Using boundary layer data with regard to sea fog observed at the Science Experiment Base for Marine Meteorology at Bohe,Guangdong Province,the structure of the atmospheric boundary layer and the characteristics of the...Using boundary layer data with regard to sea fog observed at the Science Experiment Base for Marine Meteorology at Bohe,Guangdong Province,the structure of the atmospheric boundary layer and the characteristics of the tops of the fog and the clouds were analyzed.In addition,the effects of advection,radiation,and turbulence during sea fog were also investigated.According to the stability definition of saturated,wet air,the gradient of the potential pseudo-equivalent temperature equal to zero was defined as the thermal turbulence interface.There is evidence to suggest that two layers of turbulence exist in sea fog.Thermal turbulence produced by long-wave radiation is prevalent above the thermal turbulence interface,whereas mechanical turbulence aroused by wind shear is predominant below the interface.The height of the thermal turbulence interface was observed between 180 m and 380 m.Three important factors are closely related to the development of the top of the sea fog：（1） the horizontal advection of the water vapor,（2） the long-wave radiation of the fog top,and（3） the movement of the vertical turbulence.Formation,development,and dissipation are the three possible phases of the evolution of the boundary-layer structure during the sea fog season.In addition,the thermal turbulence interface is the most significant turbulence interface during the formation and development periods;it is maintained after sea fog rises into the stratus layer.展开更多
基于日本气象厅Multi-functional Transport Satellite（MTSAT）可见光卫星云图、韩国气象局天气图和美国国家环境预报中心Climate Forecast System Reanalysis（CFSR）数据,选取2007-2012年2～6月发生的32次黄海海雾个例进行研究.首先...基于日本气象厅Multi-functional Transport Satellite（MTSAT）可见光卫星云图、韩国气象局天气图和美国国家环境预报中心Climate Forecast System Reanalysis（CFSR）数据,选取2007-2012年2～6月发生的32次黄海海雾个例进行研究.首先统计分析了黄海海雾的天气特征,接着归纳总结了有利于黄海海雾生成的天气系统类型,进而分别挑选了各类型的一次个例,解释其海上大气逆温层成因.结果表明：（1）黄海海雾天气系统可分为入海变性高压（南高北低、东高西低和独立高压）、中国大陆东移低压或低槽、北太平洋高压脊和入西太平洋高压4类,各自所占比例约为62.5％、21.9％、9.4％和6.2％.（2）天气系统控制下的冷暖平流与海面湍流冷却作用决定了海上大气逆温层的形成.海雾生成前,天气系统在演变过程中支配着形成逆温的暖气团,暖气团来源于陆上,则主要是上层强暖平流、下层弱暖（冷）平流导致逆温;暖气团来源于海上,则多由近冷海面的湍流混合、冷却降温形成逆温.展开更多
基金sponsored jointly by the Chinese Special Scientific Research Project for Public Interest (Grant No. GYHY200906008)the National Natural Science Foundation of China (Grant No.40675013)+1 种基金the Science and Technology Project of Guangdong Province (Grant No. 2008B030303072)the Meteorological Sciences Research Project of the Weather Bu-reau of Guangdong Province (Grant No. 201003)
文摘Using boundary layer data with regard to sea fog observed at the Science Experiment Base for Marine Meteorology at Bohe,Guangdong Province,the structure of the atmospheric boundary layer and the characteristics of the tops of the fog and the clouds were analyzed.In addition,the effects of advection,radiation,and turbulence during sea fog were also investigated.According to the stability definition of saturated,wet air,the gradient of the potential pseudo-equivalent temperature equal to zero was defined as the thermal turbulence interface.There is evidence to suggest that two layers of turbulence exist in sea fog.Thermal turbulence produced by long-wave radiation is prevalent above the thermal turbulence interface,whereas mechanical turbulence aroused by wind shear is predominant below the interface.The height of the thermal turbulence interface was observed between 180 m and 380 m.Three important factors are closely related to the development of the top of the sea fog：（1） the horizontal advection of the water vapor,（2） the long-wave radiation of the fog top,and（3） the movement of the vertical turbulence.Formation,development,and dissipation are the three possible phases of the evolution of the boundary-layer structure during the sea fog season.In addition,the thermal turbulence interface is the most significant turbulence interface during the formation and development periods;it is maintained after sea fog rises into the stratus layer.
文摘基于日本气象厅Multi-functional Transport Satellite（MTSAT）可见光卫星云图、韩国气象局天气图和美国国家环境预报中心Climate Forecast System Reanalysis（CFSR）数据,选取2007-2012年2～6月发生的32次黄海海雾个例进行研究.首先统计分析了黄海海雾的天气特征,接着归纳总结了有利于黄海海雾生成的天气系统类型,进而分别挑选了各类型的一次个例,解释其海上大气逆温层成因.结果表明：（1）黄海海雾天气系统可分为入海变性高压（南高北低、东高西低和独立高压）、中国大陆东移低压或低槽、北太平洋高压脊和入西太平洋高压4类,各自所占比例约为62.5％、21.9％、9.4％和6.2％.（2）天气系统控制下的冷暖平流与海面湍流冷却作用决定了海上大气逆温层的形成.海雾生成前,天气系统在演变过程中支配着形成逆温的暖气团,暖气团来源于陆上,则主要是上层强暖平流、下层弱暖（冷）平流导致逆温;暖气团来源于海上,则多由近冷海面的湍流混合、冷却降温形成逆温.
