[A-CG41] 植物プランクトン増殖に関わる海洋－大気間の生物地球化学

[ACG41-04] 西部北太平洋域での東アジア由来大気窒素化合物沈着による海洋低次生態系への寄与

*竹谷 文一¹、相田 真希¹、山地 一代^1,2、関谷 高志¹、池田 恒平^3,1、笹岡 晃征¹、橋岡 豪人¹、本多 牧生¹、松本 和彦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、エアロゾル、海洋生態系、数値計算

To investigate the influence for the deposition of inorganic nitrogen compounds derived from the East Asian continent on the marine ecosystem in the North Western Pacific Ocean (NWPO), we performed numerical simulations with and without atmospheric deposition of inorganic nitrogen compounds, using a 3-D lower trophic-marine ecosystem model (COCO-NEMURO), coupled with an atmospheric regional chemical transport model (WRF-CMAQ). The monthly mean data of wet and dry deposition data of inorganic nitrogen compounds consisted of gases (HNO₃ and NH₃) and aerosol particles (NO₃^- and NH₄⁺) at NWPO region in 2009 – 2016 produced by WRF-CMAQ were inputted to the COCO-NEMURO as a new nitrogen nutrients supplying process from the atmosphere. The results indicated that the annual average chlorophyll mass concentration at the surface in the subtropical region (20N–30N, 125E–150E) of the NWPO increased from 0.04 to 0.10 mg/m3. Similarly, gross primary productivity integrated over sea depths of 0–200 m increased from 85 to 147 mg C/m2/day, related to this deposition. This study indicates that the supply of atmospheric inorganic nitrogen compounds from East Asia to the NWPO could lead to a high nutrient impact on the marine ecosystem within the subtropical region.