New global electron density observations from GPS-RO in the D- and E-Region ionosphere

2018 ◽  
Vol 171 ◽  
pp. 36-59 ◽  
Author(s):  
Dong L. Wu
Keyword(s):  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Caitano L. da Silva ◽  
Sophia D. Salazar ◽  
Christiano G. M. Brum ◽  
Pedrina Terra

AbstractOptical observations of transient luminous events and remote-sensing of the lower ionosphere with low-frequency radio waves have demonstrated that thunderstorms and lightning can have substantial impacts in the nighttime ionospheric D region. However, it remains a challenge to quantify such effects in the daytime lower ionosphere. The wealth of electron density data acquired over the years by the Arecibo Observatory incoherent scatter radar (ISR) with high vertical spatial resolution (300-m in the present study), combined with its tropical location in a region of high lightning activity, indicate a potentially transformative pathway to address this issue. Through a systematic survey, we show that daytime sudden electron density changes registered by Arecibo’s ISR during thunderstorm times are on average different than the ones happening during fair weather conditions (driven by other external factors). These changes typically correspond to electron density depletions in the D and E region. The survey also shows that these disturbances are different than the ones associated with solar flares, which tend to have longer duration and most often correspond to an increase in the local electron density content.


2011 ◽  
Vol 29 (1) ◽  
pp. 81-89 ◽  
Author(s):  
P. S. Brahmanandam ◽  
Y.-H. Chu ◽  
K.-H. Wu ◽  
H.-P. Hsia ◽  
C.-L. Su ◽  
...  

Abstract. From global soundings of ionospheric electron density made with FORMOSAT 3/COSMIC satellites for September 2006–August 2009, day-night variations in vertical and longitudinal structures of the electron densities in equatorial E- and F-regions for different seasons are investigated for the first time. The results reveal that the wavenumber-3 and wavenumber-4 patterns dominated the nighttime (22:00–04:00 LT) F-region longitudinal structures in solstice and in equinox seasons, respectively. In daytime (08:00–18:00 LT) F-region, the wavenumber-4 patterns governed the longitudinal structures in the September equinox and December solstice, and wavenumber-3 in March equinox and June solstice respectively. A comparison of the daytime and nighttime longitudinal electron density structures indicates that they are approximately 180° out of phase with each other. It is believed that this out of phase relation is very likely the result of the opposite phase relation between daytime and nighttime nonmigrating diurnal tidal winds that modulate background E-region dynamo electric field at different places, leading to the day-night change in the locations of the equatorial plasma fountains that are responsible for the formation of the F-region longitudinal structures. Further, a good consistency between the locations of the density structures in the same seasons of the different years for both daytime and nighttime epochs has been noticed indicating that the source mechanism for these structures could be the same.


2017 ◽  
Vol 122 (7) ◽  
pp. 7473-7490 ◽  
Author(s):  
Diana Loucks ◽  
Scott Palo ◽  
Marcin Pilinski ◽  
Geoff Crowley ◽  
Irfan Azeem ◽  
...  

1959 ◽  
Vol 12 (1) ◽  
pp. 42 ◽  
Author(s):  
FF Gardner

The effects of sudden ionospheric disturbances (S.LD.'s) on the complicated structure ()f ionospheric echoes obtained with moderately high sensitivity at 2�28 Mcls are described. The observations indicate that flares of classes 2 and 3 can produce high values of electron density near the base of the ionosphere. Mean electron density can exceed 1000/cm3 over the height range 60-75 km, where the greatest relative increase in ionization occurs. Nevertheless, the greater part of the S.LD. absorption of waves reflected from the E region or above still occurs above 85 km.


2021 ◽  
Vol 7 (1) ◽  
pp. 41-46
Author(s):  
Vera Nikolaeva ◽  
Evgeniy Gordeev ◽  
Denis Rogov ◽  
Aleksandr Nikolaev

The E-Region Auroral Ionosphere Model (AIM-E) was developed to determine the chemical composition and electron density in the auroral zone at E-layer heights (90–150 km). Solar and magnetic activity input parameters for AIM-E are the three-hour Ap index and the daily solar radio flux at a wavelength of 10.7 cm (index F10.7). In this paper, we compare AIM-E calculations of the electron density for the daytime with EUV radiation spectrum specified in two different ways: 1) the EUV spectrum theoretically calculated using the F10.7 index as an input parameter; 2) using TIMED satellite direct measurements of the EUV spectrum. We have corrected the EUVAC EUV radiation model to specify a photoionization source in AIM-E. Calculations of regular E-region critical frequencies show good agreement with the vertical sounding data from Russian high-latitude stations. Results we obtained make it possible to do a quick on-line assessment of the regular E layer, using the daily index F10.7 as an input parameter.


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