scholarly journals Modeling the electron temperature distribution in F2 region of high-latitude ionosphere for winter solstice conditions

2016 ◽  
Vol 2 (4) ◽  
pp. 54-62
Author(s):  
Иннокентий Голиков ◽  
Innokentiy Golikov ◽  
Артем Гололобов ◽  
Artem Gololobov ◽  
Василий Попов ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Electron Temperature ◽  
High Latitude ◽  
Temporal Distribution ◽  
Universal Time ◽  
Western Hemisphere ◽  
Three Dimensional Model ◽  
Winter Solstice ◽  
Eastern Hemisphere ◽  
High Latitude Ionosphere

Using the three-dimensional model of the high-latitude ionosphere in Euler variables, which takes into account the mismatch between geographical and geomagnetic poles, we study the behavior of the electron temperature Te in the F2 region as a function of universal time. We present results of the numerical modeling of spatial-temporal distribution of electron temperature in the F2 region for winter solstice, minimum solar activity, and moderate geomagnetic activity. The electron temperature distribution in the F2 region of the high-latitude ionosphere in winter is shown to be characterized by a Te increase in dawn and dusk sectors. Further, the mismatch between the poles leads to regular longitudinal features in Te distribution during Earth’s daily rotation. Thus, at 05 UT, when the Eastern Hemisphere is illuminated, the elevated Te zone is formed only in the dawn sector, and at 17 UT, when the Western Hemisphere is illuminated, such zones are observed in both the sectors. We discuss reasons for the formation of the regions with elevated electron temperature depending on the universal time. The results of numerical experiments are compared with similar results obtained with other models.

scholarly journals Modeling the electron temperature distribution in F2 region of high-latitude ionosphere for winter solstice conditions

2017 ◽  
Vol 2 (4) ◽  
pp. 70-80 ◽  
Author(s):  
Иннокентий Голиков ◽  
Innokentiy Golikov ◽  
Артем Гололобов ◽  
Artem Gololobov ◽  
Василий Попов ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Electron Temperature ◽  
High Latitude ◽  
Temporal Distribution ◽  
Universal Time ◽  
Western Hemisphere ◽  
Three Dimensional Model ◽  
Winter Solstice ◽  
Eastern Hemisphere ◽  
High Latitude Ionosphere

Using the three-dimensional model of the high-latitude ionosphere in Euler variables, which takes into account the mismatch between geographic and geomagnetic poles, we study the behavior of the electron temperature Te in the F2 region as a function of universal time. We present results of the numerical modeling of spatial-temporal distribution of electron temperature in the F2 region for winter solstice, minimum solar activity, and moderate geomagnetic activity. The electron temperature distribution in the F2 region of the high-latitude ionosphere in winter is shown to be characterized by a Te increase in dawn and dusk sectors. Further, the mismatch between the poles leads to regular longitudinal features in Te distribution during Earth’s daily rotation. Thus, at 05 UT, when the Eastern Hemisphere is illuminated, the elevated Te zone is formed only in the dawn sector, and at 17 UT, when the Western Hemisphere is illuminated such zones are observed in both the sectors. We discuss reasons for the formation of the regions with elevated electron temperature depending on the universal time. Results of numerical experiments are compared with similar results obtained with other models.

scholarly journals The dayside high-latitude trough under quiet geomagnetic conditions: Radio tomography and the CTIP model

2005 ◽  
Vol 23 (4) ◽  
pp. 1199-1206 ◽  
Author(s):  
S. E. Pryse ◽  
K. L. Dewis ◽  
R. L. Balthazor ◽  
H. R. Middleton ◽  
M. H. Denton
Keyword(s):  
High Latitude ◽  
Large Scale ◽  
Physical Models ◽  
Physical Processes ◽  
Winter Solstice ◽  
Ion Density ◽  
Plasma Production ◽  
Radio Tomography ◽  
High Latitude Ionosphere

Abstract. The dayside high-latitude trough is a persistent feature of the post-noon wintertime auroral ionosphere. Radio tomography observations have been used to map its location and latitudinal structure under quiet geomagnetic conditions (Kp≤2) near winter solstice. The trough is also a clear feature in the ion density distribution of the Coupled Thermosphere-Ionosphere-Plasmasphere model (CTIP) under similar geophysical conditions. Comparisons of the measured and modelled distributions show that the plasma production equatorward of the trough is mainly controlled by solar radiation, but there are also other processes maintaining the equatorward trough-wall that are open to debate. The poleward trough-wall is produced by particle precipitation, but the densities are significantly overestimated by the model. At the trough minimum the observed densities are consistent with low nighttime densities convecting sunward to displace the higher daytime densities, but this is not borne out by the CTIP model. The study shows the potential of combining radio tomography and modelling to interpret the balance of the physical processes responsible for large-scale structuring of the high-latitude ionosphere, and highlights the role of tomographic imaging in validating and developing physical models.

scholarly journals The formation of electron-temperature hot spots in the main ionospheric trough by the internal processes

1996 ◽  
Vol 14 (8) ◽  
pp. 816-825 ◽  
Author(s):  
G. I. Mingaleva ◽  
V. S. Mingalev
Keyword(s):  
Electron Temperature ◽  
Electron Density ◽  
High Latitude ◽  
Hot Spots ◽  
Electron Gas ◽  
Three Dimensional ◽  
Neutral Atmosphere ◽  
F Region ◽  
Main Ionospheric Trough ◽  
High Latitude Ionosphere

Abstract. A mathematical model of the convecting high-latitude ionosphere is described which produces three-dimensional distributions of electron density, positive-ion velocity and electron and ion temperatures at the F-layer altitudes. The results of simulation of the behaviour of the high-latitude ionosphere, in particular, the heat regime of the F-layer, are presented and analysed. From our study, it was found that electron-temperature hot spots in the main ionospheric trough can arise owing to internal ionospheric processes, and not due to effects of any external causes. Three conditions, to be satisfied simultaneously, are necessary for the formation of the considered electron-temperature hot spots: first, low values of electron density; second, solar illumination of the upper F region and darkness of the lower F region; third, low values of neutral-component densities. These conditions are valid in the main ionospheric trough near the terminator on the nightside when the density of the neutral atmosphere is not high. The physical processes which lead to the formation of the electron-temperature hot spots are the heat transfer from the upper into the lower F region, the reduced heat capacity of electron gas and the weakened cooling of electron gas due to inelastic collisions with neutral atoms and molecules. Also investigated is the influence of seasonal and solar-activity variations on the efficiency of the identified mechanism responsible for the formation of the electron temperature peaks in the main ionospheric trough by the internal processes.

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