author = "Fejer, B. G. and Jensen, J. W. and Kikuchi, T. and Abdu, 
                         Mangalathyil Ali and Chau, J. L.",
          affiliation = "Center for Atmospheric and Space Science, Utah State University 
                         and Center for Atmospheric and Space Science, Utah State 
                         University and Solar Terrestrial Environment Laboratory, Nagoya 
                         University and {Instituto Nacional de Pesquisas Espaciais (INPE)} 
                         and Radio Observatorio de Jicamarca, Instituto Geofisico del 
                title = "Equatorial ionospheric electric fields during the November 2004 
                         magnetic storm",
              journal = "Journal of Geophysical Research",
                 year = "2007",
               volume = "112",
               number = "A10",
                pages = "A10304 (11pp)",
                month = "Oct.",
             keywords = "disturbance electric fields, ionospheric storm effects, ionos 
                         plasma drifts.",
             abstract = "We use radar measurements from the Jicamarca Radio Observatory, 
                         magnetometer observations from the Pacific sector and ionosonde 
                         data from Brazil to study equatorial ionospheric electric fields 
                         during the November 2004 geomagnetic storm. Our data show very 
                         large eastward and westward daytime electrojet current 
                         perturbations with lifetimes of about an hour (indicative of 
                         undershielding and overshielding prompt penetration electric 
                         fields) in the Pacific equatorial region during the November 7 
                         main phase of the storm, when the southward IMF, the solar wind 
                         and reconnection electric fields, and the polar cap potential 
                         drops had very large and nearly steady values. This result is 
                         inconsistent with the recent suggestion that solar wind electric 
                         fields penetrate without attenuation into the equatorial 
                         ionosphere for several hours during storm main phase. The largest 
                         daytime prompt penetration electric fields (about 3 mV/m) ever 
                         observed over Jicamarca occurred during the November 9 storm main 
                         phase, when large equatorial electrojet current and drift 
                         perturbations were also present in the Pacific and Brazilian 
                         equatorial regions. The rise and decay times of these equatorial 
                         electric fields were about 20 min longer than of the corresponding 
                         solar wind electric fields. The ratios of prompt penetration 
                         electric fields and corresponding solar wind electric field 
                         changes were highly variable even during the day, and had largest 
                         values near dawn. Also, the prompt penetration electric fields did 
                         not show polar cap potential drop saturation effects. Our results 
                         clearly highlight that the relationships of prompt penetration and 
                         solar wind electric fields, and polar cap potentials are far more 
                         complex than implied by simple proportionality factors.",
                  doi = "10.1029/2007JA012376",
                  url = "http://dx.doi.org/10.1029/2007JA012376",
                 issn = "0148-0227 and 2156-2202",
             language = "en",
           targetfile = "jgra18869.pdf",
        urlaccessdate = "27 jan. 2021"