We evaluate the performance of GAMILI.1.1 in a 27-year forced simulation of the summer intraseasonal oscillation （ISO） over East Asia （EA）-western North Pacific （WNP）. The assessment is based on two mea- sures：...We evaluate the performance of GAMILI.1.1 in a 27-year forced simulation of the summer intraseasonal oscillation （ISO） over East Asia （EA）-western North Pacific （WNP）. The assessment is based on two mea- sures： climatological ISO （CISO） and transient ISO （TISO）. CISO is the ISO component that is phase-locked to the annual cycle and describes seasonal march. TISO is the ISO component that varies year by year. The model reasonably captures many observed features of the ISO, including the stepwise northward advance of the rain belt of CISO, the dominant periodicities of TISO in both the South China Sea-Philippine Sea （SCS-PS） and the Yangtze River Basin （YRB）, the northward propagation of 30-50-day TISO and the westward propagation of the 12-25-day TISO mode over the SCS-PS, and the zonal propagating features of three major TISO modes over the YRB. However, the model has notable deficiencies. These include the early onset of the South China Sea monsoon associated with CISO, too fast northward propagation of CISO from 20°N to 40°N and the absence of the CISO signal south of 10°N, the deficient eastward propagation of the 30-50-day TISO mode and the absence of a southward propagation in the YRB TISO modes. The authors found that the deficiencies in the ISO simulation are closely related to the model＇s biases in the mean states, suggesting that the improvement of the model mean state is crucial for realistic simulation of the intraseasonal variation.展开更多
There’re 4 types of crustobodies and total 6.Each has its own way of evolu-tion and movement. Their combination and separation depict a complex history of geotectonics.
利用1961—2022年四川155个国家气象站逐日气温、降水资料和NCEP/NCAR再分析资料等,对2022年四川持续高温干旱事件特征及成因进行分析。结果表明:2022年夏季四川出现极端高温干旱天气,全省平均气温、最高气温、高温日数均突破历史同期极...利用1961—2022年四川155个国家气象站逐日气温、降水资料和NCEP/NCAR再分析资料等,对2022年四川持续高温干旱事件特征及成因进行分析。结果表明:2022年夏季四川出现极端高温干旱天气,全省平均气温、最高气温、高温日数均突破历史同期极值,73.0%的站点出现重旱及以上旱情,为1961年以来最严重高温伏旱天气气候事件。南亚高压北跳东进,异常偏强偏北,500 h Pa青藏高压发展东移,或西太平洋副热带高压加强西伸北抬,与南亚高压叠加,形成稳定正压结构控制四川,是造成高温干旱的主要原因。亚洲中纬度地区盛行纬向环流,伊朗高压、青藏高压和西太平洋副热带高压打通形成高压带,盛行下沉辐散气流,阻挡中高纬冷空气南下和低纬暖湿气流北上,导致四川地区降水异常偏少,是高温干旱的间接原因。展开更多
基金supported by the Innovative Research Group Funds (Grant No. 408210921)the CAS International Partnership Project+1 种基金the 973 Project(Grant Nos. 2005CB321703 and 2006CB403602)fund from State Key Laboratory of Earth Surface Processes and Resource Ecology (No. 070205) in Beijing Normal University
文摘We evaluate the performance of GAMILI.1.1 in a 27-year forced simulation of the summer intraseasonal oscillation （ISO） over East Asia （EA）-western North Pacific （WNP）. The assessment is based on two mea- sures： climatological ISO （CISO） and transient ISO （TISO）. CISO is the ISO component that is phase-locked to the annual cycle and describes seasonal march. TISO is the ISO component that varies year by year. The model reasonably captures many observed features of the ISO, including the stepwise northward advance of the rain belt of CISO, the dominant periodicities of TISO in both the South China Sea-Philippine Sea （SCS-PS） and the Yangtze River Basin （YRB）, the northward propagation of 30-50-day TISO and the westward propagation of the 12-25-day TISO mode over the SCS-PS, and the zonal propagating features of three major TISO modes over the YRB. However, the model has notable deficiencies. These include the early onset of the South China Sea monsoon associated with CISO, too fast northward propagation of CISO from 20°N to 40°N and the absence of the CISO signal south of 10°N, the deficient eastward propagation of the 30-50-day TISO mode and the absence of a southward propagation in the YRB TISO modes. The authors found that the deficiencies in the ISO simulation are closely related to the model＇s biases in the mean states, suggesting that the improvement of the model mean state is crucial for realistic simulation of the intraseasonal variation.
文摘There’re 4 types of crustobodies and total 6.Each has its own way of evolu-tion and movement. Their combination and separation depict a complex history of geotectonics.
文摘利用1961—2022年四川155个国家气象站逐日气温、降水资料和NCEP/NCAR再分析资料等,对2022年四川持续高温干旱事件特征及成因进行分析。结果表明:2022年夏季四川出现极端高温干旱天气,全省平均气温、最高气温、高温日数均突破历史同期极值,73.0%的站点出现重旱及以上旱情,为1961年以来最严重高温伏旱天气气候事件。南亚高压北跳东进,异常偏强偏北,500 h Pa青藏高压发展东移,或西太平洋副热带高压加强西伸北抬,与南亚高压叠加,形成稳定正压结构控制四川,是造成高温干旱的主要原因。亚洲中纬度地区盛行纬向环流,伊朗高压、青藏高压和西太平洋副热带高压打通形成高压带,盛行下沉辐散气流,阻挡中高纬冷空气南下和低纬暖湿气流北上,导致四川地区降水异常偏少,是高温干旱的间接原因。
