Japan Geoscience Union Meeting 2025

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[E] Poster

A (Atmospheric and Hydrospheric Sciences ) » A-OS Ocean Sciences & Ocean Environment

[A-OS15] Marine ecosystems and biogeochemical cycles: theory, observation and modeling

Thu. May 29, 2025 5:15 PM - 7:15 PM Poster Hall (Exhibition Hall 7&8, Makuhari Messe)

convener:Takafumi Hirata(Arctic Research Center, Hokkaido University), Shin-ichi Ito(Atmosphere and Ocean Research Institute, The University of Tokyo), Jessica A. Bolin(University of California, Davis), Cecile S Rousseaux(NASA Goddard Space Flight Center)


5:15 PM - 7:15 PM

[AOS15-P01] Description of IAP ocean biogeochemical model version 2.0 (IAP-OBGCM v2.0)

*YongFu XU1, Yangchun LI1 (1.Institute of Atmospheric Physics, Chinese Academy of Sciences)

Keywords:ocean biogeochemical model, IAP-OBGCM, CAS-ESM, air-sea carbon exchange flux, atmospheric CO2 concentration

A global ocean biogeochemical model with six biochemical variables was established by the Institute of Atmospheric Physics (IAP) around 2010, which is named as IAP-OBGCM. Based on IAP-OBGCM, a new version named as IAP-OBGCM v2.0 was developed. In this model, there are 14 variables including two types of phytoplankton (nitrogen fixing phytoplankton and non-nitrogen fixing phytoplankton), zooplankton, nitrate, ammonium, phosphate, dissolved iron, dissolved inorganic carbon (DIC), total alkalinity, dissolved oxygen, detritus, dissolved organic carbon, dissolved organic nitrogen, and other inorganic nitrogen. It is still a simple model compared with many of those currently complex global ocean biogeochemical models, but it is suitable for the computationally overburdened earth system models. It is one of important component models of the second version of Chinese Academy of Sciences Earth System Model (CAS-ESM2), and offers the air-sea carbon exchange flux (FCO2) to the atmospheric component model of CAS-ESM2. To save computing sources, IAP-OBGCM v2.0 can work offline. When the model is run offline, it needs to couple with an ocean general circulation model which is pre-set to LICOM. LICOM is a global ocean circulation model that was also developed by IAP. With LICOM which has 30 vertical levels and horizontal resolution of 1ºx1º, IAP-OBGCM2 produces realistic patterns of above biochemical variables, and gets 10-year mean net primary production of 42.9 PgC/yr. With this model, we have investigated the effect of the distribution of atmospheric CO2 concentrations on FCO2. Whether concentrations of atmospheric CO2 are constant or vary with latitude only has an effect on ocean carbon uptake at high latitudes. The atmospheric CO2 concentrations which vary with latitude can increase the concentrations of sea surface DIC at high latitudes.