Carbon Uptake and Seasonal Traits in Antarctic Remineralisation Depth (CUSTARD)

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

Abstract

The surface ocean is home to billions of microscopic plants called phytoplankton which produce organic matter in the surface ocean using sunlight and carbon dioxide. When they die many of them sink, taking this carbon into the deep ocean, where it may be stored for hundreds to thousands of years, which helps keep our climate the way it is today.
In general terms the size of the effect they have on our climate is linked to how deep they sink before they dissolve - the deeper they sink, the more carbon is stored. This effect is particularly important in the northern part of the Southern Ocean where the pattern of ocean currents means that the difference between shallow and deep dissolution controls whether this carbon is locked away from the surface ocean for just a few years or for centuries. This is because the area is a junction in the ocean circulation. Stacked up on each other from the surface to the seafloor at almost 5km depth are four oceanic 'motorways', taking water to different parts of the global ocean. The motorway that the carbon is dissolved into determines how long it will be kept away from the atmosphere.
For this reason, if we want to understand the role of this northern part of the Southern Ocean in regulating global climate we need to understand both how big carbon uptake is at the ocean surface and also how deep sinking material dissolves. Unfortunately we don't understand either well; data are scarce in the Southern Ocean as the weather is poor and few commercial vessels pass through there. Consequently, our theories about the pattern of the fate of sinking carbon and what controls this are untested. As a result the models that we use for predicting future climate have massive uncertainty in this region. However, the evidence that we have suggests that changes in the depth of carbon dissolution are key to understanding how the system works.
In this project we will tackle this by making new observations in a remote region of the Southern Ocean using an exciting combination of robotic vehicles and sophisticated new sensors. We will make new observations of how much carbon the ocean takes up in this key motorway junction of the Southern Ocean. We will examine the processes that control the uptake of carbon and its fate, in particular how seasonal availability of nutrients can affect the make-up of the phytoplankton which changes the depth to which carbon sinks before being dissolved.
We will combine these observations with a novel modelling approach that allows us to run the ocean part of our climate model much faster than normally. This allows us to explore the consequences of the seasonal interplay between nutrients and phytoplankton found in our data. In particular, the model allows us to 'tag' carbon so that we can trace where it goes. In this way we can measure the amount of sinking carbon ending up on each motorway and how this varies through the year.
Together with observations of the seasonal changes in nutrients and sinking carbon the model will allow us to determine the key processes regulating carbon uptake in this important area. This will provide important information to those building the UK's climate model at a time when it is being developed to provide input to a future high profile report (from the IPCC) on the state of the world's climate.

Planned Impact

CUSTARD will engage fully with the other funded RoSES projects and NERC to ensure CUSTARD's impact plan is integrated with wider impact activities. In addition, CUSTARD will achieve impact in the following areas:

Climate prediction:
International agreements to limit the impact of anthropogenic climate change such as COP21 are based upon accurate and precise predictions of how the earth system will respond to potential scenarios of future greenhouse gas release. Our ability to predict future trajectories of atmospheric CO2 and climate is, in turn, strongly dependent on our ability to develop robust and accurate climate models that can quantitatively demonstrate their skill in reproducing the existing CO2 record. CUSTARD will contribute directly to two aspects of this.
First, CUSTARD will collect ocean CO2 flux data year-round in the chronically under-sampled Southern Ocean. Co-I Bakker is a key member of SOCAT (http://www.socat.info), the standard source of flux data globally and widely used for policy briefings (e.g. Pollution in the open oceans: 2009-2013. Boelens, R. et al., GESAMP reports and Studies 91) and climate model testing (e.g. ESMValTool (v1.0) - A tool for evaluation of Earth System Models in CMIP: Eyring, V., et al., 2016. Geoscientific Model Development 9, doi:10.5194/gmd-9-1747-2016).
Second, CUSTARD will provide mechanistic information on the controls on carbon uptake and redistribution in the Southern Ocean. The new insights generated in CUSTARD into the seasonal variability of production and remineralisation, and the implications for ocean carbon storage will be fed through existing links into ongoing development of UKESM2, the next generation UK Earth System model for the UK's contribution to future IPCC assessments.

Autonomous sensing:
Robotics and autonomous systems were identified by the UK government in 2013 as one of 8 great technologies that will help drive economic growth. This was followed by a large (£10 million) capital investment into the MARS national facility. CUSTARD will thus be of interest to the growing community of AUV and sensors manufacturers and users, including agencies with marine monitoring obligations, e.g. Defra and CEFAS. We will hold a community workshop which will focus on best practice for using autonomous vehicles to derive information on carbon fluxes, which we will host at the NOC. Similar previous events have successfully attracted many representatives of AUV manufacturers, however, we will extend the reach to include stakeholders with a remit for ocean monitoring, such as Defra and CEFAS.

Technology:
A novel dissolved silica sensor developed by NOC's Ocean Technology and Engineering group will be deployed during CUSTARD. This is the first autonomous sensor, suitable for the marine environment, capable of measuring in situ silicate, a key component of ocean biogeochemistry. The successful demonstration of this sensor to provide high quality silicate measurements autonomously over an extended period of time will be exploited to generate interest in commercialisation of the sensor.

Science communication:
The CUSTARD team includes co-I Henson, an experienced and effective communicator to general audiences, having participated in multiple public engagement and schools activities, ranging from on-screen contributions to BBC4 TV series 'The Spectrum of Science', to being a panel member at Royal Institution debates, to lectures at the Cheltenham Science Fair, to exhibiting events aimed at school children such as the Big Bang science fair.
Project staff will also be encouraged to undertake public engagement training, such as through the public engagement courses run by NERC or Sense about Science. In addition, a new public engagement activity will be designed as part of CUSTARD and used during the annual Ocean and Earth day held at NOC (attracts > 3000 visitors) and at other events.

Publications

10 25 50
 
Description Main achievements so far...

o Demonstration that seasonal variability in how marine life processes carbon has significant impact on its storage in the ocean
Marine life helps store huge amounts of carbon in the ocean, by turning it into it organic material which then spreads to the very deepest parts of the ocean as it is in turn eaten and recycled by other creatures. Many of the processes involved take place in the dark waters below the surface. Because of the absence of light, seasons have been largely ignored. However, the 'marine snow' of material sinking out of the sunlit surface is strongly seasonal. We have shown that the seasonal response can have a significant impact on how much carbon is stored in the ocean each year by marine life.

o New theoretical understanding of how seasonal cycle in the ocean can be mistaken for geographical variability
Conventional wisdom holds that the rate at which organic material is consumed and respired back to carbon dioxide varies strongly with location, with highly productive areas showing different rates of consumption to less productive ones. We have shown that such conventional wisdom is influenced by a failure to take into account seasonality. Purely having seasonality with no geographical variation can reproduce observations.

o Investigation of how changes in dust supply from land may influence phytoplankton productivity in the past and future Southern Ocean
It is known that some regions of the ocean, particularly the Southern Ocean, are not as productive as they might be because they lack sufficient iron for phytoplankton to grow to their full potential. Dust from land is a major source. We have shown that phytoplankton may respond differently to different sources of dust (e.g. from different desert regions) in part because of the presence of other metals such as magnesium which may also be scarce in sea water

All of these results have implications for how we model the role of the ocean in the carbon cycle in our climate models.
Exploitation Route Informing model design for future IPCC submissions.
Sectors Environment

 
Description First cruise was used as basis for a meeting with Chilean Navy, univerisities and UK amabassador to Chile when moored in Punta Arenas, Chile.
First Year Of Impact 2019
Sector Environment
Impact Types Economic

Policy & public services

 
Description Bridging International Activity and Related Research Into the Twilight Zone (BIARRITZ)
Amount £49,729 (GBP)
Funding ID NE/S00842X/2 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 11/2019 
End 09/2021
 
Title Model output used in the manuscript "Influence of seasonal variability in flux attenuation on global organic carbon fluxes and nutrient distributions" 
Description This *.rar file contains the model output from seasonal variability experiments using the NPZD-DOP GEOMAR biogeochemical model (Kriest et al., 2010) coupled with the MITgcm 2.8deg ocean circulation via the transport matrix method (Khatiwala et al., 2005; Khatiwala, 2007, 2018). These model outputs are presented and discussed in the article "Influence of seasonal variability in flux attenuation on global organic carbon fluxes and nutrient distributions", published by Global Biogeochemical Cycles (de Melo Viríssimo et al., 2022). The manuscript also describe the experiments performed, the parameter values used and the modifications done in the original model. All files uploaded were generated from simulations run by the authors, except: the grid file and salinity, which came with the model; and the density fields, who were computed from the MITgcm 2.8deg transport matrix by Rafaelle Bernadello, using a TEOS-10 matlab routine (http://www.teos-10.org/). For specific information about each file uploaded, please refer to the README file. If you have any questions, please feel free to contact me. References: Kriest et al. (2010): https://doi.org/10.1016/j.pocean.2010.05.002 Khatiwala et al. (2005): https://doi.org/10.1016/j.ocemod.2004.04.002 Khatiwala (2007): https://doi.org/10.1029/2007GB002923 Khatiwala (2018): https://doi.org/10.5281/zenodo.1246300 de Melo Viríssimo et al. (2022): https://doi.org/10.1029/2021GB007101 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
URL https://zenodo.org/doi/10.5281/zenodo.4926061
 
Title Model output used in the manuscript "Influence of seasonal variability in flux attenuation on global organic carbon fluxes and nutrient distributions" 
Description This *.rar file contains the model output from seasonal variability experiments using the NPZD-DOP GEOMAR biogeochemical model (Kriest et al., 2010) coupled with the MITgcm 2.8deg ocean circulation via the transport matrix method (Khatiwala et al., 2005; Khatiwala, 2007, 2018). These model outputs are presented and discussed in the article "Influence of seasonal variability in flux attenuation on global organic carbon fluxes and nutrient distributions", published by Global Biogeochemical Cycles (de Melo Viríssimo et al., 2022). The manuscript also describe the experiments performed, the parameter values used and the modifications done in the original model. All files uploaded were generated from simulations run by the authors, except: the grid file and salinity, which came with the model; and the density fields, who were computed from the MITgcm 2.8deg transport matrix by Rafaelle Bernadello, using a TEOS-10 matlab routine (http://www.teos-10.org/). For specific information about each file uploaded, please refer to the README file. If you have any questions, please feel free to contact me. References: Kriest et al. (2010): https://doi.org/10.1016/j.pocean.2010.05.002 Khatiwala et al. (2005): https://doi.org/10.1016/j.ocemod.2004.04.002 Khatiwala (2007): https://doi.org/10.1029/2007GB002923 Khatiwala (2018): https://doi.org/10.5281/zenodo.1246300 de Melo Viríssimo et al. (2022): https://doi.org/10.1029/2021GB007101 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
URL https://zenodo.org/doi/10.5281/zenodo.4926060
 
Title Model output used in the manuscript "Seasonality in carbon flux attenuation explains spatial variability in transfer efficiency" 
Description This *.rar file contains the model output from seasonal variability experiments using the NPZD-DOP GEOMAR biogeochemical model (Kriest et al., 2010) coupled with the MITgcm 2.8deg ocean circulation via the transport matrix method (Khatiwala et al., 2005; Khatiwala, 2007, 2018). These model outputs are presented and discussed in the Preprint "Seasonality in carbon flux attenuation explains spatial variability in transfer efficiency", available on EarthArXiv (de Melo Viríssimo et al., 2023). The manuscript describes the experiments performed, the parameter values used and the modifications done to the original model. For this matter, we also refer you to de Melo Viríssimo et al. (2022). All files uploaded were generated from simulations run by the authors, except: the grid file, the salinity field, and the temperature field, which came with the model; and the density fields, who were computed from the MITgcm 2.8deg transport matrix by Rafaelle Bernadello, using a TEOS-10 matlab routine (http://www.teos-10.org/). For specific information about each file uploaded, please refer to the README file. If you have any questions, please feel free to contact me. References: Kriest et al. (2010): https://doi.org/10.1016/j.pocean.2010.05.002 Khatiwala et al. (2005): https://doi.org/10.1016/j.ocemod.2004.04.002 Khatiwala (2007): https://doi.org/10.1029/2007GB002923 Khatiwala (2018): https://doi.org/10.5281/zenodo.1246300 de Melo Viríssimo et al. (2022): https://doi.org/10.1029/2021GB007101 de Melo Viríssimo et al. (2023): https://doi.org/10.31223/X5966J 
Type Of Material Database/Collection of data 
Year Produced 2023 
Provided To Others? Yes  
URL https://zenodo.org/doi/10.5281/zenodo.7514128
 
Description Endorsed Programme for the UN Ocean Decade - JETZON - Joint Exploration of the Twilight Zone Ocean Network 
Organisation AZTI
Country Spain 
Sector Academic/University 
PI Contribution This initial initiative came out of the workshop run by BIARRITZ at NOC in July 2019, bringing together over 70 scientists and 14 projects internationally with interest in the Twilight Zone. Subsequently we at NOC set up the JETZON webpage, led on planning for a Town Hall meeting at Ocean Sciences to launch JETZON and coordinated the start of data-sharing. Building on this, in 2021 NOC successfully led the application that led to JETZON being endorsed as one of the first Programmes for UN Ocean Decade for Sustainable Development
Collaborator Contribution Backing of 25+ projects internationally for the Programme
Impact UN Ocean Decade endorsed programme - JETZON
Start Year 2019
 
Description Endorsed Programme for the UN Ocean Decade - JETZON - Joint Exploration of the Twilight Zone Ocean Network 
Organisation Bjerknes Centre for Climate Research
Country Norway 
Sector Academic/University 
PI Contribution This initial initiative came out of the workshop run by BIARRITZ at NOC in July 2019, bringing together over 70 scientists and 14 projects internationally with interest in the Twilight Zone. Subsequently we at NOC set up the JETZON webpage, led on planning for a Town Hall meeting at Ocean Sciences to launch JETZON and coordinated the start of data-sharing. Building on this, in 2021 NOC successfully led the application that led to JETZON being endorsed as one of the first Programmes for UN Ocean Decade for Sustainable Development
Collaborator Contribution Backing of 25+ projects internationally for the Programme
Impact UN Ocean Decade endorsed programme - JETZON
Start Year 2019
 
Description Endorsed Programme for the UN Ocean Decade - JETZON - Joint Exploration of the Twilight Zone Ocean Network 
Organisation Geomar, Kiel
Country Germany 
Sector Academic/University 
PI Contribution This initial initiative came out of the workshop run by BIARRITZ at NOC in July 2019, bringing together over 70 scientists and 14 projects internationally with interest in the Twilight Zone. Subsequently we at NOC set up the JETZON webpage, led on planning for a Town Hall meeting at Ocean Sciences to launch JETZON and coordinated the start of data-sharing. Building on this, in 2021 NOC successfully led the application that led to JETZON being endorsed as one of the first Programmes for UN Ocean Decade for Sustainable Development
Collaborator Contribution Backing of 25+ projects internationally for the Programme
Impact UN Ocean Decade endorsed programme - JETZON
Start Year 2019
 
Description Endorsed Programme for the UN Ocean Decade - JETZON - Joint Exploration of the Twilight Zone Ocean Network 
Organisation National Aeronautics and Space Administration (NASA)
Country United States 
Sector Public 
PI Contribution This initial initiative came out of the workshop run by BIARRITZ at NOC in July 2019, bringing together over 70 scientists and 14 projects internationally with interest in the Twilight Zone. Subsequently we at NOC set up the JETZON webpage, led on planning for a Town Hall meeting at Ocean Sciences to launch JETZON and coordinated the start of data-sharing. Building on this, in 2021 NOC successfully led the application that led to JETZON being endorsed as one of the first Programmes for UN Ocean Decade for Sustainable Development
Collaborator Contribution Backing of 25+ projects internationally for the Programme
Impact UN Ocean Decade endorsed programme - JETZON
Start Year 2019
 
Description Endorsed Programme for the UN Ocean Decade - JETZON - Joint Exploration of the Twilight Zone Ocean Network 
Organisation Rutgers University
Country United States 
Sector Academic/University 
PI Contribution This initial initiative came out of the workshop run by BIARRITZ at NOC in July 2019, bringing together over 70 scientists and 14 projects internationally with interest in the Twilight Zone. Subsequently we at NOC set up the JETZON webpage, led on planning for a Town Hall meeting at Ocean Sciences to launch JETZON and coordinated the start of data-sharing. Building on this, in 2021 NOC successfully led the application that led to JETZON being endorsed as one of the first Programmes for UN Ocean Decade for Sustainable Development
Collaborator Contribution Backing of 25+ projects internationally for the Programme
Impact UN Ocean Decade endorsed programme - JETZON
Start Year 2019
 
Description Endorsed Programme for the UN Ocean Decade - JETZON - Joint Exploration of the Twilight Zone Ocean Network 
Organisation University of California, Santa Barbara
Country United States 
Sector Academic/University 
PI Contribution This initial initiative came out of the workshop run by BIARRITZ at NOC in July 2019, bringing together over 70 scientists and 14 projects internationally with interest in the Twilight Zone. Subsequently we at NOC set up the JETZON webpage, led on planning for a Town Hall meeting at Ocean Sciences to launch JETZON and coordinated the start of data-sharing. Building on this, in 2021 NOC successfully led the application that led to JETZON being endorsed as one of the first Programmes for UN Ocean Decade for Sustainable Development
Collaborator Contribution Backing of 25+ projects internationally for the Programme
Impact UN Ocean Decade endorsed programme - JETZON
Start Year 2019
 
Description Endorsed Programme for the UN Ocean Decade - JETZON - Joint Exploration of the Twilight Zone Ocean Network 
Organisation University of East Anglia
Department School of Environmental Sciences UEA
Country United Kingdom 
Sector Academic/University 
PI Contribution This initial initiative came out of the workshop run by BIARRITZ at NOC in July 2019, bringing together over 70 scientists and 14 projects internationally with interest in the Twilight Zone. Subsequently we at NOC set up the JETZON webpage, led on planning for a Town Hall meeting at Ocean Sciences to launch JETZON and coordinated the start of data-sharing. Building on this, in 2021 NOC successfully led the application that led to JETZON being endorsed as one of the first Programmes for UN Ocean Decade for Sustainable Development
Collaborator Contribution Backing of 25+ projects internationally for the Programme
Impact UN Ocean Decade endorsed programme - JETZON
Start Year 2019
 
Description Endorsed Programme for the UN Ocean Decade - JETZON - Joint Exploration of the Twilight Zone Ocean Network 
Organisation University of Seville
Country Spain 
Sector Academic/University 
PI Contribution This initial initiative came out of the workshop run by BIARRITZ at NOC in July 2019, bringing together over 70 scientists and 14 projects internationally with interest in the Twilight Zone. Subsequently we at NOC set up the JETZON webpage, led on planning for a Town Hall meeting at Ocean Sciences to launch JETZON and coordinated the start of data-sharing. Building on this, in 2021 NOC successfully led the application that led to JETZON being endorsed as one of the first Programmes for UN Ocean Decade for Sustainable Development
Collaborator Contribution Backing of 25+ projects internationally for the Programme
Impact UN Ocean Decade endorsed programme - JETZON
Start Year 2019
 
Description Endorsed Programme for the UN Ocean Decade - JETZON - Joint Exploration of the Twilight Zone Ocean Network 
Organisation University of Tasmania
Department Institute for Marine and Antarctic Studies
Country Australia 
Sector Public 
PI Contribution This initial initiative came out of the workshop run by BIARRITZ at NOC in July 2019, bringing together over 70 scientists and 14 projects internationally with interest in the Twilight Zone. Subsequently we at NOC set up the JETZON webpage, led on planning for a Town Hall meeting at Ocean Sciences to launch JETZON and coordinated the start of data-sharing. Building on this, in 2021 NOC successfully led the application that led to JETZON being endorsed as one of the first Programmes for UN Ocean Decade for Sustainable Development
Collaborator Contribution Backing of 25+ projects internationally for the Programme
Impact UN Ocean Decade endorsed programme - JETZON
Start Year 2019
 
Description Endorsed Programme for the UN Ocean Decade - JETZON - Joint Exploration of the Twilight Zone Ocean Network 
Organisation Villefranche Oceanographic Laboratory
Country France 
Sector Charity/Non Profit 
PI Contribution This initial initiative came out of the workshop run by BIARRITZ at NOC in July 2019, bringing together over 70 scientists and 14 projects internationally with interest in the Twilight Zone. Subsequently we at NOC set up the JETZON webpage, led on planning for a Town Hall meeting at Ocean Sciences to launch JETZON and coordinated the start of data-sharing. Building on this, in 2021 NOC successfully led the application that led to JETZON being endorsed as one of the first Programmes for UN Ocean Decade for Sustainable Development
Collaborator Contribution Backing of 25+ projects internationally for the Programme
Impact UN Ocean Decade endorsed programme - JETZON
Start Year 2019
 
Description Endorsed Programme for the UN Ocean Decade - JETZON - Joint Exploration of the Twilight Zone Ocean Network 
Organisation Woods Hole Oceanographic Institution
Country United States 
Sector Charity/Non Profit 
PI Contribution This initial initiative came out of the workshop run by BIARRITZ at NOC in July 2019, bringing together over 70 scientists and 14 projects internationally with interest in the Twilight Zone. Subsequently we at NOC set up the JETZON webpage, led on planning for a Town Hall meeting at Ocean Sciences to launch JETZON and coordinated the start of data-sharing. Building on this, in 2021 NOC successfully led the application that led to JETZON being endorsed as one of the first Programmes for UN Ocean Decade for Sustainable Development
Collaborator Contribution Backing of 25+ projects internationally for the Programme
Impact UN Ocean Decade endorsed programme - JETZON
Start Year 2019
 
Description International symposium of the Twilight Zone 
Organisation Grantham Foundation for the Protection of the Environment
Country United States 
Sector Private 
PI Contribution The CUSTARD project supported an international workshop of over 100 participants from around the world involving under-represented countries and policy experts.
Collaborator Contribution The event was hosted and part-funded by WHOI. The Grantham Foundation provided funds to support the attendance of early career researchers.
Impact None as yet
Start Year 2023
 
Description International symposium of the Twilight Zone 
Organisation Woods Hole Oceanographic Institution
Country United States 
Sector Charity/Non Profit 
PI Contribution The CUSTARD project supported an international workshop of over 100 participants from around the world involving under-represented countries and policy experts.
Collaborator Contribution The event was hosted and part-funded by WHOI. The Grantham Foundation provided funds to support the attendance of early career researchers.
Impact None as yet
Start Year 2023