DOI: 10.1002/jgrd.50120
论文题名: View-angle-dependent AIRS cloudiness and radiance variance: Analysis and interpretation
作者: Gong J. ; Wu D.L.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 5 起始页码: 2327
结束页码: 2339
语种: 英语
英文关键词: AIRS
; anvil
; asymmetry
; cloud
Scopus关键词: Air
; Climatology
; Clouds
; Infrared devices
; Uncertainty analysis
; anvil
; asymmetry
; Atmospheric circulation
; Atmospheric infrared sounders
; Global energy budget
; Measurement uncertainty
; Radiative transfer calculations
; Simultaneous measurement
; Infrared instruments
; AIRS
; anisotropy
; asymmetry
; atmospheric circulation
; climatology
; cloud cover
; extratropical environment
; humidity
; inhomogeneity
; NOAA satellite
; radiative transfer
; satellite imagery
; troposphere
; view
; wind shear
英文摘要: Upper tropospheric clouds play an important role in the global energy budget and hydrological cycle. Significant view-angle asymmetry has been observed in upper-level tropical clouds derived from 8 years of Atmospheric Infrared Sounder (AIRS) 15 μm radiances. Here we find that the asymmetry also exists in the extratropics. It is larger during day than that during night, more prominent near elevated terrain, and closely associated with deep convection and wind shear. The cloud radiance variance, a proxy for cloud inhomogeneity, has consistent characteristics of the asymmetry to those in the AIRS cloudiness. The leading causes of the view-dependent cloudiness asymmetry are the local time difference and small-scale organized cloud structures. The local time difference (1-1.5 h) of upper-level clouds between two AIRS outermost views can create parts of the observed asymmetry. On the other hand, small-scale tilted and banded structures of the upper-level clouds can induce about half of the observed view-angle-dependent differences in the AIRS cloud radiances and their variances. This estimate is inferred from analogous study using microwave humidity sounder radiances observed during the period of time when there were simultaneous measurements at two different view-angles from NOAA-18 and NOAA-19 satellites. The existence of tilted cloud structures and asymmetric 15 μm and 6.7 μm cloud radiances implies that cloud statistics would be view-angle-dependent, and should be taken into account in radiative transfer calculations, measurement uncertainty evaluations and cloud climatology investigations. In addition, the momentum forcing in the upper troposphere from tilted clouds is also likely asymmetric, which can affect atmospheric circulation anisotropically. © 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/63872
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
There are no files associated with this item.
作者单位: University Space Research Association, NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States; NASA Goddard Space Flight Center, Greenbelt MD, United States
Recommended Citation:
Gong J.,Wu D.L.. View-angle-dependent AIRS cloudiness and radiance variance: Analysis and interpretation[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(5)