Buscar
Mostrando ítems 61-70 de 569
Spread F - an old equatorial aeronomy problem finally resolved?
(European Geosciences Union (EGU), 2009-05-04)
One of the oldest scientific topics in Equatorial Aeronomy is related to Spread-F. It includes all our efforts to understand the physical mechanisms responsible for the existence of ionospheric F-region irregularities, the ...
Observations and modeling of post-midnight uplifts near the magnetic equator
(European Geosciences Union (EGU), 2006-07-03)
We report here on post-midnight uplifts near the magnetic equator. We present observational evidence from digital ionosondes in Brazil, a digisonde in Peru, and other measurements at the Jicamarca Radio Observatory that ...
Effects of disturbed electric fields in the low‐latitude and equatorial ionosphere during the 2015 St. Patrick's Day storm
(American Geophysical Union, 2016-09-02)
The 2015 St. Patrick's Day geomagnetic storm with SYM‐H value of −233 nT is an extreme space weather event in the current 24th solar cycle. In this work, we investigated the main mechanisms of the profound ionospheric ...
Variability of ionospheric parameters during geomagnetic storms at a middle latitude station: Comparisons with IRI model
(Elsevier, 2004-12)
This paper discusses the behavior of ionospheric parameters that were obtained from electron density profiles derived from ionograms recorded at El Arenosillo (37.1°N, 353.2°E; Dip = 52; Modip = 45.5) during some intense ...
Equatorial 150 km echoes and daytime F-region vertical plasma drifts in the Brazilian longitude sector
(European Geosciences Union, 2013-10-31)
Previous studies showed that conventional coherent backscatter radar measurements of the Doppler velocity of the so-called 150 km echoes can provide an alternative way of estimating ionospheric vertical plasma drifts during ...
Multimodel comparison of the ionosphere variability during the 2009 sudden stratosphere warming
(American Geophysical Union, 2016-07-18)
A comparison of different model simulations of the ionosphere variability during the 2009 sudden stratosphere warming (SSW) is presented. The focus is on the equatorial and low‐latitude ionosphere simulated by the ...
Sensitivity studies of equatorial topside electron and ion temperatures
(American Geophysical Union, 2011-06-30)
Even in the recent extremely low solar minimum the electron and ion temperatures in the low‐latitude topside ionosphere display a great deal of day‐to‐day variability. This paper explores this variability using both the ...
Lunar tidal effects in the electrodynamics of the low latitude ionosphere
(Elsevier, 2013-02-04)
The low latitude ionosphere is highly variable over a large range of temporal and spatial scales even during geomagnetically quiet periods, largely as a result of electrodynamic plasma drift effects. Several recent ...
Full profile incoherent scatter analysis at Jicamarca
(European Geosciences Union (EGU), 2008-02-04)
Incoherent scatter data from a hybrid longpulse/double-pulse experiment at Jicamarca are analyzed using a full-profile analysis similar to the one implemented by Holt et al. (1992). In this case, plasma density, electron ...
Ionospheric effects of sudden stratospheric warming during moderate-to-high solar activity: Case study of January 2013
(American Geophysical Union, 2013-09-24)
A major sudden stratospheric warming (SSW) occurred in January 2013 during moderate-to-high solar activity conditions. Observations during the winter of 2012/2013 reveal strong ionospheric disturbances associated with this ...