摘要
本文根据西北太平洋近46年(1949年~1994年)热带气旋和5°×5°经纬网格点月均海表温度系列资料,对西北太平洋热带气旋频数的时空变化及与海表温度之间可能存在的相关关系进行了系统的研究。结果表明:在西北太平洋海域,海表温度偏高对应热带气旋频数也偏多,在20°N以北、140°E以西海域偏多趋势更为明显。进一步的相关计算显示,近25年来(1970年~1994年)两者之间的各种相关以非线性(指数型)为最佳,以5年滑动平均代表的多年变化之间的相关性远远高于逐年变化,高度显著的相关出现在热带气旋频数多年变化滞后海表温度1年左右。
Tropical cyclones are the most devastating natural disasters causing severe losses of lives and property. One question that merits analysis is whether the frequency, intensity and location of tropical cyclones will change with future global warming. Based on data for 1949 ̄1994 on the frequencies, locations of formation of the tropical cyclones and the monthly average sea surface temperatures ( SST ) in the latitudinal and longitudinal zone of 5°×5° that occurred in the northwestern Pacific, this paper focuses on the temporal and spatial changes of the cyclones and the relationship of cyclone frequency and the SST . The study shows that the frequency of the storms increased unsteadily from the mid 1950s to the late 1960s and again from the mid 1970s to the 1980s. The frequency decreased unsteadily from the late 1960s to the mid 1970s and again in the early and the mid 1980s and the early 1990s. Such changes corresponded roughly with the changes of SST in the waters of 10°N ̄30°N, 125°E ̄170°E. Since the 1970s, high SST corresponded with high storm frequency and low SST corresponded with low cyclone frequency. Before the 1970s, the changes were inconsistent which could have been due to the incomplete statistics of storm frequency because of the lack of weather satellite coverage. Spatially, high SST corresponded roughly with high storm frequency in the waters north from of 20°N and west from 140°E, and with low storm frequency in the waters south from 10(N and east from 140°E since the 1970s. Additional correlation calculations indicate that the relationship between SST and cyclone frequencies was nonlinear ( P=a e b(SST-26) ) for the 25 year period 1970~1994 in the waters of 10°N ̄30°N, 125°E ̄170°E, and the correlativity of long term change of 5 year running average SST and the frequencies is better than that of their annual change. The relationship between long term change in SST and cyclone frequencies is the best when the change in cyclone frequencies lags behind that of SST for about one year, the calculated parameters being a =10 89, b =0 88 and the correlation coefficient exceeding 0 76. This means that once the SST of northwestern Pacific rises with global warming, the frequency of tropical cyclones will also increase, and the trend of increase will be more obvious in the waters north from 20°N and west from 140°E.
出处
《地理学报》
EI
CSCD
北大核心
1999年第1期22-29,共8页
Acta Geographica Sinica
基金
中国科学院"九五"资源与生态环境研究重点资助
关键词
热带气旋
西北太平洋
频数变化
海表温度
Tropical cyclones, frequency changes, sea surface temperature ( SST ), western North Pacific