近55年广州霜冻的年际和年代际变化特征

采用趋势分析、小波分析等统计方法,分析1951～2005年广州霜冻天气的年际和年代际变化,并对异常年景的500hPa环流场进行合成分析。结果表明,1980年代至今广州霜冻天气呈锐减趋势,初霜日略有推迟,终霜日提前,霜期明显缩短;近55年来广州霜冻天气具有准2～3年的年际和准13年的年代际变化周期。巴尔喀什湖-贝加尔湖附近的位势高度偏高(低)、东亚大槽较深(浅)、有(不)利于引导冷空气南下,导致广州的霜冻天气偏多(少)。

Inter-annual and Inter-decadal Variations of the Frost in Guangzhou during the Past 55 Years

On the basis of wavelet and correlation analysis, the inter - annual and inter - decadal variations of the frost weather in Guangzhou during the past 55 years are studied, as well as the 500 - hPa circulations in the anomalous years with synthesis analysis. The main results show that the frost in Guangzhou has oscillation periods of quasi - 2 - 3 years and cluasi - 13 years;the frost has a significant decreasing tendency in Guangzhou in last 30 years;the first date of frost is put off while the last date of it comes earlier,and thus the period of frost is shortened in Guangzhou. The results also indicate that the more（less） frost of the year in guagnzhou comes with deeper（shallower） East Asia trough and the region influenced by westerly trough is more southward （northward）.