Photosyntheticaly available radiation in the central and eastern Arabian Sea

Abstract

In this article, we present the analysis of the photosynthetically available radiation(PAR, 400-700 nm) in the eastern and central Arabian Sea (21° 30' N, 64° E to 12° N, 74° E) during February-March, 1995 using data collects with quantum PAR sensor and maritime solar radiation models for clear sky. The peak values observed were in the range of about 1700 to 1830 μmole s^-1m^-2 or equivalent to about 365 to 435 Wm^-2. The radiative transfer models of Gregg and Carder, and Frouin et al. were used to investigate relationship between the quantum and energy of solar radiation available in the PAR region. The average ratio of this quanta per energy was found to be about 4.2 μmole W^-1s^-1. Aerosol optical depth obtained using the sun photometer at 498 nm for the region was found to vary from 0.07 to 0.19.