Power Spectra of Geomagnetic Fluctuations between 0.1 and 10.0 Hz.
Abstract
An optically pumped Cesium vapor magnetometer was used to measure the temporal fluctuations of the total geomagnetic field at Monterey, California. Power spectra were obtained from these recordings for the frequency range 0.1-10 Hz. Measurements were made during the month of April 1978 with the Kp index varying from 0+-8+. The power spectra obtained displayed a characteristic -20 dB/decade slope from 0.1-2.0 Hz and were essentially flat between 2.0-10 Hz. Measurement times were: Local night (0000-0200), local morning (0800-1000) and local afternoon (1600-1800). Local morning exhibited the highest power density levels, exceeding the lowest power density levels (recorded during local night) by 10dB at .1 Hz and 3dB at 10 Hz. A comparison of a magnetically disturbed day (Fredricksburg a index of 7) with a magnetically quiet day (Fredricksburg a index of 3) showed that at the low frequency end of the spectrum (.1-.6 Hz) there was 10dB more power on the disturbed day. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1978
- Accession Number
- ADA057419
Entities
People
- John Michael Barry
Organizations
- Naval Postgraduate School