Recent research on magnetospheric wave-particle interactions

• Main Authors: R.A. Helliwell, U.S. Inan, J.P. Katsufrakis, D.L. Carpenter, E.W. Paschal
• Format: Report
• Language: English
• Published: Space, Telecommunications, and Radioscience Laboratory, Stanford University/Space, Telecommunications, and Radioscience Laboratory, Stanford University/Space, Telecommunications, and Radioscience Laboratory, Stanford University/Space, Telecommunications, and Radioscience Laboratory, Stanford University/Space, Telecommunications, and Radioscience Laboratory, Stanford University 1985
• Subjects: Antarctic; Siple; The Antarctic; Trimpi; Antarc*; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1808; http://id.nii.ac.jp/1291/00001808/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1808&item_no=1&attribute_id=18&file_no=1

Highlights of recent Stanford University VLF research in the Antarctic include new observations of wave-induced particle precipitation and controlled experiments on nonlinear wave growth phenomena. Higher-than-expected levels of burst precipitation have been discovered inside the plasmasphere, near L=2,using subionospheric signal perturbations called "Trimpi events". Studies of burst precipitation have been extended to the region poleward of the plasmapause using the Siple transmitter signal as a waveguide probe. Experiments on the "coherent wave instability", using the amplitude and frequency modulation capability of the new Siple transmitter, have produced exciting new results. Examples are : 1) better definition of the power threshold for the stimulation of temporal wave growth, 2) generation of strong sidebands by unamplified "beat" waves and 3) generation of chorus-like elements within a band of simulated hiss. Using a new digital processing technique developed at Stanford, new features of the phase behavior of growing waves have been found. Opportunities for extending these experiments are discussed.