大面积果园春季近地逆温分布特征初探

Preliminary Study on Distributive Characteristics of Temperature Inversion near Ground of Large-area Orchard in Spring

为了科学利用逆温资源有效防御霜冻,利用天水市大面积果园近地气温、风速观测资料,分析了春季（3～5月）近地逆温的时空分布特征及风速对其的影响。结果表明：不同高度处的气温呈现出＂一峰一谷＂的月变化特征,在1～10 m高度范围内,3月（4月、5月）的逆温在17：00至次日8：00（7：00、7：00）出现,从中高层（8～10 m）最先开始形成,在近地层（1～2 m）最先开始消亡;3月、4月、5月逆温的可连续维持时间分别为15、15、14 h;逆温形成集中在17：00～19：00;3月、4月逆温消亡时间集中在8：00～10：00,5月逆温消亡时间集中在7：00～9：00;1～10 m逆温强度呈现出先增加后减小的变化特征,3、4、5月分别在24：00至次日7：00、24：00至次日6：00、22：00至次日4：00较强;在逆温存在时间段内,当风速小于（或大于）3.3 m/s时,逆温较明显（或不明显）。

In order to defend frost by utilizing of temperature inversion resources,based on the observation data of temperature and wind speed in the large apple orchards of Tianshui city,the temporal and spatial distribution characteristics of temperature inversion near ground and the effect of winds in spring（ from March to May） were analyzed. The results showed that the different high temperature presented monthly change of peak and valley,within the range of 1 ～ 10 m height,March（ April,May）temperature inversion occurred from 17： 00 to 8： 00,which were first beginning to form first from the top（ 8 ～ 10 m）,first beginning to die from surface layer（ 1 ～ 2 m）. Inversion could continuously maintain 15 h,15 h and 14 h in March,April and May,respectively. Inversion forming concentrated from 17： 00 to 19： 00. March and April inversion demising concentrated from 8： 00 to10： 00. May inversion demising concentrated from 7： 00 to 9： 00. The intensity of temperature inversion increased then turn to decrease,in which the larger between 24： 00 and 7： 00,between 24： 00 and 6： 00,between 22： 00 and 4： 00 in March,April,May,respectively. In the period of temperature inversion occurred,when the wind speed was less（ more） than 3.3 m / s,temperature inversion was more obvious（ or not obvious）.