Wavelet analysis of quasi-3-year temperature oscillations in China in last 50 years, and predicted changes in the next 20 years

摘要

The wavelet analysis method is used to analyze the annual and winter temperature data of 98 observation stations in China in eight climate zones during the last 50 years(1961–2009).The periodicities of temperature changes are investigated,and the possible temperature change trends in China in the next 20 years(2012–2029)are also predicted.Our results show that in the inter-annual temperature variability there are pervasive quasi-3-to quasi-4-year cycles,and these cycle changes are relatively steady.The periodic characteristics of the annual temperature changes are clearly different between northern and southern China,and our period superimposition extrapolation shows that both annual and winter temperatures in China will continue to increase in the next 20 years,more so in northern China and in the Qinghai-Xizang Plateau(QXP)than in the southern region,except in the southwest.If temperatures follow historic increasing linear trends,the overall temperature is expected to increase by 1°C between 2010 and 2029.