Quantification of Transient Changes of Thermospheric Neutral Density
Abstract
The project objective was to determine how the thermosphere responds to transient energy inputs from solar flares and from magnetospheric coupling at high latitudes. GITM simulations showed that both Poynting flux and soft electron precipitation are important in producing neutral density enhancements near 400 km in the cusp observed by the CHAMP satellite. The height-integrated Pedersen conductivities in the E and F regions were calculated from COSMIC radio occultations to estimate the comparative importance of Joule heating in the two regions. Our team analyzed conductivity and ion-drift data from the Sondrestrom radar to obtain vertical profiles of Joule heating. Thermosphere modeling with input from the Flare Irradiance Spectral Model showed that the density impact at 400 km is largest for the 25-105 nm waveband. Empirical orthogonal function (EOF) analysis of SuperDARN data identified the dominant modes of high-latitude ionospheric electric-field variability and quantified its temporal and spatial coherence. A SuperDARN assimilative mapping (SAM) procedure based on EOFs was developed and implemented at the SuperDARN web site.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 24, 2014
- Accession Number
- ADA619895
Entities
People
- A. D. Richmond
- Li Qian
- Y. Deng
Organizations
- High Altitude Observatory