 |
| Titel |
Global and regional evaluation of over-land spectral aerosol optical depth retrievals from SeaWiFS |
| VerfasserIn |
A. M. Sayer, N. C. Hsu, C. Bettenhausen, M.-J. Jeong, B. N. Holben, J. Zhang |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1867-1381
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 5, no. 7 ; Nr. 5, no. 7 (2012-07-25), S.1761-1778 |
| Datensatznummer |
250003014
|
| Publikation (Nr.) |
 copernicus.org/amt-5-1761-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| This study evaluates a new spectral aerosol optical depth (AOD) dataset
derived from Sea-viewing Wide Field-of-view Sensor (SeaWiFS) measurements
over land. First, the data are validated against Aerosol Robotic Network
(AERONET) direct-sun AOD measurements and found to compare well on a global
basis. If only data with the highest quality flag are used, the correlation
is 0.86 and 72% of matchups fall within an expected absolute uncertainty
of 0.05 + 20% (for the wavelength of 550 nm). The quality is similar at
other wavelengths and stable over the 13-yr (1997–2010) mission length.
Performance tends to be better over vegetated, low-lying terrain with typical
AOD of 0.3 or less, such as found over much of North America and Eurasia.
Performance tends to be poorer for low-AOD conditions near backscattering
geometries, where SeaWiFS overestimates AOD, or optically-thick cases of
absorbing aerosol, where SeaWiFS tends to underestimate AOD. Second, the
SeaWiFS data are compared with midvisible AOD derived from the Moderate
Resolution Imaging Spectrometer (MODIS) and Multiangle Imaging
Spectroradiometer (MISR). All instruments show similar spatial and seasonal
distributions of AOD, although there are regional and seasonal offsets
between them. At locations where AERONET data are available, these offsets
are largely consistent with the known validation characteristics of each
dataset. With the results of this study in mind, the SeaWiFS over-land AOD
record is suitable for quantitative scientific use. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|