Model of the Position of the Main Ionospheric Trough in the Eccentric Dipole Coordinates

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Abstract

Based on the data of probe measurements of the electron density in the ionosphere on the CHAMP satellite from July 2000 to December 2007, an analysis of the possibility of using the coordinates of the eccentric dipole (ED) in the model for the invariant latitude of the minimum of the main ionospheric trough, Φm, was carried out. It has been established that the Φm model constructed from these data in the coordinates of the corrected geomagnetic (CGM) latitude can be used without changes in the ED coordinates, since the standard deviation of the model is less than the difference in the Φm values for these two options for specifying geomagnetic latitudes. The difference in the Φm values for these two options is minimal for the Southern Hemisphere and can be noticeable for the Northern Hemisphere, especially at the longitudes of the East Siberian Magnetic Anomaly. The dependence of Φm on local time and geomagnetic activity is the main one. The dependence of Φm on geographic longitude is relatively weak, therefore the difference in the Φm values between the CGM and ED coordinates even at the longitudes of the East Siberian Magnetic Anomaly is less than the standard deviation of the model.

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About the authors

V. N. Shubin

Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences

Author for correspondence.
Email: shubin@izmiran.ru
Russian Federation, Troitsk

V. I. Badin

Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences

Email: shubin@izmiran.ru
Russian Federation, Troitsk

M. G. Deminov

Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences

Email: shubin@izmiran.ru
Russian Federation, Troitsk

R. G. Deminov

Kazan Federal University

Email: shubin@izmiran.ru
Russian Federation, Kazan

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Supplementary files

Supplementary Files
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1. JATS XML
2. Fig. 1. Daily variations of the function Φ (t) according to equation (2) (solid line) and experimental data in CGM (dots) and ED (rhombics) coordinates. Vertical lines show the standard deviations of the experimental data in CGM coordinates.

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3. Fig. 2. Deviations of the latitude of the ionospheric failure minimum from the background ∆Φm due to the change of the geomagnetic activity index Kp* according to equation (7) (thick lines) and according to the experimental data in CGM (thin lines) and ED (dashed lines) coordinates.

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4. Fig. 3. Dependence of the function Φ (λ) on the geographic longitude λ using equations (3) and (4) (thick lines) and equation (8) in CGM and ED coordinates (thin and dashed lines, respectively).

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