Atmospheric Electricity

We study electrical discharges powered by thunderstorms, such as lightning leaders, streamers, and terrestrial gamma-ray flashes, as well as discharges in the stratosphere, some reaching up to the ionosphere. These include red sprites, blue luminous events, ELVEs and gigantic jets. We also study the electrification of the atmosphere and the conditions that cause these high-energy events using data from satellites, the ISS, and Earth-based lightning networks. To help understand what we are seeing our group also develops mathematical simulation software to model the microscopic processes leading up to these brief, luminous events.

Research group

Torsten Neubert

Torsten Neubert Chief Consultant

Olivier Arnaud Chanrion

Olivier Arnaud Chanrion Senior Researcher

Christoph Köhn

Christoph Köhn Senior Researcher

Pierre Alexandre Gourbin

Pierre Alexandre Gourbin Postdoc

Carol Anne Oxborrow

Carol Anne Oxborrow Deputy Head of Astrophysics and Atmospheric Physics

Freddy Christiansen

Freddy Christiansen Scientist

Dongshuai Li

Dongshuai Li Senior Researcher

Elloise Jensen Fangel-Lloyd

Elloise Jensen Fangel-Lloyd PhD student

Ib Lundgaard Rasmussen

Ib Lundgaard Rasmussen Senior Advisor Emeritus

Nicolas Pedersen

Nicolas Pedersen PhD Student

Poorly understood natural phenomena

Though lightning has been studied for hundreds of years, there are still many questions about the processes that electrify clouds and trigger lightning discharges, as well as discharges above the clouds known as Transient Luminous Events (TLEs). This category of electrical discharges was first documented in 1989 and since then an array of high-altitude transient phenomena have been discovered, including gamma-ray flashes, first discovered in 1990, by a satellite looking for gamma-ray flashes from distant galaxies.

The understanding that we are bringing to atmospheric electricity has many applications including:

  • Finding the connection between TGFs and atmospheric chemistry that can affect the Earth’s energy balance.
  • Protecting wind turbine blades from lightning strikes.
  • Discovering the meteorological conditions and geographic regions that produce the most energetic storms and the most TLEs.
  • Determining whether TGFs could help produce pre-biotic molecules in primordial Earth’s atmosphere. And could the happen on planets outside our solar system?
  • Demonstrating the micro-physics within and around all kinds of discharges and how this is affected by atmospheric composition.

The Atmosphere-Space Interactions Monitor (ASIM)

The Atmospheric Electricity group at DTU Space led the ASIM project from  2005 to its launch in 2018 to the International Space Station. The mission is under the management of ESA’s Directorate for Human and Robotic Exploration (HRE). ASIM is designed to view energetic thunderstorms from the ISS (400 km altitude) in a number of different wavelengths: blue light, red light, ultraviolet, x-rays and gamma-rays. 

Read the article: The ASIM Mission on the International Space Station here.

Each physical process produces particular wavelengths of electron-magnetic radiation, so that for example, in 2019 we could elucidate the triggering and propagation processes involved in Terrestrial Gamma-ray flashes (TGFs). Since its launch in 2018, ASIM has studied many electrical phenomena in the Earth’s atmosphere, and also serendipitously seen gamma-ray outbursts from neutron start and other compact sources in outer space.

Read the article: Very-high-frequency oscillations in the main peak of magnetar giant flare.

The ASIM mission is scheduled to run until March 2025, but our group and international partners are working towards an extension of the mission beyond 2025. During the coming years, ASIM will study objects and phenomena other than electrical discharges:

  • Aurorae (southern/northern lights)
  • Noctilucent clouds
  • Meteor trails and break-up
  • Wildfire ignition
  • Serendipitous astronomical x-ray and gamma-ray sources

The central processing centre for the ASIM data (ASDC) is housed at DTU Space and run by members of the Atmospheric Electricity research group. The raw telemetry received from ASIM is filtered, corrected and calibrated before being released to the scientific community via the ASDC website only registered researchers with an approve proposal can download the data at present, but interested members of the public can read our news feed.

While ASDC is the hub of ASIM scientific activity many other organizations contribute to the success of the mission:

  • ESA provides the mission engineering, operation infrastructure and long-term planning.
  • B.USOC in Brussels is the user operations centre that receives the raw telemetry and sends it to ASDC, as well as sending telecommands to the instruments.
  • The University of Bergen provides offline data analysis to track down terrestrial gamma-ray flashes in the data.
  • The University of Valencia provides offline data analysis that can pinpoint the location of the sources of terrestrial gamma-ray flashes.
  • Terma, Denmark, provides instrument and engineering knowledge.
  • The ASIIM Facility Science Team determines the science programme and observation schedule of the ASIM instruments.

Collaborations and complementary data

While ASIM is our biggest source of research data, we also use data from dedicated satellites and ISS instruments such as the MTG Lightning Imager; Andreas Mogensen’s observations from ISS in 2015 and in 2023 (in Danish); and astronomical satellites such as Fermi.

The ASIM and ASDC teams also have extensive collaborations with researchers all over Europe and the rest of the world. Several of these teams have their own Lightning Mapping Arrays around their institutes which provide additional data for the analysis and understanding of ASIM data.

Data from Earth-based lightning detection networks such as Vaisala GLD360 and WWLLN are also used to corroborate and compare induvial events and the lighting strikes that trigger them.

Creating lightning and TGFs in a computer

The wealth of data to which we have access can only yield new break-through discoveries when compared to mathematical models of cloud electrification, discharge triggering and lightning propagation. About half of our group work on creating computationally heavy computer codes to simulate the microphysics within the atmosphere and clouds, during all phases of the development of lighting flashes and TLEs. You can read about how these codes are being used to study biotic molecules in primordial Earth and TGFs on exoplanets elsewhere on this website.