scholarly journals Equatorial plasma bubbles: Variations of occurrence and spatial scale in local time, longitude, season, and solar activity

2017 ◽  
Vol 122 (5) ◽  
pp. 5743-5755 ◽  
Author(s):  
Jonathon Smith ◽  
Rod A. Heelis
Keyword(s):  
Solar Activity ◽  
Spatial Scale ◽  
Local Time ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles

On the solar activity dependence of midnight equatorial plasma bubbles during June solstice periods

2021 ◽  
Vol 5 (4) ◽  
pp. 1-9
Author(s):  
K. K. Ajith ◽  
◽  
S. Tulasi Ram ◽  
GuoZhu Li ◽  
M. Yamamoto ◽  
...  
Keyword(s):  
Solar Activity ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
June Solstice ◽  
Activity Dependence

scholarly journals Occurrence climatology of equatorial plasma bubbles derived using FormoSat-3 ∕ COSMIC GPS radio occultation data

2020 ◽  
Vol 38 (3) ◽  
pp. 611-623
Author(s):  
Ankur Kepkar ◽  
Christina Arras ◽  
Jens Wickert ◽  
Harald Schuh ◽  
Mahdi Alizadeh ◽  
...  
Keyword(s):  
Solar Activity ◽  
Radio Occultation ◽  
Signal To Noise Ratio ◽  
Strong Dependence ◽  
Occurrence Rate ◽  
High Solar Activity ◽  
Altitudinal Distribution ◽  
Plasma Bubbles ◽  
Ionosphere Plasma ◽  
Equatorial Plasma Bubbles

Abstract. The Global Positioning System – Radio Occultation (GPS-RO) observations from FormoSat-3 ∕ COSMIC are used to comprehend the global distribution of equatorial plasma bubbles which are characterized by depletion regions of plasma in the F region of the ionosphere. Plasma bubbles that cause intense scintillation of the radio signals are identified based on the S4 index derived from the 1 Hz raw signal-to-noise ratio measurements between 2007 and 2017. The analyses revealed that bubbles influenced by background plasma density occurred along the geomagnetic equator and had an occurrence peak around the dip equator during high solar activity. The peak shifted between the African and American sectors, depending on different solar conditions. Plasma bubbles usually developed around 19:00 local time (LT), with maximum occurrence around 21:00 LT during solar maximum and ∼22:00 LT during solar minimum. The occurrence of bubbles showed a strong dependence on longitudes, seasons, and solar cycle with the peak occurrence rate in the African sector around the March equinox during high solar activity, which is consistent with previous studies. The GPS-RO technique allows an extended analysis of the altitudinal distribution of global equatorial plasma bubbles obtained from high vertical resolution profiles, thus making it a convenient tool which could be further used with other techniques to provide a comprehensive view of such ionospheric irregularities.

scholarly journals Plasma bubble zonal velocity variations with solar activity in the Brazilian region

2004 ◽  
Vol 22 (9) ◽  
pp. 3123-3128 ◽  
Author(s):  
P. M. Terra ◽  
J. H. A. Sobral ◽  
M. A. Abdu ◽  
J. R. Souza ◽  
H. Takahashi
Keyword(s):  
Solar Activity ◽  
Local Time ◽  
Time Frame ◽  
Maximum Activity ◽  
Bubble Velocity ◽  
Activity Period ◽  
Plasma Bubble ◽  
Plasma Bubbles ◽  
Velocity Magnitude ◽  
Zonal Velocity

Abstract. A statistical study of the zonal drift velocities of the ionospheric plasma bubbles using experimental airglow data acquired at the low-latitude station Cachoeira Paulista (Geogr. 22.5° S, 45° W, dip angle 28° S) during the period of October to March, between 1980 and 1994, is presented here. This study is based on 109 nights of zonal plasma bubble velocity estimations as determined from bubbles signatures on the OI 630nm scanning photometer airglow data. The zonal velocity magnitudes of the plasma bubbles are investigated with respect to solar activity and local time. It is verified that these velocities tend to increase with the solar EUV flux, using the solar 10.7-cm radio flux as a proxy (F10.7). These velocities are seen to be larger during the solar maximum activity period than in the solar minimum period. As to the local time variation, they are seen to peak before midnight, in the 20:30-22:30 LT time frame, depending on the season. The all-data plot based on the 109 nights of airglow experiments shows that the plasma bubble mean zonal drift velocities tend to decrease with local time, but they peak at 22:25 LT, where the velocity magnitude reaches 127.4ms-1. The zonal drift variations with local time and solar flux are shown in Figs. 1 and 2, respectively.

scholarly journals Occurrence climatology of equatorial plasma bubbles (EPBs) using optical observations over Kolhapur, India during solar cycle-24

2020 ◽  
Vol 63 (6) ◽  
Author(s):  
Onkar Gurav ◽  
Rupesh Ghodpage ◽  
Parashram Patil ◽  
Sripathi Samireddipalle ◽  
Ashok Sharma ◽  
...  
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Optical Observations ◽  
Occurrence Rate ◽  
High Solar Activity ◽  
Storm Events ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Solar Cycle 24 ◽  
Cycle 24

In this paper, the occurrence characteristics of the equatorial plasma bubbles (EPBs) using OI 630.0 nm all sky imager (ASI) night airglow observations over Kolhapur (16.8o N, 74.2o E, 10.6o dip. Lat.) during the solar cycle-24 are presented. These results are discussed in terms of season, solar and magnetic activity during years 2011 to 2018. The ASI observations were only carried out during January to May and October to December months due to unfavorable weather conditions. The results suggest that while January, February and December are the only months where EPBs were found to occur over Kolhapur in any year, but the percentage of occurrence of EPBs during these months suggests their low occurrence rate during solar minimum. A total of 683 nights of observations were carried, out of which, 93 nights are found to be magnetically disturbed nights having Ap>18. In addition, the ASI observations are also correlated with Pre-Reversal Enhancement of the vertical drift of the evening sector at Tirunelveli on few storm events for comparison. The important findings of this study are: 1) increase in the occurrence of EPBs with respect to the solar activity; 2) suppression of EPBs on 71 disturbed nights, while enhancement of EPBs on 22 nights under magnetic disturbance; 3) EPBs occurrence during equinox months is found to be higher than winter months during ascending phase of solar cycle-24.; and, 4) EPBs are mostly observed in the pre-midnight sector in the high solar activity (HSA) period, while they are seen in the post-midnight to dawn sector during the low solar activity (LSA) period. We also noticed non-occurrence of EPBs during equinox month in the year 2018 which seems to be peculiar and needs further investigations.

Relevant aspects of equatorial plasma bubbles under different solar activity conditions

2001 ◽  
Vol 27 (6-7) ◽  
pp. 1213-1218 ◽  
Author(s):  
A.A. Pimenta ◽  
P.R. Fagundes ◽  
J.A. Bittencourt ◽  
Y. Sahai
Keyword(s):  
Solar Activity ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles
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