Air‐Sea Fluxes of CO<sub>2</sub> in the Indian Ocean Between 1985 and 2018: A Synthesis Based on Observation‐Based Surface CO<sub>2</sub>, Hindcast and Atmospheric Inversion Models

Sridevi, B.; Metzl, Nicolas; Patra, Prabir K.; Lachkar, Zouhair; Chakraborty, Kunal; Goyet, C.; Lévy, Marina; Mehari, M.; Chandra, Naveen

doi:10.1029/2023gb007694

Cited by 15 publications

(3 citation statements)

References 115 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This may impact the biogeochemistry of carbon in the water column and ecosystem structure (Hunt et al 2008, Moy et al 2009, Bednaršek et al 2012, particularly the survival of aragonite-secreting organisms (Bednaršek et al 2012). Recently Sarma et al (2023) compared the performance of 16 hindcasts, 9 empirical and 2 atmospheric inversion models in the Indian Ocean with observations and noticed that all models lack real-time river discharge data and atmospheric pollutant inputs. As a result, the prediction given by the models may not be accurate and necessary modifications are required for better prediction in future.…”

Section: Discussionmentioning

confidence: 99%

Rapid shoaling of aragonite saturation horizon in the northern Indian Ocean

Sridevi,

Sarma

2024

Environ. Res. Commun.

View full text Add to dashboard Cite

Anthropogenic carbon dioxide (CO2) is penetrating up to 1000 m of water column in the Indian Ocean resulting in acidification and corrosion of aragonite skeletal material. The shallowest aragonite saturation horizon (ASH) was observed in the Bay of Bengal (BoB; 219±10 m) within the tropical Indian Ocean. The ASH shoaled at the rate of 6.3±5 and 4.4±3 m yr-1 in the past four decades in the BoB and Arabian Sea respectively. As a result, an increase in total alkalinity (TA) was observed at the rate of 0.5±0.3 and 0.25±0.2 mol kg-1 yr-1 at the depth of ASH in the BoB, and Arabian Sea respectively. While shoaling rate of ASH remained same in the Arabian Sea over past four decades, in contrast, the rapid shoaling was observed in the BoB in the recent decades due to higher accumulation of anthropogenic CO2 in the upper ocean associated with an increase in river discharge and decomposition of riverine organic matter. These two processes decreased the pH resulting in corrosion of aragonite skeletal material and increased TA at the depth of ASH in the BoB. Under a business-as-usual scenario, aragonite-secreting organisms will be seriously affected by the middle of this century in the BoB.

show abstract

Section: Discussionmentioning

confidence: 99%

Rapid shoaling of aragonite saturation horizon in the northern Indian Ocean

Sridevi,

Sarma

2024

Environ. Res. Commun.

View full text Add to dashboard Cite

show abstract

“…The Indian Ocean north of 18°S is considered to serve as a net source of CO 2 , with an estimated annual flux of CO 2 across 14°N-14°S of the Indian Ocean of 0.18 PgC yr −1 (Takahashi et al, 2002;Sarma et al, 2023b). However, the sea-air fluxes measured in our study were slightly higher than those reported previously, which was likely due to the high instantaneous wind speeds (>13 m s −1 ) at some stations and the slight difference in the location of the study area (15°N-15°S of the Indian Ocean).…”

Section: Comparison With Other Areas In the Indian Oceanmentioning

confidence: 99%

“…However, the sea-air fluxes measured in our study were slightly higher than those reported previously, which was likely due to the high instantaneous wind speeds (>13 m s −1 ) at some stations and the slight difference in the location of the study area (15°N-15°S of the Indian Ocean). According to Sarma et al (2023b), the CO 2 fluxes in the equatorial Indian Ocean displayed seasonality with high fluxes occurring from January to May and low fluxes occurring from June to October. In addition, they found a prominent trend of seasonality in the BoB characterized by higher CO 2 fluxes from May to August associated with monsoon mixing and lower fluxes from October to December due to river discharge and stratification (Sarma et al, 2018), which is in line with our finding of higher fluxes in May 2021 than in October 2020.…”

Section: Comparison With Other Areas In the Indian Oceanmentioning

confidence: 99%

Distributions and controlling processes of the carbonate system in the Eastern Indian Ocean during autumn and spring

Wu,

Yuan,

Liu

et al. 2024

Front. Mar. Sci.

View full text Add to dashboard Cite

The Eastern Indian Ocean (EIO) is an ideal region to explore the variability and controlling mechanisms of the seawater carbonate system and their potential influence on global climate change due to the distinctive environmental features, while studies in the EIO is far from sufficient. The spatiotemporal distributions of pH, dissolved inorganic carbon (DIC), alkalinity (Alk), and partial pressure of carbon dioxide (pCO2) were investigated in the EIO during autumn 2020 and spring 2021. The respective quantitative contributions of different controlling processes to DIC were further delineated. Significant seasonal variations were observed in the study area. Overall, the surface pH was lower and DIC, Alk, and pCO2 were higher during spring 2021 than during autumn 2020. The pH generally decreased from east to west during autumn 2020, whereas it decreased from north to south during spring 2021. The low values of DIC and Alk that were detected in the Bay of Bengal in these two seasons were mainly attributed to the influence of river inputs. Coastal upwelling during monsoon periods led to higher pCO2 and DIC values near Sumatra and Sri Lanka during spring 2021. The relationships of carbonate system parameters with different types of nutrients and different sized chlorophyll-a in the two seasons indicated the shifts of nutrients utilized by the phytoplankton, and phytoplankton species dominated the carbonate system variabilities. In vertical profiles, carbonate system parameters showed strong correlations with other physical and biogeochemical parameters, and these correlations were more robust during spring 2021 than during autumn 2020. The average sea–air flux of CO2 was 10.00 mmol m−2 d−1 during autumn 2020 and was 16.00 mmol m−2 d−1 during spring 2021, which revealed that the EIO served as a CO2 source during the study period. In addition, the separation of different controlling processes of DIC indicated stronger mixing processes, less CaCO3 precipitation, more intensive sea–air exchange, and weaker photosynthesis during spring 2021 than during autumn 2020.

show abstract

Weakening Indian Ocean carbon uptake in 2015: The role of amplified basin‐wide warming and reduced Indonesian throughflow

Liao,

Lu,

Xue

et al. 2024

Limnol Oceanogr Letters

View full text Add to dashboard Cite

In 2015, the Indian Ocean exhibits an exceptionally weakened CO2 uptake, highlighting strong interannual variability of ocean carbon sink. By utilizing multiple ocean CO2 partial pressure (pCO2) data and a state‐of‐the‐art ocean biogeochemical model, we show that the 2015 ocean CO2 anomaly is characterized by a basin‐wide amplification of ocean pCO2, differing from ocean pCO2 responses to other Indian Ocean Dipole events (e.g., 1997 and 2019). The distinct ocean pCO2 anomaly is attributed to an amplified warming and an unprecedented weakening Indonesian Throughflow under the influence of co‐occurrence of positive IOD and extreme El Niño in 2015. The amplified warming drives higher ocean pCO2 in the western and central Indian Ocean, while the ITF transports anomalously high ocean pCO2 water from the Pacific Ocean to the southeastern Indian Ocean. This newly identified ocean carbon response provides deeper insights into the Indian Ocean carbon interannual variability.

show abstract

Air‐Sea Fluxes of CO₂ in the Indian Ocean Between 1985 and 2018: A Synthesis Based on Observation‐Based Surface CO₂, Hindcast and Atmospheric Inversion Models

Cited by 15 publications

References 115 publications

Rapid shoaling of aragonite saturation horizon in the northern Indian Ocean

Rapid shoaling of aragonite saturation horizon in the northern Indian Ocean

Distributions and controlling processes of the carbonate system in the Eastern Indian Ocean during autumn and spring

Weakening Indian Ocean carbon uptake in 2015: The role of amplified basin‐wide warming and reduced Indonesian throughflow

Contact Info

Product

Resources

About

Air‐Sea Fluxes of CO2 in the Indian Ocean Between 1985 and 2018: A Synthesis Based on Observation‐Based Surface CO2, Hindcast and Atmospheric Inversion Models

Cited by 15 publications

References 115 publications

Rapid shoaling of aragonite saturation horizon in the northern Indian Ocean

Rapid shoaling of aragonite saturation horizon in the northern Indian Ocean

Distributions and controlling processes of the carbonate system in the Eastern Indian Ocean during autumn and spring

Weakening Indian Ocean carbon uptake in 2015: The role of amplified basin‐wide warming and reduced Indonesian throughflow

Contact Info

Product

Resources

About

Air‐Sea Fluxes of CO₂ in the Indian Ocean Between 1985 and 2018: A Synthesis Based on Observation‐Based Surface CO₂, Hindcast and Atmospheric Inversion Models