Publication Date:
2020-12-14
Description:
An unusual nighttime impulsive electron density enhancement was observed on 6
March 2010 over a wide region of South America, below the southern crest of the equatorial anomaly, under low solar activity and quiet geomagnetic conditions. The phenomenon was observed almost simultaneously by the F2 layer critical frequency ( foF2) recorded at
three ionospheric stations which are widely distributed in space, namely Cachoeira Paulista (22.4°S, 44.6°W, magnetic latitude 13.4°S), São José dos Campos (23.2°S, 45.9°W,
magnetic latitude 14.1°S), Brazil, and Tucumán (26.9°S, 65.4°W, magnetic latitude
16.8°S), Argentina. Although in a more restricted region over Tucumán, the phenomenon was also observed by the total electron content (TEC) maps computed by usingmeasurements from 12 GPS receivers. The investigated phenomenon is very particular because besides being of brief duration, it is characterized by a pronounced compression of the ionosphere. This compression was clearly visible both by the virtual height of the base of the F region (h′F) recorded at the aforementioned ionospheric stations, and by both the vertical electron density profiles and the slab thickness computed over Tucumán. Consequently, neither an
enhanced fountain effect nor plasma diffusion from the plasmasphere can be considered as the single cause of this unusual event. A thorough analysis of isoheight and isofrequency ionosonde plots suggest that traveling ionospheric disturbances (TIDs) caused by gravity
wave (GW) propagation could have likely played a significant role in causing the
phenomenon.
Description:
Published
Description:
A12314
Description:
1.6. Osservazioni di geomagnetismo
Description:
1.7. Osservazioni di alta e media atmosfera
Description:
3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale
Description:
5.4. Banche dati di geomagnetismo, aeronomia, clima e ambiente
Description:
JCR Journal
Description:
open
Keywords:
equatorial ionosphere
;
travelling ionospheric disturbance
;
ionosphere-atmosphere interactions
;
instrument and techniques
;
01. Atmosphere::01.02. Ionosphere::01.02.99. General or miscellaneous
;
01. Atmosphere::01.02. Ionosphere::01.02.02. Dynamics
;
01. Atmosphere::01.02. Ionosphere::01.02.04. Plasma Physics
;
01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation
;
01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques
;
05. General::05.07. Space and Planetary sciences::05.07.99. General or miscellaneous
;
05. General::05.07. Space and Planetary sciences::05.07.01. Solar-terrestrial interaction
;
05. General::05.07. Space and Planetary sciences::05.07.02. Space weather
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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