Earth and Planetary Science
EPS Near-Surface Geochemistry and Geobiology

Carbon export and fate beneath a dynamic upwelled filament off the California coast

Monday, May 31, 2021
Photo: taken by EPS Professor Jim Bishop. Showing one of Berkeley's autonomous Carbon FLux Explorers being recovered by R/V Revelle after a multi day mission. The inset of the figure deptics 4 mechanisms by which carbon can be moved in the ocean.

Hannah Bourne (EPS PhD 2018) has published a paper on her studies of carbon flux in coastal California waters. The online public access article is available here: https://bg.copernicus.org/articles/18/3053/2021/bg-18-3053-2021.html

To learn how the biological carbon pump works in productive coastal upwelling systems, four autonomous carbon flux explorers measured carbon flux to depths of 500 m through the twilight zone beneath an offshore-flowing filament of biologically productive water. Strikingly different particle classes dominated the carbon fluxes during successive stages of the filament evolution over 30 d. Both flux and transfer efficiency were far greater than expected, suggesting an outsized filament impact in California waters.

Hannah's work was aided by Marine Science graduates Elizabeth Connors (Scripps), William Kumler (University of Washington), Jessica Kendall Bar (UC Santa Cruz), and Casey Fritz. Further help at sea came from undergraduates YiZhuang Liu (Engineering), Xiao Fu (Chemistry), and Sylvia Targ (ESPM). Hannah's study took place in June 2017 was part of the California Current Ecosystem Long Term Ecological Research (CCE-LTER) process study and was supported by the National Science Foundation.

Bourne, H. L., Bishop, J. K. B., Connors, E. J., and Wood, T. J.: Carbon export and fate beneath a dynamic upwelled filament off the California coast, Biogeosciences, 18, 3053–3086, https://doi.org/10.5194/bg-18-3053-2021, 2021.