EGUsphere

Copernicus Publications

Göttingen, Germany

10.5194/egusphere-2022-1067

Seasonal to interannual variabilities of sea–air CO2 exchange across Tropical Maritime Continent indicated by eddy–permitting coupled OGCM experiment

Amri

Faisal

https://orcid.org/0000-0003-0881-6963

¹ Nakamura

Takashi

¹ Watanabe

Atsushi

² Kartadikaria

Aditiya R.

³ Nadaoka

Kazuo

Transdisciplinary Science and Engineering Department, Tokyo Institute of Technology, Tokyo, Japan

Ocean Policy Research Institute, The Sasakawa Peace Foundation, Japan

Faculty of Earth Sciences and Technology, Oceanography Research Group, Institut Teknologi Bandung, Bandung, Indonesia

14 10 2022

2022 1 25

2022

This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/

This article is available from https://egusphere.copernicus.org/preprints/2022/egusphere-2022-1067/

The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2022/egusphere-2022-1067/egusphere-2022-1067.pdf

The lack of long–term observational data has limited research on sea–air CO2 exchange variabilities in the Tropical Maritime Continent (TMC). To address the issue, we utilized a three–dimensional high–resolution physical–biogeochemical ocean numerical model and applied it to simulate sea–air CO2 exchange in the region over the last decade (2010–2019). Some key features like atmospheric CO2 source signature and high sea surface pCO2 environment inside the TMC were captured by the model. Within the TMC, model results indicated strong CO2 degassing along the south of Java associated with the seasonal cycle of the upwelling system. Abundant supply of inorganic carbon during upwelling season and strong wind speed results in CO2 degassing that could reach as high as 30 gC m–2 year–1 around the area. In addition to the region acting as a full–year atmospheric CO2 source, the TMC also exhibited interannual modulation in both sea–air CO2 flux and sea surface pCO2 which can be related to the El Niño–Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD). Large–scale anomalous strong CO2 degassing and high sea surface pCO2 from 2015 to 2016 in response to the 2015/2016 El Niño evolution was observed and dominated by modulation within the TMC. It is further found that modulation of CO2 degassing related to IOD were confined along the west of south of Java with a higher magnitude compared with anomalies related to ENSO which shows larger spatial scale but lower in the magnitude. Study conducted here may provide insight about possible variabilities of sea–air CO2 exchange in the area that still poorly represented in many global–scale modelling and reconstruction efforts.