Analysis of the spatio-temporal distribution of chlorophyll-a in the eastern Indian Ocean near the time of the 2004 South Asian tsunami

Abstract

This study analysed the spatio-temporal distributions of chlorophyll-a (chl-a) in the Indian Ocean during the 2004 South Asian tsunami and the effects of four variables (sea surface temperature, normalized water-leaving radiance, rainfall and wind speed) on chl-a distributions during the tsunami, using satellite data and spatial models. The results showed considerable variations in the spatio-temporal distributions of chl-a, and the effects of the four variables on chl-a around the tsunami. The results revealed that sea surface temperature and rainfall had negative effects on chl-a, while normalized water-leaving radiance and wind speed had positive effects. The effects of all the four explanatory variables were significant (positive or negative) before the tsunami. Except normalized water-leaving radiance, the other three variables all showed certain degrees of weakened effects on chl-a after the tsunami, which suggested the physical disturbance of the tsunami on the effects of these variables on chl-a distribution.

Acknowledgements

This study was supported by (1) the National Natural Science Foundation of China (40576053, 40976091 and 40811140533), (2) Chinese Academy of Sciences and the South China Sea Institute of Oceanology (LYQY200701, kzcx2-yw-226), (3) The CAS/SAFEA International Partnership Program for Creative Research Teams (KZCX2-YW-T001). X.F. Zhang was supported by the China Scholarship Council. The authors thank those professors who have made a contribution to this study.