Large Scale Ocean Processes and Climate

Learning Outcomes

Learning Outcomes

Having successfully completed this module you will be able to:

• Quantify large-scale ocean processes in terms of water mass transformation
• Synthesize observations and models to explain the ocean's key role in climate change, with a focus on the meridional overturning circulation
• Understand the utility of numerical ocean models for simulation and prediction
• Understand ocean-atmosphere-cryosphere interactions, in relation to weather and climate
• Apply Lagrangian diagnostics to understand ocean circulation and mixing, in the context of simplified momentum balances and energetics respectively

The module will explore processes that determine the physical state and circulation of the World Ocean. Observations and model data will be used together with a water mass transformation framework and virtual particle tracking, to explore how the ocean is forced to move and mix. Following an introduction to ocean and atmosphere re-analysis datasets, and ocean/climate models, analyses will be undertaken to reveal the patterns and timescales of climate variability and change, with a focus on dramatic changes that have played out across the North Atlantic and Arctic since 1980.

Computer based practicals and example sheets will underline key concepts in the module.

Teaching and learning methods

Formal Lectures (10 x 2-hour lecture sessions): in the first half of the module, lectures will introduce water masses, the basic character of ocean currents and ocean circulation, and the water mass transformation framework; in the second half of the module, lectures introduce re-analysis data for the ocean and atmosphere, and ocean/climate models, proceeding to cover processes driving climate variability and change in low, mid and high latitudes, with a focus on the North Atlantic and Arctic. Copies of the PowerPoint slides and selected pre-recordings are available on the blackboard website prior to each lecture and the Panopto recordings of the lecture sessions will be available there afterwards.

Practical sessions: (10 x 2 hour computing practicals): in the first half of the module, particle trajectory data are analysed to obtain key Lagrangian statistics for selected current systems in the World Ocean, followed analysis of surface properties and heat/freshwater fluxes to diagnose water mass transformation, globally and for the North Atlantic; in the second half of the module, ocean, atmosphere and cryosphere data are analysed to reveal patterns and timescales of climate variability and change since 1980.

A wide range of support can be provided for those students who have further or specific learning and teaching needs.

Assessment strategy

Coursework 2 (60%): Using the Matlab scripts and datasets provided through Practicals 6-10, you will characterize ocean and climate variability in the North Atlantic / Arctic sector, and associated drivers. You will write a report (up to 24 pages), ‘Climate Variability and Change in the North Atlantic and Arctic since 1980’.

Coursework 1 (40%): Using the Matlab scripts and datasets provided through Practicals 1-5, the coursework comprises two parts: Part 1. Surface pathways and air-sea fluxes of heat and freshwater in the low and mid-latitude oceans; Part 2. Water mass formation rates in the subtropical and subpolar North Atlantic, and long-term salinity changes in global ocean. You will a report (up to 8 pages), ‘Global ocean pathways and water mass transformation’.

Problem sessions (formative assessment): Practicals 1-10 will prepare you for the two coursework assignments.

Summative

This is how we’ll formally assess what you have learned in this module.