[A-OS09] Marine ecosystems and biogeochemical cycles: theory, observation and modeling

[AOS09-13] A phytoplankton model with dynamic stoichiometry based on a new instant acclimation scheme: good reproduction of the subsurface chlorophyll maximum and primary production

*増田 良帆¹、山中 康裕¹、平田 貴文¹、中野 英之² (1.北海道大学地球環境科学研究院、2.気象研究所)

キーワード：植物プランクトン、順化、ストイキオメトリー、クロロフィル、一次生産

Oceanic phytoplankton adjust to a change in surrounding environment, where the chlorophyll/carbon and nitrogen/carbon rations are changed. Based on Smith et al. (2015), we introduced new phytoplankton acclimation scheme into a biogeochemical model combined with an OGCM. The scheme is based on the assumption of instant acclimation; that is, phytoplankton stoichiometry (chl:C:N:Fe) is uniquely determined by a surrounding environmental condition. Therefore, it can represent dynamic stoichiometry with low computational costs. The model well reproduces the latitudinal distribution of the subsurface chlorophyll maximum. The simulated net primary production is similar to the observed, and it is underpinned by the good reproduction of chlorophyll distribution and variable nitrogen/carbon ratio.