Examples of fast solar wind transients, their sources and the forecast of possible geomagnetic impact

We present examples of solar ejecta, including possible interplanetary magnetic clouds, which generated fast forward interplanetary shocks as they moved rapidly through the interplanetary medium. These events occurred before and during the ISTP era. The example from 1982, close to solar maximum, was observed by the SOLWIND, ISEE, HELIOS, and IMP spacecraft which provide wide coverage of the Sun and inner heliosphere. The second event occurred on May 1998. A detailed description of its solar origin is provided by observations from instruments on the SOHO spacecraft, while observations of the shock-generated radio emissions and energetic particles and near-earth solar wind magnetic fields and plasmas are provided by the Wind spacecraft. We revisit potential tools for space weather forecasting, namely: the power of monitoring the Sun with sensors located within a wide range of heliospheric longitudes and distances, the high resolution in time and light-intensity of the extreme ul traviolet imager and solar coronograph, the remote sensing of drifting radio emissions and the local observation of MeV energetic ions.

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