Night and day relationships between polar cap riometer absorption and solar protons

Journal Article · Sat Jan 01 04:00:00 EST 1977 · Radio Sci.; (United States)

DOI:https://doi.org/10.1029/RS012i005p00779· OSTI ID:7208484

Sellers, B ^[1]; Hanser, F A; Stroscio, M A; Yates, G K

---

1. Panametrics, Inc., Waltham, MA

The relation between riometer-measured absorption of 30 MHz cosmic radio waves at Thule, Greenland, and the extramagnetospheric 1 to 100 MeV solar proton event fluxes observed by satellite OV5-6 during 1969 to 1972 is studied, with night and day conditions at Thule separated. In the 70 to 90 km region in which most nighttime absorption occurs, ionization conditions are, in fact, relatively simple. This leads to a nighttime relation between absorption and the square root of the integral proton flux, which is similar to that for daytime conditions. Based on previously measured effective recombination coefficients, theoretically optimum energy thresholds are determined for use in this approximate relation. The values are 2.2 and 5.2 MeV for night and day conditions, respectively. Both the approximate absorption and that calculated by a reformulation of the standard approach compare satisfactorily with extensive riometer measurements at Thule. The approximate relations are employed in a real-time system that uses satellite proton data for prediction of radio wave (riometer) absorption.

• OSTI ID: 7208484
• Journal Information: Radio Sci.; (United States), Journal Name: Radio Sci.; (United States) Vol. 12:5; ISSN RASCA
• Country of Publication: United States
• Language: English

Related Subjects

640101 -- Astrophysics & Cosmology-- Cosmic Radiation
640104 -- Astrophysics & Cosmology-- Solar Phenomena
640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
BARYONS
COSMIC RADIATION
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FERMIONS
FLUX DENSITY
HADRONS
IONIZATION
IONIZING RADIATIONS
NUCLEONS
POLAR-CAP ABSORPTION
PROTONS
RADIATIONS
RADIOWAVE RADIATION
SOLAR PARTICLES
SOLAR PROTONS
SOLAR RADIATION
STELLAR RADIATION