Air‐Water Exchange and Gas‐Particle Partitioning of Polycyclic Aromatic Hydrocarbons (PAHs) in Coral Reef Areas of the South China Sea

In this study, we collected gas, particulate, and surface water‐dissolved phase samples from 16 sites in the South China Sea from March 21 to April 12, 2018. Thereafter, all the samples were analyzed for the air‐water exchange and source apportionment of polycyclic aromatic hydrocarbons (PAHs). Thus, it was observed that the overall PAH concentrations in the water and gas phases were 8.0 ± 5.5 ng/L and 41.3 ± 24.7 ng/m3, respectively. Back trajectory simulation showed that the air masses in the South China Sea primarily originated from mainland China during the heating period, and air‐water exchange analysis showed net deposition from air to water, with fluxes ranging from −5.53 to −89.72 ng/m2/d. Further, the logarithmic gas‐particle partitioning coefficient (logKp) of the PAHs regressed linearly with the logarithmic subcooled liquid vapor pressure (log P0 L), with an average slope of −0.3 ± 0.13.