Seasonal variation and source of organic carbon in aerosols in Xiamen
Ruoyang Zhang
College of Ocean and Earth Sciences, Xiamen University, China
As a potential source of marine dissolved organic carbon, the flux of atmospheric deposition can reach 0.09pg. Comparing with other sources, the annual input of atmospheric deposition can reach nearly half of that of rivers. Atmospheric deposition is an important source of nutrients in marine ecosystem, which can affect the marine primary production process and biogeochemical cycle. The difference organic carbon (OC) components in atmospheric deposition is related to its source and the process before settling to the ocean surface. It is worth exploring the seasonal concentration variation of organic carbon in Xiamen aerosol and its relationship with influencing factors. Taking the coastal city of Xiamen as an example, the concentration of organic carbon (OC) in Xiamen aerosol shows an obvious seasonal trend of high in spring and winter and low in summer and autumn. By measuring the mass concentrations of OC and EC and spectral characteristic parameters (s275-295, suva254) of Xiamen aerosol, it can be found that OC mainly comes from the emission of vehicles and coal combustion and water-soluble organic carbon components in Xiamen aerosol and have large molecular weight and high aromaticity in the composition of WSOC. It is speculated that the aerosol molecules contain inert substances with larger molecular weight and higher proportion. Atmospheric dry deposition is an important carrier and way to understand the inert organic carbon in the atmosphere,it is also an important source of inert organic carbon in the ocean.
