Abstract：

The downward flux of organic carbon exported from the surface ocean is of great importance to the Earth's climate because it represents the major pathway for transporting CO₂ from the surface ocean and atmosphere into the deep ocean and sediments where it can be sequestered for a long time. However, current estimates on this downward flux have large uncertainties, and the flux of dissolved organic carbon/non-sinking particles is generally ignored. Here, I present global-scale estimates of the fluxes of total, particulate, and dissolved organic carbon (TOC, POC, and DOC, respectively) constrained by observational concentrations of dissolved inorganic phosphorus/carbon, total alkalinity,  dissolved organic carbon, and dissolved oxygen in a global inverse biogeochemical model for the cycling of phosphorus, carbon, and oxygen. I show that TOC (POC+DOC) flux is high in coastal upwelling regions, the Southern Ocean, the high latitude Atlantic and Pacific Oceans, and is low in the subtropical oceans, the tropical Indian and Atlantic Oceans. POC flux has a similar pattern as the TOC flux, but at a smaller magnitude. Strong DOC fluxes occur mainly in the subduction zones, possibly due to the detrainment of DOC rich surface water during mixing events into subsurface waters.  Moreover, I show that organic carbon/phosphorus remineralization/dissolution rates are positively related to temperature. Increase of temperature results in a shallower organic matter remineralization/dissolution and an expansion of the subtropical gyres, both of which could weaken the biological carbon pump.  I conclude by discussing how climate change will impact carbon export and the CO₂ partition between the ocean and the atmosphere.

Bio：

Wei-Lei Wang is a new professor in the College of Ocean and Earth Sciences, Xiamen University (XMU). Before joining XMU, Wei-Lei is an assistant project scientist in the Department of Earth System Science, University of California at Irvine. Wei-Lei obtained his Ph.D. at Stony Brook University under the supervision of Dr. Robert Armstrong. Wei-Lei specializes in biogeochemical inverse models and is keen to study oceanic cycles of nitrogen, carbon, and trace elements. Wei-Lei also has a strong interest in machine learning and its applications in ocean science. Wei-Lei is a person with enthusiasm, a positive attitude, and a good sense of humor. In his spare time, Wei-Lei likes to hike, bike, and skateboard with his son.

Conference ID (For ZOOM): 1557429205

Suihui (随会) link:  https://private.suimeeting.com/share/j/1557429205