Towards using radar data to understand changes in sub-daily rainfall extremes: An Australian case study

 

Prof. Simon Tett 

The University of Edinburgh, UK

 

邀请人/报告会主持人 ： 张文霞 副研究员

 

2024年12月10日（周二）10:00

3号楼1218会议室

 

报告摘要:

One expected impact of climate warming is an increase in sub-daily extreme rainfall. A simple thermodynamic argument suggests that extremes should increase at a rate of about 7.5%/K of warming. Convective permitting models and some in situ gauge data suggests sub-daily extreme intensity increases by more than 7.5%/K.  In situ gauge data is sparse and so will miss many small-scale extreme rainfall events. Radar rainfall can sample a large region with high space and time resolution but has its own problems. Australian radar data has been homogenised through comparison with the Tropical Rainfall Measuring and Global Precipitation Missions. This gives 20+ year records for about ten sites in Eastern Australia. Radar reflectivity is converted to rainfall intensity using power-law behaviour estimates from distrometer data. Rainfall data is then averaged to 30 minute, 1hour, 2 hour and 4 hour accumulations and seasonal maxima extracted.  For each radar a GEV fit with covariates on local temperature was fit to samples from the seasonal maxima.  No strong evidence is found that extreme rainfall intensity increases by more than 7.5%/K. 

 

报告人简介:

Prof. Simon Tett，Chair in Earth System Dynamics, School of Geosciences at the University of Edinburgh

At the heart of my research is the quantitative analysis of models and observations of climate change in order to constrain the future. The approach I am currently working on is to generate "plausible" climate models through careful comparison of simulations and observations and use the properties of these plausible models to reason about future climate change. I am interested in extreme climate events and their causes for which I believe that high resolution modelling is the way forward.  I also aim to improve my knowledge and understanding of the carbon cycle and try and develop ways of constraining its possible futures.