Measurements and Modeling of the Volume Scattering Function in the Northern Adriatic Sea

Measurements of the Volume Scattering Function (VSF) were performed on water samples collected in the northern Adriatic Sea coastal area in the frame of the CoASTS time-series in the period 2004-06 using a prototype instrument (Lee and Lewis, 2003). The VSF was measured for angles going from 0.5 to 179° with a resolution of 0.3° at 443, 490, 510, 532, 555, 590 and 620 nm. Vertical profiles of absorption a, scattering b, and back-scattering bb (AC-9 and Hyd-6) were simultaneously performed. The values of bp and bbp for particles at 510 nm derived from the integration of the VSF varied between 0.2 and 1.7 m-1 for the first and between 0.004 and 0.045 m-1 for the latter whereas their ratio varied between 0.014 and 0.029. Significant differences were observed with respect to the Petzold functions. The Kopelevich model (1983) however, was shown to provide a good description (within 40%) of the measured VSF. The comparison of the derived bp and bbp with the same quantities measured with the AC-9 and Hyd-6 showed agreement within 20% and 25% for bp and bbp, respectively, with a general underestimation of bbp by the Hyd6. The use of the empirical relationship for the derivation of bb from a unique measurement of scattering at 140° as performed by the Hyd-6 was validated for this area although 117° was confirmed to be the most appropriate angle. Finally, the use of the Kopelevich model together with an AC-9 measurement of bp at 555 nm allows to reconstruct the VSF within about 35%.

BERTHON Jean-Francois;  LEE Michael;  SHYBANOV Evgeni;  ZIBORDI Giuseppe; 

2009-09-09

Office of Naval Research

JRC33615

https://publications.jrc.ec.europa.eu/repository/handle/JRC33615,