SO-CHIC WorkPackage 4

Abrupt large polynya events shortcutting conventional pathways

Objectives

The overall goal of WP4 is to assess the balance of multiscale physical processes controlling the emergence and remarkable persistence of Weddell Polynyas, and their key impacts on the large-scale circulation of the Southern Ocean. To fulfil this goal, four specific objectives will be addressed:

1. To obtain first-of-a-kind, systematic observations of the range of candidate Polynya-controlling processes over a representative period (autumn to spring);
2. To document and quantify the processes underpinning the Polynyas’ lifecycle;
3. To develop a mechanistic synthesis of the Polynyas’ lifecycle, and establish the baseline requirements for its realistic representation in climate-scale ocean models;
4. To determine the impacts of Polynya events on the large-scale circulation of the Southern Ocean.

This work package will conduct a hierarchy of innovative, synergistic observational and modelling activities to assess the balance of physical processes governing the occurrence of Weddell Polynyas; determine their large-scale, climate-relevant impacts; and design a roadmap for realistic Polynya representation in climatescale ocean models.

Tasks

• Task 4.0: Scientific Coordination [Lead: A. Naveira Garabato (Southampton); participants: F. Roquet (UGOT)]
• Task 4.1: Systematic observation of candidate Polynya-controlling processes in the Maud Rise region [Lead: A. Naveira Garabato (Southampton); participants: A. Brearley (UKRI-BAS), S. Swart (UGOT), J-B. Sallée (SU); external collaborator: M. Steele, V. Thierry]
• Task 4.2: Analysis of balance of physical processes regulating the lifecycle of Weddell Polynyas [Lead: A. Naveira Garabato (Southampton); participants: A. Brearley (UKRI-BAS), S. Swart (UGOT), J-B. Sallée (SU); external collaborator: M. Steele]
• Task 4.3: Development of a realistic high-resolution model of the Maud Rise area for investigation of Polynya controls [Lead: F. Roquet (UGOT); participants: G. Madec (SU)]
• Task 4.4: Analysis of balance of processes controlling Polynya development in high-resolution model [Lead: F. Roquet (UGOT); participants: G. Madec (SU), A. Naveira Garabato (Southampton)]
• Task 4.5: Analysis of Polynya impacts on large-scale ocean circulation [Lead: F. Roquet (UGOT); participants: J-B. Sallée (SU), D. Ferreira (UREAD), A. Naveira Garabato (Southampton)

Partners

WP leaders: A. Naveira Garabato (Southampton, lead) and F. Roquet, (UGOT, co-lead)

Other participants: A. Brearley (UKRI-BAS), D. Ferreira (UREAD), G. Madec (SU), J-B. Sallée (SU), S. Swart (UGOT)

External collaborator: Michael Steele (Uni. Washington, USA), V. Thierry (IFREMER, France)