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Influence of Active Regions on Solar Wind Characteristics at the Cycle Maximum

Reva, A. A.; Kirichenko, A. S.; Ulyanov, A. S. +2 more

Active regions (ARs) on the Sun are discussed as a possible source of the slow solar wind (SW) whose origin is still a subject of debates. In this paper we present experimental evidence for the possible influence of ARs on the SW speed and temperature near the maximum of solar cycle 23 (2000-2002). We have studied separately the characteristics of…

Unusual stripes in emission and absorption in solar radio bursts: Ropes of fibers in the meter wave band

Chernov, G. P.

Based on data from the spectrographs of IZMIRAN and Tremsdorf station (Astronomical Institute, Potsdam), we analyze the ropes of narrow-band fibers in the spectra of solar radio bursts in the meter wave band by invoking events of satellite data (SOHO/LASCO, EIT, MDI) for the analysis. We consider in detail basic properties of the ropes in four eve…

Fine structure of decametric type II radio bursts

Konovalenko, A. A.; Chernov, G. P.; Stanislavsky, A. A. +3 more

We have performed a comparative analysis of the fine structure of two decametric type II bursts observed on July 17 and August 16, 2002, with the 1024-channel spectrograph of the UTR-2 radio telescope in the frequency range 18.5 29.5 MHz and with the IZMIRAN spectrograph in the frequency range 25 270 MHz. The August 16 burst was weak, ∼2 5 s.f.u.,…

Slow Solar Wind: Sources and Components of the Stream Structure at the Solar Maximum

Vladimirsky, K. V.; Lotova, N. A.; Obridko, V. N.

We study the sources and components of the solar-wind spatial stream structure at the maximum of the solar cycle 23. In our analysis, we use several independent sets of experimental data: radio-astronomical observations of scattered radiation from compact sources with the determination of the distance from the Sun to the inner boundary of the tran…

Acoustic Power Mapping for Active Regions from MDI, HLH, and TON Data

Hill, F.; Ladenkov, O. V.; Egamberdiev, Sh. A. +1 more

Small-Scale High-Temperature Structures in Flare Regions

Chernov, G. P.; Kovalev, V. A.; Hanaoka, I.

When analyzing YOHKOH/SXT, HXT (soft and hard X-ray) images of solar flares against the background of plasma with a temperature T ~ 6 MK, we detected localized (with minimum observed sizes of approximately 2000 km) high-temperature structures (HTSs) with T = (20-50) MK with a complex spatial-temporal dynamics. Quasi-stationary, stable HTSs form a …

Observations of Bright Coronal Points at Wavelengths of 5.2 and 1.76 cm

Maksimov, V. P.; Prosovetskii, D. V.; Krissinel, B. B.

Based on two-dimensional solar images obtained with the Siberian Solar Radio Telescope and the Nobeyama Radio Heliograph and using YOHKOH soft X-ray images, we investigate bright coronal points. The principal microwave emission mechanism of these points is shown to be the thermal bremsstrahlung of an optically thin plasma. The fact that, in severa…

Internal Rotation of the Sun as Inferred from GONG Observations

Gavryusev, V. G.; Gavryuseva, E. A.; di Mauro, M. P.

Helioseismology is a direct and most informative method of studying the structure and dynamics of the Sun. Determining the internal differential rotation of the Sun requires that the frequencies of its eigentones be estimated with a high accuracy, which is possible only on the basis of continuous long-term observations. The longest quasi-continuou…