Atmospheric dry and wet deposition of nitrogen species and its implication for primary productivity in coastal region of the Yellow Sea, China

The size-fractionated dry deposition fluxes of aerosol particles and nitrogen species were estimated in coastal region of the Yellow Sea from July 2005 to March 2006 using size-dependent particle dry deposition velocities and measurements for size-segregated aerosol samples. During the study period, the estimated dry deposition fluxes of aerosol particles, total dissolved nitrogen (TDN), total inorganic nitrogen (TIN), dissolved organic nitrogen (DON), ammonium and nitrate were 1067.5 ± 903.3 mg m−2 month−1, 15.9 ± 7.2 mg N m−2 month−1, 12.6 ± 6.6 mg N m−2 month−1, 3.3 ± 1.5 mg N m−2 month−1, 6.5 ± 4.2 mg N m−2 month−1 and 7.2 ± 4.5 mg N m−2 month−1, respectively. The dry deposition flux for the coarse mode of aerosol particles and nitrogen species consisted more than 66% of the total deposition flux. This result suggests that nitrogen species in coarse particles are important in the estimation of atmospheric deposition input. The estimated wet deposition fluxes of TDN, DON, TIN, ammonium and nitrate were 154.5 ± 178.9 mg N m−2 month−1, 126.9 ± 152.2 mg N m−2 month−1, 24.2 ± 34.1 mg N m−2 month−1, 85.4 ± 98.6 mg N m−2 month−1, and 40.8 ± 56.1 mg N m−2 month−1, respectively. The wet deposition contributed 65%, 72%, 55%, and 56% to the sum of the dry and wet flux of TDN, ammonium, nitrate, and DON, respectively. Inorganic nitrogen contributed much more than DON to the TDN, with a percentage of 75% and 86% in the dry and wet deposition, respectively. The dry and wet nitrogen deposition can be converted to a new primary biological productivity of 1.5–30.0 gC m−2 yr−1 in the Yellow Sea, and the nitrogen input accounts for 0.3–6.7% of the new productivity in the Yellow Sea. As an important nutrient source, the atmospheric deposition of nitrogen could have a significant influence on biogeochemical cycles.