Quantifying Interocean Fluxes across the Cape Cauldron Hotspot of Eddy Kinetic Energy

Lead Research Organisation: Bangor University
Department Name: Sch of Ocean Sciences

Abstract

The Agulhas current carries warm and salty subtropical Indian Ocean water south along the coast of east Africa. Past the Cape of Good Hope, the Agulhas Current overshoots the tip of the African continent and turns back towards the Indian Ocean, throwing lots of eddies into the south Atlantic across the Cape Basin, located southwest of South African coast. These eddies are large rotating vortex rings that interact with each other, sometimes merging, sometimes breaking up into smaller structures. All together this energetic flow field moves northwest across the Cape Basin carrying heat and salt into the fresher south Atlantic. It turns out this influx of heat and salt from the Indian Ocean is really important for the large-scale overturning circulation of our oceans which redistribute heat and salt from basin to basin and across latitudes in a way that helps control our climate. However, measuring the heat and sal flux from the Indian to Atlantic Oceans is not trivial because of the chaotic nature of the flow field. We propose a novel set of measurements that will let us measure the heat and salt fluxes, not just in the really large eddies that can be seen from space (aka Agulhas Rings), but also the smaller eddying features whose contribution to the interocean fluxes is still unaccounted for. These measurements include moorings, ocean turbulence, fine-resolution hydrographic surveys, seagliders and two different types of lagrangian drifters set to measure at the surface and at 2000-m depth. In addition, we will make these measurements at a time that coincides with the science calibration phase of the upcoming SWOT satellite, so as to provide ground-truthed data for that mission.

Publications

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Title Cape Cauldron Challenge 
Description A top-trumps style card game featuring the instruments, science and personnel of the QUICCHE cruise in 2023. This was created to promote science literacy and 1000 card packs will be distributed to schools in Cape Town in 2024. 
Type Of Art Artefact (including digital) 
Year Produced 2024 
Impact TBC 
 
Description AGU Ocean Sciences 2024: poster 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact I presented a poster at AGU OSM24 about the development of card games for ocean literacy. To this meeting, I brought a box of 250 packs of Changing Arctic Ocean Challenge, which showcased the work of the whole programme that PEANUTS was a part of. I also had a box of Cape Cauldron Challenge for distribution - another new top-trumps styles card game that featured the instruments, science and personnel of the QUICCHE cruise.
Year(s) Of Engagement Activity 2023
 
Description BBC New Live- SWOT 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I gave a brief interview on BBC News Live about the SWOT satellite on the day of it's launch on the 16 December 2022. I highlighted the ability of SWOT to resolve submesoscale ocean features that we think are responsible for many processes, including the leakage from the Indian Ocean to the Atlantic Ocean
Year(s) Of Engagement Activity 2022,2023