Araujo-Pradere, Eduardo A.Fang, Tzu WeiAnderson, David N.Fedrizzi, MariangelStoneback, Russell2018-11-092018-11-092012-04-26Araujo-Pradere, E. A., Fang, T. W., Anderson, D. N., Fedrizzi, M., & Stoneback, R. (2012). Modeling the daytime, equatorial ionospheric ion densities associated with the observed, four‐cell longitude patterns in E × B drift velocities.==$Radio science, 47$==(4), RS0L12. https://doi.org/10.1029/2011RS004930http://hdl.handle.net/20.500.12816/3488Previous studies have quantified the longitude gradients in E × Bdrift associated with the four‐cell tidal structures and have confirmed that these sharp gradients exist on a day‐to‐day basis. For this paper, we incorporate the Ion Velocity Meter (IVM) sensor on the Communications/Navigation Outage Forecasting System satellite to obtain the daytime, verticalE × B drift velocities at the magnetic equator as a function of longitude, local time, and season and to theoretically calculate the F region ion densities as a function of altitude, latitude, longitude, and local time using the Global Ionosphere Plasmasphere model. We compare calculated ion densities assuming no longitude gradients in E × Bdrift velocities with calculated ion densities incorporating the IVM‐observedE × Bdrift at the boundaries of the four‐cell tidal structures in the Peruvian and the Atlantic longitude sectors. Incorporating the IVM‐observedE × B drift velocities, the ion density crests rapidly converge to the magnetic equator between 285 and 300°E geographic longitude, are absent between 300° and 305°, and move away from the magnetic equator between 305° and 340°. In essence, the steeper the longitude gradient in E × B drifts, the steeper the longitude gradient in the equatorial anomaly crest location.application/pdfenginfo:eu-repo/semantics/restrictedAccessEquatorial E×B driftsFour‐cell patternModeling ion densityForecasting systeminfo:eu-repo/semantics/articlehttp://purl.org/pe-repo/ocde/ford#1.05.01Radio sciencehttps://doi.org/10.1029/2011RS004930