|
Detailed Reference Information |
Woo, R. (1988). A synoptic study of doppler scintillation transients in the solar wind. Journal of Geophysical Research 93: doi: 10.1029/88JA01111. issn: 0148-0227. |
|
This paper presents the first synoptic study of Doppler scintillation transients caused by the passage of interplanetary disturbances. It is based on 40,000 hours of 2.3-GHz Doppler scintillation measurements surrounding 15 superior conjunctions of planetary spacecraft during 1979--1983, a period that includes solar maximum. A total of 148 separate transients covering a heliocentric distance range of 5--179 Rs were detected: 122 by one spacecraft and 26 by more than one. The enhancement in scintillation level (termed EF for enhancement factor) of the transients varied from 2 to 100. The multispacecraft measurements of 22 disturbances showed that they attenuated and expanded as they propagated outward from the Sun with propagation speeds varying from 200 to 2000 km/s. The propagation speed was highly correlated with EF (correlation coefficient of 0.91), showing that EF serves as a good indicator of propagation speed, at least for large EF. The frequency of occurrence was highest near the Sun (within 40 Rs), where it was 0.29 transients/d, and decreased with radial distance, a reflection of the radial evolution of the transients and the sensitivity of the Doppler scintillation measurements to transients. Since the Doppler scintillation measurements are most effective near the Sun, they ideally complement in situ spacecraft observations farther away. An earlier study of nine interplanetary shock waves based on scintillation, Solwind coronagraph, and Helios plasma measurements showed a significantly wider range of shock velocities close to the Sun than near 1 AU. The results of this synoptic study indicate that this is apparently a long-term feature of the solar wind around solar maximum. ¿ American Geophysical Union 1988 |
|
|
|
BACKGROUND DATA FILES |
|
|
Abstract |
|
|
|
|
|
Keywords
Interplanetary Physics, Solar wind plasma, Interplanetary Physics, Interplanetary shocks, Solar Physics, Astrophysics, and Astronomy, Flares, Space Plasma Physics, Shock waves |
|
Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
|
|
|