Share Email Print
cover

Proceedings Paper

Problems in assessment of the UV penetration into natural waters from space-based measurements
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

Satellite instruments currently provide global maps of surface UV irradiance by combining backscattered radiance data with radiative transfer models. The models are often limited by uncertainties in physical input parameters of the atmosphere and surface. Global mapping of the underwater UV irradiance creates further challenges for the models. The uncertainties in physical input parameters become more serious because of the presence of absorbing and scattering quantities affected by biological processes within the oceans. In this presentation we summarize the problems encountered in the assessment of the underwater UV irradiance from space-based measurements, and propose approaches to resolve the problems. We have developed a radiative transfer scheme for computation of the UV irradiance in the atmosphere-ocean system. The scheme makes use of input parameters derived from satellite instruments such as TOMS and SeaWiFS. The major problem in assessment of the surface UV irradiance is to accurately quantify the effects of clouds. Unlike the standard TOMS UV algorithm, we use the cloud fraction products available from SeaWiFS and MODIS to calculate instantaneous surface flux at the ocean surface. Daily UV doses can be calculated by assuming a model of constant daily cloudiness. Both SeaWiFS and MODIS provide some estimates of seawater optical properties in the visible.

Paper Details

Date Published: 17 January 2002
PDF: 10 pages
Proc. SPIE 4482, Ultraviolet Ground- and Space-based Measurements, Models, and Effects, (17 January 2002); doi: 10.1117/12.452912
Show Author Affiliations
Alexander Vassilkov, Science Systems and Applications, Inc. (United States)
Jay R. Herman, NASA Goddard Space Flight Ctr. (United States)
Nickolay A. Krotkov, Univ. of Maryland/Baltimore County (United States)
B. Greg Mitchell, Scripps Institution of Oceanography (United States)
Mati Kahru, Scripps Institution of Oceanography (United States)


Published in SPIE Proceedings Vol. 4482:
Ultraviolet Ground- and Space-based Measurements, Models, and Effects
James R. Slusser; Jay R. Herman; Wei Gao, Editor(s)

© SPIE. Terms of Use
Back to Top