Heavy ions in Earth’s magnetotail: Redistribution and total transport

To understand atmospheric escape at Earth, we must first understand the plasma transport in the magnetotail. The transport of H+ ions is quite well understood, but not that of heavy ions (He+, He++, O+).

The reason is that very few spacecraft can measure heavy ions.Heavy ions can be transported very differently than H+ since their gyroradii are much larger.

Hence, they are more likely to be unmagnetized when interacting with so called meso-scale phenomena (e.g., of the scale of the gyroradius), and their interaction is much more complicated: While H+ typically follows the meso-scale motion, heavy ions may well be scattered all over the place in phase space, and this will affect the total transport.

However, this have never been investigated.We will focus on two of the most important meso-scale phenomena in the tail: Fast Earthward and tailward plasma flows, and magnetotail flapping waves.Our main science question is: How are heavy ions redistributed in phase space by meso-scale phenomena, and how does this affect the total transport?We will use unique data from the ESA Cluster and NASA MMS multi-spacecraft missions.

They measure the heavy ion motion in high resolution and they have now collected enough data for robust statistical studies.

The optimal Cluster satellite separation enables us to use multi-spacecraft methods to study the spatio-temporal evolution of the ions.The project is adapted to a PhD student in collaboration with our international team of applicants.