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Name of speaker:  Huiji Lee from Seoul National University, South Korea.                 

Abstract

The ocean is a crucial sink for anthropogenic CO2 emissions, yet its future response remains uncertain. Here, using the Community Earth System Model (CESM2) under different CO2 emission rates, we find a pronounced weakening of ocean CO2 uptake in the Subpolar North Atlantic (SPNA), distinct from the global response. Initially, the SPNA is an effective CO2 sink, but due to the contraction of deep convection, the uptake decreases and the oceanic pCO2 exceeds the global average. Recognizing the importance of regional ocean circulation in CO2 uptake, we identify a nonlinear relationship between environmental conditions and uptake response, revealing consistent thresholds for the emergence of uptake weakening. Overall, the distinct uptake response reflects the key role of regional dynamics in regulating the CO2 budget and geochemical environment, and such abrupt change in the regional carbon cycle may ultimately trigger severe ecosystem disruptions. This highlights the importance of accounting for regional dynamics in future CO2 mitigation strategies.

About the speaker

I am currently a PhD student at the Seoul National University, South Korea, and a visiting researcher at NORCE/Bjerknes Centre for six months. My research interests focus on the ocean carbon cycle and marine ecosystems, with particularly how ocean buffering capacity regulates climate projections and the potential of ocean-based carbon dioxide removal strategies.

Zoom details https://uib.zoom.us/j/62554083320?pwd=w66YFoIhFNBTjgDA4bKppdlKAzpOoj.1