Keywords:Nitrogen compounds, deposition, Japan Sea, marine ecosystem
The sensitivity of the atmospheric deposition of inorganic nitrogen compounds to the surface chlorophyll-a mass concentration at the Japan Sea was investigated using a 3-D lower trophic-marine ecosystem model (NEMURO) combined with an atmospheric regional chemical transport model (WRF-CMAQ). The monthly mean values for the wet and dry deposition of nitrogen compounds including gases (HNO3 and NH3) and aerosol particles (NO3- and NH4+) over the Japan Sea were determined using the WRF-CMAQ, indicating that wet deposition was dominant in all seasons. These values were input into the surface of ocean of NEMURO as a new nitrogen source. The annual average of surface chlorophyll-a mass concentration at the Japan Sea was increased from 0.26 to 0.35 mg/m3. The growth ratios of chlorophyll-a mass concentration in summer was factor of ~2.1, while that in wintertime was factor of ~1.1, indicating that the atmospheric deposition of inorganic nitrogen compounds highly influence to the surface chlorophyll-a mass concentration in summer.