NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Spectral Kernel Approach to Study Radiative Response of Climate Variables and Interannual Variability of Reflected Solar SpectrumThe radiative kernel approach provides a simple way to separate the radiative response to different climate parameters and to decompose the feedback into radiative and climate response components. Using CERES/MODIS/Geostationary data, we calculated and analyzed the solar spectral reflectance kernels for various climate parameters on zonal, regional, and global spatial scales. The kernel linearity is tested. Errors in the kernel due to nonlinearity can vary strongly depending on climate parameter, wavelength, surface, and solar elevation; they are large in some absorption bands for some parameters but are negligible in most conditions. The spectral kernels are used to calculate the radiative responses to different climate parameter changes in different latitudes. The results show that the radiative response in high latitudes is sensitive to the coverage of snow and sea ice. The radiative response in low latitudes is contributed mainly by cloud property changes, especially cloud fraction and optical depth. The large cloud height effect is confined to absorption bands, while the cloud particle size effect is found mainly in the near infrared. The kernel approach, which is based on calculations using CERES retrievals, is then tested by direct comparison with spectral measurements from Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) (a different instrument on a different spacecraft). The monthly mean interannual variability of spectral reflectance based on the kernel technique is consistent with satellite observations over the ocean, but not over land, where both model and data have large uncertainty. RMS errors in kernel ]derived monthly global mean reflectance over the ocean compared to observations are about 0.001, and the sampling error is likely a major component.
Document ID
20110012701
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Jin, Zhonghai (Science Systems and Applications, Inc. Hampton, VA, United States)
Wielicki, Bruce A. (NASA Langley Research Center Hampton, VA, United States)
Loukachine, Constantin (NASA Langley Research Center Hampton, VA, United States)
Charlock, Thomas P. (NASA Langley Research Center Hampton, VA, United States)
Young, David (NASA Langley Research Center Hampton, VA, United States)
Noeel, Stefan (Bremen Univ. Germany)
Date Acquired
August 25, 2013
Publication Date
May 26, 2011
Publication Information
Publication: Journal of Geophysical Research
Volume: 116
ISSN: 0148-0227
Subject Category
Meteorology and Climatology
Report/Patent Number
NF1676L-12943
Distribution Limits
Public
Copyright
Other