Title
Concurrent observations at the magnetic equator of small-scale irregularities and large-scale depletions associated with equatorial spread F
Date Issued
01 December 2015
Access level
open access
Resource Type
journal article
Author(s)
Hickey D.A.
Martinis C.R.
Rodrigues F.S.
Varney R.H.
Nicolls M.J.
Strømme A.
Arratia J.F.
Jicamarca Radio Observatory
Publisher(s)
Blackwell Publishing Ltd
Abstract
In 2014 an all-sky imager (ASI) and an Advanced Modular Incoherent Scatter Radar consisting of 14 panels (AMISR-14) system were installed at the Jicamarca Radio Observatory. The ASI measures airglow depletions associated with large-scale equatorial spread F irregularities (10-500 km), while AMISR-14 detects small-scale irregularities (0.34 m). This study presents simultaneous observations of equatorial spread F (ESF) irregularities at 50-200 km scale sizes using the all-sky imager, at 3 m scale sizes using the JULIA (Jicamarca Unattended Long-term Investigations of the Ionosphere and Atmosphere) radar, and at 0.34 m scales using the AMISR-14 radar. We compare data from the three instruments on the night of 20-21 August 2014 by locating the radar scattering volume in the optical images. During this night no topside plumes were observed, and we only compare with bottomside ESF. AMISR-14 had five beams perpendicular to the magnetic field covering ~200 km in the east-west direction at 250 km altitude. Comparing the radar data with zenith ASI measurements, we found that most of the echoes occur on the western wall of the depletions with fewer echoes observed the eastern wall and center, contrary to previous comparisons of topside plumes that showed most of the echoes in the center of depleted regions. We attribute these differences to the occurrence of irregularities produced at submeter scales by the lower hybrid drift instability. Comparisons of the ASI observations with JULIA images show similar results to those found in the AMISR-14 and ASI comparison.
Start page
10883
End page
10896
Volume
120
Issue
12
Language
English
OCDE Knowledge area
Meteorología y ciencias atmosféricas
Scopus EID
2-s2.0-84957844517
Source
Journal of Geophysical Research: Space Physics
ISSN of the container
21699380
Sponsor(s)
This work was supported by grants from the Office of Naval Research for DURIP instrumentation at Jicamarca Observatory and data analysis funds from the NSF''s Programs for Aeronomy 1123222 and 0925893. D.H. acknowledges NSF grant IIA-1139862, which allowed student travel to Jicamarca. Work at UT Dallas was supported by AFOSR (FA9550-13-1-0095) and NSF (AGS-1303658). Work at SRI International was supported by NSF Cooperative Agreement AGS-1133009. Work at Anna G. Mendez University System was supported by NSF (AGS-1039593). JULIA measurements used in this study were made available by the Jicamarca Radio Observatory, a facility of the Instituto Geofisico del Peru operated with support from the NSF AGS-1433968 through Cornell University. JULIA measurements and contact information can be found at http://jro.igp.gob.pe. Information about the AMISR-14 measurements presented in this study can be obtained by contacting Fabiano Rodrigues (fabiano@utdallas.edu).
Sources of information: Directorio de Producción Científica Scopus