A case study of VLF phase and amplitude variation at 12.1 kHz (Aldra) in Iceland

• Main Authors: Takashi Araki, Natsuo Sato, Ryoichi Fujii, Takashi Kikuchi, Susumu Kokubun
• Format: Report
• Language: English
• Published: Faculty of Education, Hirosaki University/National Institute of Polar Research/National Institute of Polar Research/Radio Research Laboratories/Geophysics Research Laboratory, Faculty of Science, University of Tokyo 1986
• Subjects: Norway; Aldra; Iceland; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1990; http://id.nii.ac.jp/1291/00001990/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1990&item_no=1&attribute_id=18&file_no=1

The phase and the field strength of 12.1-kHz VLF signals propagating from Aldra, Norway have been continuously recorded at Tjornes, Iceland using a phase-locked receiver with a loop antenna parallel to the great circle path between Norway and Iceland. Nighttime records represent irregular phase and amplitude fluctuations and sometimes involve quasi-sinusoidal fluctuations. The phase and amplitude change associated with cosmic noise absorption (CNA) are observed on the VLF signals, for which the phase is advanced with the change of the electron number density distribution of lower ionosphere.