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Ocean storms and its representation in climate models: the role of energy and the counter-intuitive impacts of energy dissipation
Speaker Name
Dr. Julian Mak
Speaker Detail

Postdoctoral Research Associate, Department of Physics, University of Oxford

B5-309, 5/F, Yeung Kin Man Academic Building (YEUNG), City University of Hong Kong, Kowloon Tong, Kowloon, Hong Kong


School of Energy and Environment
City University of Hong Kong


The representation of ocean mesoscale eddies (analogous to mid-latitude atmospheric storms) presents a formidable theoretical and computational challenge in ocean global circulation models. At present ocean mesoscale eddies are often not explicitly resolved in models (including those involved contributing to the IPCC reports through the CMIP exercises) due to computation cost, at least not over the high latitudes and the Southern Ocean, and eddy effects are often parameterised. Increasingly however the emergent ocean climatology and its sensitivity between eddy resolving and eddy parameterising models have been found to diverge, in turn impacting model properties such as ocean ventilation time scales, heat content, and so forth. A new geometrically informed, energetically constrained parameterisation is presented, which predicts and demonstrates eddy saturation and degrees of eddy compensation, and in turn on ocean heat content. The rather counter-intuitive role of eddy energy dissipation in setting global ocean stratification and ocean heat content is discussed.

About the Speaker

Dr Julian Mak is currently a postdoctoral research associate at the Department of Physics (Atmospheric, Oceanic and Planetary Physics sub-department) at the University of Oxford, under the UK NERC grant GEOMETRIC held by Prof. David Marshall. Previously he was a postdoctoral research associate at the School of Mathematics at the University of Edinburgh in the UK and at the Department of Geosciences at Tel Aviv University in Israel. He completed his PhD in applied mathematics at the University of Leeds and MMath at Durham University. His research, motivated by rotating stratified turbulence and its role in shaping the Earth's climate, revolves around using computational and mathematical techniques to tackle problems in fluid dynamics..