scholarly journals Zonal Drift Velocity of Equatorial Plasma Bubbles During Ascending Phase of 24th Solar Cycle Using All‐Sky Imager Over Kolhapur, India

2018 ◽  
Author(s):  
O. B. Gurav ◽  
A. K. Sharma ◽  
R. N. Ghodpage ◽  
D. P. Nade ◽  
G. A. Chavan ◽  
...  
Keyword(s):  
Solar Cycle ◽  
Drift Velocity ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Sky Imager

scholarly journals Seasonal-longitudinal variability of equatorial plasma bubbles

2004 ◽  
Vol 22 (9) ◽  
pp. 3089-3098 ◽  
Author(s):  
W. J. Burke ◽  
C. Y. Huang ◽  
L. C. Gentile ◽  
L. Bauer
Keyword(s):  
Solar Cycle ◽  
Phase Shifts ◽  
Linear Growth Rate ◽  
Cycle Phase ◽  
Loss Cone ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Evening Sector ◽  
Radiation Belt Electrons ◽  
Longitudinal Variability

Abstract. We compare seasonal and longitudinal distributions of more than 8300 equatorial plasma bubbles (EPBs) observed during a full solar cycle from 1989-2000 with predictions of two simple models. Both models are based on considerations of parameters that influence the linear growth rate, γRT, of the generalized Rayleigh-Taylor instability in the context of finite windows of opportunity available during the prereversal enhancement near sunset. These parameters are the strength of the equatorial magnetic field, Beq, and the angle, α, it makes with the dusk terminator line. The independence of α and Beq from the solar cycle phase justifies our comparisons. We have sorted data acquired during more than 75000 equatorial evening-sector passes of polar-orbiting Defense Meteorological Satellite Program (DMSP) satellites into 24 longitude and 12 one-month bins, each containing ~250 samples. We show that: (1) in 44 out of 48 month-longitude bins EPB rates are largest within 30 days of when α=0°; (2) unpredicted phase shifts and asymmetries appear in occurrence rates at the two times per year when α≈0°; (3) While EPB occurrence rates vary inversely with Beq, the relationships are very different in regions where Beq is increasing and decreasing with longitude. Results (2) and (3) indicate that systematic forces not considered by the two models can become important. Damping by interhemispheric winds appears to be responsible for phase shifts in maximum rates of EPB occurrence from days when α=0°. Low EPB occurrence rates found at eastern Pacific longitudes suggest that radiation belt electrons in the drift loss cone reduce γRT by enhancing E-layer Pedersen conductances. Finally, we analyze an EPB event observed during a magnetic storm at a time and place where α≈-27°, to illustrate how electric-field penetration from high latitudes can overwhelm the damping effects of weak gradients in Pedersen conductance near dusk.

First Zonal Drift Velocity Measurement of Equatorial Plasma Bubbles (EPBs) From a Geostationary Orbit Using GOLD Data

2020 ◽  
Vol 125 (9) ◽  
Author(s):  
Deepak K. Karan ◽  
Robert E. Daniell ◽  
Scott L. England ◽  
Carlos R. Martinis ◽  
Richard W. Eastes ◽  
...  
Keyword(s):  
Drift Velocity ◽  
Velocity Measurement ◽  
Geostationary Orbit ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles

Equatorial plasma bubbles observed by DMSP satellites during a full solar cycle: Toward a global climatology

2002 ◽  
Vol 107 (A12) ◽  
pp. SIA 7-1-SIA 7-10 ◽  
Author(s):  
C. Y. Huang ◽  
W. J. Burke ◽  
J. S. Machuzak ◽  
L. C. Gentile ◽  
P. J. Sultan
Keyword(s):  
Solar Cycle ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles

scholarly journals Equatorial Plasma Bubbles Developing Around Sunrise Observed by an All-Sky Imager and GNSS Network during the Storm Time

2019 ◽  
Author(s):  
Kun Wu ◽  
Jiyao Xu ◽  
Xinan Yue ◽  
Chao Xiong ◽  
Wenbin Wang ◽  
...  
Keyword(s):  
Geomagnetic Storm ◽  
Southern China ◽  
Recovery Phase ◽  
Peak Height ◽  
Development Stage ◽  
Global Navigation Satellite Systems ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Sky Imager ◽  
Gnss Network

Abstract. A large number of studies have shown that equatorial plasma bubbles (EPBs) occur mainly after sunset, and they usually drift eastward. However, in this paper, an unusual EPB event was simultaneously observed by an all-sky imager and the Global Navigation Satellite Systems (GNSS) network in southern China, during the recovery phase of geomagnetic storm happened on 6–8 November 2015. Observations from both techniques show that the EPBs appeared near dawn. Interestingly, the observational results show that the EPBs continued to develop after sunrise, and disappeared about one hour after sunrise. The development stage of EPBs lasted for at least about 3 hours. To our knowledge, this is the first time that the evolution of EPBs developing around sunrise was observed by an all-sky imager and the GNSS network. Our observation showed that the EPBs drifted westward, which was different from the usually eastward drifts of post-sunset EPBs. The simulation from TIE-GCM model suggest that the westward drift of EPBs should be related to the enhanced westward winds at storm time. Besides, break and recombination processes of EPBs were observed by the all-sky imager in the event. Associated with the development of EPBs, increasing in the ionospheric F region peak height was also observed near sunrise, and we suggest the enhance upward vertical plasma drift during geomagnetic storm plays a major role in triggering the EPBs near sunrise.

Variation in occurrence of equatorial plasma bubbles (EPBs) using All Sky Imager from low latitude station Kolhapur (16.8 °N, 74.2 °E, 10.6° dip. Lat.)

2017 ◽  
Vol 60 (11) ◽  
pp. 2452-2463 ◽  
Author(s):  
A.K. Sharma ◽  
O.B. Gurav ◽  
G.A. Chavan ◽  
H.P. Gaikwad ◽  
R.N. Ghodpage ◽  
...  
Keyword(s):  
Low Latitude ◽  
Plasma Bubbles ◽  
Latitude Station ◽  
Equatorial Plasma Bubbles ◽  
Sky Imager

Study of equatorial plasma bubbles using all sky imager and scintillation technique from Kolhapur station: a case study

2018 ◽  
Vol 363 (4) ◽  
Author(s):  
A. K. Sharma ◽  
O. B. Gurav ◽  
H. P. Gaikwad ◽  
G. A. Chavan ◽  
D. P. Nade ◽  
...  
Keyword(s):  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Sky Imager

scholarly journals The study of equatorial plasma bubble during January to April 2012 over Kolhapur (India)

2016 ◽  
Vol 59 (2) ◽  
Author(s):  
Parashram T. Patil ◽  
Rupesh N. Ghodpage ◽  
Alok K. Taori ◽  
Rohit P. Patil ◽  
Subramanian Gurubaran ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Emission Line ◽  
Drift Velocity ◽  
Velocity Variation ◽  
Plasma Bubble ◽  
Low Latitude ◽  
Plasma Bubbles ◽  
F Region ◽  
Equatorial Plasma Bubbles ◽  
Observation Period

<p>Over 53 nights of all sky airglow imager data collected during January-April 2012 from the low latitude station Kolhapur (16.68°N, 74.26°E; 10.6°N dip latitude) have been analyzed to study the F-region dynamics through the imaging of OI 630 nm emission line. The observed night airglow data were supported by the ionosonde measurements from Tirunelveli (8.7°N, 77.8°E; 0.51°N dip latitude). Well defined magnetic field aligned depletions were observed during the observation period. Out of 53 nights, 40 nights exhibited the occurrence of north-south aligned equatorial plasma bubbles. These plasma bubbles were found moving towards east with drift speed in range between 70 to 200 m s<span><sup>-1</sup></span>. We have analyzed the zonal drift velocity variation and relation of bubble occurrence with the base height of the ionosphere together with the effects of the geomagnetic Ap and solar flux F<span><sub>10.7</sub></span> cm index in its first appearance.</p>

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.

scholarly journals Semimonthly oscillation observed in the start times of equatorial plasma bubbles

2020 ◽  
Vol 38 (2) ◽  
pp. 437-443
Author(s):  
Igo Paulino ◽  
Ana Roberta Paulino ◽  
Ricardo Y. C. Cueva ◽  
Ebenezer Agyei-Yeboah ◽  
Ricardo Arlen Buriti ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Case Studies ◽  
Lunar Tide ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Sky Imager

Abstract. Using airglow data from an all-sky imager deployed at São João do Cariri (7.4∘ S, 36.5∘ W), the start times of equatorial plasma bubbles was studied in order to investigate the day-to-day variability of this phenomenon. Data from a period over 10 years were analyzed from 2000 to 2010. Semimonthly oscillations were clearly observed in the start times of plasma bubbles from OI6300 airglow images during this period of observation, and four case studies (September 2003, September–October 2005, November 2005 and January 2008) were chosen to show in detail this kind of modulation. Since the airglow measurements are not continuous in time, more than one cycle of oscillation in the start times of plasma bubbles cannot be observed from these data. Thus, data from a digisonde at São Luís (2.6∘ S, 44.2∘ W) in November 2005 were used to corroborate the results. Technical/climate issues did not allow one to observe the semimonthly oscillations simultaneously by the two instruments, but from October to November 2005 there was a predominance of this oscillation in the start times of the irregularities over Brazil. Besides, statistical analysis for the data in the whole period of observation has shown that the lunar tide, which has semimonthly variability, is likely the main forcing for the semimonthly oscillation in the start times of equatorial plasma bubbles. The presence of this oscillation can contribute to the day-to-day variability of equatorial plasma bubbles.

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