2018.A.3.3. Computing solar wind helicity from magnetic data of CubeSat fleet

Author(s)

Eija Tanskanen (1)
Jouni Envall (2)
Maarit Käpylä (3)
Nishant Singh (3)
Mika Väänänen (1)
Ilpo Virtanen (4)

Aalto University, Finland
Finnish Meteorological Institute, Finland
Max Planck Institute for Solar System Research Göttingen, Germany
Oulu University, Finland

Session

A.3

Keywords

CubeSat fleet, small magnetometer, magnetic structures, magnetic activity, solar storm effects, predicting interplanetary magnetic field complexity

Abstract

We have examined solar wind intervals with Alfvénic fluctuations (ALFs) by computing solar wind cross helicity from single spacecraft magnetic field and velocity data. Cross helicity, being a measure of a correlation between the fluctuations of magnetic field and solar wind velocity, can be used for finding the structures originating from the Sun that have a potential to cause trouble to near-Earth space infrastructure. We found out that high-latitude geomagnetic activity increases by 40% simultaneous to similar increase of ALF activity in interplanetary space. This indicates that highly Alfvénic intervals are hazardous for the sensitive instruments e.g. on-board interplanetary CubeSats as well as for CubeSats themselves. Large number of magnetometers on-board fleet of CubeSats would enable computing solar wind magnetic helicity, in addition to cross helicity, and thus better estimate magnetic field complexity and internal twist of magnetic structures in interplanetary space. Better knowledge on spatial and time evolution of magnetic structures in interplanetary space would offer new ways of predicting when and where the most extreme and complex solar storms hit the Earth and have a largest potential to cause trouble to infrastructure on ground and in space.