An overview of the early November 1993 geomagnetic storm

This paper describes the development of a major space storm during November 2–11, 1993. We discuss the history of the contributing high‐speed stream, the powerful combination of solar wind transients and a corotating interaction region which initiated the storm, the high‐speed flow which prolonged the storm and the near‐Earth manifestations of the storm. The 8‐day storm period was unusually long; the result of a high‐speed stream (maximum speed 800 km/s) emanating from a distended coronal hole. Storm onset was accompanied by a compression of the entire dayside magnetopause to within geosynchronous Earth orbit (GEO). For nearly 12 hours the near‐Earth environment was in a state of tumult. A super‐dense plasma sheet was observed at GEO, and severe spacecraft charging was reported. The effects of electrons precipitating into the atmosphere penetrated into the stratosphere. Subauroral electron content varied by 100% and F layer heights oscillated by 200 km. Equatorial plasma irregularities extended in plumes to heights of 1400 km. Later, energetic particle fluxes at GEO recovered and rose by more than an order of magnitude. A satellite anomaly was reported during the interval of high energetic electron flux. Model results indicate an upper atmospheric temperature increase of 200°K within 24 hours of storm onset. Joule heating for the first 24 hours of the storm was more than 3 times that for typical active geomagnetic conditions. We estimate that total global ionospheric heating for the full storm interval was ∼190 PJ, with 30% ofthat generated within 24 hours of storm onset.