Peak-flux-density Spectra of Large Solar Radio Bursts and Proton Emission from Flares

Peak-flux-density Spectra of Large Solar Radio Bursts and Proton Emission from Flares
Author: Edward W. Cliver
Publisher:
Total Pages: 62
Release: 1985
Genre: Proton flares
ISBN:

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) 100 sfu (18 percent). 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. We were unable to classify 15 percent 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 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.

Solar and Space Weather Radiophysics

Solar and Space Weather Radiophysics
Author: D.E. Gary
Publisher: Springer Science & Business Media
Total Pages: 414
Release: 2006-01-20
Genre: Science
ISBN: 1402028148

This volume is the outgrowth of several international meetings to discuss a vision for the future of solar radio physics: the development of a new radio instrument. From these discussions, the concept for the Frequency Agile Solar Radiotelescope (FASR) was born. Most of the chapters of this book are based oninvitedtalksattheFASRScienceWorkshop,heldinGreenbank,WVinMay 2002, and a special session on Solar and Space Weather Radiophysics held at the 200th American Astronomical Society meeting held in Albuquerque, NM in June 2002. Although many of the chapters deal with topics of interest in planning for FASR, other topics in Solar and Space Weather Radiophysics, such as solar radar and interplanetary scintillation, are covered to round out the discipline. The authors have been asked to write with a tutorial approach, to make the book useful to graduate students and scientists new to radio physics. This book is more than a compilation of FASR science topics. The FASR instrument concept is so revolutionary—by extending capability by an order of magnitude in several dimensions at once (frequency coverage, spatial reso- tion,dynamicrange,timeresolution,polarizationprecision)—thatitchallenges scientiststothinkinnewways. Theauthorsofthefollowingchaptershavebeen taskednotonlywithreviewingthecurrentstateofthe?eld,butalsowithlooking to the future and imagining what is possible. Radio emission is extremely complex because it is generated so readily, and every imaginable plasma parameter affects it. This is both its great strength and its weakness.