Cosmic rays at balloon altitudes and the solar cycle

Journal Article · Sun Apr 01 04:00:00 EST 1962 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/JZ067i004p01309· OSTI ID:4831553

Neher, H. V.; Anderson, Hugh R.

Measurements of cosmic-ray intensity are made for most of the past solar cycle at balloon altitudes near the north geomagnetic pole. Such experiments were conducted during the summer months, but these data represent a relatively true measure of cosmic rays in the vicinity of the earth for that particular phase of the solar cycle, since large solar-flare activity was absent when these flights were made. The energy density of cosmic rays in the vicinity of the earth was 40% less in 1958 to 1959 than in 1954; new particles present in 1954 that were not present in 1951 were almost entirely those absorbed in 200 g cm^-2 of the atmosphere; after the cosmic-ray maximum of 1954, the first particles to disappear were very absorbable, having an absorption length of about 60 g cm^-2; as the solar cycle progressed, the particles removed became increasingly energetic, until those that disappeared between 1957 and 1958 were absorbed about like primaries of mean rigidity 9 Bev; the particles reappearing after the cosmic-ray minimum of 1958 to 1959 have close to the same rigidity as those removed before the cosmic-ray minimum was reached, when the intensity was approximately the same; if the general solar activity can be measured by the Zurich sunspot numbers, a 9- to 12-month lag of cosmic-ray change from being anti-correlated with solar activity appears; and sunspot numbers averaged over periods comparable to 3 months appear to be a better measure of solar activity as it relates to cosmic-ray intensity than do similarly-averaged planetary magnetic- character figures.

• Research Organization: California Inst. of Tech., Pasadena
• Sponsoring Organization: USDOE
• NSA Number: NSA-16-018300
• OSTI ID: 4831553
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: 4 Vol. 67; ISSN 0148-0227
• Publisher: American Geophysical Union
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BALLOONS
COSMIC RADIATION
EARTH
ENERGY
ENERGY RANGE
GEOMAGNETIC COORDINATES
GEOMAGNETIC POLES
LEVELS
MAGNETIC FIELDS
MEASURED VALUES
RADIATIONS
SPACE
STRATOSPHERE
SUN
VARIATIONS