QUICCHE: QUantifying Interocean fluxes in the Cape Cauldron Hotspot of Eddy kinetic energy

PIs: L. Beal, K. Donohue, Y. Lenn, S. Swart, C. Roman

The Cape Basin in the southeast Atlantic is a global hotspot of eddy kinetic energy, fed by a leakage of waters from the subtropical Indian Ocean via the Agulhas Current. A proportion of warm and salty Agulhas waters are vigorously stirred and mixed into the cooler and fresher Atlantic by co-interacting rings and eddies.  Recent studies suggest that most Agulhas leakage is found outside these rings. We hypothesize that a large proportion of the Indian Ocean waters that leak into the Atlantic are to be found in submesoscale features generated by the mesoscale strain field. Observations of these features are lacking, as are estimates of the fluxes they affect. To fill this gap we propose to:

(1) Observe and characterize submesoscale features generated by the mesoscale eddy strain field. (2) Make novel estimates of Agulhas leakage with new observations, using theoretical eddy diffusivity and eddy flux frameworks. (3) Relate diffusivity and fluxes to new (SWOT) and existing satellite altimeter observations to infer variability in Agulhas leakage.


Funding: National Science Foundation (NSF), Swart funded by Wallenberg Academy Fellowship

Reducing Future Global Climate Uncertainty: Regulation of the ocean’s heat and carbon by small-scale processes in the Antarctic sea-ice regions 

PI: S. Swart

The seas surrounding Antarctica are where vast amounts of heat and carbon exchange between the atmosphere and the deep ocean. The physical processes in the Southern Ocean that underpin these exchanges ultimately determine the rate of climate change and therefore mitigation measures. Despite outstanding progress in observational techniques, there are extremely few observations, which has led to arguably the largest knowledge ‘blind spot’ in global ocean-climate research and predictability.

Specifically, new evidence suggests we urgently require to understand highly energetic upper ocean flows and instabilities (called submesoscale eddies and fronts, which evolve at scales of 0.1-10 km and hours-days). Through enhanced vertical exchange of properties, these phenomena change upper ocean mixing and stratification, thereby amplifying heat and carbon exchange at the air-sea interface. The changes in stratification by submeoscale processes can directly alter the transport of these climate-acute properties to the ocean interior, where they are stored at centennial timescales. Critically, contemporary understanding of these processes occurring in the sea ice regions surrounding Antarctica are severely poor due to a dearth of field data. This, in turn, has led to global climate models experiencing the greatest biases of key processes in the Southern Ocean.

To undertake this scientific challenge, we will coordinate state-of-the-art field observations and fit-for-purpose modelling experiments, including deploying under-ice capable ocean robots from ice breaker expeditions. A new ocean topography satellite mission will provide unprecedented high-resolution ‘surface views’ of the submesoscaleprocesses. These cornerstone observations will be combined with models, of varying complexity, to provide new knowledge on how sensitive ocean-ice processes are to our changing climate and thereby improve climate prediction.


Funding: Prolongation of Wallenberg Academy Fellowship – Knut and Alice Wallenberg Foundation – 2021-2026

Marie Curie Fellowship: Submesoscale Processes in a Changing Environment

PI: M. du Plessis; Host: S. Swart; Collaborators: S. Speich, B. Ward

In SPICE, our aim is to enhance our knowledge of oceanic heat and carbon uptake in the Southern Ocean in order to reduce uncertainties in future global climate model projections. Using ocean observations from state-of-the-art autonomous platforms and high-resolution numerical simulations, we will 1) quantify the variability of heat and carbon air-sea fluxes in the Southern Ocean and 2) better understand how ocean submesoscale processes modulate heat and carbon exchange between the atmosphere and ocean interior. These findings will enhance our understanding of both contemporary and future climate and will provide a benchmark for future research to critically assess climate models – an exercise vital to improving forecasts and thus mitigating against the effects of our changing climate.

Funding: European Research Commission: 2021-2023

GROOM-II: Gliders for Research, Ocean Observations and Management: Infrastructure and Innovation

PI: L. Moutier; Co-PIs: S. Swart; L. Biddle; B. Queste; et al. 


Funding: European Union Horizon 2020 – 2020-2023

Surface ocean physical dynamics of the Southern Ocean with a focus on the Marginal Ice Zone

Fine scale dynamics to large- scale climate sensitivities

PI: S. Swart

The Southern Ocean is a region rich in dynamics in terms of fine scale and high frequency variability of the surface ocean as well as the enhanced forcing of the atmosphere on the upper ocean. There is increasing evidence that seasonal to subseasonal temporal scales, meso- and submesoscale physical processes play an important role in understanding the sensitivity of ocean primary productivity to climate change in the Southern Ocean. However, surface ocean processes are poorly quantified due to lack of observations made at the right time and space scales. These scale gaps have been recognized by the global science community as being a key link towards improving our understanding of the sensitivity of the Southern Ocean to climate change. This project aims, for the first time, to thoroughly and systematically observe and investigate the role and scales of which these processes have in modulating the full seasonal cycle of upper ocean physics in the Southern Ocean.

Annually, 18 million km2 of ice grows and melts around Antarctica. We have limited knowledge of the ocean within, and at the edge, of this enormous sea-ice impacted domain of the Southern Ocean. ROAM-MIZ aims to observe the full seasonal cycle of the upper ocean at high-resolution in the MIZ near the Greenwich Meridian. Visit the live missions site for real time data visualisation.



Knut and Alice Wallenberg Foundation (Wallenberg Academy Fellowship) – 2016-2021

Swedish Research Council (VR) – 2020-2024

Southern Ocean Carbon and Heat Impact on Climate 


PI: J.B. Sallee; co-PI and lead of WP1: S. Swart

The overall objective of SO-CHIC is to understand and quantify variability of heat and carbon budgets in the Southern Ocean through an investigation of the key processes controlling exchanges between the atmosphere, ocean and sea ice using a combination of observational and modelling approaches. SO-CHIC considers the Atlantic sector of the Southern Ocean as a natural laboratory both because of its worldwide importance in water-mass formation and because of the strong European presence in this sector already established at national levels, which allow to best leverage existing expertise, infrastructure, and observation network, around one single coordinated overall objective. SO-CHIC also takes the opportunity of the recent re-appearance of the Atlantic Sector Weddell Polynya to unveil its dynamics and global impact on heat and carbon cycles. A combination of dedicated observation, existing decades- long time-series, and state-of-the-art modelling will be used to address specific objectives on key processes, as well as their impact and feedback on the large-scale atmosphere-ocean system.


Funding: European Union Horizon 2020 – 2019-2022

Swedish Center for Ocean Observing Technology (SCOOT)

PIs: S. Swart, A. Wahlin, O. Oskarsson, A. Wranne, T. Linders

In the current rapid transformation of ocean observations, SCOOT is the Swedish node and enabler. The project focuses on small and innovative companies in automation, sensor technology, communication and adjacent areas of ocean technology. SCOOT provides ocean expertise and infrastructure (ships, autonomous platforms, instruments, sensors, workshops), to researchers, entrepreneurs and SMEs. Together we create a dynamic environment with collaboration and problem solving.

Behind SCOOT is a consortium consisting of University of Gothenburg, MMT Sweden AB and Swedish Meteorological and Hydrological Institute

Funding: European Regional Development Fund (Tillvaxtverket) – 2019-2022

The Ocean Beneath Antarctic Sea-ice: observing new scales to address a global challenge

PI (Sweden): S. Swart; PI (South Africa): S. Thomalla & S. Nicholson

The Antarctic sea-ice covered ocean remains one of the least observed systems on the planet and has been severely under investigated in climate research. It is arguably the largest ‘blind spot’ of current global ocean-climate research. Through an innovative, coordinated and multidisciplinary approach, Sweden and South Africa will conduct novel autonomous ocean glider observations in the Antarctic marginal ice zone (MIZ) and augment this with realistically forced process study and 1D model simulations. Achieving this will shed light onrapidly evolving dynamics and processes of the upper ocean and their impacts on biology and carbon export. This partnership is extremely timely due to the availability of new technological capabilities for under ice observations, current government research strategy and access to the remote field sitesThis project is to support exchange and collaborations between Sweden and South Africa.


Funding: STINT (Sweden) & National Research Foundation (S Africa) – 2019-2021

Gliders in the Agulhas Current (GINA)

PI: M. Krug; co-PI: S. Swart & J. Hermes

This project aims to better understand the response of the coastal and shelf regions to changes in the Agulhas Current off the SE coast of South Africa.

In this project, interactions between the Agulhas Current and coastal and shelf regions are investigated using data collected from autonomous Seagliders and Wave Gliders (autonomous robotic platforms) in the oceanic shelf regions along the extent of the Agulhas Current. The Seagliders measure a wide range of seawater variables (temperature, salinity, pressure, dissolved oxygen, light, bio-optics) that are then communicated back via satellite in real-time to land or ship-based users for analysis.

Research objectives include:

  • Improve our fundamental understanding of the role of western boundary current on the across-shelf exchange between the coastal and deep ocean.
  • Improve our understanding of sub-mesoscale dynamics in western boundary current regimes
  • Better understand and exploit synergies between satellite and glider-based observations
  • Test the feasibility of operating autonomous platforms in the highly turbulent and energetic Agulhas Current region


Funding: GINA is a multi-institutional funded project, namely by CSIR, SAEON, SAIAB, University of Gothenburg (through the K & A Wallenberg Foundation) – 2016 – ongoing.

The role of storms in shaping upper ocean physics and primary production in the Southern Ocean

PI: S. Nicholson; co-PI: S. Swart, P. Monteiro

The Southern Ocean is one of the stormiest places on earth; here strong mid­latitude storms frequently traverse large distances of this ocean. Beneath these passing storms, this ocean is characterized high eddy kinetic energy (eddies and fronts occupying the meso to sub­mesoscale). The passage of intense storms over this underlying meso to sub­mesoscale eddy variability may strongly impact the upper­ ocean environment where phytoplankton live, yet exactly how remains unclear. This project plans for the first time to address this important climate knowledge gap by showing how these intense storms impact upper ocean physics and biogeochemistry with unique observations and modeling. Novel twinned autonomous ocean robots (Wave Glider coupled to a Slocum with a MicroRider package) experiments have been designed to directly observe scale sensitivities and links between storm driven wind forcing, upper­ocean mixing and phytoplankton growth. Several numerical models (idealised and regional) have been setup to (a) understand further the associated storm­driven mechanisms and (b) explore how changes in storm characteristics could impact annual primary production in the SO. Given that the SO is arguably the main source of medium­term uncertainty in global CO2 fluxes, understanding such climate sensitivities is of critical importance.

More info here.


Funding: National Research Foundation – South African National Antarctic Programme

Reducing the climate impact of marine research using carbon neautral autonomous platforms

PI: S. Swart; co-PI: A. Wåhlin, C. Húezé

Marine and oceanographic research requires the use of large research ships for access to the ocean, especially in remote areas such as the high latitudes. These vessels are normally large (±100m) and consume vast amounts of fuel (crude oil & diesel) during their usually long voyages that can extend between days or months. Ocean robotics, on the other hand, are small, relatively cheap and yet sophisticated science platforms that enable scientists to collect observations of unprecedented resolution in support of improved climate and ecosystem understanding. These robots, or ocean gliders, are intelligent autonomous platforms that are deployed in the ocean to conduct surveys, monitoring or scientific experiments.

Their low power requirements and advanced design means they can remain at sea for multiple months at a time, collecting and transmitting data in real time via satellite communication (Iridium) to researchers anywhere in the world. One of their key advantages is that they can collect high resolution, continuous data at a fraction of the cost and effort compared to conventional means, such as ships. These robotic platforms are carbon neutral instruments, while at the same they collect information about the carbon uptake by the ocean – a crucial process that helps us understand how the ocean regulates global climate.

AWGII System Overview

Funding: Climate Fund, University of Gothenburg

Previous projects

Training in Gliders (TING)

PI: S. Swart; co-PI: K. Assman

Funding: Swedish Royal Academy of Sciences (KVA)

Surface ocean physical dynamics of the Southern Ocean

PI: S. Swart; co-PI: P. Monteiro; N. Chang

Funding: National Research Foundation – South African National Antarctic Programme

Southern Ocean observational infrastructure for oceanography and climate research

PI: S. Swart & P. Monteiro

Funding: Department of Science & Technology, South Africa

South Atlantic Meridional Overturning Circulation (SAMOC)

PI: I. J. Ansorge; co-PI: S. Swart

Funding: National Research Foundation – South African National Antarctic Programme

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