STUDY OF THE RELATIONSHIP BETWEEN IWC AND Z FOR NONSPHERICAL ICE PARTICLES AT MILLIMETER WAVELENGTH

WANG Jin-hu; GE Jun-xiang; WEI Ming; GU Song-shan; YANG Ze-xin

doi:10.16555/j.1006-8775.2016.S1.008

Abstract:

Ice water content (IWC) plays important roles in weather and climate change. Determining the IWCs of cirrus clouds with millimeter-wavelength radar can be problematic due to influences of ice particle rotation on their backscattering cross sections. We here introduce models to describe the radiation patterns of six nonspherical particles of specific sizes. Simulations using HFSS software were applied to describe the differences resulting from different orientations and equivalent spheres. A double exponential function was used for fitting to describe the relationship between the particles’ maximum sizes and backscattering cross sections. The backscattering cross sections of nonspherical ice particles were computed by the method of moment, and those of the equivalent spherical particles were computed by Lorenz-Mie theory for three different orientations: fixed, horizontal, and random. Assuming that a mixture of nonspherical ice particles follows the B-H mixing model, the size distribution of cirrus particles obeys the exponential distribution measured by NASA in 2007. By computing the IWCs of cirrus clouds, which follows the above mentioned B-H model and exponential distribution, the radar reflectivity factors of nonspherical ice particles and equivalent spheres at three different orientations can be computed. Subsequently, the IWC results can be acquired by inputting the radar reflectivity variables into the well-known IWC-Z formula. The analysis described here demonstrates that when using the radar reflectivity Z, the orientation must be considered in order to determine the IWC. Using equivalent sphere theory, the derived IWCs underestimate the actual IWCs. These results are important for accurately retrieving the microphysical parameters of cirrus clouds.

Get Citation+

WANG Jin-hu, GE Jun-xiang, WEI Ming, et al. STUDY OF THE RELATIONSHIP BETWEEN IWC AND Z FOR NONSPHERICAL ICE PARTICLES AT MILLIMETER WAVELENGTH [J]. Journal of Tropical Meteorology, 2016, 22(S1): 78-88, https://doi.org/10.16555/j.1006-8775.2016.S1.008

Export:

Article Metrics

STUDY OF THE RELATIONSHIP BETWEEN IWC AND Z FOR NONSPHERICAL ICE PARTICLES AT MILLIMETER WAVELENGTH

Jiangsu Key Laboratory of Meteorological Observation and Information Processing, Nanjing University of Information Science and Technology, Nanjing 210044 China Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing

Rev Recd Date: 2016-02-26

Abstract: Ice water content (IWC) plays important roles in weather and climate change. Determining the IWCs of cirrus clouds with millimeter-wavelength radar can be problematic due to influences of ice particle rotation on their backscattering cross sections. We here introduce models to describe the radiation patterns of six nonspherical particles of specific sizes. Simulations using HFSS software were applied to describe the differences resulting from different orientations and equivalent spheres. A double exponential function was used for fitting to describe the relationship between the particles’ maximum sizes and backscattering cross sections. The backscattering cross sections of nonspherical ice particles were computed by the method of moment, and those of the equivalent spherical particles were computed by Lorenz-Mie theory for three different orientations: fixed, horizontal, and random. Assuming that a mixture of nonspherical ice particles follows the B-H mixing model, the size distribution of cirrus particles obeys the exponential distribution measured by NASA in 2007. By computing the IWCs of cirrus clouds, which follows the above mentioned B-H model and exponential distribution, the radar reflectivity factors of nonspherical ice particles and equivalent spheres at three different orientations can be computed. Subsequently, the IWC results can be acquired by inputting the radar reflectivity variables into the well-known IWC-Z formula. The analysis described here demonstrates that when using the radar reflectivity Z, the orientation must be considered in order to determine the IWC. Using equivalent sphere theory, the derived IWCs underestimate the actual IWCs. These results are important for accurately retrieving the microphysical parameters of cirrus clouds.

HTML

Reference (40)

[1]	ZHANG Lin. Study on the radiative transmission and scattering properties of cirrus clouds [D]. Master’s thesis, Xidian University, 2010:1-2. (in Chinese)
[2]	WANG Jin-hu, GE Jun-xiang, WEI Ming, et al. Research progress on theoretical computation and experimental measurement of scattering properties of ice particles [J]. Comput Tech Automat, 2013, 32 (3): 128-131 (in Chinese) .
[3]	WANG Jin-hu, GE Jun-xiang, WEI Ming, et al. Analysis of backscattering property of Cirrus cloud based on HFSS [C]. The 30th China Meteorological Conference, Nanjing, China, 2013: 1-8 (in Chinese).
[4]	FAN Ya-wen, HUANG Xing-you, LI Feng. A case study on cloud measurement with a 35 GHz millimeter-wave cloud radar [J]. Trans Atmos Sci, 2013, 36 (5): 554-559 (in Chinese).
[5]	ZHONG Ling-zhi, LIU Li-ping, GE Run-sheng. Characteristics about the millimeter-wavelength radar and its status and prospect in and abroad [J]. Adv Earth Sci, 2009, 24 (4): 383-391 (in Chinese).
[6]	WANG Jin-hu, GE Jun-xiang, WEI Ming, et al. Error analysis of equivalent sphere theory for calculating the scattering properties of ice crystals at millimeter wavelength [J]. J Henan Normal Univ (Nat Sci Ed), 2014, 42 (5): 40-44 (in Chinese).
[7]	ZHU Ya-ping, CHEN Zhou-jie, LIU Jian-Wen, et al. A technique of analyzing multi-spectral clouds for southeast coast of china based on daytime satellite imagery [J]. J Trop Meteorol, 2014, 30 (4): 612-622 (in Chinese).
[8]	TENG Xu. A study of relationships amongst Z-LWC, Z-IWC at millimeter wavelength [C]. The 30th China Meteorological Conference, Nanjing, China, 2013: 1-6 (in Chinese).
[9]	ATLAS D. The estimation of cloud parameters by radar [J]. J Meteorol, 1954, 11: 309-317.
[10]	SAUVAGEOT H, OMAR J. Radar reflectivity of cumulus clouds [J]. J Atmos Oceanic Tech, 1987, 4: 264-272
[11]	LIAO L, SASSEN K. Theoretical investigation of the relationship between ice mass content and Ka-band radar reflectivity facote [C]. 11th Int. Conference on Cloud Physics and Precipitation, Montreal, Amer Meteorol Soc, 1992: 1 005-1 008.
[12]	SEKELSKY S M, MCINTOSH R E. Cloud observation with a polarimetric 33GHz and 95 GHz [J]. Meteorol Atmos Phys, 1996, 59: 123-140.
[13]	LIU Li-ping, ZHONG Ling-zhi, JIANG Yuan et al. Cloud radar and its field experiments in China [J]. Meteorol Sci Tech, 2009, 37 (5): 567-572 (in Chinese).
[14]	WANG Zhen-hui, TENG Xu, JI Lei, et al. A study of the relationship between the attenuation coefficient and radar reflectivity factor for spherical particles in clouds at millimeter wavelengths [J]. Acta Meteorol Sinica, 2011, 69 (6): 1 020-1 028 (in Chinese).
[15]	MATROSOV S Y, HEYMSFIELD A J. Estimating ice content and extinction in precipitating cloud systems from CloudSat radar measurements [J]. J Geophys Res: Atmospheres, 2008, 113: D00A05
[16]	TYYNELA J, LEINONEN J, MOISSEEV D, et al. Radar backscattering from snowflakes: comparison of fractal, aggregate, and soft spheroid models [J]. J Atmos Oceanic Tech, 2011, 28 (11): 1 365-1 372.
[17]	HOGAN R J, TIAN L, BROWN P R A, et al. Radar scattering from ice aggregates using the horizontally aligned oblate spheroid approximation [J]. Appl Meteorol Climatol Mag, 2012, 51 (3): 655-671.
[18]	SCHNEIDER T L, STEPHENS G L. Theoretical aspects of modeling backscattering by cirrus ice particles at millimeter wavelengths [J]. J Atmos Sci, 1995, 52 (23): 4 367-4 385.
[19]	PETTY G W, HUANG W M. Microwave backscatter and extinction by soft ice spheres and complex snow aggregates [J]. J Atmos Sci, 2010, 67 (3): 769-787.
[20]	LEINONEN J, KNEIFEL S, MOISSEEV D, et al. Evidence of nonspherical behavior in millimeter-wave length radar observations of snowfall [J]. J Geophys Res: Atmospheres, 2012, 117: 1-10.
[21]	ZHANG Z B. Computation of the scattering properties of nonspherical ice crystals [D]. Texas: Texas A & M University, 2004: 57-78.
[22]	WANG Jin-hu, Ge Jun-xiang, WEI Ming. Theoretical study on single-scattering properties of ice particles of different orientation at 94 GHz [J]. Prog Electromag Res M, 2014, 36: 39-46.
[23]	WANG Jin-hu, Ge Jun-xiang, WEI Ming. The influence of aspect ratio and orientation to scattering properties of ellipsoid ice particles [J]. TELKOMNIKA Indonesian J Electr Engin, 2014, 12 (11): 7 543-7 548.
[24]	EOM H J. Electromagnetic wave theory for boundary-value problems [M]. Berlin: Springer, 2002: 125-143.
[25]	CHEW W C, JIN J M, MICHELLSEN E, et al. Song, eds. Fast and Efficient Algorithms in Computational Electromagnetics [M]. Boston: Artech House, 2001.
[26]	RAO S M. Electromagnetic scattering and radiation of arbitrary shape surfaces by triangular patch modeling[D]. Ph.D. Dissertation, Mississippi: Univ Mississippi, 1980: 1-20.
[27]	NIE Zai-ping, FANG Da-gang. Electromagnetic scattering characteristics of target and modeling, theory, method and implementation (elementary) [M]. Beijing: National Defense Industry Press, 2009a: 82-88 (in Chinese).
[28]	NIE Zai-ping, FANG Da-gang. Electromagnetic scattering characteristics of target and modeling, theory, method and implementation (advanced) [M]. Beijing: National Defense Industry Press, 2009b: 51-56 (in Chinese).
[29]	MAKAROV S. Antenna and EM modeling with MATLAB [M]. Princeton Univ Press, 2002: 10-40.
[30]	GALLAGHER M W, WHITEWAY J, FLYNN M J, et al. An overview of the microphysical structure of cirrus clouds observed during EMERALD-1 [J]. J Roy Meteorol Soc, 2004, 131: 1 143-1 169.
[31]	GANG Hong. Parameterization of scattering and absorption properties of nonspherical ice crystals at microwave frequencies [J]. J Geophys Res, 2007, 112: D11208.
[32]	AYDIN K, WALSH T M. Millimeter wave scattering from spatial and planar bullet rosettes [J]. IEEE Trans Geosci Remot Sen, 1999, 37 (2): 1 138-1 150.
[33]	ZHANG Pei-chang, DU Bing-yu, DAI Tie-pi. Radar Meteorolog, [M]. Beijing: China Meteorological Press, 2000: 145-165 (in Chinese).
[34]	TIAN L, HEYMISFIELD G M, HEYMSFIELD A J, et al. A study of cirrus ice particle size distribution using TC4 observations [J]. J Atmos Sci, 2010, 67(1): 195-216.
[35]	BAUM B A, HEYMSFIELD A J, YANG P, et al. Bulk scattering properties for the remote sensing of ice clouds. Part I: microphysical data and models [J]. J Appl Meteorol, 2005, 44: 1 885-1 895.
[36]	LIU C L, ILLINGWORTH A J. Toward more accurate retrievals of ice water content from radar measurements of clouds [J]. J Appl Meteorol, 2000, 39: 1 130-1 146.
[37]	MACE G G, HEYMSFIELD A J, POELLOT M R. On retrieving the microphysical properties of cirrus clouds using the moments of the millimeter-wavelength Doppler spectrum [J]. J Geophys Res, 2002, 107 (D24), 4815, doi:10.1029/2001JD001308.
[38]	SEO E K, LIU G . Retrievals of cloud ice water path by combining ground cloud radar and satellite high-frequency microwave measurements near the ARM SGP site [J]. J Geophy Res, 2005, 110, D14203, doi:10.1029/2004JD005727.
[39]	BROWN P R A, ILLINGWORTH A J, HEYMSFIELD A J, et al. The role of spaceborne millimeter-wave radar in the global monitoring of ice-cloud [J]. Appl Meteorol, 1995, 34: 2 346-2 366.
[40]	AYDIN K, TANG C. Relationships between IWC and polarimetric radar measurements at 94 and 220 GHz for hexagonal columns and plates [J]. J Atmos Ocean Tech, 1997, 14 (5): 1 055-1 063.

STUDY OF THE RELATIONSHIP BETWEEN IWC AND Z FOR NONSPHERICAL ICE PARTICLES AT MILLIMETER WAVELENGTH

Abstract:

References

Get Citation+

Share Article

Article Metrics

Proportional views

Manuscript History

Online:

通讯作者: 陈斌, bchen63@163.com