Biogeochemical significance of Asian aerosol deposition in the southern East Sea

Abstract

We presented results from the atmospheric investigation for metals and ions in the southern East Sea (35°-39°N and 129°-134°E), a marginal sea between Korea and Japan. Five-year observations (Oct. 2003-Oct. 2008) at Ulleung Island revealed that seasonal change of the atmospheric concentration and chemical composition was related to relative intensity of crustal and anthropogenic-originated aerosols. Atmospheric metal fluxes to the southern East Sea showed that Al and Co fluxes were similar to those to the Mediterranean Sea. On the other hand, anthropogenic-originated Pb and Zn fluxes were comparable to those over the North Sea.In addition, we investigated the transport patterns of aerosols on the east coast of Korea (37.58°N 129.11°E) using backward trajectories and the associated concentrations of water-soluble ions (NO3-, NH4+ and nss-SO42-) and certain metals (Al, Na, nss-Ca, V, Zn and Pb). Air masses passing slowly over eastern China contributed higher concentrations of water-soluble ions than those fast-moving northwesterly winds. With measured NO3- and NH4+ concentrations during the period Mar. 2002-Feb. 2003, the dry N deposition flux was 460 mg N m-2 year-1. Taking into account wet N deposition flux of 613 mg N m-2 year-1, the atmospheric deposition flux of N over the southern East Sea was higher than that reported for the Mediterranean Sea and the North Sea. Contribution of atmospheric N deposition led that seasonal change of the atmospheric concentration and chemical composition was related to relative intensity of crustal and anthropogenic-originated aerosols. Atmospheric metal fluxes to the southern East Sea showed that Al and Co fluxes were similar to those to the Mediterranean Sea. On the other hand, anthropogenic-originated Pb and Zn fluxes were comparable to those over the North Sea.In addition, we investigated the transport patterns of aerosols on the east coast of Korea (37.58°N 129.11°E) using backward trajectories and the associated concentrations of water-soluble ions (NO3-, NH4+ and nss-SO42-) and certain metals (Al, Na, nss-Ca, V, Zn and Pb). Air masses passing slowly over eastern China contributed higher concentrations of water-soluble ions than those fast-moving northwesterly winds. With measured NO3- and NH4+ concentrations during the period Mar. 2002-Feb. 2003, the dry N deposition flux was 460 mg N m-2 year-1. Taking into account wet N deposition flux of 613 mg N m-2 year-1, the atmospheric deposition flux of N over the southern East Sea was higher than that reported for the Mediterranean Sea and the North Sea. Contribution of atmospheric N deposition