CIM Seminar with Melinda Galfi

  • Date: 1 February 2022, 12:15–13:00
  • Location: Ångström Laboratory, Å4004
  • Type: Seminar
  • Lecturer: Melinda Galfi
  • Contact person: Oskar Tegby

Title: A large deviation theory-based analysis of persistent atmospheric extreme events

Abstract
Persistent atmospheric extreme events, like heatwaves, cold spells, rainfall events of several days, have a huge impact since they exert a long-lasting anomalous stress on human health, infrastructure and natural ecosystems. I will present in this talk a method to analyse persistent extreme events based on large deviation theory (LDT). I will discuss two applications. First, I will show an analysis of heatwaves and cold spells as temporal averages of surface air temperature. One can an estimate the probability of these events based on a large deviation principle and assess the change in probability as an effect of global warming. Additionally, one finds typical spatial structures of extreme heatwaves or cold spells. Second, I will present a study on rare and persistent configurations of the North Atlantic jet stream based on temporal averages of jet indices. Again, the probability of these persistent anomalies can be obtained based on a large deviation principle. The relevance of anomalous and persistent jet configurations is underlined by an increase in the frequency of temperature and precipitation extremes over Europe during these events.

Registration
Register to the event here. The registration closes January 30.

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