DOI: 10.1002/jgrd.50163
论文题名: Linking snowflake microstructure to multi-frequency radar observations
作者: Leinonen J. ; Moisseev D. ; Nousiainen T.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 8 起始页码: 3259
结束页码: 3270
语种: 英语
英文关键词: backscattering
; microphysics
; radar
; snowfall
Scopus关键词: Backscattering
; Density functional theory
; Ice
; Microstructure
; Radar
; Regression analysis
; Autocorrelation functions
; Function of frequency
; Microphysics
; Particle microstructure
; Radar backscattering
; Radar reflectivities
; Significant differences
; Spheroidal particles
; Snow
; aggregate
; backscatter
; Gaussian method
; ice crystal
; microstructure
; radar
; Rayleigh number
; snow
英文摘要: Spherical or spheroidal particle shape models are commonly used to calculate numerically the radar backscattering properties of aggregate snowflakes. A more complicated and computationally intensive approach is to use detailed models of snowflake structure together with numerical scattering models that can operate on arbitrary particle shapes. Recent studies have shown that there can be significant differences between the results of these approaches. In this paper, an analytical model, based on the Rayleigh-Gans scattering theory, is formulated to explain this discrepancy in terms of the effect of discrete ice crystals that constitute the snowflake. The ice crystals cause small-scale inhomogeneities whose effects can be understood through the density autocorrelation function of the particle mass, which the Rayleigh-Gans theory connects to the function that gives the radar reflectivity as a function of frequency. The derived model is a weighted sum of two Gaussian functions. A term that corresponds to the average shape of the particle, similar to that given by the spheroidal shape model, dominates at low frequencies. At high frequencies, that term vanishes and is gradually replaced by the effect of the ice crystal monomers. The autocorrelation-based description of snowflake microstructure appears to be sufficient for multi-frequency radar studies. The link between multi-frequency radar observations and the particle microstructure can thus be used to infer particle properties from the observations. ©2013. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63802
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Earth Observation, Finnish Meteorological Institute, Helsinki, Finland; Department of Applied Physics, Aalto University, Espoo, Finland; Department of Physics, University of Helsinki, Helsinki, Finland
Recommended Citation:
Leinonen J.,Moisseev D.,Nousiainen T.. Linking snowflake microstructure to multi-frequency radar observations[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(8)