Publications

Venugopal, T; Rahaman, H; Ravichandran, M; Ramakrishna, SSVS (2016). Evaluation of MODIS/CERES Downwelling Shortwave and Longwave Radiation over global tropical oceans. REMOTE SENSING OF THE ATMOSPHERE, CLOUDS, AND PRECIPITATION VI, 9876, UNSP 98761F.

Abstract
In the present work, we have evaluated the satellite estimated daily downwelling shortwave (Q(I)) and Longwave (Q(A)) radiation from Moderate Resolution Imaging Spectrometer (MODIS) / Clouds and the Earth's Radiant Energy System (CM) with moored buoy observations of Global Tropical Moored Buoy Array (GTMBA) during 2001-2009. The global observed mean of Q(I) and Q(A) in GTMBA (CM) are 228 (233) W/m(2) and 410 (405) W/m(2) respectively. The mean Q(I) shows a positive bias (similar to 3-7 W/m(2)) whereas Q(A) underestimates with a mean negative bias of similar to 3-6 W/m(2) in the tropical Pacific, Atlantic and Indian Ocean. CM underestimates the buoy observed variability in both Q(I) and Q(A) in all the tropical oceans. The correlation coefficient (CC) values in Q(I) (Qa) are 0.79(0.88) 0.79(0.84) and 0.81(0.94) over the Pacific, Atlantic and Indian ocean respectively. The Root Mean Square Error (RMSE) values in Q(I) ranged between 35-43 W/m(2) with lowest values in the Atlantic Ocean and highest in the Indian Ocean. The RMSE values in Q(A) are less as compared to Q(I) and it is similar to 9 W/m(2) in all the tropical ocean. The spatial distributions of Q(I) and Q(A) shows seasonality with lower and higher values coinciding with the Inter Tropical Convergence Zone(ITCZ) locations in the Q(I) and Q(A).

DOI:
10.1117/12.2228041

ISSN:
0277-786X