The halo CME was observed in SOHO/LASCO C2 instrument at 06:30 UT with an estimated frontal speed of ~600 km/s [Plunkett et al., 1998] and onset time between 04:30-05:00 UT. For about 10 days before the event, the Earthward directed solar wind consisted of relatively slow (i.e., bulk flow speed less than 400 km/s) dense ambient material. The shock produced by the interplanetary coronal mass ejection (ICME) arrived at L1 early on the 15th followed by a magnetic cloud and then a high-speed stream, which is speculated [Webb et al., 2000] to have compressed the cloud from behind. The ICME produced a moderate geomagnetic storm with a maximum Dst of -115nT. Figure 1 summarizes the key solar wind plasma parameters from the WIND satellite for the nine-day period centered on the May 15th ICME arrival at L1, as well as the Dst geomagnetic index as provided by Kyoto University ( http://swdcdb.kugi.kyoto-u.ac.jp/dstdir/). More comprehensive summaries of the event can be found in papers by Webb et al. [2000], Thompson et al. [1998], and Plunkett [1998] along with the references found therein.
Figure 1 * Solar wind key plasma parameters from the WIND satellite (a-h) and the Dst geomagnetic index (i) as provided by Kyoto University (http://swdcdb.kugi.kyoto-u.ac.jp/dstdir/) for the nine-day period May 11-20, 1997. a) Proton temperature (K), b) Proton number density (cm-3), c) Vx (km s-1) , d) Dynamic Pressure (nPa), e) Bx(GSM) (nT), f) By(GSM) (nT), g) Bz(GSM) (nT), h) |B| (nT), i) Dst (nT). The red vertical lines separate the different types of solar wind plasma labeled at the bottom of the plot. (Plot courtesy of Dr. Yan Li.)
data/ presentations/ publications/ links/ Back to the SHINE Campaign Home Page