Project/Area Number |
02640328
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
Space and upper atmospheric physics
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Research Institution | National Institute of Polar Research |
Principal Investigator |
SATO Natsuo National Institute of Polar Research (NIPR), Professor, 研究系, 教授 (50132709)
|
Co-Investigator(Kenkyū-buntansha) |
MIYAOKA Hiroshi National Institute of Polar Research Research Associate, 研究系, 助手 (10150046)
FUJII Ryoichi National Institute of Polar Research Research Associate, 研究系, 助手 (00132712)
ONO Takayuki National Institute of Polar Research Associate Professor, 資料系, 助教授 (10141996)
YAMAGISHI Hisao National Institute of Polar Research Associate Professor, 研究系, 助教授 (20132714)
EJIRI Masaki National Institute of Polar Pesearch Professor, 情報科学センター, 教授 (30013692)
|
Project Period (FY) |
1990 – 1991
|
Project Status |
Completed (Fiscal Year 1991)
|
Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1991: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1990: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
Keywords | Solar Activity / Electromagnetic Noise / ELF / VLF Wave / ULF Wave / HF Wave / Conjugate Point / Anatarctica / Human Activity / HF帯波動 / ULF帯波動 / 南極の昭和基地 / アイスランド / 地磁気共役点 / 南極 / 日照 |
Research Abstract |
Solar and human activity influence on electromagnetic noise were studied using data observed at geomagnetically conjugate stations, Syowa Station in Antarctica and Husafell in Iceland. In order to study the science project, we analyzed statistical characteristics of ELF/VLF (750 Hz, 2 kHz), ULF (0.01-0.1 Hz) and HF (30 MHz) wave intensity. The results are as follows, 1. ELF/VLF wave intensity became maximum during daytime and summer season. The intensity was also influenced by solar activity with periodicity of 27 days and 11 years. 2. ULF wave intensity showed strong seasonal variation with maximum during winter season. This characteristics mean that ULF waves are dumped in the sunlight ionosphere when it propagates from the magnetosphere to the ground. 3. MHz HF waves became maximum during sunlight time and also solar activeperiod. Furthere more, 30 MHz waves intensit, became minimum on Sunday. Sunday is a holyday and human activity may be quiet. That is, we found that human activity influences on HF waves noise in the polar regions.
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