Mechanisms of Air-Sea Gas Exchange: Beyond Wind Speed

durch Yuanxu Dong (GEOMAR)

Donnerstag 22.01.2026, 10:00 → 11:15 Europe/Berlin

5-1.213 - PAZIFIK / PACIFIC- Rechte Seite - Großer, unterteilbarer Konferenzraum (GEOMAR - Standort Ostufer / GEOMAR - East Shore)

Abstract:

Air-sea gas exchange regulates Earth's climate and ocean health. This exchange is driven by factors such as wind, waves, bubbles, and surfactants. However, the air-sea gas transfer velocity is often parameterized solely as a function of wind speed. This simplification constrains our ability to represent underlying mechanisms and introduces potential biases into flux estimates. In this talk, I will present the work conducted during my Humboldt Fellowship about the air-sea gas exchange mechanisms.

In the first part, I will examine the role of bubbles in air-sea gas exchange, drawing on theory, laboratory studies, field observations, and modeling results. I will also highlight new insights from our laboratory experiments in a large annular wave tank and discuss the potential implications on global ocean CO₂ flux estimates.

In the second part, I will focus on the influence of fetch and surfactants on CO₂ exchange based on the CenBASE and BASS cruises in the Baltic Sea. I will also introduce a sea state and surfactant included parameterization of the gas transfer velocity and investigate how that impacts the CO₂ flux estimates in the Baltic Sea.

Together, these findings underscore the need to integrate wind, wave, bubble, and surfactant effects into parameterizations of the gas transfer velocity to improve the accuracy of the current carbon budgets and the future climate predictions.