Seminars

Lecturer: Hans Nilsson
Date: 2012-11-22 10:30
Place: Aniara

Ion heating, acceleration and escape at Earth, Mars and Venus, similarities and differences

Hans Nilsson
Swedish Institute of Space Physics
Kiruna

Ion heating, acceleration and escape at Mars and Venus occur due to a relatively direct interaction between the solar wind and the planetary ionosphere. At Earth the situation is rather different, as the presence of a strong internal magnetic field causes the separation between the solar wind origin and planetary origin plasma domains, the magnetopause, to be located about 10 $R_{E}$ away from the planet. Despite this, very effective energy transfer and atmospheric removal does occur over the polar caps of the Earth. At Earth we also have much better observations available so that processes such as wave-particle interaction may be studied in much more detail. We therefore compare plasma observations at Mars, Venus and Earth and discuss similarities and differences. We also discuss the ion flow patterns and escape paths of the three planets, as these must be well known in order to study the ionosphere - magnetosphere response to extreme solar wind events. Extreme events are short lived, so the spacecraft will often not be in an optimal position to observe escaping ions. This must be taken into account when we try to compare the response of the different planetary space environments to particular solar wind events.

Created 2012-02-17 08:45:57 by Uwe Raffalski
Last changed 2012-11-19 09:46:04 by Mats Holmström