Publications

Shanthi, R; Poornima, D; Thangaradjou, T; Saravanakumar, A; Choudhury, SB; Roy, R (2022). Decadal Variability of Satellite-Derived Air-Sea CO2 Flux in Southwestern Part of the Bay of Bengal. OCEAN SCIENCE JOURNAL, 57(2), 211-223.

Abstract
Understanding the relationship between atmospheric and oceanic carbon cycles necessitates measuring geographical and temporal variations of surface water partial pressure of carbon dioxide (pCO(2)). The seasonal pCO(2) maps have been developed using MODIS-derived SST and chlorophyll for four different seasons to calculate air-sea flux of CO2 at basin scale. Summer in 2017 had the lowest pCO(2) value (263 mu atm), whereas monsoon season in 2016 had the highest (553 mu atm). From 2010 to 2019, atmospheric pCO(2) level fluctuated from 371 to 396 mu atm with progressive growth of atmospheric pCO(2) at 2.5 mu atm year(-1). The inter-annual CO2 flux ranged between - 3.58 and 3.64 mmol C m(-2) day(-1). Significant negative CO2 flux (- 3.58 mmol C m(-2) day(-1)) was observed in 2015 premonsoon, indicating that the Bay of Bengal was a net sink for atmospheric CO2, while served as a net source of CO2 to the atmosphere in 2013 monsoon season with a significant positive flux of CO2 (3.64 mmol C m(-2) day(-1)) to the atmosphere. The annual CO2 sink was active in 2015 (- 1.17 mmol C m(-2) day(-1)) which showed increased trend from 2014 to 2018 with a range of - 1.17 to - 0.26 mmol C m(-2) day(-1). The Bay of Bengal was found to be a substantial CO2 contributor to the atmosphere in 2013 (3.64 mmol C m(-2) day(-1)) and 2012 (3.27 mmol C m(-2) day(-1)). In this context, the southwest Bay of Bengal serves as a net sink of atmospheric pCO(2) during summer season on an annual scale, and a weak sink during postmonsoon and premonsoon seasons, while served as a strong source of CO2 to the atmosphere during monsoon season from 2010 to 2019 with super saturation of CO2.

DOI:
10.1007/s12601-022-00063-1

ISSN:
2005-7172