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Detailed Reference Information |
Sheeley, N.R., Hakala, W.N. and Wang, Y.-M. (2000). Detection of coronal mass ejection associated shock waves in the outer corona. Journal of Geophysical Research 105: doi: 10.1029/1999JA000338. issn: 0148-0227. |
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White light coronal images from the Large-Angle Spectrometric Coronagraph (LASCO) on the Solar and Heliospheric Observatory (SOHO) spacecraft show disturbances propagating away from high-speed coronal mass ejections (CMEs). The disturbances are faintly visible ahead of the ejected material at the noses of the CMEs but are strongly visible along the flanks and rear ends, where they produce kinks in the streamers and other raylike features that extend in all directions from the Sun at this phase of the sunspot cycle. The kinks decelerate as they move radially outward along the rays, apparently indicating the slowing of the entire wave front as it passes by. For a fast CME seen head on (or tail on) the deceleration occurs at virtually all position angles around the occulting disk. However, for a CME seen obliquely the speed varies strongly with position angle, being fast and uniform near the nose but slower and decelerating at the sides and rear where the deflected rays are more inclined from the sky plane and farther from the Sun. The initial speeds (~800--1400 km/s) are faster than the nominal MHD speed (~600 km/s) at these heights, implying that these disturbances are shock waves, made visible like amber waves of grain [Bates, 1895> in the field of coronal rays around the Sun. ¿ 2000 American Geophysical Union |
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Abstract |
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Keywords
Interplanetary Physics, Interplanetary shocks, Solar Physics, Astrophysics, and Astronomy, Corona, Solar Physics, Astrophysics, and Astronomy, Coronal mass ejections, Space Plasma Physics, Shock waves |
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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 |
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