|
Detailed Reference Information |
Riley, P., Sonett, C.P., Tsurutani, B.T., Balogh, A., Forsyth, R.J. and Hoogeveen, G.W. (1996). Properties of arc-polarized Alfvén waves in the ecliptic plane: Ulysses observations. Journal of Geophysical Research 101: doi: 10.1029/96JA01743. issn: 0148-0227. |
|
Ulysses observations of the interplanetary magnetic field reveal well-ordered rotations on the timescale of several hours. These have been previously identified as arc-polarized Alfv¿n waves. Rotational discontinuities (RDs) are often an integral part of the wave. This study focuses on a statistical description of these rotations (ARCs) in the ecliptic plane. It is found that (1) most ARCs are limited to 180¿ or less in rotation; (2) these ARCs account for between 5 and 10% of the total data set; (3) there appears to be no preferred helicity; (4) the minimum-variance direction typically makes a large oblique angle with the average magnetic field (〈B〉), while the intermediate-variance direction is loosely aligned with 〈B〉; (5) most of the events display a small but significant nonzero magnetic field component in the direction of minimum variance; (6) the cross helicity of the ARCs tends to be higher than during non-ARC intervals; (7) there are 2.4 times more discontinuities during ARC intervals than during non-ARC intervals; (8) essentially all ARCs are propagating outward in the rest frame of the solar wind plasma; and (9) there is no simple relationship between the rate of occurrence of the ARCs and heliocentric distance. Comparing these results with the predicted signatures of a number of models, it is found that arc-polarized Alfv¿n waves with embedded RDs propagating along the minimum-variance direction best fit the majority of events.¿ 1996 American Geophysical Union |
|
|
|
BACKGROUND DATA FILES |
|
|
Abstract |
|
|
|
|
|
Keywords
Interplanetary Physics, Interplanetary magnetic fields, Interplanetary Physics, MHD waves and turbulence, Interplanetary Physics, Plasma waves and turbulence, Interplanetary Physics, Sources of the solar wind |
|
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 |
|
|
|