ASIM

ASIM RESEARCH THEMES AND OBJECTIVES
ASIM research has three main general themes: Climate processes, the interplay of the atmosphere with the Earth's surface and changes of the atmosphere from space processes.
Climate processes
- Thunderstorms
- Electrical discharges (TLEs) in the stratosphere and mesosphere
- X- and gamma-radiation from thunderstorms
- Water vapor transport
- Cloud nucleation
- Gravity waves
- Noctilucent clouds
- The dynamics of the upper atmosphere
Earth's surface and the atmosphere
- Hurricanes
- Dust storms
- Volcanoes
- Forest fires
Interactions of space processes with the atmosphere
- Comets and meteors
- NO from solar radiation
- Thunderstorm interactions with the ionosphere and magnetosphere
- Aurora
Measurements from other satellites and instrumentation on the ground and on aircraft and/or balloons will also be used.
Primary research objectives:
- Study the physics of TLEs including possible NOx production from TLEs. Optical detection of TLEs with high spatial and time resolution in selected spectral bands to have a comprehensive global survey.
- Study the physics of TGFs (Terrestrial Gamma-ray Flashes) and their relationship with TLEs and thunderstorms. X-ray and γ-ray detection of TGFs with high time resolution and at photon energies reaching between 10-keV up to 10 MeV.
- Simultaneous optical detection of thunderstorm and TLE activity with TGF activity. The optical instruments must view with the X- and γ-ray detector towards the nadir
- Study the coupling to the mesosphere, thermosphere and ionosphere of thunderstorms and TLEs
- Observations from space during a minimum of one year at all local times to observe seasonal and local time variations in thunderstorm, TLE and TGF activity.
Secondary research objectives:
- Spectroscopic studies of the aurora
- Studies of greenhouse gas concentrations above thunderstorms (NOx, O3)
- Studies of meteor ablation in the mesosphere and thermosphere.
Optical and X-ray measurements are used to study aurora, differential absorption of light emissions from lightning-illuminated thunderstorm clouds measured by photometers defines ozone column densities. NOx production in TLEs is to be monitored by the UV (145 – 230 nm) photometer and optical imaging and photometers will be used to study meteor ablation.

Figure 3: ASIM at the COLUMBUS module of the ISS. ASIM is the grey instrument in the right side of the drawing. Below is shown the atomic clock called ACES of CNES (gold box), tip companion of ASIM. Above can be seen other future instruments.