Toward optical closure in coastal waters

An instrument has been developed for the simultaneous in situ measurement of inherent and apparent optical properties, enabling: various radiative transfer models to he tested. The Southampton Underwater Multi-parameter Optical Spectrometer System (SUMOSS) measures up- and downwelling irradiance, beam transmission and forward, side and backward scatter. These inherent optical properties can be measured both at 670nm using: a laser diode, ol spectrally using a white light;. The instrument resolution ranges from 0.47nm to 6.7nm. This extended abstract describes the new instrument, and presents preliminary data from all experiment to monitor the optical properties at the mouth of tile Hamble river (Southampton Water, UK) over a spring tidal cycle. Optical data are compared with measurements of suspended particulate matter and chlorophyll concentrations.