Helga Kristin Olafsdottir EVA Talk Preview
From Anna Munro
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Name: Helga Kristin Olafsdottir
Talk Title: Frequency increase in extreme rainfall events in the Northeastern USA with stable intensity distribution
Abstract: For infrastructure planning, information of both intensities and frequencies of individual extreme rainfall events are of importance. Climate change brings an additional complexity, since extreme daily rainfalls can be increased by the individual extreme rainfalls becoming more frequent, more intense, or both. We develop a new statistical extreme value model, the PGEV model, to predict to what extent these three scenarios will occur. The model combines the Generalized Extreme Value (GEV) distribution for annual maxima series and General Pareto (GP) distribution for exceedances over threshold for the partial duration series. This allows the use of high quality annual maxima series data instead of less well checked daily data to estimate trends in intensity and frequency separately.
The median of the frequency trends corresponds to extreme rainfalls becoming 83% more frequent for each centigrade degree of temperature increase, but there is an important local variation in the trends. For many stations, the frequency increase exceeds 150% per centigrade temperature increase. The analysis is extended to three other large areas in the contiguous USA, showing a similar but weaker effect.
This talk is a contributed talk at EVA 2021. View the programme here.