渤海冷空气大风过程中3次风速波动的原因分析  

Cause Analysis of Three Wind Speed Fluctuation Events during a Cold Air Gale Process over Bohai Sea

作　　者：黄彬[1] 杨超[1] 朱男男[2] 易笑园[2] 魏晓琳 

机构地区：[1]中国气象局国家气象中心,北京100081 [2]天津市气象台,天津300074 [3]深圳市气象局,深圳518000

出　　处：《气象科技》2017年第3期499-507,共9页Meteorological Science and Technology

基　　金：公益行业专项"船舶气象资料业务应用中的关键技术研究"(GYHY201206001);环渤海区域科技协同创新基金"环渤海海上阵风预报技术方法研究"(QYXM2016)资助

摘　　要：根据FY-2G卫星遥感监测资料、常规气象观测资料和NCEP逐6h1°×1°再分析资料,分析2014年12月31日至2015年1月1日渤海大风过程中风速的3次波动特征以及影响系统,并对大风期间物理量进行了诊断分析,揭示了冷空气影响过程中渤海大风的突增以及波动性成因。结果表明:当冷空气影响渤海时,冷暖空气对比使低空锋区迅速加强,风力突增明显。大风期间高层深厚的冷平流自上而下形成了一条西北东南向后倾式的冷平流传输通道,平流分3次传送到底层对应着大风期间的3次波动峰值。整个过程动量下传起了重要的作用,下沉气流的径向度越大,高层下沉运动越强,对应地面的风速越大。There was occurred a strong wind process from 31 December 2014 to 1 January 2015 over the Bohai Sea, which has the characteristics of strong burst, long duration, strong winds with three wave peak of wind Speed. The reanalysis data of NCEP/NCAR are used in the diagnosis and analysis of the offshore wind induced by strong cold air. The analysis shows that when the cold air affected the Bohai Sea, the warm and cold air contrast enlarged the low-level front zone, and wind force increased obviously. Three fluctuations of the Bohai Sea wind correspond to the low layer cold advection strengthening, and temperature advection and vertical structural variation indicate that above the deep cold advection from top to bottom formed a retroverted cold advection transport channel, which transmitted the cold air to the lower levels for three times, corresponding to the three peaks of wind fluctuation. The high-level downward momentum transformation played an important role in the rapid growth and maintenance of the strong winds. The three wind speed fluctuations over the Bohai Sea are related to the high-level downward momentum transformation and the higher the radial degree of the air flows, the stronger the momentum transformation at the upper levels, the greater the wind speeds on the ground were.

关 键 词：冷空气大风 风速波动 变压梯度 温度平流 动量下传 

分 类 号：P47[天文地球—大气科学及气象学]