西北区冰雹分布及与地温场的相关分析

Distribution of Hail in Northwest China and Its Correlation to Soil Temperature Field

利用1970—2001年历年1～12月中国西北地区冰雹日数资料,研究了它与3.2m深度的地温场及西北区降水场的关系。结果表明:西北区多雹区与少雹区均呈带状分布,并且山区多雹,平川少雹。进一步分析还发现,年雹日距平图与当年夏季3.2m地温场吻合得相当好,多雹带总与高地温带相吻合,少雹带则与低地温带相吻合。因此,一定深度的地温是控制冰雹多少的重要因子。

Based on the data of daily numbers of annual hail from 1970 to 2000, we analyzed the relationship between daily numbers of annual hail and summer soil temperature and precipitation field, the conclusions obtained are as follows: The hails in Northwest China show the distribution in belt patterns and the hail of mountainous region is more than that of plain region. The result also shows that there is a better relationship between daily anomaly of annual hail and summer soil temperature fields at 3.2 m derpth. When summer soil temperature is higher, the daily numbers of annual hail obviously increase; when summer soil temperature is lower, the daily numbers of annual hail obviously decrease. So the soil temperature for a certain depth is a very important factor to controlfor haildays.