Premium
Examining the Impact of Tropical Cyclones on Air‐Sea CO 2 Exchanges in the Bay of Bengal Based on Satellite Data and In Situ Observations
Author(s) -
Ye Haijun,
Sheng Jinyu,
Tang Danling,
Morozov Evgeny,
Kalhoro Muhsan Ali,
Wang Sufen,
Xu Huabing
Publication year - 2019
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1029/2018jc014533
Subject(s) - alkalinity , bay , environmental science , tropical cyclone , oceanography , atmospheric sciences , climatology , geology , chemistry , organic chemistry
The impact of tropical cyclones (TCs) on the CO 2 partial pressure at the sea surface (pCO 2sea ) and air‐sea CO 2 flux (F CO2 ) in the Bay of Bengal (BoB) was quantified based on satellite data and in situ observations between November 2013 and January 2017. The in situ observations were made at the BoB Ocean Acidification mooring buoy. A weak time‐mean net source of 55.78 ± 11.16 mmol CO 2 m −2 year −1 at the BoB Ocean Acidification site was estimated during this period. A wide range in increases of pCO 2sea (1.0–14.8 μatm) induced by TCs occurred in postmonsoon (October–December), and large decreases of pCO 2sea (−14.0 μatm) occurred in premonsoon (March–May). Large vertical differences in the ratio of dissolved inorganic carbon (DIC) to total alkalinity (TA) in the upper layer (ΔDIC/TA) were responsible for increasing pCO 2sea in postmonsoon. Relatively small values of ΔDIC/TA were responsible for decreasing pCO 2sea in premonsoon. Five TCs (Hudhud, Five, Kyant, Vardah, and Roanu) were considered. Hudhud significantly enhanced CO 2 efflux (18.49 ± 3.70 mmol CO 2 /m 2 ) in oversaturated areas due to the wind effect during the storm and wind‐pump effects after the storm. Vardah insignificantly changed F CO2 (1.22 ± 0.24 mmol CO 2 /m 2 ) in undersaturated areas because of the counteraction of these two effects. Roanu significantly enhanced CO 2 efflux (19.08 ± 3.82 mmol CO 2 /m 2 ) in highly oversaturated conditions (ΔpCO 2 > 20 μatm) since the wind effect greatly exceeded the wind‐pump effects. These five TCs were estimated to account for 55 ± 23% of the annual‐mean CO 2 annual efflux, suggesting that TCs have significant impacts on the carbon cycle in the BoB.