Artificial periodic irregularities, wave phenomena in the lower ionosphere, and the sporadic E layer

2010 ◽  
Vol 53 (2) ◽  
pp. 69-81 ◽  
Author(s):  
N. V. Bakhmet’eva ◽  
V. V. Belikovich ◽  
M. N. Egereva ◽  
A. V. Tolmacheva
2018 ◽  
Author(s):  
Bingkun Yu ◽  
Xianghui Xue ◽  
Chengling Kuo ◽  
Gaopeng Lu ◽  
Xiankang Dou ◽  
...  

Abstract. We present a multi-instrument experiment to study the effects of tropospheric thunderstorms on the mesopause region and the lower ionosphere. The sodium (Na) lidar observation and the ionospheric observation by two digital ionospheric sounders are used to study the variation of the neutral metal atoms and metallic ions above thunderstorms. The enhanced ionospheric sporadic E layer with a downward tidal phase is observed followed by a subsequent intensification of neutral Na density with an increase of 600 cm−3 in the mesosphere. In addition, the Na neutral chemistry and ion-molecule chemistry reactions are considered in the Na chemistry model to simulate the dynamical and chemical coupling processes in the mesosphere and ionosphere above thunderstorms. The enhanced Na layer in the simulation using the ionospheric observation as input is in agreement with the Na lidar observation. We find that the intensification of metallic layered phenomena above thunderstorms is associated with the atmospheric tides, as a result of the troposphere-mesosphere-ionosphere coupling.


Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1093
Author(s):  
Kamil M. Yusupov ◽  
Nataliya V. Bakhmetieva

In this study, we analyzed a large number of vertical sounding ionograms, obtained by the mid-latitude Cyclone ionosonde (55.85° N; 48.8° E) of Kazan (Volga Region) Federal University, which operates in a rapid-run mode of ionograms (1 ionogram per minute). Ionograms with a sporadic E layer type c, which have an unusual double cusp on the trace from the sporadic layer, were found among them. We attempted to simulate this unusual double cusp trace shape. Model calculations were performed to clarify the reasons for the appearance of the double cusp and to determine the shape of the lower part of the E and Es layers. The simulation was performed by fitting the profile of the electron densities of the E and Es layers, calculating the virtual reflection heights based on the refractive index using the Appleton-Hartree formula, and comparing them with the virtual heights of the layers on the ionogram. An estimate of the half-thickness of the lower part of the Es-layer was obtained. The possible reasons for the appearance of a trace with a double cusp of the Es layer are discussed. We assumed that the possible reasons for this phenomenon were the stratification of the E layer, and the interaction between the E and F layers in the form of descending or intermediate layers and atmospheric wave propagation. As an illustration of these phenomena, examples of an intermediate (descending) sporadic E layer and stratification of the E region and the Es layer are given according to observations of the lower ionosphere. These examples were obtained through the resonant scattering of probe radio waves by artificial periodic irregularities (API technique) of the ionospheric plasma, performed on the SURA mid-latitude heating facility (56.1° N; 46.1° E). The scattering of probe radio waves on the APIs generated by the heating facility made it possible to study various phenomena in the Earth’s ionosphere.


2017 ◽  
Vol 122 (12) ◽  
pp. 12,517-12,533 ◽  
Author(s):  
J. Moro ◽  
L. C. A. Resende ◽  
C. M. Denardini ◽  
J. Xu ◽  
I. S. Batista ◽  
...  

1968 ◽  
Vol 11 (9) ◽  
pp. 756-759
Author(s):  
Yu. A. Ignat'ev

2008 ◽  
Vol 26 (9) ◽  
pp. 2929-2936 ◽  
Author(s):  
K.-I. Oyama ◽  
K. Hibino ◽  
T. Abe ◽  
R. Pfaff ◽  
T. Yokoyama ◽  
...  

Abstract. The electron temperature (Te), electron density (Ne), and two components of the electric field were measured from the height of 90 km to 150 km by one of the sounding rockets launched during the SEEK-2 campaign. The rocket went through sporadic E layer (Es) at the height of 102 km–109 km during ascent and 99 km–108 km during decent, respectively. The energy density of thermal electrons calculated from Ne and Te shows the broad maximum in the height range of 100–110 km, and it decreases towards the lower and higher altitudes, which implies that a heat source exists in the height region of 100 km–110 km. A 3-D picture of Es, that was drawn by using Te, Ne, and the electric field data, corresponded to the computer simulation; the main structure of Es is projected to a higher altitude along the magnetic line of force, thus producing irregular structures of Te, Ne and electric field in higher altitude.


2008 ◽  
Vol 26 (3) ◽  
pp. 533-541 ◽  
Author(s):  
K.-I. Oyama ◽  
T. Abe ◽  
H. Mori ◽  
J. Y. Liu

Abstract. Electron temperature in the sporadic E layer was measured with a glass-sealed Langmuir probe at a mid-latitude station in Japan in the framework of the SEEK (Sporadic E Experiment over Kyushu)-2 campaign which was conducted in August 2002. Important findings are two fold: (1) electron temperature and electron density vary in the opposite sense in the height range of 100–108 km, and electron temperature in the Es layer is lower than that of ambient plasma, (2) electron temperature in these height ranges is higher than the possible range of neutral temperature. These findings strongly suggest that the heat source that elevates electron temperature much higher than possible neutral temperature exists at around 100 km, and/or that the physical parameter values, which are used in the present theory to calculate electron temperature, are not proper.


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