Electrical Discharges in the Atmosphere

ASIM mounted on ISS. (Image: NASA)

Members of this research group are:

Torsten Neubert, Chief Consultant
Olivier Chanrion, Senior Researcher
Christoph Köhn, Senior Researcher
Dongshuai Li, Postdoc
Nicolas Pedersen, Research Assistent
Carol Anne Oxborrow, Special Consultant
Freddy Christiansen, Scientist
Lasse Husbjerg, PhD student
Federica Defranchi Bisso, PhD student
Elloise Fangel-Lloyd, PhD student
Ib Lundgaard Rasmussen, Senior Advisor Emeritus

We study electric al discharges powered by thunderstorms, such as lightning leaders, streamers and terrestrial gamma-ray flashes, and the discharges in the stratosphere and mesosphere above, the red sprites, blue jets and the gigantic jets reaching from cloud tops to the ionosphere . We conduct observations of thunderstorms from space and ground, and develop simulation codes of discharges.

 

Our activities are rooted in fundamental research, with applications related to improved quantification of thunderstorm perturbation of greenhouse gas concentrations, lightning on other planets and on primordial earth, lightning protection of wind turbines and validation of lightning imager data from the new generation of geostationary meteorological satellites. We develop new space mission concepts such as the TOTEM experiment (with ESA) and computer algorithms that take advantage of the new generation of super computers such as LUMI.

 

TOTEM – Top of Thunderstorms Experimental Module for the International Space Station. (Illustration: DTU Space)

 
TOTEM – Top of Thunderstorms Experimental Module for the International Space Station. (Illustration: DTU Space)

 

ASIM – The Atmosphere-Space Interactions Monitor is a suite of instruments mounted on an external platform of the Columbus module of the International Space Station (ISS). It includes optical UV and X- and gamma-ray sensors for the measurement of electrical processes of thunderstorms. Launched in April 2018, it has provided a wealth of high-quality data from the vantage point of the ISS, which is in the lowest available orbit covering all the major thunderstorm regions of the Earth. The group leads the ASIM mission and houses the main hub of the ASIM Science Data Centre (ASDC).

 

ASIM is an ESA mission, developed by DTU space and Terma, with partners in Norway, Spain Italy and Poland. It has received funding from ESA, from the Ministry of Education and Research, and from national funding sources in partner countries.

 

High-speed observations from the ground of sprites, jets and elves are taken from southern France by cameras and photometers. They are fielded in two locations, one is at the Observatoire Midi Pyrénées on Pic du Midi and the other Laboratoire Souterrain à Bas Bruit de Rustrel (LSBB).

 

Installation of a high-speed camera at 5 kHz frame rate on Observatoire Midi Pyrénées by Ph.D. student Maja Tomicic. (Picture: Olivier Chanrion)

Installation of a high-speed camera at 5 kHz frame rate on Observatoire Midi Pyrénées by Ph.D. student Maja Tomicic. (Picture: Olivier Chanrion)

 

The group develops computer algorithms for simulations of electrical discharges such as streamers and terrestrial gamma-ray flashes and are planning to take advantage of the new generation super computers that is becoming available for studies of the generation of terrestrial gamma-ray flashes, their chemical impact on the atmosphere as relate to greenhouse gas concentrations and to high-energy discharges in primordial earth.

 

The ASIM Science Data Centre is the data processing and distribution hub for the ASIM mission to the ISS. ASDC is the portal for all scientific exploitation of the ASIM data. ASDC is based at DTU Space with contributions to the offline analysis from the University of Bergen and the University of Valencia. ASDC was established at DTU Space in 2015 to receive raw telemetry from the instruments and turn it into usable science data that is available for down-load by scientists all over the world via the ASDC website. ASDC also helps researchers understand and utilize the data, with technical documentation, user support, workshops and special studies of instrument behaviour and data anomalies. All research groups engaged in the study of atmospheric discharges are encouraged to submit proposals to use the ASIM data via the ASDC website: https://asdc.space.dtu.dk/ 

The website maintains
 a list of scientific publications based on ASIM data, and an archive of news items about the ASIM mission. 

ASDC is the central hub of the large international collaboration that keeps the ASIM mission running and scientifically productive:
ESA provides the  mission engineering and long-term planning
B.USOC in Brussels is the user operations centre that receives the raw telemetry and sends it to ASDC
The ASIIM Facility Science Team determines the science programme and observation schedule of the ASIM 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
DTU Space is the home institute that combines all these strands into a coherent mission and source of scientific data

ASDC also calculates and provides other data to scientists that are needed to understand the scientific data: the time of each observation with microsecond accuracy, the position and orientation of the instruments during each observation, the sensitivity and energy calibration of the instruments, and the instrument modes and health at the time of the observations.