Generation of the ocean's permanent pycnocline in the ice-covered Southern Ocean

Lead Research Organisation: University of Southampton
Department Name: Sch of Ocean and Earth Science

Abstract

The permanent pycnocline (PP) is the ocean's main organising feature - an interface of elevated stratification that sets apart near-surface waters exchanging heat and carbon with the atmosphere from deeper waters storing those tracers for as long as millennia. Yet despite its basic underpinning of the ocean's role in climate, and decades of investigation, the processes governing the PP's formation remain unknown. PycnoGen will tackle this critical knowledge gap by generating the first observationally-grounded mechanistic paradigm for the establishment of the PP. To accomplish this, the project will address four objectives: (O1) to develop a suite of cutting-edge, long-endurance autonomous robotic system and distributed sensor network technologies to measure the polar oceans under ice; (O2) to generate first-of-a-kind, process-targeted observations - enabled by the innovative technologies in O1 - of the PP's formation in a representative region of the seasonally ice-covered Southern Ocean, where the PP originates; (O3) to determine the processes controlling the formation of, and flow across, the PP from the observations in O2; and (O4) to assess the mechanisms by which the PP is projected from its formation region into the global ocean, the PP's large-scale impacts on oceanic ventilation and overturning, and the system's sensitivities to key climate forcings. PycnoGen will leave an influential and long-lasting legacy in oceanography and climate science by: (i) generating a step change in international capability for polar ocean observation, through the technological breakthroughs in O1; (ii) producing a benchmark observational data set of the PP's formation (in O2), poised to serve as a launchpad to fundamentally advance climate-scale ocean models; and (iii) transforming our mechanistic understanding of one of the foremost components of the ocean-climate system (in O3-O4), with profound ramifications for many high-ranking global climate change problems.

Publications

10 25 50
 
Description Development of acoustic navigation for ocean gliders 
Organisation National Oceanography Centre
Country United Kingdom 
Sector Academic/University 
PI Contribution I have established a partnership with the Marine Autonomous Robotics Systems (MARS) group at the National Oceanography Centre to develop acoustic navigation capabilities for Slocum gliders, with a view to using such gliders under ice in this project. I am providing scientific leadership for this technological development.
Collaborator Contribution The MARS group is conducting the technical work involved in the technological development.
Impact No specific outputs as yet.
Start Year 2022
 
Description Development of distributed optical fibre sensing for physical oceanography 
Organisation National Oceanography Centre
Country United Kingdom 
Sector Academic/University 
PI Contribution I am providing scientific leadership to steer the technological development of the distributed optical fibre sensing (DOFS) system.
Collaborator Contribution Partners at the National Oceanography Centre are leading the technological development of the DOFS system.
Impact None as yet.
Start Year 2022