利用EOF方法,分析了NCEP/NCAR1948-2002年再分析资料中月平均全球地面感热资料,揭示了北非和青藏高原感热的振荡特征。分析了振荡关键区的感热距平与我国东部51个测站1951-2000年汛期降水距平的相关关系,用SVD方法分析了关键区感热距平场与我国东部51个测站全年各月降水距平场的空间耦合和时滞关系及关键区感热异常对我国东部降水异常的影响。结果表明,北非和青藏高原两个区域的感热变化呈负相关,它们对我国华北、江淮和华南三个区域的汛期降水滞后影响明显。感热对我国降水的影响以年代际为主。
By use of the NCEP/NCAR 1948-2002 reanalysis monthly data of sensible heat flux density, the monthly rainfall data at 51 stations of East China in 1951-2000 and the EOF analysis, the oscillation characteristics of sensible heat in North Africa and the Qinghai-Xizang Plateau and their relationship with the rainfall at 51 stations in East China are analyzed. Their spatial coupling patterns and time-lag relationships, as well as the impacts of the sensible heat fields on rainfall are also diagnosed by using the SVD technique. The results show that changes of sensible heat fields in North Africa and over the west of Qinghai-Xizang Plateau are in opposite phase, and both have good time persistence. The sensible heat fields have obvious leading impacts on rainfall in the flood seasons of three regions in East China, including the North China, the Yangtze River drainage area and the South China with evident decadal and interdecadal variations.