Global, seasonal, and local time variations of ion density structure at the low-latitude ionosphere and their relationship to the postsunset equatorial irregularity occurrences

2010 ◽  
Vol 115 (A2) ◽  
pp. n/a-n/a ◽  
Author(s):  
S.-Y. Su ◽  
M. Q. Chen ◽  
C. K. Chao ◽  
C. H. Liu
2008 ◽  
Vol 26 (4) ◽  
pp. 867-876 ◽  
Author(s):  
A. Dmitriev ◽  
H.-C. Yeh

Abstract. Ion density enhancements at the topside low-latitude ionosphere during a Bastille storm on 15–16 July 2000 and Halloween storms on 29–31 October 2003 were studied using data from ROCSAT-1/IPEI experiment. Prominent ion density enhancements demonstrate similar temporal dynamics both in the sunlit and in the nightside hemispheres. The ion density increases dramatically (up to two orders of magnitude) during the main phase of the geomagnetic storms and reaches peak values at the storm maximum. The density enhancements are mostly localized in the region of a South Atlantic Anomaly (SAA), which is characterized by very intense fluxes of energetic particles. The dynamics of near-Earth radiation was studied using SAMPEX/LEICA data on >0.6 MeV electrons and >0.8 MeV protons at around 600 km altitude. During the magnetic storms the energetic particle fluxes in the SAA region and in its vicinity increase more than three orders of magnitude. The location of increased fluxes overlaps well with the regions of ion density enhancements. Two mechanisms were considered to be responsible for the generation of storm-time ion density enhancements: prompt penetration of the interplanetary electric field and abundant ionization of the ionosphere by enhanced precipitation of energetic particles from the radiation belt.


1988 ◽  
Author(s):  
Wayne I. Klemetti ◽  
Paul A. Kossey ◽  
John E. Rasmussen ◽  
Maria Sueli Da Silveira Macedo Moura

2018 ◽  
Vol 36 (3) ◽  
pp. 809-823 ◽  
Author(s):  
Navin Parihar ◽  
Sandro Maria Radicella ◽  
Bruno Nava ◽  
Yenca Olivia Migoya-Orue ◽  
Prabhakar Tiwari ◽  
...  

Abstract. Simultaneous observations of OI 777.4 and OI 630.0 nm nightglow emissions were carried at a low-latitude station, Allahabad (25.5° N, 81.9° E; geomag. lat.  ∼  16.30° N), located near the crest of the Appleton anomaly in India during September–December 2009. This report attempts to study the F region of ionosphere using airglow-derived parameters. Using an empirical approach put forward by Makela et al. (2001), firstly, we propose a novel technique to calibrate OI 777.4 and 630.0 nm emission intensities using Constellation Observing System for Meteorology, Ionosphere, and Climate/Formosa Satellite Mission 3 (COSMIC/FORMOSAT-3) electron density profiles. Next, the electron density maximum (Nm) and its height (hmF2) of the F layer have been derived from the information of two calibrated intensities. Nocturnal variation of Nm showed the signatures of the retreat of the equatorial ionization anomaly (EIA) and the midnight temperature maximum (MTM) phenomenon that are usually observed in the equatorial and low-latitude ionosphere. Signatures of gravity waves with time periods in the range of 0.7–3.0 h were also seen in Nm and hmF2 variations. Sample Nm and hmF2 maps have also been generated to show the usefulness of this technique in studying ionospheric processes.


2016 ◽  
Vol 121 (4) ◽  
pp. 3421-3438 ◽  
Author(s):  
B. Nava ◽  
J. Rodríguez‐Zuluaga ◽  
K. Alazo‐Cuartas ◽  
A. Kashcheyev ◽  
Y. Migoya‐Orué ◽  
...  

1999 ◽  
Vol 104 (A8) ◽  
pp. 17091-17106 ◽  
Author(s):  
M. A. Biondi ◽  
S. Y. Sazykin ◽  
B. G. Fejer ◽  
J. W. Meriwether ◽  
C. G. Fesen

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