摘要
热对流降水是副热带高压控制下常见的一种天气现象,突发性强且时空尺度小,是目前天气预报业务中的难点。本文尝试使用对流温度（T<sub>c</sub>）预报热对流降水。首先改进了MICAPS3中T<sub>c</sub>的算法。然后使用2004-2013年7-8月南京站的探空和地面观测资料,探讨了在副热带高压控制下时使用T<sub>c</sub>预报热对流降水的可行性。结果表明,南京站热对流降水发生的气候平均概率约为1/6;热对流降水的发生概率随日最高温度(T<sub>max</sub>)与T<sub>c</sub>的差值先增大后减小;当T<sub>max</sub>比T<sub>c</sub>低0,5℃以上时,发生概率低于平均概率;当T<sub>max</sub>比T<sub>c</sub>高0.5<sup>1</sup>.5℃时,热对流降水的发生概率最大,达到了40%。T<sub>max</sub>】30℃、T<sub>max</sub>-T<sub>c</sub>】-3.5℃是副热带高压控制下的热对流降水发生的两个必要条件。另外,对34个热对流降水的统计表明,热对流降水主要出现在每日13-18时,平均持续时间为50 min,平均降水量为7.8 mm。
Thermal convective precipitation(TCP) is a usual weather phenomenon under subtropical high.TCP always occurs suddenly with small temporal and spacial scales,and it is a difficult point in the current weather forecasting operations.In this article,the convective temperature(T_c) is used to forecast TCP.First,the algorithm of T_c in MIC APS 3 is improved,and then the sounding and surface observation data from Nanjing Station in July and August during 2004 — 2013 are used to discuss the feasibility of forcasting TCP depending on T_c under the control of subtropical high.The results show that,the average probability of TCP occurrence at Nanjing Station is 1/6.The probability of TCP occurrence increases and then decreases with the change of temperature difference between the day high temperature T_(max) and T_c.When T_(max)—T_c is smaller than — 0.5℃,the probability of occurrence is lower than average probability.When T_(max) — T_c is 0.5 to 1.5℃,the probability of TCP occurrence is the highest,reaching 40%.The two requirements for TCP occurrence under the control of subtropical high are T_(max)> 30℃ and T_(max) — T_c> —3.5℃.In addition,statistics of 34 TCP cases show that TCP mainly occurs from 13:00 —18:00 BT every day and its duration is 50 min averagely with the mean precipitation being 7.8 mm.
出处
《气象》
CSCD
北大核心
2015年第1期52-58,共7页
Meteorological Monthly
基金
国家自然科学基金项目(41305051)
江苏省气象局预报员专项项目(201208)
国家科技支撑计划项目(2011BAK21B04)共同资助
关键词
对流温度
副热带高压
热对流降水
地面露点
convective temperature
subtropical high
thermal convective precipitation
surface dew point
