The Xiamen Symposium on Marine Environmental Sciences

2027 Xiamen Symposium on Marine Environmental Sciences

January 12-15, 2027

Air-sea gas exchange in nearshore environments: Implications for marine carbon dioxide removal
ID:1318 Oral Presentation

2027-01-15 14:15 (China Standard Time)

Session:Session 58 - Carbon Dynamics in Coastal Ocean: Benthic-Pelagic Coupling and Interfacial Fluxes

Abstract
The relationship between wind speed and air-sea gas exchange in nearshore environments could differ significantly from that in the open ocean due to wind fetch limitation, younger wave ages, and higher surfactant concentrations. Indeed, dual tracer (3He/SF6) experiments that we have conducted in diverse nearshore environments, including Florida Bay, the coastal Baltic Sea, an Icelandic fjord, and a coastal salt pond in Rhode Island, consistently show that nearshore gas transfer velocities fall below open ocean predictions. Yet current oceanographic models almost universally apply open ocean wind speed parameterizations, which substantially overestimate gas transfer in coastal and nearshore environments by up to 65%. This overestimation has important implications for marine carbon dioxide removal (mCDR), since these deployments will occur nearshore, close to the energy, infrastructure, and human resources needed to operate them. Because mCDR pathways such as ocean alkalinity enhancement (OAE) and direct ocean removal (DOR) rely on the transfer of CO2 across the air-sea interface, accurate knowledge of gas exchange is fundamental to monitoring, reporting, and verification (MRV). Currently, observations of nearshore gas exchange remain sparse, leaving insufficient data to establish a robust, universal nearshore parameterization, which is a key bottleneck to accurate MRV and scalable mCDR deployment. Future air-sea gas exchange experiments should prioritize nearshore sites representative of planned mCDR deployment regions, across a range of wind fetch and wave conditions. 
Speaker
David Ho University of Hawaii at Manoa

Author
David Ho University of Hawaii at Manoa

    Important Dates

    • Jan 30

      2026

      Session / Event proposals open

    • Mar 31

      2026

      Session / Event proposals close
      (Extended to April 7)

    • Apr 30

      2026

      Session acceptance notifications

    • Apr 30

      2026

      Abstract submissions & registration open

    • Jun 30

      2026

      Abstract submissions close
      (Extended to July 21)

    • Aug 31

      2026

      Abstract acceptance notifications

    • Sep 15

      2026

      Scientific program released

    • Oct 15

      2026

      Early bird registration closes

    • Jan 12–15

      2027

      XMAS 2027