Radio Physics of the Sun

For over 35 years, radio astronomical techniques have made an impressive series of advances in our understanding of solar phenomena. However, although the subject has been partially discussed in "Paris Symposium on Radio Astronomy" in 1958, NASA-GSFC Symposium on "Physics of Solar Flares" in 1963, and the lAU Symposium No. 57 on "Coronal Disturbances" in 1973, there has not been a major international meeting dedicated to "Radio Physics of the Sun". This is the first major symposium on the subject held under the auspices of the International Astronomical Union. It was jointly spon­ sored by lAU Commission 40, Radio Astronomy, and by lAU Commission 10, Solar Activity. It was also sponsored by the Solar Physics Division of the American Astronomical Society. Thig volume contains the proceedings of this meeting, lAU Symposium No. 86 on "Radio Physics of the Sun" that was held in College Park, Maryland, August 7-10, 1979. The Scientific Organizing Committee of the Symposium consisted of M. R. Kundu (chairman), G. A. Dulk, O. Hachenberg, M. Kuperus, D. J. McLean, D. Melrose, M. Pick, J. L. Steinberg, T. Takakura, A. Tlamicha and V. V. Zheleznyakov. The topics and speakers were chosen in order to emphasize the current observational material with particular reference to centi­ meter wavelength observations of a few arc-second resolution, fast two-dimensional pictures of the sun at meter-decameter wavelengths and the recent advances in plasma and radiation theory.

Special Session — Introduction and Perspective Introductory.- Introductory Address.- The Sun of Stefan Smerd (The S.F. Smerd Memorial Lecture).- Session I — Quiet Sun.- The Quiet Sun at cm- and mm-Wavelengths (Invited Review).- Quiet Sun at Metric and Decametric Wavelengths (Invited Review).- Observations of the Quiet Sun with 6? Resolution.- Shock Wave Transit Through the Transition Region and Related Radio Fluctuations.- Interferometric Observations of the Extreme Solar Limb at 2.8 and 6 cm During the October 1977 Eclipse.- On the Fluctuations in the Solar Flux at cm-Wavelengths Monitored on Small Areas of the Sun’s Disk.- Session II — Active Regions.- Microwave, EUV, and X-ray Observations of Active Region Loops and Filaments [Invited Review).- Thermal Cyclotron Radiation from Solar Active Regions (Invited Talk).- Active Region Magnetic Fields and cm-? Emission.- Observations of Solar Active Regions at 2 and 6 cm Wavelengths with 3 Arc Second Resolution.- Very Large Array (VLA) Observations of Solar Active Regions.- On the Origin of Microwave Emission from Sunspots.- Recent Development of the Nobeyama 17 GHz Interferometer and Some Initial Results.- Interferometric Observations of Radio Bursts at 35 GHz.- Time-Variations of 17 GHz Radio Bursts with Multi-Source Structures.- Solar Observations with the Very Large Array.- Radio Emission of the Solar Polar Regions at Millimeter Wavelengths.- Session III — Solar Bursts — CM Wavelengths.- Radio Burst Emission Mechanisms: General Review (Invited Review).- Solar Burst Observations at Centimeter Wavelengths (Invited Review).- Microwave Emission from Flaring Magnetic Loops.- Flare of 1970 March 01 A Review and Further Evidence for Adiabatic Heating.- Investigation of Microwave Burst Spectra for the Determination of Source Inhomogeneities.- Bursts Observed at 21 cm with the Westerbork Interferometer.- The Spatial Structure of Solar Microwave Bursts.- Fast Fine Structure in Solar Microwave Flares.- Some Characteristics of Ultra-Fast Time Structures Superimposed on Impulsive mm-Wave Bursts.- Nonthermal Microwave Phenomena in Other Stars (Invited Talk).- Session IV — Solar Bursts — Meter Wavelengths.- Solar Burst Observations at Metre and Decametre Wavelengths (Invited Review).- Observations of Solar type III Radio Bursts with the Nançay Radioheliograph (Invited Talk).- Polarization of Herringbone Structure in type III Bursts.- First Solar Radar Observations in Microwaves.- Solar type I Radio Bursts: An Ion-Acoustic Wave Model.- On the Statistical Nature of type I Bursts.- Digitally Recorded type I Bursts and Some Theoretical Aspects of Continuum and Burst Generation.- The Application of Coronal Scattering Measurements to Solar Radio Bursts.- Complementary Bursts, Coronal Inhomogeneities and New Microscopic Spectral Features of Solar Bursts in type IV Bursts.- Fine Structure in Solar type III Radio Bursts Spectra.- Pecularities of the Dynamic Spectra of type V Solar Radio Bursts.- An Observed Correlation Between the Flux Densities of Extended Hard X-ray and Microwave Solar Bursts.- Session V — Solar Bursts — Meter — Decameter Wavelengths.- Current Understanding of the Physics of type III Solar Radio Bursts (Invited Review).- Numerical Simulation of type III Bursts (Invited Talk).- Quasi-Linear Dynamics of a Hot Maxwellian Electron Distribution Released from a Localized Region in a Homogeneous Plasma.- Origin of Plasma Wave Clumping in type III Radio Burst Sources.- Distribution Functions of type III Electrons Observed in Interplanetary Space.- Polarization and Position Measurements of type III Bursts.- F & H Solar Radio Emission: Delayed Fundamental.- On the Propagation of the Electrons Related to type III Bursts.- On Modulations of Radio type IV Bursts.- The Polarization of type V Bursts.- Session VI — Solar Bursts — Decimeter And Low Frequency Observations.- Theory of type IV dm Bursts (Invited Review).- Transition Between type I and type III Bursts in Closed or Open Magnetic Field Lines.- Plasma Oscillations and the Emissivity of type III Radio Bursts.- Observations of Solar Bursts of types II and III at Kilometric Wavelengths from Voyager.- Satellite Observations of Solar Radio Bursts (Invited Reveiw).- Type I Radio Emission and the Structure of the Solar Corona: Results of the Stereo-I Experiment.- Hectometer and Kilometer Solar Observations (Invited Talk).- One Dimensional High Time Resolution Observations with the Westerbork Array.- Session VII — Solar Bursts — Radio, White Light And X-Ray Observations.- Radio and White-Light Observations of Coronal Transients (Invited Review).- Decametric Radio Bursts Associated with Coronal Loop Structures.- Satellite Observations of the Outer Corona Near Sunspot Maximum.- Observation of a Coronal Impulsive X-Ray Burst and its Implications Regarding the Associated Microwave Source.- On the Possibility of Radio Observations of Current Sheets on the Sun.- An Interpretation of Solar Flare Microwave Spikes as Gyrosynchrotron Masering.- Temporal and Spectral Investigation of Two Thermal Impulsive Microwave and X-ray Bursts of 1972 May 18 for the Determination of Source Parameters.- Flare Characteristics and type III Bursts: A Statistical Approach.- Observations of the Structure of type IIIb Radio Bursts.