Peak-flux-density spectra of large solar radio bursts and proton emission from flares /

We have reexamined the relationship between U-shaped peak-flux-density microwave spectra and solar proton events 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 percent of all events), and (b) cutoff spectra with a maximum> or = 800 sfu at f> or = 2 GHz and Sp (200 MHz) or = 800 sfu at f> or = 2 GHz and 100 sfu 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 percent of large microwave bursts with U-shaped spectra are associated with Type II/IV events), protons (77 percent); intermediate Type II/IV (78 percent), protons (73 percent); and cutoff Type II/IV (22 percent), protons (33 percent). 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 supported by the Air Force Geophysics Laboratory, United States AIr Force, Hanscom AFB, Massachusetts.Space Physics Division Project 2311.ADA164458 (from http://www.dtic.mil)."19 August 1985."Includes bibliographical references (pages 50-53).We have reexamined the relationship between U-shaped peak-flux-density microwave spectra and solar proton events 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 percent of all events), and (b) cutoff spectra with a maximum> or = 800 sfu at f> or = 2 GHz and Sp (200 MHz) or = 800 sfu at f> or = 2 GHz and 100 sfu 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 percent of large microwave bursts with U-shaped spectra are associated with Type II/IV events), protons (77 percent); intermediate Type II/IV (78 percent), protons (73 percent); and cutoff Type II/IV (22 percent), protons (33 percent). 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.Mode of access: Internet