全球变暖后西北太平洋台风频率的可能变化

THE POSSIBLE RESPONSE OF HURRICANE FREQUENCY IN NORTHWEST PACIFIC TO GLOBAL WARMING

通过对近百年来气象记录的分析发现,西北太平洋的台风发生频率及在中国登陆的台风频率的变化与全球地面平均气温变化之间,在滞后26年的情况下存在明显的线性相关关系。据线性回归模型初步预测,随着全球气候的变暖,西北太平洋的台风发生频率及在中国登陆的台风频率将会明显增大。当全球地面平均气温分别升高0.25、0.50、0.75和1.00℃时,西北太平洋的台风发生频率将依次增大27、63、99和134%,在中国登陆的台风频率将依次增大34、63、90和119%。

Known to all,the development of hurricane is in some aspects dependent on sea surfacetemperature.The higher sea surface temperature is,the easilier hurricane develops.The globalwarming (due to greenhouse effects) would make sea surface temperature rise and then affectthe hurricane development.Emanuel's(1987) analysis suggests that global warming would yieldan increase in hurricane intensity.Then,how about the hurricane frequency change?Thestatistical analysis in this paper shows that a good correlation exists between hurricane frequen-cies in Northwest Pacific and global air temperature changes (Hansen,et al.,1981) for thelast century.It can be described usingPHF=a△T_(t-t_(?))+bwhere PHF and △T are 5 years means of hurricane frequency in Northwest Pacific and glo-bal air temperature changes and t is time.Parameters a and b were obtained by least squareslinear regression.The time lag to was chosen t(?) minimize the variance between hurricanefrequency and temperature.The results were a=40.14 hurricanes/yr·℃,b=21.89 hurricanes/yr and t(?)=26 years with a correlation coefficient of 0.9.The regression equation provides a simple forecast of the hurricane frequency responseto global warming.The global air temperature rise of 0.25,0.50,0.75 or 1.00℃ would resultin 27,63,99 or 134% increasing of hurricane frequency in Northwest Pacific (relative to theaverage of 1951—1980).