潍坊近40年寒潮特征与变化趋势

Macroscopical Characteristics and Trend of Cold Wave in Weifang City in Recent 40 Years

利用1961-2000年潍坊地区气象资料,分析了寒潮天气的气候特征,结果表明,近40年寒潮天气逐年减少,60和90年代寒潮过程较强,降温过程为平均11.68℃/次,70和80年代较弱,平均降温11.08℃/次;影响系统主要有:低槽型,占52.7%,并以4.5次/10a的趋势减少;小槽发展型占19.4%,以1.3次/10a的趋势增加。不同地形区的寒潮次数和降温幅度有一定差异。

Based on meteorological data from 1961 to 2000 in Weifang, the macroscopical characteristics of cold wave in recent 40 years are analyzed. The result show that the number of cold wave per year appears to be descending in recent 40 years, such as, the times of cold wave is from 3.9 in 1960s to 2.0 in 1990s with a gradient of -0.62/10a .The distribution of temperature dropped within 48 hours a process peaks to 11.68℃ in 1960s and 1990s, while it's lower 11.08℃ in 1970s and 1980s. Among weather systems , the pattern of trough moved towards east takes up 52.7% with a descending trend of -4.5 /10a compared with the pattern of small trough developed 19.4% with a increasing trend of 1.3 /10a. The different surface have marked effect on distribution of cold wave and degree of temperature dropped, and from frequency and distribution of temperature, we can see that: Qingzhou(mountain area )>Shouguang (coast)>Zhucheng(plain) >Weifang (the city zone).