An Empirical Model of FUV Auroral Intensity
Abstract
A statistical model of auroral intensity as a function of magnetic activity was created. The model was derived from several hundred 1356A images of the aurora borealis obtained by Polar BEAR at solar minimum. Intensities were averaged in 35 divisions of CGL (from 55 deg to 90 deg, each division 1 deg long), 48 divisions of MLT (each division half an hour wide), and 5 divisions of magnetic activity (K sub p = 0-4). The peak oval intensity is located near midnight for all K sub p values but 0. Two secondary maxima in the average 1356A intensity are found in the dayside part of the oval: one in morning and one in the afternoon. The peak nightside, morning, and afternoon intensity increase monotonically with magnetic activity. The latitude of peak emission increases with K sub p at night and decreases in the dayside. The latitudinal extent of the oval is largest at or near the intensity peaks and increases with magnetic activity. The model of average auroral intensity was related to a statistical model of electron precipitation into the high-latitude ionosphere. The precipitation data leading to auroral emissions show a power law relationship between the energy flux and the average energy of the precipitation electrons. The average electron energy associated with the peak 1356A oval emission is 0.8- 1.7 keV at night, predominantly 0.3-0.7 keV in the morning, and predominantly 0. 2-0.5 keV in the afternoon. Polar cap emissions are associated with very cold electrons (0.3-0.4 keV).
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 25, 1992
- Accession Number
- ADA253688
Entities
People
- Israel Oznovich
- Moshe Tur
Organizations
- Tel Aviv University