Diurnal Variation in Cosmic-Ray Intensity, 1937–1959, at Cheltanham (Fredericksburg), Huancayo, and Christchurch

  1. James A. Van Allen
  1. Scott E. Forbush and
  2. D. E. Venkatesan

Published Online: 20 MAR 2013

DOI: 10.1029/SP037p0275

Cosmic Rays, the Sun and Geomagnetism: The Works of Scott E. Forbush

Cosmic Rays, the Sun and Geomagnetism: The Works of Scott E. Forbush

How to Cite

Forbush, S. E. and Venkatesan, D. E. (1993) Diurnal Variation in Cosmic-Ray Intensity, 1937–1959, at Cheltanham (Fredericksburg), Huancayo, and Christchurch, in Cosmic Rays, the Sun and Geomagnetism: The Works of Scott E. Forbush (ed J. A. Van Allen), American Geophysical Union, Washington, D. C.. doi: 10.1029/SP037p0275

Author Information

  1. Department of Terrestrial Magnetism, Carnegie Institution Of Washington, Washington, D.C.

Publication History

  1. Published Online: 20 MAR 2013
  2. Published Print: 1 JAN 1993

ISBN Information

Print ISBN: 9780875908335

Online ISBN: 9781118667996

SEARCH

Keywords:

  • Cosmis ray variations;
  • Solar activity;
  • Geomagnetism

Summary

The 24-hour and 12-hour waves in cosmic-ray intensity at Cheltenham (Fredericksburg), Huancayo, and Christchurch and their variability are analysed statistically, using data, corrected for pressure, for the period 1937‒1959 from Compton-Bennett ionization chambers. The degree of correlation between the deviations of yearly mean 24-hour waves (from their 23-year means) at any two of the stations is almost as great as can be expected when account is taken of the noise level inherent in the instruments. The deviations of yearly means, from their 23-year averages, indicate large secular variations which may be due to s quasi-systematic 22-year variation. The phase difference between these yearly deviation vectors at Huancayo and Cheltenham (or Christchurch) is considerably less than that between the average vectors for 23 years. The statistical reality of the 12-hour wave is definitely established at all three stations, although, at least at Huancayo, the average 12-hour wave probably results entirely from systematic errors due to exceedingly small frictional effects in the barograph.