Ka波段毫米波云雷达多普勒谱降雪微物理特征分析
|
摘要
构建了一种基于毫米波云雷达多普勒谱的过冷水滴、冰晶、雪花的识别算法,通过对全局谱的谱峰识别,分离出了不同类型粒子的局部谱,得出了不同类型粒子的反射率因子、多普勒速度、谱宽等谱矩参数及含水量.通过对一次降雪过程Ka波段测云雷达多普勒谱的分析,结果表明:(1)混合相云中,由于雪花对毫米波雷达总回波强度贡献较大,基于总雷达反射率因子直接反演液态水含量会忽略过冷水滴的贡献,造成云中含水量的低估;(2)多普勒谱反演得到过冷水的液态水路径(LWP)与微波辐射计反演结果一致性较好,说明毫米波雷达能够有效估量云中液态水路径;(3)冰雪晶粒子在过冷水层(SWL)中下落速度随反射率因子的变化梯度(d V/d Z)比在冰雪层(ISL)中大,这主要是因为冰雪晶粒子在SWL中通过凇附增长比在ISL中通过碰并增长要增长得更快.
The identification of supercooled water droplets in the cloud is of great significance for the physical process of cloud-precipitation and warning aircraft icing. In this paper,the spectral peak recognition algorithm is established by the U. S. ARM1-AMF2 spectral data of the 35 GHz cloud radar in Finland. The spectral separation of the total spectrum is obtained,and then the supercooled water droplets are identified. Next the supercooled water droplets are identified. Next,the reflectivity,doppler velocity and spectral width of different types of particles are calculated by spectral moment. Finally,the liquid water content in the cloud is retrieved from the empirical relationship and compared with the detection results of the microwave radiometer. The results are as follows( 1) The radar reflectivity factor of mixed-phase clouds mainly depends on snow. Therefore,it is considered that the effective volume of radar is snow. The cloud liquid water content will be underestimated according to the total reflectivity.( 2) The gradient of Doppler velocity( V) of ice and snowparticles in the supercooled water layer( SWL) larger than that in the ice and snowlayer( ISL).( 3) The liquid path( LWP) obtained by the Doppler spectrum is good agreement with the microwave radiometer. It shows that the millimeter wave radar can effectively estimate the liquid water path in the cloud.
The identification of supercooled water droplets in the cloud is of great significance for the physical process of cloud-precipitation and warning aircraft icing. In this paper,the spectral peak recognition algorithm is established by the U. S. ARM1-AMF2 spectral data of the 35 GHz cloud radar in Finland. The spectral separation of the total spectrum is obtained,and then the supercooled water droplets are identified. Next the supercooled water droplets are identified. Next,the reflectivity,doppler velocity and spectral width of different types of particles are calculated by spectral moment. Finally,the liquid water content in the cloud is retrieved from the empirical relationship and compared with the detection results of the microwave radiometer. The results are as follows( 1) The radar reflectivity factor of mixed-phase clouds mainly depends on snow. Therefore,it is considered that the effective volume of radar is snow. The cloud liquid water content will be underestimated according to the total reflectivity.( 2) The gradient of Doppler velocity( V) of ice and snowparticles in the supercooled water layer( SWL) larger than that in the ice and snowlayer( ISL).( 3) The liquid path( LWP) obtained by the Doppler spectrum is good agreement with the microwave radiometer. It shows that the millimeter wave radar can effectively estimate the liquid water path in the cloud.
引文
[1]CHEN Yi-Chen,JIN Yong-Li,DING De-Ping,et al.Preliminary analysis on the application of millimeter wave cloud radar in snow observation[J].Chinese Journal of Atmospheric Sciences(陈羿辰,金永利,丁德平,等.毫米波测云雷达在降雪观测中的应用初步分析.大气科学),2018,42(1):134-149.
[2]Kollias P,Clothiaux E E,Albrecht B A,et al.The atmospheric radiation measurement program cloud profiling radars:An evaluation of signal processing and sampling strategies[J].Journal of Atmospheric&Oceanic Technology,2005,22(7):930-948.
[3]Moran K P,Martner B E,Post M J,et al.An unattended cloud-profiling radar for use in climate research.[J].Bulletin of the American Meteorological Society,1998,79(3):443-455.
[4]Hamazu K,Hashiguchi H,Wakayama T,et al.A 35 GHz scanning Doppler radar for fog observations[J].Journal of Atmospheric&Oceanic Technology,2003,20(7):972-986.
[5]郑佳锋.Ka波段-多模式亳米波雷达功率谱数椐处理方法及云内大气垂直速度反演研究[D].中国气象科学研究院,2016.
[6]Shupe M D,Kollias P,Matrosov S Y,et al.Deriving mixed-phase cloud properties from Doppler radar spectra[J].Journal of Atmospheric&Oceanic Technology,2004,21(21):660-670.
[7]Luke E P,Pavlos K,Shupe M D.Detection of supercooled liquid in mixed‐phase clouds using radar Doppler spectra[J].Journal of Geophysical Research Atmospheres,2012,115(D19):201.
[8]Oue M,Kollias P,Ryzhkov A,et al.Toward exploring the synergy between cloud radar polarimetry and Doppler spectral analysis in deep cold precipitating systems in the Arctic[J].Journal of Geophysical Research Atmospheres,2018,123(5):2797-2815.
[9]Kneifel S,Kollias P,Battaglia A,et al.First observations of triple‐frequency radar Doppler spectra in snowfall:Interpretation and applications[J].Geophysical Research Letters,2016,43(5):2225-2233.
[10]WANG Liu-Liu,LIU Li-Ping,YU Ji-Zhou,et al.Microphysics and Dynamic characteristic analysis of freezing rain and snow observed by millimeter wave radar[J].Meteorological Monthly(王柳柳,刘黎平,余继周,等.毫米波云雷达冻雨-降雪微物理和动力特征分析.气象),2017,43(12):1473-1486.
[11]PetT,O'Connor E J,Moisseev D,et al.BAECC:A field campaign to elucidate the impact of biogenic aerosols on clouds and climate[J].Bulletin of the American Meteorological Society,2016,97(10):1909-1928.
[12]Kneifel S,Lerber A,Tiira J,et al.Observed relations between snowfall microphysics and triple‐frequency radar measurements[J].Journal of Geophysical Research Atmospheres,2015,120(12):6034-6055.
[13]L9hnert U,Crewell S.Accuracy of cloud liquid water path from ground‐based microwave radiometry 1.Dependency on cloud model statistics[J].Radio Science,2003,38(3):8041-8051.
[14]Marchand R,Ackerman T,Westwater E R,et al.An assessment of microwave absorption models and retrievals of cloud liquid water using clear﹕ky data[J].Journal of Geophysical Research Atmospheres,2003,108(D24):4773-4783.
[15]Hildebrand P H.Objective determination of the noise level in Doppler spectra[J].Journal of Applied Meteorology,1974,13(7):808-811.
[16]ZHANG Yong-Tao,JIA Yan-Ming.Analysis and program implementation ofleast squares polynomial curve fitting[J].Computer&Digital Engineering(张永涛,贾延明.最小二乘法中代数多项式曲线拟合的分析及实现.计算机与数字工程),2017,45(4):637-639.
[17]Kollias P,Albrecht B A,Lhermitte R,et al.Radar observations of updrafts,downdrafts,and turbulence in fairweather cumuli.[J].Journal of the Atmospheric Sciences,2001,58(13):1750-1766.
[18]Shupe M D.A ground-based multisensor cloud phase classifier[J].Geophysical Research Letters,2007,34(22):48-55.
[19]盛裴轩.大气物理学[M].北京大学出版社,2013.
[20]Sassen K,Liao L.Estimation of cloud content by W-band radar.[J].Journal of Applied Meteorology,2010,35(6):932-938.
[21]Straka J M,Zrni D S,Ryzhkov A V.Bulk hydrometeor classification and quantification using polarimetric radar data:Synthesis of relations.[J].Journal of Applied Meteorology,2000,39(8):1341-1372.
[22]Kalesse H,Kollias P,Szyrmer W.On using the relationship between Doppler velocity and radar reflectivity to identify microphysical processes in midlatitudinal ice clouds[J].Journal of Geophysical Research Atmospheres,2013,118(21):12-12,179.
[23]Griggs D J,Choularton T W.The effect of rimer surface temperature on ice splinter production by the HallettMossop process[J].Quarterly Journal of the Royal Meteorological Society,2010,112(474):1254-1256.
[2]Kollias P,Clothiaux E E,Albrecht B A,et al.The atmospheric radiation measurement program cloud profiling radars:An evaluation of signal processing and sampling strategies[J].Journal of Atmospheric&Oceanic Technology,2005,22(7):930-948.
[3]Moran K P,Martner B E,Post M J,et al.An unattended cloud-profiling radar for use in climate research.[J].Bulletin of the American Meteorological Society,1998,79(3):443-455.
[4]Hamazu K,Hashiguchi H,Wakayama T,et al.A 35 GHz scanning Doppler radar for fog observations[J].Journal of Atmospheric&Oceanic Technology,2003,20(7):972-986.
[5]郑佳锋.Ka波段-多模式亳米波雷达功率谱数椐处理方法及云内大气垂直速度反演研究[D].中国气象科学研究院,2016.
[6]Shupe M D,Kollias P,Matrosov S Y,et al.Deriving mixed-phase cloud properties from Doppler radar spectra[J].Journal of Atmospheric&Oceanic Technology,2004,21(21):660-670.
[7]Luke E P,Pavlos K,Shupe M D.Detection of supercooled liquid in mixed‐phase clouds using radar Doppler spectra[J].Journal of Geophysical Research Atmospheres,2012,115(D19):201.
[8]Oue M,Kollias P,Ryzhkov A,et al.Toward exploring the synergy between cloud radar polarimetry and Doppler spectral analysis in deep cold precipitating systems in the Arctic[J].Journal of Geophysical Research Atmospheres,2018,123(5):2797-2815.
[9]Kneifel S,Kollias P,Battaglia A,et al.First observations of triple‐frequency radar Doppler spectra in snowfall:Interpretation and applications[J].Geophysical Research Letters,2016,43(5):2225-2233.
[10]WANG Liu-Liu,LIU Li-Ping,YU Ji-Zhou,et al.Microphysics and Dynamic characteristic analysis of freezing rain and snow observed by millimeter wave radar[J].Meteorological Monthly(王柳柳,刘黎平,余继周,等.毫米波云雷达冻雨-降雪微物理和动力特征分析.气象),2017,43(12):1473-1486.
[11]PetT,O'Connor E J,Moisseev D,et al.BAECC:A field campaign to elucidate the impact of biogenic aerosols on clouds and climate[J].Bulletin of the American Meteorological Society,2016,97(10):1909-1928.
[12]Kneifel S,Lerber A,Tiira J,et al.Observed relations between snowfall microphysics and triple‐frequency radar measurements[J].Journal of Geophysical Research Atmospheres,2015,120(12):6034-6055.
[13]L9hnert U,Crewell S.Accuracy of cloud liquid water path from ground‐based microwave radiometry 1.Dependency on cloud model statistics[J].Radio Science,2003,38(3):8041-8051.
[14]Marchand R,Ackerman T,Westwater E R,et al.An assessment of microwave absorption models and retrievals of cloud liquid water using clear﹕ky data[J].Journal of Geophysical Research Atmospheres,2003,108(D24):4773-4783.
[15]Hildebrand P H.Objective determination of the noise level in Doppler spectra[J].Journal of Applied Meteorology,1974,13(7):808-811.
[16]ZHANG Yong-Tao,JIA Yan-Ming.Analysis and program implementation ofleast squares polynomial curve fitting[J].Computer&Digital Engineering(张永涛,贾延明.最小二乘法中代数多项式曲线拟合的分析及实现.计算机与数字工程),2017,45(4):637-639.
[17]Kollias P,Albrecht B A,Lhermitte R,et al.Radar observations of updrafts,downdrafts,and turbulence in fairweather cumuli.[J].Journal of the Atmospheric Sciences,2001,58(13):1750-1766.
[18]Shupe M D.A ground-based multisensor cloud phase classifier[J].Geophysical Research Letters,2007,34(22):48-55.
[19]盛裴轩.大气物理学[M].北京大学出版社,2013.
[20]Sassen K,Liao L.Estimation of cloud content by W-band radar.[J].Journal of Applied Meteorology,2010,35(6):932-938.
[21]Straka J M,Zrni D S,Ryzhkov A V.Bulk hydrometeor classification and quantification using polarimetric radar data:Synthesis of relations.[J].Journal of Applied Meteorology,2000,39(8):1341-1372.
[22]Kalesse H,Kollias P,Szyrmer W.On using the relationship between Doppler velocity and radar reflectivity to identify microphysical processes in midlatitudinal ice clouds[J].Journal of Geophysical Research Atmospheres,2013,118(21):12-12,179.
[23]Griggs D J,Choularton T W.The effect of rimer surface temperature on ice splinter production by the HallettMossop process[J].Quarterly Journal of the Royal Meteorological Society,2010,112(474):1254-1256.