Remote sensing and modeling of energetic electron precipitation into the lower ionosphere using VLF/LF radio waves and field aligned current data

• Main Author: E. D. Schmitter
• Format: Article
• Language: deu
• Published: Copernicus Publications 2015-11-01
• Series: Advances in Radio Science
• Online Access: http://www.adv-radio-sci.net/13/233/2015/ars-13-233-2015.pdf

A model for the development of electron density height profiles based on space time distributed ionization sources and reaction rates in the lower ionosphere is described. Special attention is payed to the definition of an auroral oval distribution function for energetic electron energy input into the lower ionosphere based on a Maxwellian energy spectrum. The distribution function is controlled by an activity parameter which is defined proportional to radio signal amplitude disturbances of a VLF/LF transmitter. Adjusting the proportionality constant allows to model precipitation caused VLF/LF signal disturbances using radio wave propagation calculations and to scale the distribution function. Field aligned current (FAC) data from the new Swarm satellite mission are used to constrain the spatial extent of the distribution function. As an example electron precipitation bursts during a moderate substorm on the 12 April 2014 (midnight–dawn) are modeled along the subauroral propagation path from the NFR/TFK transmitter (37.5 kHz, Iceland) to a midlatitude site.