天津科技
天津科技
천진과기
TIANJIN SCIENCE & TECHNOLOGY
2014年
10期
108-111,114
,共5页
大雪%湿位涡%倾斜涡度
大雪%濕位渦%傾斜渦度
대설%습위와%경사와도
heavy snow%moist potential vorticity(MPV)%slantwise vorticity
应用湿位涡理论及NCEP再分析资料(水平分辨率1°×1°)，对2013年12月17日滨海新区出现的大雪过程进行诊断分析。结果表明：500,hPa 高空冷涡和中低空切变线是造成强降雪的主要天气系统。降水时刻滨海新区相对湿度大于90%。偏东气流带来渤海海面的水汽，同时低空流场汇合有利于水汽辐合。暴雪发生在850,hPa 湿位涡正压项MPV1零值区和湿位涡斜压项MPV2负值区中。MPV2绝对值增大，大气湿斜压性增强导致下滑倾斜涡度发展是形成此次暴雪的重要原因，它对暴雪预报有着很好的指示作用。
應用濕位渦理論及NCEP再分析資料(水平分辨率1°×1°)，對2013年12月17日濱海新區齣現的大雪過程進行診斷分析。結果錶明：500,hPa 高空冷渦和中低空切變線是造成彊降雪的主要天氣繫統。降水時刻濱海新區相對濕度大于90%。偏東氣流帶來渤海海麵的水汽，同時低空流場彙閤有利于水汽輻閤。暴雪髮生在850,hPa 濕位渦正壓項MPV1零值區和濕位渦斜壓項MPV2負值區中。MPV2絕對值增大，大氣濕斜壓性增彊導緻下滑傾斜渦度髮展是形成此次暴雪的重要原因，它對暴雪預報有著很好的指示作用。
응용습위와이론급NCEP재분석자료(수평분변솔1°×1°)，대2013년12월17일빈해신구출현적대설과정진행진단분석。결과표명：500,hPa 고공랭와화중저공절변선시조성강강설적주요천기계통。강수시각빈해신구상대습도대우90%。편동기류대래발해해면적수기，동시저공류장회합유리우수기복합。폭설발생재850,hPa 습위와정압항MPV1령치구화습위와사압항MPV2부치구중。MPV2절대치증대，대기습사압성증강도치하활경사와도발전시형성차차폭설적중요원인，타대폭설예보유착흔호적지시작용。
Based on the theory of moist potential vorticity(MPV) and NCEP reanalysis data(Horizontal resolution 1° ×1°),a heavy snow took place on Dec. 17,2013,in Tianjin Binhai New Area was analyzed. The results showed that cold vortex at 500,hPa and low-altitude shear line formed the main weather system that caused this large-scale heavy snow. Relative humidity in the area was above 90%on the precipitation moment;easterly winds brought moistures from Bohai Sea,and the convergence of the flow field at low altitude was advantageous to the moisture convergence. The heavy snow occurred in the value of zero area of MPV1 at 850,hPa and negative area of MPV2 at 850,hPa. It pre-sented that the development of down sliding slantwise vorticity caused by both the increasing of absolute value of MPV2 and atmospheric wet baroclinity was the main reason that caused this heavy snow. This may be a good indicator for heavy snow forecast.
