Title: Complex functionality with minimal computation: Promise and pitfalls of reduced‐tracer ocean biogeochemistry models

Abstract

Abstract Earth System Models increasingly include ocean biogeochemistry models in order to predict changes in ocean carbon storage, hypoxia, and biological productivity under climate change. However, state‐of‐the‐art ocean biogeochemical models include many advected tracers, that significantly increase the computational resources required, forcing a trade‐off with spatial resolution. Here, we compare a state‐of‐the art model with 30 prognostic tracers (TOPAZ) with two reduced‐tracer models, one with 6 tracers (BLING), and the other with 3 tracers (miniBLING). The reduced‐tracer models employ parameterized, implicit biological functions, which nonetheless capture many of the most important processes resolved by TOPAZ. All three are embedded in the same coupled climate model. Despite the large difference in tracer number, the absence of tracers for living organic matter is shown to have a minimal impact on the transport of nutrient elements, and the three models produce similar mean annual preindustrial distributions of macronutrients, oxygen, and carbon. Significant differences do exist among the models, in particular the seasonal cycle of biomass and export production, but it does not appear that these are necessary consequences of the reduced tracer number. With increasing CO ₂ , changes in dissolved oxygen and anthropogenic carbon uptake are very similar across the different models.more » Thus, while the reduced‐tracer models do not explicitly resolve the diversity and internal dynamics of marine ecosystems, we demonstrate that such models are applicable to a broad suite of major biogeochemical concerns, including anthropogenic change. These results are very promising for the further development and application of reduced‐tracer biogeochemical models that incorporate “sub‐ecosystem‐scale” parameterizations.« less

Authors:

Galbraith, Eric D. ^[1]; Dunne, John P. ^[2]; Gnanadesikan, Anand ^[3]; Slater, Richard D. ^[4]; Sarmiento, Jorge L. ^[4]; Dufour, Carolina O. ^[4]; de Souza, Gregory F. ^[4]; Bianchi, Daniele ^[5]; Claret, Mariona ^[6]; Rodgers, Keith B. ^[4]; Marvasti, Seyedehsafoura Sedigh ^[7]

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+ Show Author Affiliations

1. Institucio Catalana de Recerca i Estudis Avancats—Institut de Ciencia i Tecnologia Ambientals, Universitat Autonoma de Barcelona, Bellaterra Barcelona Spain, Department of Earth and Planetary Science McGill University Montreal Québec Canada
2. NOAA Geophysical Fluid Dynamics Laboratory Princeton New Jersey USA
3. Department of Earth and Planetary Sciences Johns Hopkins University Baltimore Maryland USA
4. Atmospheric and Oceanic Science Program Princeton University Princeton New Jersey USA
5. Department of Earth and Planetary Science McGill University Montreal Québec Canada, Department of Atmospheric and Oceanic Sciences University of California Los Angeles CA, USA
6. Institucio Catalana de Recerca i Estudis Avancats—Institut de Ciencia i Tecnologia Ambientals, Universitat Autonoma de Barcelona, Bellaterra Barcelona Spain
7. Department of Earth and Planetary Sciences Johns Hopkins University Baltimore Maryland USA, Department of Marine Sciences Science and Research Branch, Islamic Azad University Tehran Iran

Publication Date:

Mon Dec 21 00:00:00 EST 2015

Research Org.:

Princeton Univ., NJ (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1235486

Alternate Identifier(s):

OSTI ID: 1243072

Grant/Contract Number:  

SC0006848

Resource Type:

Published Article

Journal Name:

Journal of Advances in Modeling Earth Systems

Additional Journal Information:

Journal Name: Journal of Advances in Modeling Earth Systems Journal Volume: 7 Journal Issue: 4; Journal ID: ISSN 1942-2466

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English

Subject:

58 GEOSCIENCES