【摘要】 在青藏高原地面感热通量的基本气候特征以及异常变化的空间结构和时间演变趋势研究的基础上 ,进一步就高原地面感热异常对北半球大气环流和中国气候异常的影响进行诊断研究 ,并利用IAP2 LAGCM对青藏高原地面感热异常的影响进行了数值试验。结果表明 :冬季地面感热在青藏高原西部、藏南谷地、横断山地区异常偏强 ,中、东部异常偏弱时 ,可使北半球 50 0hPa高度场表现出较明显的EU型和PNA型 ;高原西部、青海中北部异常偏弱 ,高原中部及东南部异常偏强时 ,使北半球 1 0 0hPa高度场的年际差异加强 ;西部、南部为正 ,柴达木及青海东部地区为负时 ,则新疆南部、西北东部及江南地区少雨 ,全国大部地区气温偏高。夏季高原地面感热通量距平特征为西南、藏南谷地、横断山区偏强 ,高原大部(中心在青海南部 )异常偏弱时 ,则 50 0hPa高度场上青藏高原南部 (孟加拉湾 )高度偏高 ,高原北部高度偏低 ,负值区在帕米尔 ;当感热通量距平特征为高原西南、藏南谷地、横断山区偏弱 ,高原大部异常偏强时 ,有利于南亚高压的建立与维持 ;当地面感热通量呈南正北负距平差异时 ,长江上游、黄河源头及西北地区东部和东北部分地区降水量比常年偏多 ,气温偏低 ,中国东部、南部降水偏少 ,气温偏高。通过数值模式进行的敏感性试验证实了?更多还原

【Abstract】 Based on the studies of the climatic characteristics and the spatial features and temporal tendencies of the surface sensible heat flux (SSHF) on the Qinghai-Xizang Plateau, its effects on the general atmospheric circulation over the Northern Hemisphere and climatic anomaly of China have been further studied by the statistical diagnoses and the IAP2-LAGCM modeling. The results show that the 500 hPa geopotential heights over the Northern Hemisphere are obviously dominated by the EU and PNA patterns when the SSHF is anomalous strong in the west of the plateau, the valley of south Xizang and the Hengduan mountains, but weak in the central and the east of the plateau (i.e., L 2 pattern of SSHF) in winter. As the SSHF is anomalous weak on the west of the plateau and the north and middle of Qinghai, but strong on the central and the southeast of the plateau (L1), the interannual variability of 100 hPa height over the Northern Hemisphere is increased. When the positive anomalies of SSHF occur on the west and the south of the plateau and negative on the area of the Qaidam Basin and east of Qinghai, precipitation is less in south Xinjiang, east of northwest China and the south of the Yangtze River, and also temperature is higher in most of China. With accompaniment of L 2, the positive departure of 500 hPa heights exists over south of the plateau (the Bay of Bengal) and negative over the north of the plateau, with negative center located in Pamir. The inverse L 2 pattern of SSHF is favorable for formation and subsistence of the 100 hPa anticyclone over south Asia. If the positive anomaly of SSHF is on the south of the plateau and negative on the north of the plateau, the precipitation is more than usual and the temperature is lower than usual in the east of the plateau, the east of the northwest China as well as some of the northeast China, but the less precipitation and higher temperature occur on the east and the south of China.The sensitive experiments with IAP2-LAGCM verified the response of the general circulation and regional climate changes to the anomaly of the surface sensible heat flux.更多还原