Seasonal Optical Properties Derived from Coastal Zone Color Scanner Satellite Data Along the Somali Coast and the Gulf of Aden.

摘要

Optical water properties of the world's oceans can be obtained from data collected with Coastal Zone Color Scanner (CZCS) aboard Nimbus-7. Our understanding of the spatial and temporal variability of surface optical properties is greatly improved from synoptic images from visible channel satellites. Current satellite data processing techniques can eliminate the atmospheric contamination that contributes 90% of the visible channel signal. The remaining signal, which constitutes the ocean color, is directly related to the diffuse attenuation coefficient (K) at 490 nanometers for the upper surface waters. Calculation and geographic registration of K can be performed on each sqm image-pixel of the CZCS data, and results show that the accuracy is within 92% of ship measurements. Regional costal optical atlases are required for planning bathymetric surveys using the Airborne Bathymetric System, CZCS data provide a method of deriving temporal and spatial variability of costal optical properties in regions where limited ship measurements are available. This report presents a demonstration of the capability of a regional optics data base generated using CZCS data. A series of CZCS images of the eastern Somali cost and the Gulf of Aden has been processed for the diffuse attenuation coefficient and have been used to define a regional optical database. This data base exists digital image form and clearly defines optical variability in response to continental winds, monsoon wind, and coastal upwelling. Keywords: Ocean color, Ocean optics, Satellites, Multispectral, Image processing. (jhd)