Equatorial E region electric fields at the dip equator: 1. Variabilities in eastern Brazil and Peru. Issue 10 (14th October 2016)

• Record Type: Journal Article
• Authors: Moro, J.; Denardini, C. M.; Resende, L. C. A.; Chen, S. S.; Schuch, N. J.
• Is Part Of: Journal of geophysical research. Volume 121:Issue 10(2016:Oct.)
• Page Start: 10, 220
• Page End: 10, 230
• Publication Date: 2016-10-14
• Subjects: space weather -- E region electric field -- longitudinal dependence -- coherent radar; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2016JA022751
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: The equatorial electrojet (EEJ) is an intense eastward ionospheric electric current centered at about 105 km of altitude along the dip equator, set up by the global neutral wind dynamo that generates the eastward zonal ( Ey ) and the daytime vertical ( Ez ) electric fields. The temporal variation of the EEJ is believed to be well understood. However, the longitudinal variability of the Ey and Ez between 100 and 110 km is still quite scarce. Due to their importance overall phenomenology of the equatorial ionosphere, we investigate the variabilities of the Ey and Ez inferred from measurements of the Doppler frequency of Type II echoes provided by coherent backscatter radars installed in locations close to the magnetic equator in the eastern Brazil (2.33°S, 44.20°W) and Peru (11.95°S, 76.87°W). This study is based on long‐term (609 days for both systems) radar soundings collected from 2001 to 2010. The variabilities of the electric fields are studied in terms of the position of the soundings with respect to the dip equator and the magnetic declination angle. Among the results, Ey and Ez show longitudinal dependence, being higher in Peru than east Brazil. Under quiet geomagnetic activity, the mean diurnal variations of Ey ranged from 0.21 to 0.35 mV/m between 8 and 18 h (LT) in Brazil and from 0.23 mV/m to 0.45 mV/m in Peru, while the mean diurnal variations of the Ez ranges from 7.09 to 8.80 mV/m in Brazil and from 9.00 to 11.18 mV/m in Peru. Key Points: Radar data collected from 2001 to 2010 are used to infer the E region electric fields in the American sector Ey ranges from 0.21 to 0.35 mV/m in Brazil and from 0.23 to 0.45 mV/m in Peru, under quiet geomagnetic condition Ez ranges from 7.09 to 8.80 mV/m in Brazil and from 9.00 to 11.18 mV/m in Peru, under quiet geomagnetic condition