[A-CG59] 海洋表層－大気間の生物地球化学

[ACG59-P02] 日本海における大気窒素化合物の沈着が海洋表層生態系に与える影響

*竹谷 文一¹、相田 真希¹、関谷 高志¹、山地 一代^1,2、池田 恒平³、本多 牧生¹、松本 和彦¹、笹岡 晃征¹、金谷 有剛¹ (1.海洋研究開発機構、2.神戸大学、3.国立環境研究所)

キーワード：窒素化合物、沈着、日本海、海洋生態系

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.