NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
A Critical Look at Deriving Monthly Aerosol Optical Depth from Satellite DataSatellite-derived aerosol data sets, such as those provided by NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instruments, are greatly improving our understanding of global aerosol optical depth (AOD). Yet, there are sampling issues. MODIS specific orbital geometry, convolved with the need to avoid bright surfaces (glint, desert, clouds, etc.), means that AOD can be under- or over-sampled in places. When deriving downstream products, such as daily or monthly gridded AOD, one must consider the spatial and temporal density of the measurements relative to the gradients of the true AOD. Additionally, retrieval confidence criteria should be considered. Averaged products are highly dependent on choices made for data aggregation and weighting, and sampling errors can be further propagated when deriving regional or global mean AOD. Different choices for aggregation and weighting result in estimates of regional and global means varying by 30% or more. The impacts of a particular averaging algorithm vary by region and surface type and can be shown to represent different tolerance for clouds and retrieval confidence.
Document ID
20100033711
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Levy, R. C.
(Science Systems and Applications, Inc. Lanham, MD, United States)
Leptoukh, Gregory, G.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Kahn, Ralph
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Gopalan, Arun
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 25, 2013
Publication Date
March 31, 2009
Publication Information
Publication: Geoscience and Remote Sensing, IEEE Transactions on
Publisher: Institute of Electrical and Electronics Engineers
Volume: 47
Issue: 8
ISSN: 0196-2892
Subject Category
Meteorology And Climatology
Funding Number(s)
CONTRACT_GRANT: BS123456
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available