DOI: 10.1002/2016JD025505
论文题名: Combining CrIS double CO2 bands for detecting clouds located in different layers of the atmosphere
作者: Lin L. ; Zou X. ; Weng F.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2017
卷: 122, 期: 3 起始页码: 1811
结束页码: 1827
语种: 英语
英文关键词: a scattering and emission index using double CO2 band measurements
; CrIS hyperspectral infrared instrument
; detection of clouds
Scopus关键词: AIRS
; brightness temperature
; carbon dioxide
; clear sky
; cloud cover
; detection method
; emission inventory
; fog
; infrared radiation
; instrumentation
; longwave radiation
; measurement method
; satellite data
; scattering
; shortwave radiation
; spatial distribution
; spectral analysis
; troposphere
; Atlantic Ocean
; Gulf of Mexico
; United States
英文摘要: Detection of clouds within certain vertical layers of the atmosphere from satellite infrared instruments is challenging, especially of those optically thin clouds due to their small thermal contrasts to the background. This study develops a new method for cloud detection by using the Cross-track Infrared Sounder (CrIS) hyperspectral radiances at shortwave (~4.3 µm) and longwave (~15 µm) CO2 bands. Specifically, CrIS longwave channels are first paired with shortwave channels based on weighting function altitudes and sensitivity to clouds. A linear relationship of brightness temperatures between each paired channel is then derived for predicting the shortwave channel from the longwave channel in clear-sky conditions. A cloud emission and scattering index (CESI) can finally be defined as the difference of the paired shortwave channel between the clear-sky, regression model predicted and the observed brightness temperatures. Spatial distributions of such derived CESI for several paired channels in the troposphere are examined for a winter storm that occurred in the eastern part of the United States during 22–24 January 2016. It is shown that the CESI values over the storm regions with optically thin cirrus, fog, and supercooled water clouds are positively larger than those over optically thick opaque ice and overshooting clouds or in clear-sky conditions. Of particular interest is that an area of fog and water clouds over Gulf of Mexico, which are indicated by the Visible Infrared Imaging Radiometer Suite day and night band observations, is identified by the CESI. The global distribution of CESIs derived from CrIS double CO2 bands with weighting functions peak around 321 hPa agrees well with the distribution of ice cloud optical thickness from the Atmospheric Infrared Sounder version 6 cloud product data set in both daytime and nighttime. ©2017. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62689
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: I. M. Systems Group, Inc., Rockville, MD, United States; ESSIC, University of Maryland, College Park, MD, United States; Center for Satellite Applications and Research, NOAA, College Park, MD, United States
Recommended Citation:
Lin L.,Zou X.,Weng F.. Combining CrIS double CO2 bands for detecting clouds located in different layers of the atmosphere[J]. Journal of Geophysical Research: Atmospheres,2017-01-01,122(3)