For those who missed the second EGU session on compound events or want a recap, we tried to provide a short summary of the oral presentations of the NH1.7 session. During this session we also officially launched this new community website. 🙂
From this session we learned that compound events are relevant to many research field, can comprise many different types of hazard, or a succession of events of the same hazard. Compound events characteristics are very sensitive to the definition (sampling) and selection of dependence indicator. Finally, the last presenter focused on the impacts of compound events in a nice presentation about energy black-outs in Europe.
Anaïs presented a study on compound flood hazard indicators based on global hydrological and storm surge model outputs. Different indicators highlight different types of compound flood events and the complexity of defining flood sources in coastal areas. By combining the different indicators, global hotspots of compound flood hazard are identified.
Jennifer shows which extreme hazards (extreme precipitation, wind and/or waves) are associated with certain storm types or a comdination thereof: fronts, cyclones, thunderstorms. Hazards have been identified based on ERA-Interim and BEST-track tropical cyclone tracks. Storm types are regionally identified but also characterized in terms of precipitation, wind and wave hazards, but also their combination.
Allistair shows the complexity of compound events, defined as combinations of fluvial, pluvial, surge and wave flooding. Results presented focused on flood hazard stemming from storm surge and river discharge. By identifying compound flood hazard occurrences, he finds that compound flooding in the UK occurs mostly on the West coast and come from the same storms while different storm types cause surge and discharge on the East coast. Regional variations cannot be explained by single catchment characteristics only.
Milan presented his study on the effect of the Russion heat wave on society and the terrestrial biosphere. He used a novel method that selects peak based on kernel density estimates. He showed that the impact of atmospheric extreme events on the terrestrial biosphere strongly depends on the timing, duration and ecosystem type. An ecosystem specific and multivariate perspective reveals more facets of extreme events than traditional approaches.
Tale of two storms. Nina explains the story behind the twin storm event which hit the Groningen Noorderzijlvest area in January 2012 leading to a near-flooding situation due to a lack of draining capacity. Twin storms are defined as subsequent wind extremes within a certain time window. She finds that in a future weather, sea level rise dampens the meteorological contribution to coastal water levels and would allow water levels to fall below mean sea level despite prolonged high wind and surge conditions.
Laurens studies potential black-outs from low solar radiation, low wind-driven supply or a combination of both. He combines his analysis with a empirical energy demand for Europe to identify periods where black-outs can occur. He finds that a univariate analysis (only wind or wind based approach) is not a good indicator for energy shortage. This effect is amplified when looking at a multiple day period of supply and demand which accounts for energy storage. BTW: Laurens is looking for a PhD position!
More details can be found in the abstracts on the EGU website.