Response of the topside ionosphere over Arecibo to a moderate geomagnetic storm

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Author(s):	Garzon, Diana Prado ; Brum, Christiano G. M. ; Echer, Ezequiel ; Aponte, Nestor ; Sulzer, Michael P. ; Gonzalez, Sixto A. ; Kerr, Robert B. ; Waldrop, Lara Total Authors: 8
Document type:	Journal article
Source:	JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS; v. 73, n. 11-12, p. 7-pg., 2011-07-01.
Abstract
We analyze the data obtained using the Arecibo incoherent scatter radar to examine the response of the topside ionosphere to a moderate geomagnetic storm that occurred during the period March 7-11, 2008. During this time period a magnetic storm with a non-monotonic main phase decrease in the Dst index occurred. The recovery phase also exhibited a secondary Dst decrease. During the initial phase of the storm, Te and Ti increased coincident with the arrival of the solar wind. The main phase registered an increase in proton concentration proportional to Ne while temperatures reached the lowest values. Variations in O+ concentration were not significant but a reduction in helium fraction was observed. Soon after the peak of the storm, the transition height between the topside ionosphere and the protonosphere, where H+ ions dominate composition, was lower than would be expected during quiet conditions and this behavior lasted for approximately 12 h. (C) 2011 Elsevier Ltd. All rights reserved. (AU)