Experimental estimation of effective recombination coefficients in the D-region ionosphere at high latitudes during solar eclipses by the method of partial reflections
The photochemical theory of processes in the lower ionosphere is very complicated and up to now it is not completely developed. Therefore introduction of the effective coefficients determining the total speed of several important reactions has been widely adopted when modeling the D-region of the...
| Main Author: | |
|---|---|
| Format: | Article |
| Language: | Russian |
| Published: |
Murmansk State Technical University
2017-03-01
|
| Series: | Vestnik MGTU |
| Subjects: | |
| Online Access: | http://vestnik.mstu.edu.ru/show.shtml?art=1864&pdf=1 |
| _version_ | 1811268434021842944 |
|---|---|
| author | Chernyakov S. M. |
| author_facet | Chernyakov S. M. |
| author_sort | Chernyakov S. M. |
| collection | DOAJ |
| description | The photochemical theory of processes in the lower ionosphere is very complicated and up to now it is not
completely developed. Therefore introduction of the effective coefficients determining the total speed of several
important reactions has been widely adopted when modeling the D-region of the ionosphere. Experimental
opportunities for obtaining effective recombination coefficients are rather limited. One of the methods to
estimate effective recombination coefficients uses the phenomenon of a solar eclipse. The basis of this method is
the idea of Appleton about similarity of the behavior of the linear inductive circuit and variations of the electron
concentration in the ionosphere on a fixed height in the absence of the transport processes, the change in the rate
of formation of electrons in time and the disappearance of free electrons due to recombination. By analogy with
the time constant of the electric circuit Appleton called the reaction of the ionosphere on the process of
ionization in the ionosphere as "sluggishness" with a characteristic time constant τ, which is also called the
"relaxation time" or "time constant of the ionosphere". During 11 August 1999, 1 August 2008, 11 June 2011,
20 March 2015 solar eclipses at the partial reflection facility of the observatory "Tumanny" (69.0N, 35.7E)
observations of the amplitudes of reflections of ordinary and extraordinary waves have been carried out. Using
the obtained data the two-dimensional (time, height) distribution of the electron density ne
at altitudes of the
D-region ionosphere has been calculated. This has made it possible to obtain the behavior of the electron
concentration in time at selected altitudes (temporal profiles of electron density at selected altitudes). Using the
obtained experimental profiles, the effective recombination coefficients on the heights of the D-region
ionosphere have been evaluated. Transport processes of plasma (for example, propagation of acoustic-gravity
waves, vertical motion) during eclipses have influenced on the behavior of the temporal profiles of the electron
concentration at altitudes of the D-region ionosphere. This has led to the fact that on some heights of the
D-region ionosphere determination of effective recombination coefficient became impossible |
| first_indexed | 2024-04-12T21:22:51Z |
| format | Article |
| id | doaj.art-c14d0d723dfb4dd0aa591e8dcbbc07ce |
| institution | Directory Open Access Journal |
| issn | 1560-9278 1997-4736 |
| language | Russian |
| last_indexed | 2024-04-12T21:22:51Z |
| publishDate | 2017-03-01 |
| publisher | Murmansk State Technical University |
| record_format | Article |
| series | Vestnik MGTU |
| spelling | doaj.art-c14d0d723dfb4dd0aa591e8dcbbc07ce2022-12-22T03:16:16ZrusMurmansk State Technical UniversityVestnik MGTU1560-92781997-47362017-03-01201/221923010.21443/1560-9278-2017-20-1/2-219-230Experimental estimation of effective recombination coefficients in the D-region ionosphere at high latitudes during solar eclipses by the method of partial reflectionsChernyakov S. M.0 Polar Geophysical InstituteThe photochemical theory of processes in the lower ionosphere is very complicated and up to now it is not completely developed. Therefore introduction of the effective coefficients determining the total speed of several important reactions has been widely adopted when modeling the D-region of the ionosphere. Experimental opportunities for obtaining effective recombination coefficients are rather limited. One of the methods to estimate effective recombination coefficients uses the phenomenon of a solar eclipse. The basis of this method is the idea of Appleton about similarity of the behavior of the linear inductive circuit and variations of the electron concentration in the ionosphere on a fixed height in the absence of the transport processes, the change in the rate of formation of electrons in time and the disappearance of free electrons due to recombination. By analogy with the time constant of the electric circuit Appleton called the reaction of the ionosphere on the process of ionization in the ionosphere as "sluggishness" with a characteristic time constant τ, which is also called the "relaxation time" or "time constant of the ionosphere". During 11 August 1999, 1 August 2008, 11 June 2011, 20 March 2015 solar eclipses at the partial reflection facility of the observatory "Tumanny" (69.0N, 35.7E) observations of the amplitudes of reflections of ordinary and extraordinary waves have been carried out. Using the obtained data the two-dimensional (time, height) distribution of the electron density ne at altitudes of the D-region ionosphere has been calculated. This has made it possible to obtain the behavior of the electron concentration in time at selected altitudes (temporal profiles of electron density at selected altitudes). Using the obtained experimental profiles, the effective recombination coefficients on the heights of the D-region ionosphere have been evaluated. Transport processes of plasma (for example, propagation of acoustic-gravity waves, vertical motion) during eclipses have influenced on the behavior of the temporal profiles of the electron concentration at altitudes of the D-region ionosphere. This has led to the fact that on some heights of the D-region ionosphere determination of effective recombination coefficient became impossiblehttp://vestnik.mstu.edu.ru/show.shtml?art=1864&pdf=1lower ionospheresolar eclipseeffective recombination coefficient |
| spellingShingle | Chernyakov S. M. Experimental estimation of effective recombination coefficients in the D-region ionosphere at high latitudes during solar eclipses by the method of partial reflections Vestnik MGTU lower ionosphere solar eclipse effective recombination coefficient |
| title | Experimental estimation of effective recombination coefficients in the D-region ionosphere at high latitudes during solar eclipses by the method of partial reflections |
| title_full | Experimental estimation of effective recombination coefficients in the D-region ionosphere at high latitudes during solar eclipses by the method of partial reflections |
| title_fullStr | Experimental estimation of effective recombination coefficients in the D-region ionosphere at high latitudes during solar eclipses by the method of partial reflections |
| title_full_unstemmed | Experimental estimation of effective recombination coefficients in the D-region ionosphere at high latitudes during solar eclipses by the method of partial reflections |
| title_short | Experimental estimation of effective recombination coefficients in the D-region ionosphere at high latitudes during solar eclipses by the method of partial reflections |
| title_sort | experimental estimation of effective recombination coefficients in the d region ionosphere at high latitudes during solar eclipses by the method of partial reflections |
| topic | lower ionosphere solar eclipse effective recombination coefficient |
| url | http://vestnik.mstu.edu.ru/show.shtml?art=1864&pdf=1 |
| work_keys_str_mv | AT chernyakovsm experimentalestimationofeffectiverecombinationcoefficientsinthedregionionosphereathighlatitudesduringsolareclipsesbythemethodofpartialreflections |