晋北地区霜冻发生的气候特征分析

本文采用晋北12个气象站1970年-2008年逐日最低气温资料,统计分析了晋北地区霜冻发生的气候特征.得出以下主要结论：a）晋北霜冻的发生与海拔高度密切相关,海拔越高初霜冻日到来越早、终霜冻日结束越晚;海拔高度对霜冻终日的影响大于对初日的影响.b）在晋北大部分区域,初霜冻日呈现推后、终霜冻日呈现提前的趋势,但年际间变化大,前后两年相差可达30 d以上.c）晋北地区初霜冻日的推后主要是从21世纪开始的终霜冻日的年代际变化不完全同步,大多数气象站以20世纪90年代为转折点,70年代和80年代相对偏晚、之后相对偏早.d）晋北地区霜冻日的变化趋势使该地区春玉米幼苗、成熟后期遭受霜冻危害的可能性大大降低,为当地春玉米提供了有利的生长条件.

Analysis of Climatic Characteristic for The Occurring of Frost in Northern of Shanxi Province

The climatic characteristic of frost was analyzed through the daily minimum temperature data which were from 12 weather stations in northern of Shanxi province from 1970 to 2008. The results showed： a） the occurrence of frost was closely related to altitude in northern of Shanxi Province. There was an earlier frost in higher elevation area. The frost was over later in higher elevation area. The altitude had more impact on the first day of frost than the last day. b） The first frost day had the trend of delay and the last frost day had a trend of ahead of schedule. But the in beginning ter-year changes were very different. Sometimes it could be 30 days. c） The delay of the first frost day was of the end of 21 century in northerner of Shanxi Province. But the last frost day were not fully synchronized. d） The change of frost days provided favorable growing conditions.