Alejandro Di Luca - Statistical and physical sources of future changes in hot extremes

Event type: 
Seminar
Date: 
20 June 2018
Time: 
2.00 - 3.00pm
Location: 

Climate Change Research Centre, Seminar Room, Mathews Building 4th floor, UNSW, Sydney

Presenter: 
Alejandro Di Luca
Climate Change Research Centre, UNSW, Australia
Host: 
Climate Change Research Centre, UNSW, Australia

Quantifying and understanding future changes in hot extremes has received substantial attention in the last few decades. While studies have invariably shown that the intensity and frequency of hot extremes will increase in the future, it is still open to question the specific physical and statistical sources of these changes. This presentation addresses these two issues. It first presents a simple methodology to statistically decompose daily hot extremes in various terms that reflect the contribution from different temporal and spatial scales. This analysis of projections from an ensemble of CMIP5 simulations shows that changes are largely dominated by changes in long-term mean conditions and that the largest increases in hot extremes arise in some midlatitude regions as a result of the combined effect of changes in seasonal values, diurnal temperature range and the specific anomalies on days when the extreme occurs. In the second part, some of the physical processes that explain the important regional variations projected in hot temperature extremes are discussed. This analysis shows that surface processes tend to dominate most of the changes and that changes in the atmospheric circulation usuallyplay a secondary role.

 

Brief Biography: Alejandro is an ARC DECRA Fellow working at the Climate Change Research Centre at UNSW in Sydney. He is also an Associate Investigator in the ARC Centre of Excellence for Climate Extremes and a Lead Author for Working Group 1 for the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report. Alejandro's research focuses in the understanding of future changes in the frequency and intensity of Australian East Coast Lows but he is also interested in climate extremes and general issues related with regional climate modelling.