English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

UCRL'-18092 Observations of high energy protons geomagnetically trapped in the inne.r Van Allen belt have been carried out since September 1962 with nuclear research emulsions recovered from lo~ altitude, polarorb! ting satellites. Between. November 1962 and June 1966, during the period of minimum solar activity, the omnidirection~l proton flux at 63 MeV remained constant to within ± 7.6 percent, an error comparable to the statistical accuracy of the measurement. However,.since Au~st 1966 we have obtained substantial evidence that the proton flux is decreasing in a manner which is attributable to solar cycle variations in the densitY' of the. upper atmosphere. As of our last measurement in , . November 1967, the flux has diminished by more than a factor of 2 relative to the stable flux profile observed during the last solar minimum period.

Evidence for Solar-Cycle Changes in the Inner-Belt Protons