DOI: 10.1029/2018JD028688
Scopus记录号: 2-s2.0-85052948968
论文题名: Impact of Ice Surface and Volume Scatterings on the Microwave Sea Ice Apparent Emissivity
作者: Lee S.-M. ; Sohn B.-J. ; Shi H.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2018
卷: 123, 期: 17 起始页码: 9220
结束页码: 9237
语种: 英语
英文关键词: apparent emissivity
; effective emissivity
; ice surface roughness
; microwave
; sea ice emissivity
; sea ice volume scattering
英文摘要: Emissivity retrieval for sea ice from passive microwave measurements has been an important problem in climate/environmental research because of its link to various snow/ice variables. However, so far, it has been a difficult task because of the influences of surface and snow/ice induced volume scatterings. Here we examine the influences of scatterings on the ice emissivity from 10.65, 18.7, 23.8, and 36.5 GHz Advanced Microwave Scanning Radiometer (AMSR)-E brightness temperatures over the Arctic Ocean. In doing so, we use a two-dimensional roughness parameterization, modified with surface facet orientations with an assumption that the facet emission follows the Fresnel relationship. Emitting layer temperature and refractive index retrieved from AMSR-E 6.9 GHz brightness temperature measurements were used in this study and applied to other channels of interest. We demonstrated that the obtained roughness index has a strong linear relationship with the root-mean-square height measured by Atmospheric Terrain Mapper on the National Aeronautics and Space Administration (NASA) P-3 aircraft. The obtained roughness index showed that surface scattering on the emissivity is generally insignificant except for some first-year ice regions in particular at higher frequencies. This fact implies that Fresnel relations can be applicable for most of sea ice at the low-frequency microwave spectrum. By contrast, volume scattering is found to be significant in emissivity retrieval in case of multiyear ice. Nonetheless, volume scattering influence over first-year ice appears to be minor. We suggest that Fresnel-type emissivity can be estimated once a correction factor is used for removing surface scattering and volume scattering contributions from the apparent emissivity. ©2018. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113199
Appears in Collections: 气候减缓与适应
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作者单位: School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea
Recommended Citation:
Lee S.-M.,Sohn B.-J.,Shi H.. Impact of Ice Surface and Volume Scatterings on the Microwave Sea Ice Apparent Emissivity[J]. Journal of Geophysical Research: Atmospheres,2018-01-01,123(17)