Changing Arctic Carbon cycle in the cOastal Ocean Near-shore (CACOON)

Lead Research Organisation: Plymouth Marine Laboratory
Department Name: Plymouth Marine Lab

Abstract

Global climate change has led to substantial increases in air temperatures across the Earth, particularly in Arctic regions. This has led to changes in patterns of rainfall and snow cover, as well as the structure and stability of terrestrial systems. Unlike the tropics - where the majority of land-based carbon is usually stored in trees on land, the Arctic plays host to vast quantities of carbon locked up underground in frozen soils and ice, known as permafrost. This permafrost has been locked up for tens of thousands of years, and still often contains the remains of woolly mammoth, and exotic viruses [1].

The Arctic Ocean (AO) receives huge quantities of material from the Arctic mainland, much being delivered by giant Arctic rivers that drain vast swathes of the Eurasian and American Arctic. These rivers are now delivering greater quantities of water from land to the ocean, fuelled by climate-driven increases in rainfall and permafrost thaw. This will cause a shift in the amount, age and type of materials being delivered from land to the ocean. So, should why is this important?

The AO plays a crucial role in the storage and cycling of carbon, through the uptake of CO2 by marine plants, and the subsequent export of a fraction of this to the deep ocean - locking away carbon from the atmosphere. The ocean also plays host to bacteria (and other processes), which can release carbon from the ocean to the atmosphere. The balance of these processes is critical in determining how much carbon the AO will store, or release, in the future. Currently, we think the AO is a small overall 'store' of CO2 over the year, but this could change in the future, with hazardous consequences for global temperatures.

We will examine these processes, focusing upon coastal regions where freshwaters meet the ocean. Studies to date, have focused upon rivers only, or the ocean itself, but few have investigated where they mix. We propose to carry out three different strands of research that will fill these gaps in our knowledge. We will study the East Siberian Shelf Sea (ESAS) region, and two very large Arctic river systems (the Kolyma and Lena Rivers) that drain into the AO over this shelf. We'll focus on this remote Russian Arctic area as it is currently experiencing extremely rapid climate warming, riverine runoff rates are increasing fast here, and despite the shelf covering a very large area little is known about how this region will change.

Firstly, we'll conduct field campaigns collecting waters across the two study sites, sampling waters, soils and sediments during winter, summer and spring. This will involve sampling by boat in summer, and by skidoo - with drilling over ice during the Siberian winter. Secondly, we'll bring samples back from the field to conduct detailed experiments to determine how key environmental processes, such as sunlight and bacteria, use and alter terrestrial materials as they move from the rivers into the AO. This includes shining artificial sunlight at waters to see how materials change, or allowing microbes to 'feed' on what's in the water to see what they use and how quickly. Lastly, we'll combine our findings to develop modelling tools allowing us to model, or 'simulate', how fluxes of water, and materials travel from land-to-ocean over the ESAS. This model will contain separate compartments, representing different fractions of the materials sourced from land, for example different nutrients or carbon types. Also, it will simulate the major (small to microscopic) biological groups within the ecosystem, for example bacteria, and different phytoplankton groups. This will allow us to examine how the AO, and its biological processes will respond to future changes in freshwater supply and increased permafrost, and ultimately identify how these processes may alter the role of the AO in global climate.

[1] http://www.bbc.com/earth/story/20170504-there-are-diseases-hidden-in-ice-and-they-are-waking-up

Planned Impact

Our impact objectives are to:

1. Improve policy makers' understanding of the role of the Arctic Ocean in climate mediation and how this might change in the future, in order to assist decision making.

2. Engage with a wide range of stakeholders, focusing upon young people of school- age and the general public to raise awareness of Arctic climate change, and of the UKs need for understanding what takes place there.

Who will benefit and how may they benefit from CACOON research?
(How this will be done is outlined in the Pathways to Impact document).

The UK government acknowledges that our understanding of Arctic ecosystems, and in particular marine ecosystems is limited and that this knowledge gap "hampers our ability to fully understand the effects of climate change, and of human activity, on marine species in the region" [1]. CACOON will deliver improved understanding of Arctic change at seasonal to decadal timescales, to establish knowledge and understanding on the impacts of freshwater intensification and terrestrial permafrost thaw in marine ecosystem structure and biogeochemical functioning. The project will raise the profile of the UK by developing a biogeochemical model capable of adequately representing changes in the supply and character of materials from land-to-ocean, and quantifying its consequences upon key ecosystem processes and roles. CACOON will therefore benefit policy forming bodies such as governmental environment and climate change departments (e.g. DECC, DEFRA and their international equivalents) by contributing to a new understanding of how terrestrial and marine ecosystems interact to alter planktonic food-webs, and the role (and value) of Arctic Ocean biogeochemistry in climate regulation; evidence which can underpin policy. The project focus upon the Siberian Arctic also provides opportunities to build links with Russian scientists as sought by the Science and Innovation Network [1].

Greater understanding of the functioning and role of Arctic Ocean near-shore and how this may influence changes to marine carbon cycling are directly relevant to the knowledge and confidence of environmental policy communities including the United Nations Environment Programme (UNEP), the United Nations Framework Convention on Climate Change (UNFCCC), the European Union, the Arctic Council, and the International Council for the Exploration of the Sea (ICES), as well as international science bodies such as the Scientific Committee on Ocean Research (SCOR), Future Earth (FE) and the World Climate Research Programme (WCRP) and charities with a strong Arctic interest.

CACOON will benefit young people of school-age, with the aim of increasing awareness and participation in geophysics. 'Think Geophysics' will build on the success of the pioneering NUSTEM' project led by Northumbria University, previously funded for £1.2 million from the Higher Education Funding Council for England (HEFCE). Research by the Institute of Physics revealed only 21% of physics students at UK universities were female. NUSTEM looks to target this gender imbalance by changing the way young people, particularly girls and under-represented groups, engaged with science from early years to sixth form and on to university. Think Geophysics will adopt this innovative 'blueprint as a cradle-to-career project aimed at using environmental geophysics to inspire young people, particularly in the aforementioned groups, into Science, Technology, Engineering and Mathematics (STEM) disciplines. The project will address the national shortage of STEM skills in the UK by inspiring more young people to take up these disciplines at university. 'Think Geophysics' will also help to better inform the public, by exhibiting in centres, museums, festivals and events across the North East.

[1] Government Response to the House of Lords Select Committee Report HL 118 of Session 2014-15: Responding to a changing Arctic.
 
Description During this first year we have developed and implemented a hydrodynamic-sediment model to evaluate the relative contributions of organic matter derived from permafrost originating inland and delivered by the Lena river during the freshnet and that derived from coastal/cliff erosion. The model suggests very different spatial distribution of both sources with consequences to carbon sequestration and climate significance.
Exploitation Route Both model simulations and publications will contribute to the scientific knowledge of the region and the susceptibility of its marine pelagic and benthic ecosystem to probable future changes in climate.
Sectors Environment

 
Description Results from our work are being used to develop a children's card game equivalent to Trump's card games.
First Year Of Impact 2020
Sector Education
Impact Types Cultural,Societal

 
Title FVCOM-FABM coupler 
Description We have updated the PML-maintained biogeochemical coupler (FVCOM-FABM) of the 3D hydrodynamic model FVCOM to support more varied biogeochemical model configurations, including SPM interactions and depth-integrated fish stocks as well as online and offline simulations. New functionality is designed to integrate with existing biogeochemical models in FABM, including ERSEM. 
Type Of Material Computer model/algorithm 
Year Produced 2021 
Provided To Others? Yes  
Impact Used by various partners including the NOC, Marine Scotland, NIVA in projects funded by e.g. CMEMS, NERC and Defra. 
URL https://www.pml.ac.uk/Modelling_at_PML/Access_Code
 
Title GOTM-ERSEM implementation in the Laptev sea 
Description A new model formulation describing terrigenous DOC (TDOC) dynamics has been implemented in the ERSEM model. Following Anderson et al (2019) TDOC is modelled through 2 state variables, photo-labile and non-photo-labile TDOC. ERSEM+TDOC has been coupled with the General Ocean Turbulence Model (GOTM) and implemented in the Laptev Sea. The model was run with 3 different TDOC inputs (current TDOC conc., +30% and +50%) to have a preliminary assessment on how increasing TDOC discharge (permafrost melting) might affect marine ecosystem during the productive season (June-September). Year 2012 has been taken as example. 
Type Of Material Computer model/algorithm 
Year Produced 2019 
Provided To Others? No  
Impact Model simulations suggest that increased TDOC discharge has the potential to remarkably affect the planktonic ecosystem by: 1) enhancing light limitation, 2) reducing primary production, 3) increasing bacterial production and respiration and 4) making the water column a source of CO2 for the atmosphere all through the year. These results will inform future 3-dimensional modelling works investigating the effect of TDOC on the arctic planktonic ecosystem. 
 
Title Laptev sea coupled ice-hydrodynamic model with offline tracers 
Description FVCOM model setup of the Laptev sea with coupled observed ice model. Forced by CMEMS global model boundary conditions, ECMWF surface forcing, river gauge data and a blend of satellite and modelled sea ice. The output setup to force an offline tracer model (tracers can have a variety of sediment properties; settling, resuspension etc). 
Type Of Material Computer model/algorithm 
Year Produced 2019 
Provided To Others? No  
Impact Investigating the residence time and eventual fate of riverine and coastal derived sediments 
 
Title Laptev sea coupled physics-biogeochemistry model 
Description Coupled FVCOM-ERSEM model of the laptev sea 
Type Of Material Computer model/algorithm 
Year Produced 2021 
Provided To Others? No  
Impact Allows us to run experiments changing the amount and character of terrestrial DOM into an arctic ecosystem to investigate the effects of future changes 
 
Title Laptev sea tidal model 
Description Set up of tides only FVCOM model for the laptev sea 
Type Of Material Computer model/algorithm 
Year Produced 2019 
Provided To Others? No  
Impact Allow initial investigations into sediment transport in the Laptev sea and provide base for full physics and ecosystem model 
 
Title Sensitivity of CO2 flux to terrigenous DOC lability 
Description A model sensitivity exercise has been performed to investigate the effect of terrigenous DOC (TDOC) lability on carbon fluxes within the planktonic ecosystem of the Laptev Sea. In this experiment, TDOC was assumed to have a life time ranging from 0.3 to 20 years. 
Type Of Material Computer model/algorithm 
Year Produced 2020 
Provided To Others? No  
Impact Preliminary results suggest that terrigenous DOC lability affects primary production and bacterial respiration with consequences on the CO2 exchange between surface waters and the atmosphere 
 
Title Terrigenous DOC implemented in ERSEM 
Description Two new state variables describing riverine dissolved organic carbon have been implemented in the ERSEM model. The two state variables, describing photo-labile and non photolabile terrigenous DOC, respectively, have been coded following a recently published paper (Anderson et al., 2019) 
Type Of Material Computer model/algorithm 
Year Produced 2019 
Provided To Others? No  
Impact This development will allow ERSEM to simulate terrigenous DOC and therefore to investigate the impact of this carbon source (so far neglected in marine models) on the marine carbon cycle. 
 
Description Collaboration with Akvaplan-NIVA on modelling tools and FVCOM modelling approaches 
Organisation Norwegian Institute for Water Research (NIVA)
Country Norway 
Sector Public 
PI Contribution The FVCOM modelling group in PML has been collaborating with the Akvaplan-NIVA branch of NIVA since 2017. In this period we have developped modelling tools (fvcom matlab toolbox and PyFVCOM python toolbox) that are routinely used by their group, and fortran code (fate modelling code of antiparasitic substances used in salmon fishfarms, additional advection schemes) to enhance the capabilities of FVCOM modelling suite.
Collaborator Contribution Akvaplan-NIVA have made improvements to FVCOM code related to how rivers are handled and a more accurate advection scheme which we have used in our coupled hydrodynamic-ecosystem FVCOM simulations. Both institutions have co-developed a simple organic matter transport code to track riverine and coastal erosion of permafrost.
Impact FVCOM model domain and setup for the Hardangerfjorden in Norway. One year simulation of the Hardangerfjorden hydrodynamics and the fate of organic matter and antiparastic substances resulting from the operation of 5 fish farms in the central section of the fjord. Two year simulation of fate and transport of organic matter derived from siberian permafrost in the Latvev sea/Lena delta system.
Start Year 2017
 
Description Establishment of working partnership with Prof Yianzhong Ge to develop FVCOM-FABM-ERSEM capabilities related to terrestrial carbon, land inputs and particulate-dissolved interactions 
Organisation East China Normal University (ECNU)
Country China 
Sector Academic/University 
PI Contribution We have shared our experience with FVCOM-FABM-ERSEM for modelling estuarine and coastal environments through informal online communication between the groups. We have updated FVCOM-FABM code to accommodate high concentrations of particulate materials and included the effect of dissolved terrestrial organic carbon on coastal and estuarine pelagic ecosystems.
Collaborator Contribution Prof Ge's group has improved on the vertical transport scheme of ERSEM variables in FVCOM-FABM code.
Impact We have submitted a proposal to a Chinese funding agency (Shanghai Municipality) under a China-UK collaboration funding call to further develop the work for areas of very high sediment and terrestrial organic inputs.
Start Year 2021
 
Description Submission of proposal investigating ice drift/ice leads in Ice model 
Organisation Norwegian Institute for Water Research (NIVA)
Department Akvaplan Niva
Country Norway 
Sector Private 
PI Contribution Workshopping ideas for representing ice drift and ice leads in the observed ice model. Contribution to proposal text.
Collaborator Contribution Lead on (much wider) proposal, discussion of potential ice model features.
Impact Submitted proposa to Norwegian research councill; investigating impact of changing ice conditions on fisheries near svalbard
Start Year 2021
 
Title ERSEM arctic 
Description ERSEM: European Regional Seas Ecosystem Model adapted to Arctic functional groups including spectral light P/I curves, high and low light acclimation as contributions from NIVA and terrestrial doc degradation (Permafrost) For more information please visit https://ersem.com. 
Type Of Technology Software 
Year Produced 2021 
Open Source License? Yes  
Impact This update has been used within CACOON NERC project to evaluate the impact of coastal erosion and permafrost riverine inputs into a shallow shelf in the East Siberian Seas. 
 
Title Fortran code for fate modelling of antiparasitic substances 
Description This is code to be used within the FABM framework and so it is available for multiple hydrodynamic models (FVCOM, ROMS, NEMO and others) and can be downloaded from the main fabm repository in github. The code enables the user to simulate the dispersion of organic matter (OM) originating from salmon fish cages practices (but can be use for land derived OM from permafrost erosion) and its interaction with antiparasitic substances used to treat salmon lice infections. The code is generic and can be used for substances such as Emamectin benzoate, Diflubenzuron or Teflubenzuron. The code was first use in 2018. It has been updated in 2019. 
Type Of Technology Software 
Year Produced 2019 
Open Source License? Yes  
Impact The code enables predictions of how use of antiparasitics can transfer to sea bed sediments and estimates the concentrations that can exist in the environment given the simulated hydrodynamics. 
URL http://tapas-h2020.eu/results/
 
Description FVCOM UK user group workshop 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Workshop of the UK users of the FVCOM hydrodynamic model. Shared best practice and research. Collaboration on sea-ice cover code with modellers from Aquaplan-Niva was an outcome of this workshop.
Year(s) Of Engagement Activity 2018
 
Description FVCOM uk usergroup 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Presented work on Laptev sea domain to audience of scientific and commercial users of FVCOM model. Resulted in discussions of possible future work and technical aspects.
Year(s) Of Engagement Activity 2019
 
Description School Q&A video recording 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact I answered a question relating to how the waters mixed in the ocean from a student from a local school (Oreston Community Academy, Plymstock). The answer was submitted as a video recording that was played to the entire year class.
Year(s) Of Engagement Activity 2020