Numerical Physics: Modeling

Research Focus: Extraterrestrial Physics/Solar Terrestrial Relationship

The sun is a highly variable star, sporadically emitting huge amounts of energy, plasma and energetic particles. Solar terrestrial relationship (or Space Weather for short) is concerned with the influences of these emissions on Earth and the terrestrial (or in a broaer scope planetary) environment. Some effects include aurora, disruptions in communication and power lines, atmospheric ionization, ozone depletion and reduction in GPS accuracy. Under normal conditions, these effects are limited to high latitudes due to the shielding of the geomagnetic field.

Our research topics include:

• The role of flares and shocks in the acceleration of solar energetic particles and their subsequent propagation through interplanetary space.
• The spatial and temporal patterns of atmospheric ionization due to the precipitation of these particles into the atmosphere.
• Modeling of long-term solar activity.
• The validation of our models using satellite and ground-based maesurements.

Our methods include:

• Monte Carlo simulations to model the primary interaction between particles and atmosphere.
• Finite difference methodes to model particle propagation.
• Stochastic simulations and cellular automata to model solar activity on long time scales.
• Different methods to analyse large sets of satellite data for model verification and to integrate data sets of different sources.

Projects presently include:

• Energetic charged particles in the atmosphere >>>
• Interplanetary propagation: focused transport extended to 2D (and 3D) and related problems >>>
• Solar energetic particles: acceleration, propagation and spatial variation >>>

Service to the Scientific Community (community model):

• AIMOS data server: the Atmospheric Ionization Model OSnabrück provides 3D ionization rates for the atmosphere. Its spatial resolutaion can be adjusted to a large number of model atmospheres in GCMs as well as to atmospheric chemistry models. The model also allows for a user-defined grid.