近百年气候变化与变率的诊断研究

DIAGNOSTIC STUDIES ON THE CLIMATE CHANGE AND VARIABILITY FOR THE PERIOD OF 1880-1990

总结了近百年来气候变化与变率的诊断研究结果，包括全球平均气温及降水量、中国平均气温及降水量，以及ＥＮＳＯ及ＱＢＯ。指出全球有变暖趋势，１９８０年代是最暖的１０年。但中国的情况有所不同，１９２０年代及１９４０年代最暖，而１９８０年代接近常年。全球降水量有增加趋势，但气温与降水的１０年尺度变化并不完全一致。１９５０年代及１９７０年代为多雨期，１９８０年代降水反而减少。中国夏季降水变化的主要特征是冷湿、暖干。１９２０年代及１９４０年代是近百年最干的时期。１８７１—１９９３年共发生厄尼诺事件２８次，拉尼娜２１次。气候变暖时厄尼诺强，气候较冷时拉尼娜频率高。１９５１—１９９３年赤道平流层纬向风准两年振荡的平均长度为２８．７个月，比１９５０年代末的估计（２６．３个月）要长。１９５１年以前的周期长度可能在２９个月左右。未发现ＱＢＯ与气候变化有明显关系。

iagnostic studies on the climate change and variability were reviewed. The main subjects were the global mean temperature and precipitation, temperature and precipitation in China. ENSO and QBO. It was indicated that global mean temperature experienced a warming during the 20th century. The 1980's was the warmest decade since the instrumental observations became available. However, the temperature change in China differed from the global one. The warmest decade in China was the 1920's and 1940's. Mean temperature of the 1980's was near normal. Global mean precipitation showed also an increasing trend.But, the greater positive anomaly was found in 1950's and 1970's. Mean precipitation anomaly of 1980's was near normal. The main climatic characteristics of China was cold/wet or warm/dry during the last one hundred years or so. The decade of 1920's and 1940's was the driest in China for this period. The ENSO events were identified according to SST and SOI from 1871 to 1993. 28 El Nino and 21 La Nina events were found. The frequency of El Nino increased some what when the global temperature was higher than the normal,and that of La Nina increased in the cold periods. The mean length of QBO of the equatorial zonal wind in the stratosphere from 1951 to 1993 was 28.7 months. The QBO phases were reconstructed for the period of 1873-1950 according to the numbers of subtropical cyclone in North Atlantic and Indian monsoon rainfall. No evidence was found to show any significant relationship between the QBO and the global climate change.