大气科学学报
大氣科學學報
대기과학학보
JOURNAL OF NANJING INSTITUTE OF METEOROLOGY
2012年
2期
186-196
,共11页
刘莹莹%牛生杰%封秋娟%刘端阳%陆春松%刘霖蔚
劉瑩瑩%牛生傑%封鞦娟%劉耑暘%陸春鬆%劉霖蔚
류형형%우생걸%봉추연%류단양%륙춘송%류림위
积云并合%微物理结构%粒子谱分布
積雲併閤%微物理結構%粒子譜分佈
적운병합%미물리결구%입자보분포
cloud merger%microphysical structure%size distribution
利用2009年5月8日多普勒雷达资料和飞机穿云观测资料,综合分析了西风槽影响下山西省一次积层混合云的形成过程和微物理结构。结果表明,此次飞机探测到的积层混合云是由对流单体多次并合形成的带状对流云团减弱后形成的,云中嵌有明显的对流泡,最大强度为45~50dBZ,最大垂直尺度在6km左右。CDP(cloud droplet probe,前向散射粒子谱探头)、CIP(cloud ima-ging probe,二维灰度云粒子探头)、PIP(precipitation imaging probe,二维灰度降水粒子探头)测量的平均数浓度变化范围分别是132.4~220.2cm-3、1.54×10-1~6.28×100cm-3、9.09×10-4~7.34×10-3cm-3。二维图像表明,冷层中的固态粒子主要是形状不规则的霰粒子,说明过冷水供应充足;在-7℃左右观测到柱状聚合体和凇附程度不同的冰雪晶粒子,表明柱状冰晶通过凝华形成后,碰并和凇附是其增长为霰粒子的重要机制。不同高度的CDP平均谱(2~50μm)存在一定的差异,因低层水汽凝结作用较强,2~18μm的云粒子数浓度基本随高度的增加而降低;因暖层中碰并效率低和冷层中小冰晶浓度随高度增加,24~35μm粒子数浓度随高度增加而增大。CIP平均谱(25~1550μm),除4100m为双峰谱外,其他高度均为单峰谱。PIP平均谱(100~6200μm),4450m高度处的粒子谱宽和数浓度最大,3200~4000μm之间出现大值区域,表明对流单体及周边区域为较大固态降水粒子的形成提供了良好的环境。
利用2009年5月8日多普勒雷達資料和飛機穿雲觀測資料,綜閤分析瞭西風槽影響下山西省一次積層混閤雲的形成過程和微物理結構。結果錶明,此次飛機探測到的積層混閤雲是由對流單體多次併閤形成的帶狀對流雲糰減弱後形成的,雲中嵌有明顯的對流泡,最大彊度為45~50dBZ,最大垂直呎度在6km左右。CDP(cloud droplet probe,前嚮散射粒子譜探頭)、CIP(cloud ima-ging probe,二維灰度雲粒子探頭)、PIP(precipitation imaging probe,二維灰度降水粒子探頭)測量的平均數濃度變化範圍分彆是132.4~220.2cm-3、1.54×10-1~6.28×100cm-3、9.09×10-4~7.34×10-3cm-3。二維圖像錶明,冷層中的固態粒子主要是形狀不規則的霰粒子,說明過冷水供應充足;在-7℃左右觀測到柱狀聚閤體和凇附程度不同的冰雪晶粒子,錶明柱狀冰晶通過凝華形成後,踫併和凇附是其增長為霰粒子的重要機製。不同高度的CDP平均譜(2~50μm)存在一定的差異,因低層水汽凝結作用較彊,2~18μm的雲粒子數濃度基本隨高度的增加而降低;因暖層中踫併效率低和冷層中小冰晶濃度隨高度增加,24~35μm粒子數濃度隨高度增加而增大。CIP平均譜(25~1550μm),除4100m為雙峰譜外,其他高度均為單峰譜。PIP平均譜(100~6200μm),4450m高度處的粒子譜寬和數濃度最大,3200~4000μm之間齣現大值區域,錶明對流單體及週邊區域為較大固態降水粒子的形成提供瞭良好的環境。
이용2009년5월8일다보륵뢰체자료화비궤천운관측자료,종합분석료서풍조영향하산서성일차적층혼합운적형성과정화미물리결구。결과표명,차차비궤탐측도적적층혼합운시유대류단체다차병합형성적대상대류운단감약후형성적,운중감유명현적대류포,최대강도위45~50dBZ,최대수직척도재6km좌우。CDP(cloud droplet probe,전향산사입자보탐두)、CIP(cloud ima-ging probe,이유회도운입자탐두)、PIP(precipitation imaging probe,이유회도강수입자탐두)측량적평균수농도변화범위분별시132.4~220.2cm-3、1.54×10-1~6.28×100cm-3、9.09×10-4~7.34×10-3cm-3。이유도상표명,랭층중적고태입자주요시형상불규칙적산입자,설명과랭수공응충족;재-7℃좌우관측도주상취합체화송부정도불동적빙설정입자,표명주상빙정통과응화형성후,팽병화송부시기증장위산입자적중요궤제。불동고도적CDP평균보(2~50μm)존재일정적차이,인저층수기응결작용교강,2~18μm적운입자수농도기본수고도적증가이강저;인난층중팽병효솔저화랭층중소빙정농도수고도증가,24~35μm입자수농도수고도증가이증대。CIP평균보(25~1550μm),제4100m위쌍봉보외,기타고도균위단봉보。PIP평균보(100~6200μm),4450m고도처적입자보관화수농도최대,3200~4000μm지간출현대치구역,표명대류단체급주변구역위교대고태강수입자적형성제공료량호적배경。
Based on the Doppler radar data and cloud microphysical data collected by aircraft,the formation and microphysics of a convective-stratiform mixed cloud(CSMC for short) impacted by westerly trough have been analyzed.The results are as follows.CSMC came into being from weakened zonal convective which was merged by small convective clouds.Apparent convection cells with the maximum intensity of 45—50 dBZ and the maximum vertical height of 6 km were embedded in the CSMC.The particle number concentrations measured by CDP,CIP,and PIP were 132.4—220.2 cm-3,1.54×10-1—6.28×100 cm-3and 9.09×10-4—7.34×10-3 cm-3,respectively.Two dimensional images show that graupel is the main ice particles in the cold layer,which implies that supercooled water is adequate;columnar aggregates and riming particles found at-7 ℃ imply that after columnar crystal is formed by sublimation,collision and riming are important mechanisms for graupel's formation.The average CDP spectra(diameter:2—50 μm) are different with the heights,and the concentration of particles between 2 and 18 μm decreases with height rising,because water vapor condensation is stronger in the low-level,but the concentration of those between 24 and 35 μm increases,because the collision efficiency is lower in the warm cloud and small ice particle number increases with the height rising.The average CIP spectra(diameter:25—1 550μm) follow unimodal distributions except for that at 4 100 m.The average PIP spectra(diameter:100—6 200 μm) are discontinuous at the larger size;the largest concentration and the spectral width occur at 4 450 m and the high number concentration between 3 200 and 4 000 μm implies that convective cells and the surrounding area provide a good environment for the growth of larger solid precipitation particles.