Peak-flux-density spectra of large solar radio bursts and proton emission from flares. Environmental research papers, July 1981-July 1985

Technical Report · Mon Aug 19 04:00:00 EDT 1985

OSTI ID:5728307

Cliver, E W; McNamara, L F; Gentile, L C

The relationship between U-shaped peak-flux-density microwave spectra and solar proton events was re-examined for approx 200 large (Sp(> or = 2GHz) > or = 800 solar flux uits (sfu) microwave burst (1965 - 1979). The radio spectra fell into two basic classes: (a) U-shaped with two maxima ( > or = 800 sfu) in the range from 200 MHz to > or = 10 GHz (59% of all events), and (b) 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-wavelenght bursts and > 10-MeV proton events of any size (> or = 0.01 pr per sq cm per sec per 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 (vs flash phase) accelerated electrons.

• Research Organization: Air Force Geophysics Lab., Hanscom AFB, MA (USA)
• OSTI ID: 5728307
• Report Number(s): AD-A-164458/2/XAB; AFGL-TR-85-0180
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics &amp; Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
ATMOSPHERES
BARYONS
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
EMISSION
FERMIONS
FLUX DENSITY
HADRONS
LEPTONS
MEASURING INSTRUMENTS
NUCLEONS
PROTONS
RADIATIONS
RADIOWAVE RADIATION
SHOCK WAVES
SOLAR ACTIVITY
SOLAR CORONA
SOLAR FLARES
SOLAR PARTICLES
SOLAR PROTONS
SOLAR RADIATION
SOLAR RADIO BURSTS
SPECTRA
STELLAR ATMOSPHERES
STELLAR CORONAE
STELLAR RADIATION