毛乌素沙地1969—2009年主要气候因子时间序列小波分析

采用Morlet复值小波变换法对毛乌素沙地5个气象站点1969—2009年主要气候要素不同时间尺度下的变化周期和突变点进行了分析,并根据主周期预测了未来气温、降水和相对湿度的变化趋势。结果表明:1969—2009年,毛乌素沙地年平均气温呈现出波动上升的趋势,平均上升0.401℃/10a,年降水量和年平均相对湿度的变化趋势不明显;毛乌素沙地年平均气温、年降水量和年平均相对湿度的年际变化过程中存在着多重时间尺度上的复杂嵌套结构,在不同的尺度周期中,表现出不同的冷暖、干湿振荡规律,总体表现为由小尺度无明显规律的剧烈振荡向大尺度有明显规律的振荡变化;目前气候正处于"暖干"向"暖湿"的过渡阶段,且这种暖湿化主要受气候周期性变化的影响。

Wavelet Analysis on the Temporal Series of Principal ClimateFactors in Mu Us Sandy Land during 1969-2009

Based on air temperature, precipitation and relative humidity data from 5 meteorological stations in Mu Us Sandy Land from 1969 to 2009, the periodic variations and jump features of the climate change under different time scales were analyzed by Morlet wavelet analysis method, and the future tendencies of the main meteorological element were forecasted according to their main periods. Results showed that air temperature increased with fluctuation in Mu Us Sandy Land during 1969-2009, but the change trends of precipitation and relative humidity were not significant; A complex nested structure for multi-time scales existed in the process of climate change, and the oscillation trend was not consistent for different temporal scales, while it changed from a disorderly and violent oscillation at short-term scale to a regular oscillation at long-term scale; And now the climate was at a transition stage from warm-dry to warm-wet, and the warm-wet tendency was affected mainly by the periodic climate change.