The Need for Multipoint Observations to Validate Physics-Based I-T Model Simulations of Geomagnetic Storms

Abstract:

Numerical model simulations of geomagnetic storms reveal many different physical processes at play. Enhanced and expanded high latitude magnetospheric convection, and electric field penetration to mid and low latitudes, set the plasma into motion. Ion-neutral collisions drive high velocity neutral wind and frictional/Joule heating, leading to temperature increases, thermal expansion, and neutral density enhancements. The evolving global circulation transports neutral composition causing regions of both decrease and increased plasma density. Plasma stagnation in the presence of sunlight causes a build-up of plasma at midlatitude. Networks of ground based GNSS observations of total electron content and neutral composition imaging are excellent examples of the value of multi-point measurements. The observations highlight the need for equivalent multi-point satellite observations of the neutral and plasma dynamics, along-side neutral composition, first to demonstrate the validity of the numerical simulations and then to unravel the balance of physical processes at play.