Correlation of microwave bursts with the H-alpha flares

Journal Article · Sun Jan 01 04:00:00 EST 1984 · Adv. Space Res.; (United States)

DOI:https://doi.org/10.1016/0273-1177(84)90174-1· OSTI ID:5605679

Urpo, S; Terasranta, H

The results of a direct comparison of solar microwave recordings at the Metsahovi Radio Research station, Finland, and H-alpha flares at the Hvar Observatory, Yugoslavia, during the Solar Maximum Year compaigns of 1979-1981 and 1983 are reported. At the Metsahovi station, a 14-meter radio telescope is used and at the Hvar Observatory a solar double-telescope is used. It is found that the correlation between H-alpha flares and microwave gradual rise and fall events (GRF), with a time scale of tens of minutes, is high. At Metsahovi, 23 GRF events are measured and in 22 cases (96 percent) a simultaneous flare is observed at Hvar. On the other hand, impulsive microwave bursts with a time scale of tens of seconds have low correlation with H-alpha flares. It is shown that the main contribution to the microwave GRF bursts comes from thermal radiation and that the correlation of flares and microwave events is low at long wavelengths and very high at shorter wavelengths. 6 references.

• Research Organization: Metsahovi Radio Research Station, Kylmala, Finland
• OSTI ID: 5605679
• Journal Information: Adv. Space Res.; (United States), Journal Name: Adv. Space Res.; (United States) Vol. 4; ISSN ASRSD
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BALMER LINES
ELECTROMAGNETIC RADIATION
MICROWAVE RADIATION
RADIATIONS
RADIOWAVE RADIATION
SOLAR ACTIVITY
SOLAR FLARES
SOLAR RADIATION
SOLAR RADIO BURSTS
SOLAR WIND
STELLAR RADIATION
WAVELENGTHS