Regional Ecosystem & Biogeochemical Impacts of Ocean Acidification - a modelling study.

Lead Research Organisation: NATIONAL OCEANOGRAPHY CENTRE
Department Name: Science and Technology

Abstract

Climate change is one of the main governmental and societal concerns of the current era. The cause, the emissions of huge quantities of carbon dioxide (CO2) by human activities during the industrial era, is accepted by the vast majority of scientists. One of the consequences of increased atmospheric CO2 is Ocean Acidification (OA). The seas absorb a significant proportion of the extra CO2 which reacts in water to increase acidity. This is slightly less well known, at least in the public domain, but is based on uncontroversial and highly accepted scientific understanding and recently verified by precise measurements of the oceans increasing acidity. So over the next few decades the oceans will be impacted by changing climate (increased temperature, changing circulation and mixing) and by increasing acidity. Here it gets complicated. Acidification is known to impact several different processes that are important in regulating the marine ecosystem and different species exhibit different sensitivities. Changing temperature and currents will cause the distributions of particular species to alter and modification of mixing rates (the stirring of the oceans waters) will impact the supply of essential nutrients. Further some physiological processes become more prone to acidity induced effects if those species are subject to increased temperature. The acidity (or carbonate system) of the oceans is also responsive to temperature and to terrestrial effects (changing rainfall or ice melt) that are likely to occur given global warming. In summary predicting the impact of high CO2 (climate and OA) on marine systems is a very complex question. Many scientific experiments and observational programmes are currently investigating how climate and acidity impact the marine system. However the only method we have for trying to synthesise the various impacts mentioned above and make predictions into the future are the development of mathematical models. Within this proposal our aims are to develop existing models that cover the shelf seas around the UK (which have huge resource benefits) and the Arctic region (which is imminently at risk to both climate change and OA) and improve our understanding and certainty of both the magnitude and timescale of impacts. The model system we will use incorporates hydrodynamics, marine chemistry and a representation of marine ecosystems and the processes that drive them, making it ideal to test the combined effects of climate and OA. The models will be forced by the latest and most accurate predictions of climate change and we will compare at least a high emissions scenario - which assumes that globally we do not restrict CO2 production, and a low emissions scenario - which assumes that globally significant steps will be taken to reduce CO2 production. Using information generated by experimental and observational programmes we will improve the description of acidity sensitive chemical and physiological processes in the model. By comparing hind-casts of the model system with observed data, we will establish the accuracy of the model and test uncertainty in individual processes or parameters by sensitivity analysis. We therefore aim to deliver not only predictions of future states but estimates of certainty. The improved understanding of impacts and timescales that this project will generate will be fed directly into the UK Government's advisory process and underpin the development of national and international mitigation and adaptation strategies.
 
Description Tides are in important control on the mixing of water masses in the Arctic Ocean, with consequence for transport (e.g. of carbon) and sea ice formation.
Exploitation Route This work suggest Arctic tides should be accounted for in global Earth systems models either directly or through parameterised mixing effects, to improve these simulations of the role of Arctic in the Earth System.
Sectors Environment

 
Title Northwest Europe NEMO-ERSEM ocean model hindcast and climate projection under RCP8.5 
Description Dataset of model hindcast and climate projection data from a NEMO-ERSEM simulation of the 7km-resolution Atlantic Margin Model (AMM7). Model description and data are presented in Wakelin, S. L., Y. Artioli, J. T. Holt, M. Butenschön, and J. Blackford (2020), Controls on near-bed oxygen concentration on the Northwest European Continental Shelf under a potential future climate scenario, Progress in Oceanography, 102400. doi: https://doi.org/10.1016/j.pocean.2020.102400. Coupled NEMO-ERSEM model simulations are used to study temperature, salinity and near-bed oxygen concentrations on the northwest European Continental Shelf (NWES). Data are from a hindcast (1980 to 2007) and a climate projection (1980 to 2099) under the RCP8.5 climate emissions scenario. The climate projection (1980 to 2099) under the RCP8.5 climate emissions scenario is described as experiment E1 in Holt, J., J. Polton, J. Huthnance, S. Wakelin, E. O'Dea, J. Harle, A. Yool, Y. Artioli, J. Blackford, J. Siddorn, and M. Inall (2018), Climate-Driven Change in the North Atlantic and Arctic Oceans Can Greatly Reduce the Circulation of the North Sea, Geophysical Research Letters, 45(21), 11,827-811,836. doi: 10.1029/2018gl078878. The dataset consists of Hindcast simulation data AMM7_hindcast_3D_S_1980_2007.nc - monthly mean salinity fields. AMM7_hindcast_3D_T_1980_2007.nc - monthly mean temperature fields. AMM7_hindcast_near_bed_O2o_1980_2007.nc - near-bed oxygen concentrations on the NWES. Climate projection data AMM7_RCP8_5_3D_S_1980_2099.nc - monthly mean salinity fields. AMM7_RCP8_5_3D_T_1980_2099.nc - monthly mean temperature fields. AMM7_RCP8_5_3D_U_1980_2099.nc - monthly mean eastwards currents. AMM7_RCP8_5_3D_V_1980_2099.nc - monthly mean northwards currents. AMM7_RCP8_5_near_bed_1980_2099.nc - monthly mean near-bed oxygen concentrations and near-bed bacterial respiration on the NWES. AMM7_RCP8_5_netPP_1980_2099.nc - monthly mean depth integrated net primary production. 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
URL https://zenodo.org/record/3953801
 
Title Northwest Europe NEMO-ERSEM ocean model hindcast and climate projection under RCP8.5 
Description Dataset of model hindcast and climate projection data from a NEMO-ERSEM simulation of the 7km-resolution Atlantic Margin Model (AMM7). Model description and data are presented in Wakelin, S. L., Y. Artioli, J. T. Holt, M. Butenschön, and J. Blackford (2020), Controls on near-bed oxygen concentration on the Northwest European Continental Shelf under a potential future climate scenario, Progress in Oceanography, 102400. doi: https://doi.org/10.1016/j.pocean.2020.102400. Coupled NEMO-ERSEM model simulations are used to study temperature, salinity and near-bed oxygen concentrations on the northwest European Continental Shelf (NWES). Data are from a hindcast (1980 to 2007) and a climate projection (1980 to 2099) under the RCP8.5 climate emissions scenario. The climate projection (1980 to 2099) under the RCP8.5 climate emissions scenario is described as experiment E1 in Holt, J., J. Polton, J. Huthnance, S. Wakelin, E. O'Dea, J. Harle, A. Yool, Y. Artioli, J. Blackford, J. Siddorn, and M. Inall (2018), Climate-Driven Change in the North Atlantic and Arctic Oceans Can Greatly Reduce the Circulation of the North Sea, Geophysical Research Letters, 45(21), 11,827-811,836. doi: 10.1029/2018gl078878. The dataset consists of Hindcast simulation data AMM7_hindcast_3D_S_1980_2007.nc - monthly mean salinity fields. AMM7_hindcast_3D_T_1980_2007.nc - monthly mean temperature fields. AMM7_hindcast_near_bed_O2o_1980_2007.nc - near-bed oxygen concentrations on the NWES. Climate projection data AMM7_RCP8_5_3D_S_1980_2099.nc - monthly mean salinity fields. AMM7_RCP8_5_3D_T_1980_2099.nc - monthly mean temperature fields. AMM7_RCP8_5_3D_U_1980_2099.nc - monthly mean eastwards currents. AMM7_RCP8_5_3D_V_1980_2099.nc - monthly mean northwards currents. AMM7_RCP8_5_near_bed_1980_2099.nc - monthly mean near-bed oxygen concentrations and near-bed bacterial respiration on the NWES. AMM7_RCP8_5_netPP_1980_2099.nc - monthly mean depth integrated net primary production. 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
URL https://zenodo.org/record/3953800