Christoph Köhn

Project title

Relativistic electrons and terrestrial gamma-ray flashes from lightning

What is your project about?

The project deals with the origin and effects of terrestrial gamma-ray flashes (TGFs). TGFs are bursts of energetic X- and gamma-rays from thunderstorms and are the most energetic natural phenomena on Earth. We know that they are produced by energetic electrons, which are sub-atomic particles, but we still lack details about how such electrons are energized in thunderstorms and what the effects of TGFs are, or were, on our atmosphere. In this project, we will study the role of hydrometeors, droplets of condensed water, on the production of high electric fields that enable energizing electrons and the subsequent generation of TGFs in thunderclouds. Beyond this, we will study the production of greenhouse gases to more accurately understand their natural production and better assess the impact of human-made greenhouse gases. We will also study the production of TGFs in Primordial Earth conditions 3.8 billion years ago and their role on the production of amino acids and carbon acids as precursors of life.

How did you become interested in your particular field of research?

I very early became iterested in fundamental problems and focused on the theoretical aspect of plasma physics and particle physics. This triggered my interest in studying terrestrial gamma-ray flashes, combining these two areas as they belong to the most energetic particles on Earth. Additionally, I find it extremely interesting that an everyday phenomenon such as lightning can create such high energies. However, the more I studied their production mechanism, the more I realized that we are still missing details to understand their origin and that we know extremely little about their effects, which spurred my interest in pursuing further research of TGFs.

What are the scientific challenges and perspectives in your project?

The main challenges of this project are to understand the fundamental mechanisms of terrestrial gamma-ray flashes and of their effects to the atmosphere, both now and 3.8 billion years ago, as well as to develop appropriate computational models to understand these processes. The project will lead to innovative computational programmes, developed to run on the newest generation of supercomputers, hence allowing us to study lightning-related phenomena, both on Earth and in extraterrestrial atmospheres, after the end of this project.

What is your estimate of the impact, which your project may have to society in the long term?

Although systematic lightning research dates back more than two hundred years ago until Benjamin Franklin and Jaques de Romas, there are still many mysterious phenomena associated to lightning, such as terrestrial gamma-ray flashes. The computational models which we are planning to create, will give us insight in the kinetic processes of electric discharges in thunderstorms and how these will effect the concentration of greenhouse gases, and will subsequently reduce uncertainties in climate models. Moreover, we will investigate the effect of TGFs on the formation of organic molecules and maybe open a new path for the creation of life which will change our understanding on how life and our very own existence originated.

Which impact do you expect the Sapere Aude programme will have on your career as a researcher?

The Sapere Aude programme will allow me to build a strong research group, and to establish myself as an international leader in the research field of thunderstorm research. The grant will allow me to be at the forefront of science, have long-term research perspectives and initiate long-term collaborations. Finally, this programme is the stepping stone to apply for further funding, e.g. from the European Research Council.

Background and personal life

I grew up in Northern Germany. After having done my PhD studies in the Netherlands, I moved to Belgium and then to Denmark. I live in Bagsværd and I enjoy video-gaming and reading books. If time permits, I like to be together with my friends and/or play basketball or football. During the weekends, I travel regularly to Germany to see my girlfriend Mona.