West wall structuring of equatorial plasma bubbles simulated by three-dimensional HIRB model

2015 ◽  
pp. n/a-n/a ◽  
Author(s):  
T. Yokoyama ◽  
H. Jin ◽  
H. Shinagawa
Keyword(s):  
Three Dimensional ◽  
Plasma Bubbles ◽  
West Wall ◽  
Equatorial Plasma Bubbles

scholarly journals DETECTION OF EQUATORIAL PLASMA BUBBLES USING GPS IONOSPHERIC TOMOGRAPHY OVER PENINSULAR MALAYSIA

2021 ◽  
Vol 6 (24) ◽  
pp. 152-160
Author(s):  
Siti Syukriah Khamdan ◽  
Tajul Ariffin Musa ◽  
Suhaila M. Buhari
Keyword(s):  
Three Dimensional ◽  
Peninsular Malaysia ◽  
Rate Of Change ◽  
Electron Content ◽  
Total Electron ◽  
Ionospheric Tomography ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Tomography Method

This paper presents the detection of the equatorial plasma bubbles (EPB) using the Global Positioning System (GPS) ionospheric tomography method over Peninsular Malaysia. This paper aims to investigate the capability of the GPS ionospheric tomography method in detecting the variations of the EPB over the study area. In doing so, a previous case study during post-sunset 5th April 2011 has been selected as a reference for the detection of the EPBs over the study area. It has been observed that at least three structures of the EPBs have been captured based on the rate of change total electron content (TEC) index (ROTI) from 12 UT until 19 UT. Therefore, the three-dimensional ionospheric profiles have been reconstructed over Peninsular Malaysia using the tomography method during the study period in order to capture the signature of the EPBs. In this study, the detection of the EPBs using the tomography method is based on the rate of change of electron density (ROTNe). The results from three-dimensional ionospheric tomography show only two structures of EPBs are detected during the study period. It has been observed that the ROTNe depleted up to ~-12x109el/cm. Overall, the results in this study show that the GPS ionospheric tomography capable to be utilized in detecting the variations of EPBs in support of ionospheric studies and monitoring in the Malaysian region.

scholarly journals Three-dimensional morphology of equatorial plasma bubbles deduced from measurements onboard CHAMP

2015 ◽  
Vol 33 (1) ◽  
pp. 129-135 ◽  
Author(s):  
J. Park ◽  
H. Lühr ◽  
M. Noja
Keyword(s):  
Three Dimensional ◽  
Satellite System ◽  
Low Earth Orbit ◽  
Electron Content ◽  
Total Electron ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Global Navigation Satellite ◽  
Plasma Depletion

Abstract. Total electron content (TEC) between Low-Earth-Orbit (LEO) satellites and the Global Navigation Satellite System (GNSS) satellites can be used to constrain the three-dimensional morphology of equatorial plasma bubbles (EPBs). In this study we investigate TEC measured onboard the Challenging Minisatellite Payload (CHAMP) from 2001 to 2005. We only use TEC data obtained when CHAMP passed through EPBs: that is, when in situ plasma density measurements at CHAMP altitude also show EPB signatures. The observed TEC gradient along the CHAMP track is strongest when the corresponding GNSS satellite is located equatorward and westward of CHAMP with elevation angles of about 40–60°. These elevation and azimuth angles are in agreement with the angles expected from the morphology of the plasma depletion shell proposed by Kil et al.(2009).

scholarly journals Implication of tidal forcing effects on the zonal variation of solstice equatorial plasma bubbles

2020 ◽  
Author(s):  
Loren C. Chang ◽  
Cornelius Csar Jude Hisole Salinas ◽  
Yi-Chung Chiu ◽  
McArthur Jones ◽  
Chi-Kuang Chao ◽  
...  
Keyword(s):  
Tidal Forcing ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles

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.

scholarly journals Filamentary Alfvénic structures excited at the edges of equatorial plasma bubbles

2007 ◽  
Vol 25 (10) ◽  
pp. 2159-2165 ◽  
Author(s):  
R. Pottelette ◽  
M. Malingre ◽  
J. J. Berthelier ◽  
E. Seran ◽  
M. Parrot
Keyword(s):  
Alfven Waves ◽  
Alfvén Waves ◽  
Plasma Bubble ◽  
Plasma Bubbles ◽  
Wave Measurements ◽  
Demeter Satellite ◽  
Equatorial Plasma Bubbles ◽  
Background Magnetic Field ◽  
Gravity Driven ◽  
Displacement Currents

Abstract. Recent observations performed by the French DEMETER satellite at altitudes of about 710 km suggest that the generation of equatorial plasma bubbles correlates with the presence of filamentary structures of field aligned currents carried by Alfvén waves. These localized structures are located at the bubble edges. We study the dynamics of the equatorial plasma bubbles, taking into account that their motion is dictated by gravity driven and displacement currents. Ion-polarization currents appear to be crucial for the accurate description of the evolution of plasma bubbles in the high altitude ionosphere. During their eastward/westward motion the bubbles intersect gravity driven currents flowing transversely with respect to the background magnetic field. The circulation of these currents is prohibited by large density depressions located at the bubble edges acting as perfect insulators. As a result, in these localized regions the transverse currents have to be locally closed by field aligned currents. Such a physical process generates kinetic Alfvén waves which appear to be stationary in the plasma bubble reference frame. Using a two-dimensional model and "in situ" wave measurements on board the DEMETER spacecraft, we give estimates for the magnitude of the field aligned currents and the associated Alfvén fields.

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