Accession Number : ADA521272


Title :   An Artificial Particle Precipitation Technique Using HAARP-Generated VLF Waves


Corporate Author : AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE


Personal Author(s) : Kosch, M J ; Pedersen, T ; Bortnik, J ; Esposito, R ; Gallagher, D ; Marshall, R ; McCarrick, M ; Friedel, R ; Inan, U


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a521272.pdf


Report Date : 02 Nov 2006


Pagination or Media Count : 19


Abstract : A new ground-based experimental technique is described, which is designed to optimize artificial precipitation of magnetospheric electrons at high latitudes, due to man-made VLF waves. High-latitude ionospheric modification facilities may be used to modulate the Hall conductance, which modulates the electrojet current, and in turn radiates VLF whistler waves. Assuming the VLF waves are ducted along the magnetic field lines, the frequency of the VLF wave is modulated in time such that Doppler-shifted cyclotron resonance between the wave and gyrating electrons is maintained along a large fraction of the magnetic field line for a selected particle energy. The electron travel time is a function of particle energy, which is selected to be at the loss cone, and magnetic field strength. The VLF wave travel time is a function of frequency, which we calculate, the electron gyro-frequency, which is a function of magnetic field strength, and the plasma frequency, which we model. The frequency-time modulated VLF wave patterns have been successfully implemented at the HAARP ionospheric modification facility in Alaska, USA. Two initial attempts have failed to produce an unambiguous signature of particle precipitation to date.


Descriptors :   *ARTIFICIAL PRECIPITATION , ELECTRONS , PARTICLES , HIGH LATITUDES , WAVES , CYCLOTRON RESONANCE , WHISTLERS , VERY LOW FREQUENCY , MAGNETOSPHERE , ELECTROJETS , IONOSPHERIC MODIFICATION , MAGNETIC FIELDS , DOPPLER EFFECT


Subject Categories : Meteorology


Distribution Statement : APPROVED FOR PUBLIC RELEASE