Equatorial electrojet plasma irregularities observed during late afternoon by the 30 MHz coherent scatter radar in Sao Luis, Brazil

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Author(s):	Shume, E. B. ; de Paula, E. R. ; Kherani, E. A. ; Abdu, M. A. ; Denardini, C. M. Total Authors: 5
Document type:	Journal article
Source:	JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS; v. 73, n. 11-12, p. 8-pg., 2011-07-01.
Abstract
Coherent scatter radar observations conducted right before twilight by the 30 MHz radar in Sao Luis (Brazil) during both quiet (December 10, 2001) and disturbed (December 12, 2001) conditions detected type I echoes on the shoulders of broad type II spectra (near zero Doppler velocity). Zonal electric fields inferred from the Sao Luis ionosonde have a larger magnitude during the period where these spectral observations were made than on December 18, 2001 when type I echoes were not observed during late afternoon. The IMF B-z and AE index indicate that the extended geomagnetic disturbance in the afternoon of December 12, 2001 has allowed the interaction between disturbance dynamo and prompt penetration electric fields. The latter electric field component could have exceeded the former to give rise to the observed electric fields, and make possible observation of type I echoes. (C) 2011 Elsevier Ltd. All rights reserved. (AU)

FAPESP's process:	07/08185-9 - Multi-instrument and modeling investigation of the equatorial electrojet and 150 km echo plasma irregularities in the Brazilian sector
Grantee:	Esayas Belay Shume
Support Opportunities:	Scholarships in Brazil - Post-Doctoral