华南春季低温冷害气候特征研究

The Climatic Characteristic of Spring Cool Damage in South China

利用华南地区４８个台站１９５１—１９９０年２、３月气象资料，比较详细地讨论华南春季低温冷害的气候特征，揭示出如下几点事实：（１）华南的春季低温冷害过程出现频率愈往南去，愈向２月份集中。华南北部，低温过程次数多，持续日数长，温度低，是低温冷害最重的区域，往南依次为中等与轻度低温冷害区域，雷州半岛及海南省基本无低温冷害。（２）低温冷害过程初日与终日的年际波动非常大，初日极差普遍有１个月左右，终日极差高达５０—６０天，这给早稻育秧带来了严重的困难。（３）华南春季低温冷害过程多为湿冷型，混合型次之，干冷型最少。（４）春季各候低温冷害过程频率的峰值分别出现在２月第１候、第４候和３月第１候，呈现出准两周的低频振荡特征。（５）影响整个华南地区的强低温冷害年有９年，存在着３—４年的准周期振动。（６）低温过程总日数，５０年代偏少，６０年代偏多，７０年代偏少，８０年代偏多，呈现出准２０年的周期振荡。

Bosed on meteorological data in February and March from 1951 to 1990 at the forty-eight stations in South China,climatic features of spring cool damage are discussed in detail and some facts as follows.1 The more southward in South China,the more concentration toward February with respect to occurrence frequencies of spring lOw temperature process with cool damage. Its damage extent becomes heavier with increasing of latitudes and height above sea level.2 The interannual fluctuations of beginning and ending date of spring cool damage are great with a range of 30 days and 50-60 days,respectively.3 The dominating pattern is moist-cool for spring cool damage and it is mixed pattern as well as dry-cool pattern in turn.4 The peak values of pentad frequency of spring cool damage show a quasi-two weeks oscillation. The strong cool damage has quasi-three to four years cycle.