Makela, Jonathan J.Kelley, Michael C.González, Sixto A.Aponte, NestorSojka, Jan J.2018-07-132018-07-132003-07Makela, J. J., Kelley, M. C., González, S. A., Aponte, N., & Sojka, J. J. (2003). Mid-latitude plasma and electric field measurements during space weather month, September 1999.==$Journal of Atmospheric and Solar-Terrestrial Physics, 65$==(10), 1077-1085. https://doi.org/10.1016/j.jastp.2003.07.002http://hdl.handle.net/20.500.12816/1811Using data collected during the September 1999 combined ionospheric campaign (CIC), we examine the effects of moderate geomagnetic activity on low and mid-latitudes. Perturbations in the zonal electric field, measured at both Jicamarca and Arecibo, are the most striking aspect of this data. These eastward electric fields resulted in a poleward advection of the Appleton anomaly to mid-latitudes, where it was observed as a gradient in the nighttime electron density, as measured by the Arecibo incoherent scatter radar. This gradient was severe enough that it was observable in airglow measurements at 630.0 and . To put this data into context, we also examine the worldwide conditions during this time period and find evidence for several substorms, penetrating electric fields, and disturbance dynamo electric fields.application/pdfenginfo:eu-repo/semantics/restrictedAccessMid-latitude density gradientsElectric field perturbationsMid-latitude ionosphereAirglow measurementsinfo:eu-repo/semantics/articlehttp://purl.org/pe-repo/ocde/ford#1.05.01Journal of Atmospheric and Solar-Terrestrial Physicshttps://doi.org/10.1016/j.jastp.2003.07.002