Peak flux density spectra of large solar radio bursts and proton emission from flares
The authors have reexamined the relationship between U-shaped peak flux density microwave spectra and solar proton events for approx. 200 large (Sp > or = 2 GHz) > or = 800 solar flux units (sfu)) microwave bursts (1965-1979). The radio spectra fell into two basic classes: U-shaped, with two maxima (> or = 800 sfu) in the range from 200 MHz to > or = 10 GHz (59% of all events), and cutoff spectra, with a maximum > or = 800 sfu at f > or = 2 GHz and Sp (200 MHz) < 100 sfu (18%). Nine percent of the events had intermediate spectra with a maximum > or = 800 sfu at f > or = 2 GHz and 100 sfu < or = Sp (200 MHz) < 800 sfu. The authors were unable to classify 15% of the events because of incomplete data. The associations of the three classes of spectra with type II (and/or type IV) meter-wavelength bursts and > 10-MeV proton events of any size (> or = 0.01 protons/sq cm/s/sr) are as follows: U-shaped: type II/IV (90% of large microwave bursts with U-shaped spectra are associated with type II/IV events), protons (77%); intermediate: type II/IV (78%), protons (73%); and cutoff: type II/IV (22%), protons (33%). These statistics affirm various lines of evidence linking coronal shock waves and interplanetary proton events. They also suggest that the meter wavelength branch of the U-shaped spectrum may be attributable to second-phase (versus flash phase) accelerated electrons. This latter supposition was examined, and it was found, that it cannot be true in general.
- Research Organization:
- Air Force Geophysics Lab., Hanscom AFB, MA (USA)
- OSTI ID:
- 6282284
- Report Number(s):
- AD-A-158566/0/XAB; AFGL-TR-85-0176
- Country of Publication:
- United States
- Language:
- English
Similar Records
Peak-flux-density spectra of large solar radio bursts and proton emission from flares. Environmental research papers, July 1981-July 1985
Peak-flux-density spectra of large radio bursts and proton emission from flares. Environmental research papers, July 1981-July 1985
Related Subjects
GENERAL PHYSICS
SOLAR FLARES
SOLAR PROTONS
EMISSION
SOLAR RADIO BURSTS
SPECTRA
FLUX DENSITY
BARYONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FERMIONS
HADRONS
NUCLEONS
PROTONS
RADIATIONS
RADIOWAVE RADIATION
SOLAR ACTIVITY
SOLAR PARTICLES
SOLAR RADIATION
STELLAR RADIATION
640104* - Astrophysics & Cosmology- Solar Phenomena