How flashes arise: insights into the research of Andrea Stöllner

How flashes arise: insights into the research of Andrea Stöllner

Behind solid laser protection curtains in Klosterneuburg-Gugging, in the Tulln district, is the fascinating flash laboratory by Andrea Stöllner. In her five-year PHD research, the physicist focused on the conditions that lead to the development of a flash. With two lasers that shine in a fist -sized metal chamber, she tries to decrypt the puzzle to decipher the electrostatic charging of particles. "We do not yet know exactly why particles exchange charges when touched and how they create such high loads that a flash is created," she explains.

At the center of her research is a glass particle that is kept in the air by the lasers. By simulating various environmental conditions that occur in a real storm cloud, Stöllner analyzes that the particle independently charges and unloads, although it hits all alone in the vacuum. "That was the first surprise," says the researcher. The natural load exchange in storm clouds usually takes place by touching when pattern and ice crystals collide and replace loads. "An ice crystal is usually charged positively, while the heavier pattern is negatively loaded, which leads to a dangerous imbalance that is finally unloaded in a flash," she explains.

The struggle of loads

Stöllner wants to find out exactly when this exchange of charges takes place. She describes how the two laser technologies in her laboratory observe the behavior of the loads that apparently act arbitrarily. "There are many theories, but the exact functioning on the microbiological level remains unclear," she says. A better understanding of flash formation is becoming increasingly important because global warming causes increasingly violent storms. Stöllner confirms that she perceives this trend in her observations.

The main cause of the increased storm events is the evaporation of water due to longer heat periods. "When the temperatures rise, more water evaporates from the oceans and collects in the atmosphere," explains Stöllner. This additional water, combined with the large energy that is available in the atmosphere, means that moist air amounts rise when heat islands. If you cool down and condense, clouds form. In sufficient energy, the particles in the clouds are whirled up, which leads to loading and finally flashing.

In addition, the increased amount of water in the atmosphere affects the intensity of thunderstorms, which sometimes leads to violent rainfalls and floods. An example of this was the sudden flood in Hollabrunn in August, which was caused by an extreme storm. "We have more and more water and energy in the atmosphere," emphasizes Stöllner. This has immediate consequences for the weather conditions that we experience in Austria and underlines the urgency of their research.