MESMO 3: Flexible phytoplankton stoichiometry and refractory dissolved organic matter

• Published in: Geoscientific Model Development
• Main Authors: K. Matsumoto, T. Tanioka, J. Zahn
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2021
• Subjects: Geology; QE1-996.5; Sea ice
• Online Access: https://doi.org/10.5194/gmd-14-2265-2021; https://doaj.org/article/d6657e16b30e4686b57bad4a1eb32994

We describe the third version of Minnesota Earth System Model for Ocean biogeochemistry (MESMO 3), an Earth system model of intermediate complexity, with a dynamical ocean, dynamic–thermodynamic sea ice, and an energy–moisture-balanced atmosphere. A major feature of version 3 is the flexible <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">C</mi><mo>:</mo><mi mathvariant="normal">N</mi><mo>:</mo><mi mathvariant="normal">P</mi></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="41pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="89baeb1bef20dd832e5430c0fb7046a4"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gmd-14-2265-2021-ie00001.svg" width="41pt" height="10pt" src="gmd-14-2265-2021-ie00001.png"/></svg:svg> ratio for the three phytoplankton functional types represented in the model. The flexible stoichiometry is based on the power law formulation with environmental dependence on phosphate, nitrate, temperature, and light. Other new features include nitrogen fixation, water column denitrification, oxygen and temperature-dependent organic matter remineralization, and CaCO 3 production based on the concept of the residual nitrate potential growth. In addition, we describe the semi-labile and refractory dissolved organic pools of C, N, P, and Fe that can be enabled in MESMO 3 as an optional feature. The refractory dissolved organic matter can be degraded by photodegradation at the surface and hydrothermal vent degradation at the bottom. These improvements provide a basis for using MESMO 3 in further investigations of the global marine carbon cycle to changes in the environmental conditions of the past, present, and future.