龙口市致灾晚霜冻的气候特征分析及预防措施

Characteristics Analysis and Prevention Measures of Late Frost Hazard Climate in Longkou City

通过对龙口市1988-2007年间春季出现霜冻日的背景资料分析,总结了龙口市晚霜冻出现的概率以及天气形势背景。结果表明：龙口市的终霜日有20%出现在4月下旬,由较强冷平流影响加辐射降温产生,出现在冷空气过境后微风、晴空的后半夜;造成龙口市重灾的晚霜冻均出现在4月下旬,气候背景是4月上旬、中旬气温和地温异常偏高,4月上旬、中旬日平均气温高于14℃和日平均地面温度高于18℃,导致农作物发芽早、果树开花早,承受低温能力减弱而造成重灾害。针对晚霜冻产生的天气背景以及致灾原因,提出了预防晚霜冻的措施。

Through analysis on background material of frost date which appeared in spring from 1988 to 2007 of Longkou City, the probability and the synoptic situation background were summarized. The result indicated that the last frost date probability was 20% in the late April, as a result of the radiation temperature decrease combining with the strong cold advection influence, and it most appeared transits with breeze after the cold air, the clear sky late at night. The late frost which caused the Longkou City heavy disaster to appear in the late April, the climate background is in April, the first and second ten days temperature, the ground temperature was exceptionally high. The average temperature was higher than 14 ℃ and the daily average ground temperature was higher than 18 ℃, which caused the crops to germinate, the fruit tree blossoms early, the ability of withstanding low temperature became weaken, all of which created the heavy disaster. The late frost prevention measure was put forward according to weather background and disaster reason.