Physics of auroral phenomena : proceedings of the 36th Annual seminar, Apatity, 26 February – 01 March, 2013 / [ed. board: A. G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2013. - 215 с. : ил., табл.

A model s‘ud>' ° f ,he influence o f artificial heating o f the nighttime high-latitude ionosphere on the spatial distributions o f the ionospheric parameters f the ionospheric heater. Inside this hot spot, the electron temperature increases for some thousands o f degrees, loreover, the electron concentration cavity is formed on the night side in the vicinity of the location of the inospheric heater (Figs. 2 and 3). Inside this cavity, powerful HF waves lead to a decrease of about 40% in the ectron concentration at the level o f the F2-layer peak. / / О — s f / у - Д А , X . L . r —vL 'C '\ W m m m ! V A \ \ / J f ■ \* 1 4 \ ] l (I \V‘ X4 - Щ т Ш ш x /л-л Л с г '1 - ’И1' / w чч i \ <r>/ 1 U ■ *юг Fig. 2 Simulated distributions of the electron concentration (in units o f 1011 m'3) at level of 320 km obtained under natural conditions without artificial heating (top panel) and obtained on condition that the ionospheric heater has been operated during the period o f five minutes (bottom panel). The electron concentration cavity, created artificially, is indicated by black pointer at the bottom panel. ... ) ) ) ( X / ' / ----- §33= 45 47 49 51 53 55 67 59 81 83 «5 87 09 71 73 75 77 79 81 magnetic latitude, deg X — у Я У У / ' Л 5 f / 's 's ' A '' ' ' / / s \ / У Sggggs=---— ™45 47 49 51 53 55 57 58 «1 83 83 67 M 71 73 75 77 7» 81 magnetic latitude, deg Fig. 3 Simulated distributions of the electron concentration (in units of 10n m'3) in the magnetic meridian plane, lying across the ionospheric heater, obtained under natural conditions without artificial heating (top panel) and obtained on condition that the ionospheric heater has been operated during the period of five minutes (bottom panel). The location of the Tromso heater is indicated by the black pointer at the bottom panel. The simulation results indicate that the cross sections of the artificial electron temperature hot spot and artificial electron concentration cavity have dimensions of about 100-150 km in the horizontal directions at the levels of the F layer (Figs. 2 and 3). These dimensions are much less than the horizontal sizes of the natural large-scale inhomogeneous structures characteristic for the high-latitude ionosphere, in particular, of the natural electron temperature hot spots and main ionospheric trough. It is seen that the horizontal section of the region, disturbed artificially, at F-layer altitudes is more than the horizontal section of the region, illuminated by the heater, whose diameter is approximately 88 km at 300 km altitude. This peculiarity is conditioned by the convection of the ionospheric plasma. The dimension of the artificial electron concentration cavity in the direction of the magnetic field line is about some hundreds o f kilometers (Fig. 3). C o n c lu sio n The mathematical model of the high-latitude ionosphere, developed earlier in the Polar Geophysical Institute, was utilized to calculate three-dimensional distributions of ionospheric parameters in the high-latitude F layer, modified 161