The global stratospheric ozone-layer depletion results in an increase in biologically harmful ultraviolet (UV) radiation reaching the surface and penetrating to ecologically significant depths in natural waters. Such an increase can be estimated on a global scale by combining satellite estimates of UV irradiance at the ocean surface from the Total Ozone Mapping Spectrometer (TOMS) satellite ins...

A-MODIS, AATSR, MERIS, POLDER-3 and SeaWiFS data are directly compared at top of the atmosphere level for nearly concomitant observation carried out under nearly identical or reciprocal geometries. Comparisons are carried out over the Salar de Uyuni in Bolivia. The results indicate that MERIS and A-MODIS are radiometrically in line. In comparison to these sensors, the SeaWiFS data exhibit a sys...

For instruments that carry onboard solar diffusers to orbit, such as the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS), it is possible to convert the instrument's reflectance measurements to radiance measurements by knowledge of the solar irradiance. This process, which generally requires the application of a solar irradiance model, is described. The application of the irradiance model is sep...

The introduction of the SeaWiFS ocean-color instrument in the autumn of 1997 coincided with the onset of perhaps the largest El Niño event of the century, providing us with the opportunity to monitor the impact of such events on biological and bio-optical properties in central California. The increased importance of coastal runoff (both sediments and fresh water) during the winter of 1998 have ...

Satellite ocean color data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) were used to examine distributions of chlorophyll concentration within the Southern Ocean for the period October 1997 through September 1998. Over most of the Southern Ocean, mean chlorophyll concentrations remained quite low (,0.3–0.4 mg m). Phytoplankton blooms where chlorophyll concentration exceeded 1.0 mg m...

Recent advances in global biogeochemical research demonstrate a critical need for long-term ocean color satellite data records of consistent high quality. To achieve that quality, spaceborne instruments require on-orbit vicarious calibration, where the integrated instrument and atmospheric correction system is adjusted using in situ normalized water-leaving radiances, such as those collected by...

Most ocean color algorithms are designed for optically deep waters, where the seafloor has little or no effect on remote sensing reflectance. This can lead to inaccurate retrievals of inherent optical properties (IOPs) in optically shallow water environments. Here, we investigate in situ hyperspectral bottom reflectance signatures and their separability for coral reef waters, when observed at t...

The SeaWiFS ocean colour sensor on board the SeaStar (Orbview 2) satellite is able to derive the chlorophyll concentration in the surface sea water. The chlorophyll algorithm employed is based on the ratio of radiance or reflectance measured in the blue and green spectral bands. Regression between the band ratio and the in-situ measurements of chlorophyll values gives the coefficients for the r...

To trace offshore surface low-salinity water (LSW) in the northeastern Gulf of Mexico, a proxy was developed using the surface water beam attenuation coefficient (cp), and salinity matched with synchronous Seaviewing Wide Field-of-view Sensor (SeaWiFS) satellite data from three annual summer cruises (July 1998–August 2000) using a two-step empirical approach. First, a relationship between in-si...