Efficient biological carbon export to the mesopelagic ocean induced by submesoscale fronts

Mingxian Guo; Xiaogang Xing; Peng Xiu; Giorgio Dall'Olmo; Weifang Chen; Fei Chai

doi:10.1038/s41467-024-44846-7

Efficient biological carbon export to the mesopelagic ocean induced by submesoscale fronts

Nat Commun. 2024 Jan 17;15(1):580. doi: 10.1038/s41467-024-44846-7.

Authors

Mingxian Guo^#¹, Xiaogang Xing^#², Peng Xiu³, Giorgio Dall'Olmo⁴, Weifang Chen⁵, Fei Chai⁵

Affiliations

¹ State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
² State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China.
³ State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen, China. pxiu@xmu.edu.cn.
⁴ Istituto Nazionale di Oceanografia e di Geofisica Sperimentale-OGS, Trieste, Italy.
⁵ State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.

^# Contributed equally.

Abstract

Oceanic submesoscale processes are ubiquitous in the North Pacific Subtropical Gyre (NPSG), where the biological carbon pump is generally ineffective. Due to difficulties in collecting continuous observations, however, it remains uncertain whether episodic submesoscale processes can drive significant changes in particulate organic carbon (POC) export into the mesopelagic ocean. Here we present observations from high-frequency Biogeochemical-Argo floats in the NPSG, which captured the enhanced POC export fluxes during the intensifying stages of a submesoscale front and a cyclonic eddy compared to their other life stages. A higher percentage of POC export flux was found to be transferred to the base of mesopelagic layer at the front compared to that at the intensifying eddy and the mean of previous studies (37% vs. ~10%), suggesting that the POC export efficiency was significantly strengthened by submesoscale dynamics. Such findings highlight the importance of submesoscale fronts for carbon export and sequestration in subtropical gyres.