地形闭塞的山坡下部冬季气温特征分析

Research on the Characteristics of the Air Temperature of Lower Landlocked Mountain Slopes in Winter

根据龙海站过去50a(1959-2009年)的低温历史资料分析,并没有达到荔枝树遭受冻害的标准,但1991/1992年度、1999/2000年度冬季位于该站西南偏南11km的双第华侨农场的荔枝树却遭受了较严重的冻害。为探寻冻害产生的真正原因,本文利用2008/2009年冬季在龙海气象站和龙海市境内的双第华侨农场自动站(位于地形闭塞的山坡地下部)观测的气温资料进行对比分析发现:与龙海站相比,双第站的平均气温和最低气温偏低、最高气温偏高、气温日较差偏大;两站日最低气温间呈极显著的正相关关系(r=0.9468>r0.001,n=90),两站的日最低气温差值随着龙海站最低气温的降低呈增大的趋势,说明龙海站的最低气温较低时双第站的会更低。采用差值法对龙海迁站(2001年)前后的年度极端最低气温资料进行了均一性订正,采用线性回归关系式推算出1991/1992年度和1999/2000年度冬季双第站的最低气温为-4.9℃和-3.8℃,这就是双第华侨农场当年冬季荔枝树发生冻害的真正原因。

According to the air temperature data over the last 50 years in Longhai weather station,the freezing damage for Litchi trees could be avoided. But in the year of 1991/1992 and 1999/2000,the Litchi trees were suffered serious freezing damage in Shuangdi Overseas Chinese Farm,11 km away to south-southwest of Longhai Station. To make clear of cause for freezing damage,the air temperature data in winter of 2008/2009 in Longhai weather station and auto weather station of Shuangdi Overseas Chinese Farm （lied in lower parts of landlocked mountain slopes） were comparatively analyzed. The results showed that the average temperature and the minimum temperature of weather station of Shuangdi Overseas Chinese Farm were lower than those of Longhai weather station. However,the maximum temperature observed by the latter station was higher and the daytime temperature differences between the two weather stations were wider accordingly. Moreover,there was linear relation of minimum daytime temperature of two weather stations （r=0.9468〉r0.001,n=90）,and with the decreasing of the minimum temperature of Longhai weather station,the difference value of the minimum temperature between the two weather stations presented increasing trend,and the minimum temperature of Shuangdi Overseas Chinese Farm was even lower than that of Longhai county. Furthermore,the annual extreme minimum air temperature data from the new and old weather stations in Longhai were adjusted homogeneously by difference method. By using the linear regression analysis,the minimum temperature of weather station of Shuangdi Overseas Chinese Farm in 1991/1992 and in 1999/2000 were -5.8℃ and -4.8℃ respectively,which was the real reason for the freezing damage to Litchi trees.