Atmospheric Dynamics and Applications

 

Our group works on atmospheric dynamics, mechanisms of climate variability, verification of climate forecasts, and climate forecast applications. This work comes together for example in understanding processes giving rise to droughts, where and when forecast skill is present on timescales of relevance to drought, and how to apply it.

Verification

The post-processing of forecast outputs is built in the Pangeo framework.  The verification system within this is doppyo, which provides diagnostic and skill assessment.  The skill scores are used to track the performance of the ensemble forecast system in oceans, atmosphere, land, and cryosphere. The verification work is strongly process-based and aims to assess the processes giving rise to variability and predictability in the climate system.

Teleconnections
The predictable climate signal usually emerges from the oceans and relies on teleconnection processes to carry the signal to land regions. Our work assesses the processes via which these information transfers take place in order to better understand limitations on forecast skill and its spatial variability.

Southern Hemisphere storm tracks and extremes
Variability and extremes of climate are intimately related to the storm track regions in the atmosphere. Our work assesses the behaviour of the storm track and its relationship to extreme events, including drought around the hemisphere. This work aims to provide a basis for understanding and applying seasonal to multiyear forecasts of drought and other climate extremes.

Applications of climate forecasts
Our applications work seeks to identify those parts of the climate system where there is usable skill in seasonal to multiyear to decadal climate forecasts. Where skill does exist on these timescales it is usually moderate. A key challenge of our applications work is to apply moderate skill in sectors capable of benefiting from probabilistic forecast information to improve outcomes. We are working with the water resources and agricultural sectors to understand and apply forecast skill in strategic planning.

Forecast communication and visualisation
Many generators and users of climate forecasts are not well calibrated to the levels of skill that can usefully be expected and applied from climate forecasts. The form of forecast output from ensembles also poses challenges in interpretation and use. Our group is adapting and applying visualisation tools to more clearly describe the nature and implications of the climate forecasts.

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Publications

Risbey, James; O’Kane, Terry; Monselesan, Didier; Franzke, Christian; Horenko, Illia (2018) On the dynamics of Austral heat waves Journal of Geophysical, Atmospheres 123 (1) 38-57 https://doi.org/10.1002/2017JD027222 
Risbey, J., D. Monselesan, T. O’Kane, C. Tozer, M. Pook, and P. Hayman 2019: ‘Synoptic and large-scale determinants of extreme Austral frost events’ {The Journal of Applied Meteorology and Climatology} {58} (5), 1103–1124.
Risbey, James; Grose, Michael; Monselesan, Didier; O’Kane, Terry; Lewandowsky, Stephan (2017) Transient response of the global mean warming rate and its spatial variation Weather and Climate Extremes 8 (S1) 55-64 https://doi.org/10.1016/j.wace.2017.11.002
O’Kane, Terry; Monselesan, Didier; Risbey, James;  (2017) A multiscale re-examination of the Pacific South American Pattern Monthly Weather Review 145 (1) 379-402 https://doi.org/10.1175/MWR-D-16-0291.1
Tozer, C., J. Risbey, T. O’Kane, D. Monselesan, and M. Pook 2018: ‘The relationship between wave trains in the Southern Hemisphere storm track and rainfall extremes over Tasmania’ {Monthly Weather Review}, {146} (12), 4201–4230.