟的海风明显强于RRTMG+RRTMG方案,能提供更好的水汽输送和抬升条件,有利于海风雷暴的发生发展,因此其模拟的雷暴活动范围和对流中心强度都要大于RRTMG+ RRTMG方案.
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