气候变化领域集成服务门户(CCPortal): Effects of decimetre-scale surface roughness on L-band brightness temperature of sea ice

CCPortal

DOI	10.5194/tc-14-461-2020
	Effects of decimetre-scale surface roughness on L-band brightness temperature of sea ice
	Miernecki M.; Kaleschke L.; Maaß N.; Hendricks S.; Schmidl Søbjærg S.
发表日期	2020
ISSN	19940416
EISSN	14
起始页码	461
结束页码	476
卷号	14 期号:2
英文摘要	Sea ice thickness is an essential climate variable. Current L-Band sea ice thickness retrieval methods do not account for sea ice surface roughness that is hypothesised to be not relevant to the process. This study attempts to validate this hypothesis that has not been tested yet. To test this hypothesis, we created a physical model of sea ice roughness based on geometrical optics and merged it into the L-band emissivity model of sea ice that is similar to the one used in the operational sea ice thickness retrieval algorithm. The facet description of sea ice surface used in geometrical optics is derived from 2-D surface elevation measurements. Subsequently the new model was tested with TB measurements performed during the SMOSice 2014 field campaign. Our simulation results corroborate the hypothesis that sea ice surface roughness has a marginal impact on near-nadir TB (used in the current operational retrieval). We demonstrate that the probability distribution function of surface slopes can be approximated with a parametric function whose single parameter can be used to characterise the degree of roughness. Facet azimuth orientation is isotropic at scales greater than 4.3 km. The simulation results indicate that surface roughness is a minor factor in modelling the sea ice brightness temperature. The change in TB is most pronounced at incidence angles greater than 40° and can reach up to 8 K for vertical polarisation at 60°. Therefore current and future L-band missions (SMOS, SMAP, CIMR, SMOS-HR) measuring at such angles can be affected. Comparison of the brightness temperature simulations with the SMOSice 2014 radiometer data does not yield definite results. © 2020 Copernicus GmbH. All rights reserved.
学科领域	brightness temperature; ice cover; ice thickness; sea ice; surface roughness
语种	英语
scopus关键词	brightness temperature; ice cover; ice thickness; sea ice; surface roughness
来源期刊	The Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/118762
作者单位	Institute of Oceanography (IfM), University of Hamburg, Bundesstr. 53, Hamburg, 20146, Germany; Centre d'Etudes Spatiales de la Biosphère (CESBIO), 18 avenue Edouard Belin bpi 2801, Toulouse CEDEX 9, 31401, France; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Bussestr. 24, Bremerhaven, 27570, Germany; Technical University of Denmark, Ørsteds Plads, Kgs. Lyngby, 2800, Denmark
推荐引用方式 GB/T 7714	Miernecki M.,Kaleschke L.,Maaß N.,et al. Effects of decimetre-scale surface roughness on L-band brightness temperature of sea ice[J],2020,14(2).
APA	Miernecki M.,Kaleschke L.,Maaß N.,Hendricks S.,&Schmidl Søbjærg S..(2020).Effects of decimetre-scale surface roughness on L-band brightness temperature of sea ice.The Cryosphere,14(2).
MLA	Miernecki M.,et al."Effects of decimetre-scale surface roughness on L-band brightness temperature of sea ice".The Cryosphere 14.2(2020).