Numerical Simulation and Forecast of Equatorial Spread F Under Realistic Postsunset Conditions
Abstract
A fully three-dimensional numerical simulation of plasma density irregularities in the postsunset equatorial F region ionosphere leading to equatorial spread F (ESF) has been developed. The simulation evolves under realistic background conditions including bottomside plasma shear flow and vertical current. It has been initialized and driven in accordance with background measurements obtained from the Air Force C/NOFS satellite, the Jicamarca Radio Observatory, the Altair radar on Kwajalein, and other instruments. Simulations are seeded with white noise alone and are, in that sense, agnostic with respect to the required, underlying seed mechanism. A combination of generalized Rayleigh Taylor (gRT) and collisional shear instability (CSI) has been found to produce growing waveforms with key features that agree with satellite and ground-based radar observations in several important respects, including their gross morphology, development rates, and magnetic signatures. The transient response of CSI is consistent with the observation of bottomside waves with wavelengths close to 30 km, whereas the steady-state behavior of the combined instability can account for the 100+ km wavelength waves that predominate in the F region.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 30, 2012
- Accession Number
- ADA564533
Entities
People
- D. L. Hysell
- H. A. Aveiro
Organizations
- Cornell University