The ANTARES network seeks to understand the variability of the coastal environment on a continental scale and the local, regional, and global factors and processes that effect this change. The focus are coastal zones of South America and the Caribbean Sea. The initial approach includes developing time series of in situ and satellite-based environmental observations in coastal and oceanic regions. The network is constituted by experts that seek to exchange ideas, develop an infrastructure for mutual logistical and knowledge support, and link in situ time series of observations located around the Americas with real-time and historical satellite-derived time series of relevant products. A major objective is to generate information that will be distributed publicly and openly in the service of coastal ocean research, resource management, science-based policy making and education in the Americas. As a first stage, the network has linked oceanographic time series located in Argentina, Brazil, Chile and Venezuela. The group has also developed an online tool to examine satellite data collected with sensors such as NASA's MODIS. Specifically, continental-scale high-resolution (1 km) maps of chlorophyll and of sea surface temperature are generated and served daily over the web according to specifications of users within the ANTARES network. Other satellite-derived variables will be added as support for the network is solidified. ANTARES serves data and offers simple analysis tools that anyone can use with the ultimate goal of improving coastal assessments, management and policies.
An algorithm is presented to correct SAC-C MMRS imagery in the visible for atmospheric and surface effects. These effects are due essentially to gaseous absorption, molecule and aerosol scattering, and Fresnel and whitecap reflection. Aerosol scattering is determined from measurements in the spectral bands centered at 815 and 1,625 nm, where the ocean is assumed to be totally absorbing. The information is then extrapolated to the ocean-color bands, centered at 490, 550, and 660 nm. The algorithm's theoretical performance, evaluated for varied geometry, surface conditions, aerosol loading, and mixtures of continental and maritime aerosols, is about ±0.0005 (r.m.s) on the aerosol path reflectance. This accuracy meets the requirements for ocean-color applications, at least in open waters. The algorithm is applied to MMRS imagery acquired off the Valdes Peninsula, Argentina. Compared with SeaWiFS estimates of marine reflectance, the MMRS values are too low and noisy, especially at 660 nm. The discrepancies may be due to non-zero marine reflectance at 815 nm, radiometric calibration errors, and to the large noise in the data (lack of sensitivity in the atmospheric correction bands). The results demonstrate the potential of MMRS for quantitative ocean-color remote sensing in coastal regions of South America.