近48 a浙江省不同气候态下无霜期特征对比分析

Comparative Analysis of Frost-free Period Characteristics under Different Climatic States in Zhejiang Province in the Past 48 years

采用浙江省气象信息中心提供的1971—2018年逐日最低气温数据,利用常规气象统计方法,对浙江省平均初终霜日和无霜期时空分布特征进行分析,同时基于不同气候态、年代际进行对比分析。结果表明:时间特征上,近48 a浙江省平均初霜日显著推迟,平均终霜日显著提前,平均无霜期显著延长;1981—2010年气候态的平均初终霜日和无霜期推迟、提前、延长的趋势都最为显著;20世纪90年代初终霜日和无霜期变化趋势最为显著;平均初霜日在2003年发生突变,终霜日在1997、2004年发生突变,无霜期在2002年发生突变。空间特征上,近48 a浙江省初霜日在空间上,整体呈现西东晚、北中南早的格局;1981—2010年和21世纪00年代终霜日表现为自浙南向浙北逐步推迟的趋势;1981—2010年和21世纪00年代无霜期整体分布上呈现出西东南长、中北短的特点;1981—2010年和21世纪00年代初霜日整体有推迟的趋势,终霜日整体有提前的趋势,无霜期整体有延长的趋势。

Using the daily minimum temperature data from 1971 to 2018 provided by the Zhejiang Meteorological Information Center,using conventional meteorological statistical methods,the temporal and spatial distribution characteristics of the average first and last frost days and frost-free periods in Zhejiang Province were analyzed.Based on the comparative analysis of different climatic states and decadal periods.The results show that:in terms of time characteristics,the average first frost date in Zhejiang Province in the past 48 years was significantly delayed,the average last frost date was significantly earlier,and the average frost-free period was significantly prolonged;from 1981 to 2010,the average first and last frost day and frost-free period showed the most significant trend of delay;in the early 1990s,the change trend of frost days and frost-free periods was the most significant.The average first frost day changed abruptly in 2003,the last frost day changed abruptly in 1997 and 2004,and the frost-free period changed abruptly in 2002.In terms of spatial characteristics,the first frost date in Zhejiang Province in the past 48 years showed a pattern of being late in the west and east and early in the north,middle and south;the final frost day shows a gradually delayed trend from southern Zhejiang to northern Zhejiang;the overall distribution of the frost free period shows the characteristics of being long in the southwest and short in the central and northern regions.From 1981 to 2010 and the early 2000s,there was an overall trend of delayed frost days,an overall trend of advanced final frost days,and an overall trend of extended frost free periods.