In the high altitudes of the European Eastern Alps, the number of detected lightning strikes has doubled in the course of the last 40 years. Causes for this are to be found in the effects of the climate crisis.
The climate crisis is leading to an increase in extreme weather events today and in the future, as the Intergovernmental Panel on Climate Change (IPCC) has already pointed out several times. How the consequences of global warming affect small-scale and local weather phenomena such as lightning activity is still not fully understood. The Innsbruck team with atmospheric and statistical scientists Thorsten Simon, Georg Mayr, Deborah Morgenstern, Nikolaus Umlauf and Achim Zeileis has now reconstructed the lightning activity of cloud-to-ground lightning in the area of the European Eastern Alps for a period between 1980 and 2019 with unprecedented precision using a special combination of extensive data sets. "In this study, we link two sources of information, both available at a spatio-temporal resolution of 32 km x 32 km and one hour. From these datasets we obtain, on the one hand, information on lightning activity with seamless records over the last decade. On the other hand, we access analyses of atmospheric conditions - including cloud microphysics - at an hourly resolution over the past four decades," explains Thorsten Simon. "By using machine learning, we were able to map the gapless lightning measurements from 2010-2019 with meteorological data. We then used machine learning and the meteorological data to reconstruct lightning frequencies further into the past, i.e. for a time when there were no such lightning measurements. And this even extends to variations in the diurnal cycle". The data come from the ALDIS lightning detection system and the atmospheric analyses from the fifth ERA-5 reanalysis of the European Centre for Medium-Range Weather Forecasts ECMWF (ERA5).
Read more at University of Innsbruck
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