Analysis of the ionospheric cross polar cap potentialdrop and electrostatic potential distribution patternsduring the January 1997 cme event using DMSP data

• Published in: Journal of atmospheric and solar-terrestrial physics 1999-02, Vol.61 (3), p.195-206
• Main Authors: Hairston, Marc R., Weimer, D.R., Heelis, R.A., Rich, Frederick
• Format: Article
• Language: English
• ISSN: 1364-6826; 1879-1824
• DOI: 10.1016/S1364-6826(98)00128-X

On 6 January 1997 a coronal mass ejection (CME) occurred on the sun producing amagnetic cloud in the solar wind that passed the Earth on 10–11 January 1997 and caused ageomagnetic storm. During this period there were two polar-orbiting DMSP spacecraft (F12 andF13) at 840 km carrying the SSIES plasma instruments on board, which measure the bulk flowvelocity of the thermal ions of the ionospheric plasma. These data are used to calculate theelectric field and electrostatic potential along the flight track of the spacecraft in the polar regions.The time history of the observed total cross polar cap potential drop for this event is presentedalong with comparisons to the estimates from the Weimer model and observations of the aurorafrom the UVI instrument on the POLAR spacecraft. A surprisingly large potential drop of 235 kVis observed at one point and appears to be the result of a pressure pulse in the solar windtriggering an enhancement of the geomagnetic activity. An examination of the electrostaticpotential distribution patterns in the polar ionosphere during the event is also presented.