From a weak to a strong comet - 3D global hybrid simulation studies

Abstract

Plasma structures resluting from the solar wind interaction with weak comets are discussed. Numerical simulations using a newly developed hybrid code are presented. The simulations are primarily applied to quantitative data for comet Wirtanen, which will be the target of the Rosetta mission. It is expected that Wirtanen is very weak during the first encounter. The main purpose is the discussion of the different features of the plasma environment, such as the structured cycloidal plasma tail and non-linear Mach cones typical for weak comets and their relation to structures like shocklets, bow shock, diamagnetic cavity and the "classical" magnetotail found at stronger comets. Furthermore, the sensitivity of these various features in dependence on the plasma parameters is investigated.