IIOSC - 2025

IIOSC - 2025

International Indian Ocean Science Conference - 2025

Celebrating 10 years of the Second International Indian Ocean Expedition

01-05 December 2025
INCOIS, Hyderabad, India.

Summary of Abstract Submission



Abstract Submission No.ABS-06-0228
Title of AbstractParticulate organic carbon distribution in the Western Indian Ocean based on Biogeochemical-Argo floats
AuthorsGawon Lee*, Sujin Kang, Tae-Keun Rho, Hyoun-Woo Kang, Dong-Jin Kang
OrganisationKorea Institution of Ocean Science and Technology
Address385 Haeyang-ro, Yeongdo-gu
Busan, Busan, Korea, Rep.
Pincode: 49111
E-mail: gwlee@kiost.ac.kr
CountryKorea, Rep.
PresentationPoster
AbstractPrimary producers in the surface ocean play a key role in the marine carbon cycle by fixing atmospheric carbon dioxide into particulate organic carbon (POC). While ship-based in situ measurements have improved our understanding of POC dynamics, their spatial and temporal coverage remains limited. To complement these observations, remote platforms such as satellites and Biogeochemical-Argo (BGC-Argo) floats enable continuous ocean monitoring. In this study, we analyzed a biogeochemical dataset from a BGC-Argo float deployed in the Seychelles-Chagos Thermocline Ridge (SCTR). Over the two-year period (March 2023-April 2025), the float collected 152 vertical profiles of pressure, temperature, salinity, chlorophyll-a, and backscattering. Quality assurance and quality control (QA/QC) procedures, including filtering, calibration, and outlier removal, were applied to the backscattering data, and the processed dataset was cross-validated against ship-based CTD measurements. QA/QC-processed backscattering was compared with beam transmission from CTD casts conducted within ±5 days and ±1° of the float measurements, revealing strong negative correlations (r = -0.83 to -0.93, n = 6). In addition, POC concentrations derived from discrete water samples collected during the CTD casts were analyzed to examine their relationship with both beam transmission and backscattering. This stepwise evaluation aimed to investigate the applicability of backscattering as a proxy for continuous vertical POC profiling, complementing discrete sampling and mitigating the spatiotemporal limitations of ship-based observations. Using the validated dataset, we further evaluated the potential of applying established backscattering-POC relationships to characterize vertical POC structure and seasonal variability in the SCTR.
Are you part of IIOE-2 endorsed projectno
KeywordsBGC-Argo, POC, SCTR, Backscattering
For Awardsno