南海高压的强度变异对长江中下游梅雨的影响及有无洪涝预报

用500毫巴月平均高度图,以100—120°E、≥10°N的范围内,≥588位势什米网格点数代表南海高压强度,则6—7月南海高压强度和6—7月长江中下游的梅雨量有较好的相关。由于南海高压强度有一定持续性,因而可根据前期南海高压强弱,预报6—7月长江中下游的梅雨量。用此思路得出的预报公式。能把有无梅雨洪涝反映出来,从1953—1980年,拟合率为28/28,1981—1983年试报也全正确。另外,文内还探讨了用11月环流特征,作下年初夏南海高压的强弱和长江中下游涝梅预报的可行性。 

THE INFLUENCE OF THE INTENSITY OF SUBTROPICAL HIGH OVER THE SOUTH CHINA SEA ON THE RAINFALL FOR JUNE-JULY IN THE MIDDLE AND LOWER REACHES OF THE YANGTZE RIVER AND ITS FLOOD FORECASTING

By using monthly mean charts of the 500mb level, the intensity of the subtropical high over the South China Sea (SHI) is defined as the number of grid points at which the geopotential height≥5880 meters in the 100-120°E、 10°N area. We find that the rainfall for June- July in the Middle - Lower Reaches of the Yangtze River is well related to SHI at the same time. We also find that there is good continuity in the SHI. Then according to the SHI during Apr-May, we can forecast the SHI for June-July and go on with the rainfall forecasting for June-July in the Middle-Lower Reaches of the Yangtze River.