Abstract

Estimation of primary productivity from satellite data around Japan and it comparison with other models.

Takahiro Osawa
CReSOS
Udayana University, Japan
osawa320@hotmail.com


Abstract :
Ocean primary productivity is important factor in determining the ocean’s role in the global carbon cycle. In recent years, much more chlorophyll-a concentration data in the euphotic layer was derived from satellite ocean color senor. Primary productivity algorithms have been proposed based on satellite chlorophyll measurements (Platt, 1988, morel 1991) and other environmental parameters such as sea surface temperature or mixed layer depth(Behrenfeld and Falkowski (1997)). In order to estimate integrated primary productivity in the whole water column, the vertical distribution of chlorophyll-a concentration below the sea surface should be reconstructed based on satellite data. In this paper, the vertical profile data of chlorophyll-a measured around Japan from 1974 to 1994 was reanalyzed based on the shifted Gaussian shape proposed by Platt et al (1988). Using this statistical model and photosynthesis-irradiance parameters from Asanuma (2002), the distribution of primary p productivity and its seasonal variation around Japan were estimated from Seawifs data, and the results were compared with in situ data and the other two models.