CAJ | 학술논문

利用常规气象观测资料、降雪加密观测资料和NCEP的1°×1°再分析资料，对2009年11月10—12日和2011年11月29—30日河北省南部两次回流暴雪天气过程进行对比分析。结果表明：河北省南部两次回流暴雪的时空分布具有中尺度特征。两次回流暴雪的典型天气形势为500 hPa高空河套地区有低压槽东移，700 hPa有切变线影响，地面蒙古冷高压东移至东北地区南下，河套倒槽发展，华北地面为东高西低形势。回流暴雪过程中高低空急流有非常重要的作用，冷空气自850 hPa以下随强劲的东北风回流至河北省南部形成冷垫，700 hPa暖湿气流随西南急流输送至河北省南部叠加在冷垫上辐合抬升，高空200 hPa急流右后侧的辐散抽吸作用使上升运动加强。华北平原高空存在一支垂直环流，边界层东北风到达太行山东麓，在迎风坡抬升至对流层中高层转为西南风，到达东北地区转为下沉气流，再与低层东北风构成一个完整的垂直环流。θse密集区由地面向上向北伸展至700 hPa，锋面结构特征明显，锋面的前沿从北向南推进，地面锋面附近850 hPa以下等θse线与地面垂直，具有对流中性层结。回流强降雪发生在地面锋后冷气团中。
이용상규기상관측자료、강설가밀관측자료화NCEP적1°×1°재분석자료，대2009년11월10—12일화2011년11월29—30일하북성남부량차회류폭설천기과정진행대비분석。결과표명：하북성남부량차회류폭설적시공분포구유중척도특정。량차회류폭설적전형천기형세위500 hPa고공하투지구유저압조동이，700 hPa유절변선영향，지면몽고랭고압동이지동북지구남하，하투도조발전，화북지면위동고서저형세。회류폭설과정중고저공급류유비상중요적작용，랭공기자850 hPa이하수강경적동북풍회류지하북성남부형성랭점，700 hPa난습기류수서남급류수송지하북성남부첩가재랭점상복합태승，고공200 hPa급류우후측적복산추흡작용사상승운동가강。화북평원고공존재일지수직배류，변계층동북풍도체태행산동록，재영풍파태승지대류층중고층전위서남풍，도체동북지구전위하침기류，재여저층동북풍구성일개완정적수직배류。θse밀집구유지면향상향북신전지700 hPa，봉면결구특정명현，봉면적전연종북향남추진，지면봉면부근850 hPa이하등θse선여지면수직，구유대류중성층결。회류강강설발생재지면봉후랭기단중。
Using the conventional observational meteorological data from weather stations and snowfall data from intensive automatic weather stations as well as the NCEP reanalysis data with resolution of 1 °×1 °,two return-flow snowstorm processes on November 10-12,2009 and November 29-30,201 1 in the southern Hebei province were compared.The results show that spatial and temporal distributions of the two processes have mesoscale features. Low trough moves eastward at 500 hPa in Hetao area and it has shear line at 700 hPa;the Mongolian cold high pressure in the ground moves to east and arrives in the northeastern China,and inverted trough develops in Hetao area;surface pressure is higher in east and lower in west of the north China.All the mentioned-above are the typi-cal weather patterns of the two return-flow snowstorms.Upper-level and low-level jets play a very important role during the return-flow snowstorm.Cold air returns to the southern Hebei province with the northeast stream under 850 hPa and forms cold cushion.Moist air is transported into the southern Hebei province with southwest jet and convergence uplifts on cold cushion at 700 hPa.Upward movement is strengthened by divergence pumping action on the right rear side of 200 hPa upper-level jet.There is a vertical circulation in the North China plain.The north-east wind of boundary layer arrives in the east side of Taihang Mountain then lifts to mid-upper troposphere,and it becomes southwest wind and flows to northeastern China,where it becomes downward flow and finally forms a complete vertical circulation with low-level northeast wind.The intensive area ofθse stretches to 700 hPa from the ground,and frontal structure is obvious.Front advances from north to south.θse lines are upright from the ground to 850 hPa near the front.Atmospheric stratification is neutral convection stability.Return-flow snowfall happens in cold air mass after ground front.