THE TIME VARIATIONS OF SOLAR COSMIC RAYS DURING JULY 1959 AT MINNEAPOLIS

Journal Article · Sat Apr 01 04:00:00 EST 1961 · J. Geophys. Research

DOI:https://doi.org/10.1029/JZ066i004p00995· OSTI ID:4031611

Winckler, J R; Bhavsar, P D; Peterson, L

Thirteen high-altitude balloon flights were made at Minneapolis, Minnesota, during the period July 10 - 18, 1959. Measurements with ion chambers, Geiger counters, and scintillation counters of the solar cosmic rays accompanying three large flares during that period are summarized. Very large fluxes were observed beginning with the main phase of each of the three geomagnetic storms following the flares. During this main phase period, the instrumental results are consistent with protons having a steep energy spectrum and a lower limit at the air cut-off. For example, at 1046 UT on July 15 the integral energy spectrum for protons valid between 88 and 300 Mev was found to be N(>E) = 1.05 x 10/sup 8/E/sup -2.//sup 9/ sec ster. The large increase observed in each storm can be interpreted as a rapid decrease in the cosmic-ray geomagnetic cut-off coincident with the start of the main phase of the storm. The flux returned to norma; much sooner than the recovery of the main field of the earth. At the time of the sudden commencement of the geomagnetic storm, a rapid and appreciable decrease of residual low-intensity solar cosmic rays was observed in two cases. It is suggested that these effects may be produced by ring current systems in the outer field of the earth associated with the geomagnetic storm. Following the July 15 increase, intensity oscillations in the solar proton stream with a period of 1/2 hour were observed. These oscillations are of unknown origin. (auth)

• Research Organization: Univ. of Minnesota, Minneapolis
• Sponsoring Organization: USDOE
• NSA Number: NSA-15-016289
• OSTI ID: 4031611
• Journal Information: J. Geophys. Research, Journal Name: J. Geophys. Research Vol. Vol: 66
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
AIR
BALLOONS
COSMIC RADIATION
DISTRIBUTION
EARTH
ENERGY
ENERGY RANGE
GEIGER-MUELLER COUNTERS
GEOMAGNETIC CUT-OFF RIGIDITY
IONIZATION CHAMBERS
LEVELS
MAGNETIC FIELDS
MAGNETIC STORMS
MEASURED VALUES
OSCILLATIONS
PHYSICS
PRODUCTION
PROTONS
SCINTILLATION COUNTERS
SOLAR FLARES
STRATOSPHERE
SUN
TURBULENCE
VARIATIONS