Dongshuai Li

Project title

Studying Lightning Processes with Neuromorphic Imaging on Microsecond Time Scales

What is your project about?

The project concerns the plasma physics of lightning. Lightning travels extremely fast and consists of subprocesses with short timescales and a large range of light intensity that is almost impossible to capture with cameras. We know much about the general physics of lightning, but less about its inner physics. I will address this challenge by designing a fast, optical imaging system based on the neuromorphic imaging technique, a new technique developed for use in other areas which has yet to be applied to lightning research. The system will be deployed at a lightning research facility, the Säntis Tower in Switzerland, to measure natural and laser-triggered lightning at close range. We will be able to image lightning with unprecedented detail, giving us a better understanding, for instance, of how lightning initiates, propagates and connects to structures on the ground.

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

I have been fascinated by weather phenomena since I grew up on the Mongolian plains: the clouds, the rain and snow, and the powerful and awe-inspiring lightning. At university, I selected courses that dealt with thunderstorms and lightning and did small research projects. The more I learned, the more I understood how complicated their physics is. I also understood that there are many gaps in our knowledge, which made me interested in following a research path focusing on lightning physics and the limitations of lightning detection systems. I am driven by curiosity and a desire to understand this natural phenomenon.

What are the scientific challenges and perspectives in your project?

The main challenge is to measure the micro-second scale processes of lightning. The new neuromorphic imaging technique can achieve this because it detects changes in light intensity to a camera pixel and transmits this information when it occurs, rather than sending entire frames at fixed rates. It leads to lower data rates and micro-second time resolution. In addition, the detectors have a much higher dynamic range than conventional cameras. We are testing it for lightning observations from the International Space Station in the Thor-DAVIS experiment with Danish astronaut Andreas Mogensen. I will use the same event camera to observe lightning at close range. The scientific challenge is to analyze the simultaneous observations from other optical and electromagnetic sensors to pinpoint the so-called leader-streamer interactions. Leaders are the bright, hot channels seen by the naked eye. Streamers are dimmer coronas of colder ionized plasma filaments, for instance, initiated from the leader tip, assisting its propagation.

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

Lightning occurs on average 50 times every second globally. It affects greenhouse gas concentrations, starts wildfires and causes damage to properties. It is also a signature of storm convection and can be used to predict and follow severe storm developments. Therefore, the World Meteorological Organization has adopted lightning as an essential climate variable. By introducing the neuromorphic optical system for lightning detection, we hope to better understand lightning's role in climate change. I also hope that we at DTU Space can develop neuromorphic cameras for future space applications, such as low-Earth orbit lightning observation, planetary lightning detection and the planetary landing of spacecraft.

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

The Sapere Aude: DFF Starting Grant will allow me to establish my own research group and to secure a prominent role in the field of lightning physics. The Sapere Aude grant offers valuable resources that support my collaboration with international scientists and facilities essential for my success. It will help me to attract good students and to discover new physics. I anticipate it will enhance my publication output and research impact, raise my profile within the scientific community, and lay the foundations for future proposals from, e.g., the European Research Council, the European Space Agency, and other Danish excellence grants.

Background and personal life

I grew up in a small village in Inner Mongolia in Northern China. After my PhD studies in Southern China, I have worked in Lausanne (Switzerland) and Granada (Spain), then I moved to Denmark and joined the Technical University of Denmark in 2022. I currently live in Gentofte with my husband, Tao. During our free time, we enjoy cooking, love traveling, hiking and camping in nature.