Japan Geoscience Union Meeting 2025

Presentation information

[E] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-CG Complex & General

[A-CG36] Extratropical oceans and atmosphere

Mon. May 26, 2025 1:45 PM - 3:15 PM 101 (International Conference Hall, Makuhari Messe)

convener:Yuta Ando(Department of Earth and Planetary Sciences, Kyushu University), Tong Wang(Japan Agency for Marine-Earth Science and Technology), Kenta Tamura(National Research Institute for Earth Science and Disaster Resilience), Shota Katsura(Department of Geophysics, Graduate School of Science, Tohoku University), Chairperson:Tong Wang(Japan Agency for Marine-Earth Science and Technology), Kenta Tamura(National Research Institute for Earth Science and Disaster Resilience), Yuta Ando(Department of Earth and Planetary Sciences, Kyushu University), Shota Katsura(Department of Geophysics, Graduate School of Science, Tohoku University)


1:45 PM - 2:00 PM

[ACG36-07] An overview of outstanding challenges in our understanding of controls on seasonal variability in mid-latitude marine biogeochemistry and ecosystems

★Invited Papers

*Keith Bradley Rodgers1, Ryohei Yamaguchi2, Andrea Fassbender3, Olivier Aumont4, Shinya Kouketsu2, Shota Katsura5 (1.WPI Advanced Institute for Marine Ecosystem Change, Tohoku University, Japan, 2.Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Japan, 3.NOAA/OAR Pacific Marine Environmental Laboratory, US, 4.Research Institute for Development (IRD), France, 5.Graduate School of Science, Tohoku University, Japan)

Keywords:Oceanography, Marine Carbon Cycle, Marine Biogeochemisry, Marine Ecosystems

Seasonal variability in surface ocean nutrient and dissolved inorganic carbon concentrations represent the largest mode of variabiltiy in these properties over the extra-equatorial oceans. However, the coupled model intercomparison project (CMIP) and global carbon project (GCP) marine biogeochemical models that play critical roles in assessing how the marine carbon cycle and ecosystems are changing suffer from a number of important deficiencies in representing seasonality (Goris et al., 2018). Nevertheless, the “missing processes” that account for these deficiencies remain unresolved.

These concerns motivated the marine carbon seasonality contribution to the Regional Carbon Cycle Assessment and Processes Phase 2 project (RECCAP2). There a comparison of models and observational products revealed that sea surface DIC is systematically underestimated over most of the surface extra-equatorial ocean regions across models. This has implications for pCO2 seasonality that may impact model representations of net CO2 uptake by the ocean, but also climate feedbacks (Fassbender et al., 2022). However, application of the modeling and observational resources available through RECCAP2 to disentangle the relative importance of biases in the seasonality of the physical seasonal boundary layer of the ocean (entrainment) and the seasonality of the biological pump proved inconclusive.

We conclude by presenting an overview of potential paths forward for exploring novel approaches to resolve this important and pervasive biases in models. Of interest are approaches that build on the increasing availability of seasonally-resolving measurements of upper ocean biogeochemistry and stratification, but also modeling approaches.