Energetics and Composition in the Thermosphere

In this chapter, the authors perform numerical simulations of equatorial spread F (ESF), assessing the roles of collisional shear instability (CSI) and generalized Rayleigh-Taylor (gRT) and comparing the results with different kinds of space weather diagnostics. The simulation advances the plasma number density and electrostatic potential forward in time by enforcing the constraints of quasineutrality and momentum conservation. Simulations are performed with realistic background conditions including bottomside plasma shear flow and the attendant vertical current. The results are evaluated using computed numerical proxies for ESF observations, including in situ observations from magnetometers on board satellites and remote sensing observations made by coherent/incoherent scatter radar and airglow imagers. The diagnostic codes can be used to validate the numerical simulation, which is evidently able to reproduce the salient characteristics of ESF observed by these.