Showing papers by "Dimitris Maroulis published in 1998"
TL;DR: In this article, an almost com- plete frequency coverage of a shock-associated (SA) radio event and related phenomena observed on May 6, 1996 at 9:27 UT is presented.
Abstract: We present for the rst time an almost com- plete frequency coverage of a Shock Associated (SA) radio event and related phenomena observed on May 6, 1996 at 9:27 UT. It is observed from the base of the solar corona up to almost 1 Astronomical Unit (AU) from the Sun by the following radio astronomical instruments: the Ond rejov spectrometer operating between 4.5 GHz and 1 GHz (radi- ation produced near the chromosphere); the Thermopyles Artemis-IV spectrograph operating between 600 MHz and 110 MHz (distance range about 1.1-1.4R from sun center); the Nan cay Decameter Array operating between 75 and 25 MHz (distance range about 1.4-2 R); and the RAD2 and RAD1 radio receivers on the WIND spacecraft covering the range from 14 MHz to about 20 kHz (distance range be- tween 3 R and about 1 AU). Observations at the Nan cay Decameter Array clearly show that the SA event starts from a coronal type II radio burst which traces the progression of a shock wave through the corona above 1.8 R-2 R from the sun center. This SA event has no associated radio emis- sion in the decimetric-metric range, thus there is no evidence for electron injection in the low/middle corona. The SA event enigma: What does SA stand for? Type II and type III solar radio bursts result from the interaction of a disturbing agent {a beam of energetic elec- trons or a shock wave{ with the ambient plasma (Wild and Smerd, 1972). Radiation is produced near the fundamen- tal of the local plasma frequency f p (kHz) =9 n 1 = 2 e (cm 3 ) and/or its second harmonic through various plasma mech- anisms (see e.g. Robinson, 1997). The observed frequency can be converted into an altitude in the corona, assuming a density model and the radiated mode. Dierent frequency drifts reflect dierent velocities along the density gradient in the corona and interplanetary medium, helping us to charac- terize the nature of the exciter: 0.05-0.3c electron beam for
45 citations
TL;DR: In this paper, a shock-associated radio event and related phenomena observed from the base of the solar corona to 1 AU was described. But Figure 3 was not printed in its entirety.
Abstract: In the paper “A shock-associated (SA) radio event and related phenomena observed from the base of the solar corona to 1 AU” by J.-L. Bougeret, P. Zarka, C. Caroubalos, M. Karlický, Y. Leblanc, D. Maroulis, A. Hillaris, X. Moussas, C. E. Alissandrakis, G. Dumas, and C. Perche, Geophysical Research Letters, 25 [14], 2513-2516, Figure 3 was not printed in its entirety. It is printed correctly below with its caption:
6 citations