Quantify the monthly to decadal variability of climate effects on the lower trophic levelse of shelf sea ecosystems

ECOOP WP10, Deliverable no: D10.1.2.1This report describes three studies using multi-decadal simulations of regional coupled hydrodynamics ecosystem models. These models are used to investigate the relationship between lower trophic level marine ecosystems and biogeochemistry, and the physical environment. The models considered here: POLCOMS-ERSEM Atlantic Margin Model run from 1960 to 2003 (NERC and PML) NORWECOM North Sea Model run from 1985-2006 (IMR) ECOSMO (UiB-GFI) North sea and Baltic Sea run 1980-2004 (UiB-GFI) The POLCOMS-ERSEM model is validated using in-situ data from the world ocean data centre and analysed to investigate the potential long term changes in primary production across the period 1960-2004, in the context of model open boundary conditions and drift. The model experiments demonstrate a strong sensitivity of the on-shelf primary production to the oceanic nutrient boundary conditions, suggesting cross-shelf edge nutrient fluxes provide a significant source of variability. The relationship between the model results and the North Atlantic Oscillation are also considered, demonstrating a r~0.65 correlation with on-shelf nutrients and the NAO The NORWECOM model is validated here using time series data from the Dutch coast. Correlations between model variables in a selection of ICES boxes are compared with a number of driving factors. River loads are shown to dominate coastal boxes. The relationships in open-shelf boxes are more ambiguous, although the southerly inflow is demonstrated to have an important role. The validation of the POLCOMS-ERSEM and NORWECOM models both conclude that the simulations have better skill for nutrients than chlorophyll and in open-shelf seas away from the coast. The validation of ECOSMO presented here focuses on zooplankton and comparison with data from the continuous plankton recorder, investigating six different approaches to matching CPR records with model data. Across the North Sea the mean annual cycle shows good agreement between model and CPR. There is also good correlation with along-track variability. EOF and correlation analysis is used to relate the primary production in the North Sea to atmospheric forcing parameters. The EOF patterns tend to match the distribution of summer time stratification, while the wind speed is shows the highest correlation, particularly during the onset and breakdown of stratification. This indicates the strength of cross-thermocline mixing is an important control on primary production variability. The ECOSMO model has been further developed for use in the Baltic by inclusion of nitrogen fixing cyanobacteria. These studies each demonstrate significant control of the inter-annual variability of shelf sea ecosystems through a range of external forcing vectors: oceanic through cross-shelf edge nutrient flux, terrestrial through variations in river nutrient loading, and atmospheric via the wind control of vertical mixing. Each of these vectors potentially mediates climatic variability and climate change

Challenges in integrative approaches to modelling the marine ecosystems of the North Atlantic: Physics to Fish and Coasts to Ocean

It has long been recognized that there are strong interactions and feedbacks between climate, upper ocean biogeochemistry and marine food webs, and also that food web structure and phytoplankton community distribution are important determinants of variability in carbon production and export from the euphotic zone. Numerical models provide a vital tool to explore these interactions, given their capability to investigate multiple connected components of the system and the sensitivity to multiple drivers, including potential future conditions. A major driver for ecosystem model development is the demand for quantitative tools to support ecosystem-based management initiatives. The purpose of this paper is to review approaches to the modelling of marine ecosystems with a focus on the North Atlantic Ocean and its adjacent shelf seas, and to highlight the challenges they face and suggest ways forward. We consider the state of the art in simulating oceans and shelf sea physics, planktonic and higher trophic level ecosystems, and look towards building an integrative approach with these existing tools. We note how the different approaches have evolved historically and that many of the previous obstacles to harmonisation may no longer be present. We illustrate this with examples from the on-going and planned modelling effort in the Integrative Modelling work package of the EURO-BASIN programme

Can we project changes in fish abundance and distribution in response to climate?

Large scale and long-term changes in fish abundance and distribution in response to climate change have been simulated using both statistical and process-based models. However, national and regional fisheries management requires also shorter term projections on smaller spatial scales, and these need to be validated against fisheries data. A 26-year time series of fish surveys with high spatial resolution in the North East Atlantic provides a unique opportunity to assess the ability of models to correctly simulate the changes in fish distribution and abundance that occurred in response to climate variability and change. We use a dynamic bioclimate envelope model forced by physical-biogeochemical output from eight ocean models to simulate changes in fish abundance and distribution at scales down to a spatial resolution of 0.5°. When comparing with these simulations with annual fish survey data, we found the largest differences at the 0.5° scale. Differences between fishery model runs driven by different biogeochemical models decrease dramatically when results are aggregated to larger scales (e.g. the whole North Sea), to total catches rather than individual species or when the ensemble mean instead of individual simulations are used. Recent improvements in the fidelity of biogeochemical models translate into lower error rates in the fisheries simulations. However, predictions based on different biogeochemical models are often more similar to each other than they are to the survey data, except for some pelagic species. We conclude that model results can be used to guide fisheries management at larger spatial scales, but more caution is needed at smaller scales

The UKC2 regional coupled environmental prediction system

It is hypothesized that more accurate prediction and warning of natural hazards, such as of the impacts of severe weather mediated through various components of the environment, require a more integrated Earth System approach to forecasting. This hypothesis can be explored using regional coupled prediction systems, in which the known interactions and feedbacks between different physical and biogeochemical components of the environment across sky, sea and land can be simulated. Such systems are becoming increasingly common research tools. This paper describes the development of the UKC2 regional coupled research system, which has been delivered under the UK Environmental Prediction Prototype project. This provides the first implementation of an atmosphere–land–ocean–wave modelling system focussed on the United Kingdom and surrounding seas at km-scale resolution. The UKC2 coupled system incorporates models of the atmosphere (Met Office Unified Model), land surface with river routing (JULES), shelf-sea ocean (NEMO) and ocean waves (WAVEWATCH III). These components are coupled, via OASIS3-MCT libraries, at unprecedentedly high resolution across the UK within a north-western European regional domain. A research framework has been established to explore the representation of feedback processes in coupled and uncoupled modes, providing a new research tool for UK environmental science. This paper documents the technical design and implementation of UKC2, along with the associated evaluation framework. An analysis of new results comparing the output of the coupled UKC2 system with relevant forced control simulations for six contrasting case studies of 5-day duration is presented. Results demonstrate that performance can be achieved with the UKC2 system that is at least comparable to its component control simulations. For some cases, improvements in air temperature, sea surface temperature, wind speed, significant wave height and mean wave period highlight the potential benefits of coupling between environmental model components. Results also illustrate that the coupling itself is not sufficient to address all known model issues. Priorities for future development of the UK Environmental Prediction framework and component systems are discussed

Comparison of biogeochemical dynamics in two time series sites of aNorth Atlantic Ocean site PAP and BATS a modeling approach

Plankton functional type (PFT) models are highly complex ecosystem models. Indeed, the large number of processes and plankton functional groups represented in these models make the network of interactions extremely complicated. Slight differences in parameterization or formulation of single processes, therefore, may drive these models to respond in a very different way to perturbations of the system. An evaluation of such a different responses can be very useful to understand the processes regulating the functioning of the ecosystem. In this study we analyze the sensitivity of the biological parameters in a PFT model (European Regional Seas Ecosystem Model, ERSEM) in respect to primary production and detrital export. The tests are done on a subset of key parameters that control ocean ecosystem growth in a 1-D formulation of ERSEM coupled with a turbulence model (General Ocean Turbulence Model, GOTM). Results are compared with observed data from two time-series sites Bermuda Atlantic Time-Series (BATS, 32.16 N 64.5 W) and Porcupine Abyssal Plain (PAP, 49 N 16 W). A particular focus on factors determining the timing and intensity of the bloom is also presented on the base of literature review and on 1D(GOTM-ERSEM)-3D(NEMO-ERSEM) model simulations comparison. The different processes evaluated are: i). winter convective mixing, ii) lateral advection: mesoscale and sub-mesoscale eddies, iii) turbolent mixing iv) decoupling between euphotic zone and mixed layer depth. The study presented here is carried out in the framework of the European project EURO-BASIN (European Basin-scale Analysis, Synthesis and Integration), where long term 3D simulation aimed to evaluate the variability of primary production and carbon export are planned. Parameterization in use by the 3D NEMO-ERSEM is referring to the global ocean, while simulations are planned for the North North Atlantic. This study aims to contribute to fulfill the development of a specific parameterization for the North Atlantic Ocean

Safeguarding future marine biodiversity and ecosystem services under climate change (FutureMARES)

FutureMARES brings together over 250 scientists from 32 partner institutions working across European and South American seas to provide innovative, science-based advice on how to rebuild marine biodiversity for climate change adaptation and mitigationPeer reviewe

Projecting changes in the distribution and productivity of living marine resources:A critical review of the suite of modelling approaches used in the large European project VECTORS

We review and compare four broad categories of spatially-explicit modelling approaches currently used to understand and project changes in the distribution and productivity of living marine resources including: 1) statistical species distribution models, 2) physiology-based, biophysical models of single life stages or the whole life cycle of species, 3) food web models, and 4) end-to-end models. Single pressures are rare and, in the future, models must be able to examine multiple factors affecting living marine resources such as interactions between: i) climate-driven changes in temperature regimes and acidification, ii) reductions in water quality due to eutrophication, iii) the introduction of alien invasive species, and/or iv) (over-)exploitation by fisheries. Statistical (correlative) approaches can be used to detect historical patterns which may not be relevant in the future. Advancing predictive capacity of changes in distribution and productivity of living marine resources requires explicit modelling of biological and physical mechanisms. New formulations are needed which (depending on the question) will need to strive for more realism in ecophysiology and behaviour of individuals, life history strategies of species, as well as trophodynamic interactions occurring at different spatial scales. Coupling existing models (e.g. physical, biological, economic) is one avenue that has proven successful. However, fundamental advancements are needed to address key issues such as the adaptive capacity of species/groups and ecosystems. The continued development of end-to-end models (e.g., physics to fish to human sectors) will be critical if we hope to assess how multiple pressures may interact to cause changes in living marine resources including the ecological and economic costs and trade-offs of different spatial management strategies. Given the strengths and weaknesses of the various types of models reviewed here, confidence in projections of changes in the distribution and productivity of living marine resources will be increased by assessing model structural uncertainty through biological ensemble modelling. (C) 2016 Elsevier Ltd. All rights reserved