Beam Attenuation Coefficients in the South Atlantic: Indicator of Oceanic Processes

• Main Authors: Gardner, W. D., Richardson, M. J.
• Other Authors: TEXAS A AND M UNIV COLLEGE STATION
• Format: Text
• Language: English
• Published: 1989
• Subjects: Physical and Dynamic Oceanography; *BEAMS(RADIATION); *RADIATION ATTENUATION; OPTICS; GLOBAL; DISTRIBUTION; PARAMETERS; WATER; VENTILATION; THREE DIMENSIONAL; LIGHT SOURCES; PARTICLES; COEFFICIENTS; SAMPLING; CALIBRATION; FILTERS; HYDROGRAPHY; OCEAN ENVIRONMENTS; INDICATORS; SOUTH ATLANTIC OCEAN; SPATIAL DISTRIBUTION; MEASUREMENT; SAVE(SOUTH ATLANTIC VENTILATION EXPERIMENT); South Atlantic Ocean
• Online Access: http://www.dtic.mil/docs/citations/ADA210070; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA210070

The ultimate goal of this research is to obtain global distributions of beam attenuation coefficients throughout the water column. This optical measurement will be correlated with particle concentrations to determine particle distributions and interpret oceanic processes responsible for those distributions. The objective of this proposal was to obtain an ocean-wide, three-dimensional distribution of beam attenuation coefficients in the south Equatorial Atlantic during the South Atlantic Ventilation Experiment (SAVE). These data are being correlated with particle and hydrographic parameters in order to interpret oceanic processes. A Sea Tech 25 cm transmissometer (660 nm light source) was interfaced with the CTD to obtain profiles of beam attenuation coefficient. Water samples throughout the water column were filtered to determine dry weights of filtered particles and size distribution by analysis with a multisizer. Empirical calibrations of attenuation coefficients then make it possible to map the particle concentrations throughout the water column.