| タイトル | An observational study of MHD wave-induced density fluctuations upstream of the earth's bow shock |
| 著者（英） | Spangler, Steven; Fuselier, Stephen; Anderson, Gregory; Fey, Alan |
| 著者所属（英） | Los Alamos National Lab.|Lockheed Missiles and Space Co.|Iowa Univ. |
| 発行日 | 1988-02-01 |
| 言語 | eng |
| 内容記述 | An investigation of plasma density fluctations upstream of the earth's bow shock and their association with MHD waves is reported. The normalized density fluctuation was 14 percent on a day when the plasma beta was less than unity and the waves were circularly polarized and of relatively low amplitude, and 17 percent on a day when the plasma beta was in excess of unity and the waves were elliptically polarized and of large fractional amplitude. On both days there was a feature of the density power spectrum at the MHD carrier wave frequency attributable to oblique propagation of the waves with propagation angles of a few degrees with respect to the mean field. Ponderomotive effects due to spatial gradient in the MHD wave energy density are proposed as responsible for a correlation betweeen density and transverse wave intensity on both days. Generation of density fluctuations by linear polarized MHD waves is not an important contributor to the observed density fluctuations. |
| NASA分類 | GEOPHYSICS |
| レポートNO | 88A25881 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/372501 |
