The effect of cyclone on the ocean primary productivity in Bay of Bengal

摘要

The understanding about ocean primary productivity is very important as it is a key component of the Earth’s biogeochemical carbon cycles, as well as in predicting the response of marine biota to possible changes in radiative or other physical forcing because of global warming (Wang et al., 2009). Chlorophyll-a has been known as the most important indicator for ocean productivity estimation (Nagamani et al., 2011). Many studies have been conducted to determine the variation of chlorophyll-a concentration due to several factors such as cyclone (Tripathy et al., 2012). This study focuses on examining the effect of various cyclone events on the ocean primary productivity in Bay of Bengal (BOB). BOB is the largest bay in the world with unique semi-enclosed tropical basin, monsoon variation, and experienced high rainfall and frequent cyclone (Reddy et al., 2008). Tripathy et al., 2012 had found the frequent occurrence of cyclonic events causes shortterm nutrient enrichment of upper-stratified ocean resulting in enhanced biological productivity. Upwelling and entrainment processes due to strong winds associated with cyclone will bring up nutrients and causes phytoplankton bloom (Reddy et al., 2008). Chlorophyll concentration is increased under the cyclone track and the blooms of phytoplankton were covered wide area (Smitha et al., 2006).