Time variations of radiation belt protons
| Autor: | R. Stephen White, William W. Macy, Ernest Holeman, Robert C. Filz |
|---|---|
| Rok vydání: | 1970 |
| Předmět: |
Atmospheric Science
Proton Soil Science Aquatic Science Oceanography Atmospheric sciences Atmosphere symbols.namesake Flux (metallurgy) Altitude Geochemistry and Petrology Ionization Earth and Planetary Sciences (miscellaneous) Nuclear Experiment Earth-Surface Processes Water Science and Technology Physics SIMPLE (dark matter experiment) Ecology Paleontology Forestry Geophysics Space and Planetary Science Van Allen radiation belt symbols Astrophysics::Earth and Planetary Astrophysics Convection–diffusion equation |
| Zdroj: | Journal of Geophysical Research. 75:4322-4328 |
| ISSN: | 0148-0227 |
| DOI: | 10.1029/ja075i022p04322 |
| Popis: | The time dependence of the flux of high-energy radiation belt protons at low altitudes is calculated for the time period 1961 to 1970. The calculations are made with a simple transport equation that uses the variations of atmospheric density over this time period. The source, evaluated from experiment, may vary with altitude and energy and is taken to be independent of time. The time variation in the earth's atmospheric density causes a change in the proton ionization loss and thus a change in the proton fluxes. The calculated variations in fluxes are in good agreement with experiments for 55-Mev protons at L = 1.4 at the altitudes of measurement of 440, 350, and 275 km. The theoretical ratios of the fluxes of 115- to 55-Mev protons are nearly within the uncertainties of the measured ratio of 0.46±0.06 over this time period. The calculated ratios of the fluxes at 25 to the fluxes at 55 Mev deviate from a constant by a maximum of 12%. It is definitely established that the atmospheric density controls the time variations of the energetic trapped protons at low altitudes. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text