等熵位涡分析法对内蒙古西部一次强沙尘暴特征的揭示  

The Characteristics of a Strong Sandstorm in Western Inner Mongolia Revealed by Isentropic Potential Vorticity Analysis

作　　者：邢彬[1] XING Bin(Alxa League Meteorological Bureau,Alxa League,Inner Mongolia 750306)

机构地区：[1]阿拉善盟气象局,内蒙古阿拉善盟750306

出　　处：《农业灾害研究》2022年第10期31-33,共3页Journal of Agricultural Catastrophology

摘　　要：利用地面常规观测资料和NCEP/UCAR提供的逐日1°×1°间隔6 h FNL模式的全球对流层分析资料,对2019年5月11—12日发生在内蒙古西部地区的强沙尘暴事件进行等熵位涡分析。结果表明:沙尘暴发生时,从位温垂直剖面图上分析可以得到各等压面上位温垂直分布特征;在850~700 hPa上,等位温线近似垂直与横坐标,位温随着等压面升高而不变,低层大气十分接近绝热状态,混合层状态特征显著。在700~200 hPa上,取4个可以覆盖沙尘暴发生区域的位温垂直剖面图,位温取交集合并得位温取值范围;根据位温取值范围和相应的位势高度场,选取需要的位温,计算得到位势高度和位温所对应的等熵位涡;等熵位涡与位势高度场、全风速场、高空急流、西风低空急流、强沙尘暴发生区域之间存在着数值关系特征和位置关系特征。Based on the routine observation data on the ground and the global tropospheric analysis data of FNL model with 1°×1°interval of 6 hours per day provided by NCEP/UCAR,the isentropic Potential Vorticity Analysis of the strong sandstorm event occurred in western Inner Mongolia from May 11 to 12,2019 is carried out.The results show that the vertical distribution characteristics of the upper temperature on each isobaric surface can be obtained from the analysis of the vertical profile of the potential temperature when the dust storm occurs;From 850 hPa to 700 hPa,the equipotential temperature line is approximately perpendicular to the abscissa.The equipotential temperature does not change with the rise of the isobaric surface.The lower atmosphere is very close to the adiabatic state,and the state characteristics of the mixed layer are significant.From 700 hPa to 200 hPa,take four vertical profiles of potential temperature that can cover the sand dust storm occurrence area,and take the intersection of potential temperature to obtain the value range of potential temperature;According to the range of potential temperature and the corresponding potential height field,the required potential temperature is selected,and the isentropic potential vorticity corresponding to the potential height and potential temperature is calculated;There are numerical and positional characteristics between isentropic potential vorticity and potential height field,full wind speed field,upper jet stream,westerly low-level jet stream and strong dust storm occurrence area.

关 键 词：强沙尘暴 位温 等熵位涡 

分 类 号：P425.55[天文地球—大气科学及气象学]