The exchange of carbon dioxide (CO2) between the ocean and atmosphere plays a crucial role in regulating Earth’s climate. In this study, we examined how accurately this exchange is captured along the California coast, where seasonal wind-driven upwelling brings CO2-rich waters to the surface. We compared CO2 flux estimates using data collected every 3 hours for 10 years with those derived from monthly averages. We found that monthly averages often miss important short-term variability, particularly during upwelling seasons. These seasonal changes cause the region to emit more CO2 into the atmosphere than previously thought, challenging the perception that the coastal California Current is a CO2 sink. High-frequency calculations revealed that winds and ocean conditions are closely linked, driving this variability in CO2 exchange. Our findings highlight the need for continuous and high-resolution measurements to better quantify sea-air CO2 exchange.
High-Frequency Correlations Between Winds and pCO2 Change the California Coastal Upwelling System From a CO2 Sink to a Source
- Ruiming Song, Tim DeVries, Renjian Li, Adrienne Sutton, Uwe Send, Helena C. Frazão
- Geophysical Research Letters
- July 14, 2025
Citation: Song, R., DeVries, T., Li, R., Sutton, A., Send, U., & Frazão, H. C. (2025). High-frequency correlations between winds and pCO2 change the California coastal upwelling system from a CO2 sink to a source. Geophysical Research Letters, 52, e2025GL115470. https://doi.org/10.1029/2025GL115470


