1302 / 2024-09-20 23:56:08
Spatial Variability and Source Identification of Trace Elements in Aerosols From Northwest Pacific Marginal Sea, Indian Ocean and South Pacific to Antarctica
Trace Elements;
Session 25 - IGAC-SOLAS: Chemistry and physics at surface ocean and lower atmosphere
Abstract Accepted
Aerosols continuously transport trace elements (TEs) across long distances to the ocean, fueling
marine primary production and affecting global carbon cycles. Given the multiple sources and complex
transport mechanisms, field investigations of aerosol TEs on a global scale are significant for understanding
their role in marine biogeochemical cycles. Here, aerosol samples were collected along a 50,000‐km route
covering subtropical Northwest Pacific (NWP) marginal seas, Indian Ocean, Southern Ocean, Drake Passage,
and South Pacific. Samples were analyzed for the concentrations of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As,
Cd, Tl, and Pb. Aerosol TEs were distributed heterogeneously, with significantly lower concentrations over
remote oceans compared to coastal seas. Meanwhile, TE concentrations were generally high in the Indian
Ocean, moderate in the Southern Ocean, and low in the South Pacific. Cr, Ni, Cu, Zn, Cd, As, and Pb were
widely enriched, primarily originating from anthropogenic sources, while Al, Ti, V, Mn, Fe, and Co were
mainly from crustal sources in remote oceans. Moreover, specific sources of TEs were clarified, for example, Cr
and Ni were mainly from vehicle emissions. The estimated bulk TE deposition fluxes also varied spatially. For
instance, the greatest deposition of Fe occurs in the NWP marginal sea, followed by the Drake Passage, Indian
Ocean Sector of Southern Ocean, Pacific Sector of Southern Ocean, and South Pacific. This study contributes to
a deeper understanding of the complex dynamics of aerosol TEs in the global ocean, providing valuable
information for future studies and policy making regarding climate change.