Improving Marine Ecosystem Models with Biochemical Tracers

Abstract. Mesozooplankton are cosmopolitan within the sunlit layers of the global ocean. They are important in the classical food web, having a significant feedback to primary production through their consumption of phytoplankton and microzooplankton. They are also the primary contributor to vertical particle flux in the oceans. Through both they affect the biogeochemical cycling of carbon and other nutrients in the oceans. Little, however, is known about their global distribution and biomass. While global maps of mesozooplankton biomass do exist in the literature they are usually in the form of hand-drawn maps and the original data associated with these maps are not readily available. The dataset presented in this synthesis has been in development since the late 1990's, is an integral part of the Coastal & Oceanic Plankton Ecology, Production, & Observation Database (COPEPOD), and is now also part of a wider community effort to provide a global picture of carbon biomass data for key plankton functional types, in particular to support the development of marine ecosystem models. A total of 153 163 biomass values were collected, from a variety of sources, for mesozooplankton. Of those 2% were originally recorded as dry mass, 26% as wet mass, 5% as settled volume, and 68% as displacement volume. Using a variety of non-linear biomass conversions from the literature, the data have been converted from their original units to carbon biomass. Depth-integrated values were then used to calculate mesozooplankton global biomass. Global mesozooplankton biomass, to a depth of 200 m, had a mean of 5.9 μg C l−1, median of 2.7 μg C l−1 and a standard deviation of 10.6 μg C l−1. The global annual average estimate of mesozooplankton, based on the median value, was 0.19 Pg C. Biomass was highest in the Northern Hemisphere, but the general trend shows a slight decrease from polar oceans to temperate regions with values increasing again in the tropics. Gridded dataset http://doi.pangaea.de/10.1594/PANGAEA.785501x.

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An underwater light attenuation scheme for marine ecosystem models

Optics Express ◽

10.1364/oe.16.016581 ◽

2008 ◽

Vol 16 (21) ◽

pp. 16581 ◽

Cited By ~ 17

Author(s):

Bradley Penta ◽

Zhongping Lee ◽

Raphael M. Kudela ◽

Sherry L. Palacios ◽

Deric J. Gray ◽

...

Keyword(s):

Marine Ecosystem ◽

Light Attenuation ◽

Ecosystem Models ◽

Underwater Light ◽

Marine Ecosystem Models

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Drivers and uncertainties of future global marine primary production in marine ecosystem models

Biogeosciences ◽

10.5194/bg-12-6955-2015 ◽

2015 ◽

Vol 12 (23) ◽

pp. 6955-6984 ◽

Cited By ~ 123

Author(s):

C. Laufkötter ◽

M. Vogt ◽

N. Gruber ◽

M. Aita-Noguchi ◽

O. Aumont ◽

...

Keyword(s):

Primary Production ◽

Nutrient Limitation ◽

21St Century ◽

Net Primary Production ◽

Marine Ecosystem ◽

Phytoplankton Growth ◽

Strong Increase ◽

Ecosystem Models ◽

Low Latitudes ◽

Marine Ecosystem Models

Abstract. Past model studies have projected a global decrease in marine net primary production (NPP) over the 21st century, but these studies focused on the multi-model mean rather than on the large inter-model differences. Here, we analyze model-simulated changes in NPP for the 21st century under IPCC's high-emission scenario RCP8.5. We use a suite of nine coupled carbon–climate Earth system models with embedded marine ecosystem models and focus on the spread between the different models and the underlying reasons. Globally, NPP decreases in five out of the nine models over the course of the 21st century, while three show no significant trend and one even simulates an increase. The largest model spread occurs in the low latitudes (between 30° S and 30° N), with individual models simulating relative changes between −25 and +40 %. Of the seven models diagnosing a net decrease in NPP in the low latitudes, only three simulate this to be a consequence of the classical interpretation, i.e., a stronger nutrient limitation due to increased stratification leading to reduced phytoplankton growth. In the other four, warming-induced increases in phytoplankton growth outbalance the stronger nutrient limitation. However, temperature-driven increases in grazing and other loss processes cause a net decrease in phytoplankton biomass and reduce NPP despite higher growth rates. One model projects a strong increase in NPP in the low latitudes, caused by an intensification of the microbial loop, while NPP in the remaining model changes by less than 0.5 %. While models consistently project increases NPP in the Southern Ocean, the regional inter-model range is also very substantial. In most models, this increase in NPP is driven by temperature, but it is also modulated by changes in light, macronutrients and iron as well as grazing. Overall, current projections of future changes in global marine NPP are subject to large uncertainties and necessitate a dedicated and sustained effort to improve the models and the concepts and data that guide their development.

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ESD Reviews: Evidence of multiple inconsistencies between representations of terrestrial and marine ecosystems in Earth System Models

10.5194/esd-2020-55 ◽

2020 ◽

Author(s):

Félix Pellerin ◽

Philipp Porada ◽

Inga Hense

Keyword(s):

Marine Ecosystem ◽

Marine Ecosystems ◽

Climate System ◽

Biological Processes ◽

Earth System ◽

Climate Feedbacks ◽

Ecosystem Models ◽

System Models ◽

Marine Ecosystem Models ◽

Earth System Models

Abstract. Terrestrial and marine ecosystems interact with other Earth system components through different biosphere-climate feedbacks that are very similar among ecosystem types. Despite these similarities, terrestrial and marine systems are often treated relatively separately in Earth System Models (ESM). In these ESM, the ecosystems are represented by a set of biological processes that are able to influence the climate system by affecting the chemical and physical properties of the environment. While most of the climate-relevant processes are shared between ecosystem types, model representations of terrestrial and marine ecosystems often differ. This raises the question whether inconsistencies between terrestrial and marine ecosystem models exist and potentially skew our perception of the relative influence of each ecosystem on climate. Here we compared the terrestrial and marine modules of 17 Earth System Models in order to identify inconsistencies between the two ecosystem types. We sorted out the biological processes included in ESM regarding their influence on climate into three types of biosphere-climate feedbacks (i.e. the biogeochemical pumps, the biogeophysical mechanisms and the gas and particle shuttles), and critically compare their representation in the different ecosystem modules. Overall, we found multiple evidences of unjustified differences in process representations between terrestrial and marine ecosystem models within ESM. These inconsistencies may lead to wrong predictions about the role of biosphere in the climate system. We believe that the present comparison can be used by the Earth system modeling community to increase consistency between ecosystem models. We further call for the development of a common framework allowing the uniform representation of climate-relevant processes in ecosystem modules of ESM.

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Theoretical Analysis and Optimization of Nonlinear ODE Systems for Marine Ecosystem Models

IFIP Advances in Information and Communication Technology - System Modeling and Optimization ◽

10.1007/978-3-642-36062-6_50 ◽

2013 ◽

pp. 501-510

Author(s):

Anna Heinle ◽

Thomas Slawig

Keyword(s):

Theoretical Analysis ◽

Marine Ecosystem ◽

Ecosystem Models ◽

Nonlinear Ode ◽

Marine Ecosystem Models ◽

Ode Systems

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Effect of complexity on marine ecosystem models

Marine Ecology Progress Series ◽

10.3354/meps253001 ◽

2003 ◽

Vol 253 ◽

pp. 1-16 ◽

Cited By ~ 210

Author(s):

EA Fulton ◽

ADM Smith ◽

CR Johnson

Keyword(s):

Marine Ecosystem ◽

Ecosystem Models ◽

Marine Ecosystem Models

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A guinea pig's tale: learning to review end-to-end marine ecosystem models for management applications

ICES Journal of Marine Science ◽

10.1093/icesjms/fsw047 ◽

2016 ◽

Vol 73 (7) ◽

pp. 1715-1724 ◽

Cited By ~ 19

Author(s):

Isaac C. Kaplan ◽

Kristin N. Marshall

Keyword(s):

Best Practice ◽

Nutrient Loading ◽

Marine Ecosystem ◽

Evaluation Criteria ◽

Decision Makers ◽

Ecosystem Models ◽

Climate Change Effects ◽

Marine Management ◽

End To End ◽

Marine Ecosystem Models

Abstract A shift towards ecosystem-based management in recent decades has led to new analytical tools such as end-to-end marine ecosystem models. End-to-end models are complex and typically simulate full ecosystems from oceanography to foodwebs and fisheries, operate on a spatial framework, and link to physical oceanographic models. Most end-to-end approaches allow multiple ways to implement human behaviours involving fishery catch, fleet movement, or other impacts such as nutrient loading or climate change effects. Though end-to-end ecosystem models were designed specifically for marine management, their novelty makes them unfamiliar to most decision makers. Before such models can be applied within the context of marine management decisions, additional levels of vetting will be required, and a dialogue with decision makers must be initiated. Here we summarize a review of an Atlantis end-to-end model, which involved a multi-day, expert review panel with local and international experts, convened to challenge models and data used in the management context. We propose nine credibility and quality control standards for end-to-end models intended to inform management, and suggest two best practice guidelines for any end-to-end modelling application. We offer our perspectives (as recent test subjects or “guinea pigs”) on how a review could be motivated and structured and on the evaluation criteria that should be used, in the most specific terms possible.

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