Laboratory of Radiophysical Researches of the Lower Ionosphere

Principal scientific task

Study of the structure and wave processes in the lower ionosphere by the method of partial reflections

Major fields of research

• Determination of electron concentration in the ionospheric D-region. Development of photochemical model of the ionospheric D-region at high latitudes.
• Investigation of wave processes, the structure and composition of the polar mesosphere and lower thermosphere.
• Study of the physics of the polar mesospheric echo.
• Development of the techniques for determination of lower ionosphere parameters.

Experimental equipment

• a transmitter designed on the basis of a standard VYAZ-M2 HF transmitter by transferring HF track to pulse-lamps and making a supply rectifier with enhanced output voltage
• a receiver of direct amplification with a pass band of 40 kHz
• a transmitter-receiver phased array consisting of 38 pairs of crossed dipoles
• an automated system of data collecting with a temporal resolution of 1 s
• a facility for measuring wind velocity and drift velocity of irregularities in the lower ionosphere, consisting of three cross-vibrators operating in the regime of receiving only ordinary component of the scattered signal
• a riometer adjusted at 32 MHz

Principal results of the lab

• From radiolocating researches, for the first time, an intense mesospheric echo of medium radio waves and its presence whole-year are revealed.
• It is experimentally shown that during sudden ionospheric disturbances, the losses of electrons are proportional to the ion production function.
• The theory of incoherent scattering and partial reflections has been advanced.
• The model for calculations of the ion production rates in the polar ionosphere at the heights of 50-100 km is developed.
• For the first time, the concentration of atomic oxygen at heights lower than 75 km during an intense proton event has been estimated.
• Using the data obtained by the method of partial reflections and calculation results with applying the theoretical model of the lower ionosphere, the behavior of the electron content and ion composition during powerful solar flares is determined.

Scientific problems under study

• Investigation of the effects of solar perturbances and earthquakes on the processes in the polar lower ionosphere by the method of partial reflections.
• Experimental and theoretical studies of the structure of the lower ionosphere and polar mesospheric echo.
• Photochemical model of the D-region of the polar ionosphere.

Scientific relations

For several years the lab has been a participant of the Program №16 of fundamental researches established by the Presidium of RAS “Environmental and climatic changes”, subdivision “Solar activity and physical processes in the Sun-Earth system”, and Federal principal program “Creation and development of geophysical system for monitoring of geophysical conditions over the territory of RF for 2008-2015”. Within these two programs, joint works with the Institute of solar-terrestrial physics of the Siberian Branch of RAS on the agreement “Development of the methods for monitoring wave processes of various origin at the heights of the mesosphere – lower ionosphere have been conducting.

The lab cooperates with the Research Institute of radio physics (RIRP, Nizhni Novgorod) within the contracts “Investigation of latitudinal distinctions in the electron density and turbulence at the heights of the ionospheric D-region by the method of partial reflections” and “Investigation of the ionospheric D-region by the methods of partial reflections and radio wave scattering on artificial periodic irregularities” (RFBR projects № 01-05-64504 and № 05-05-64304).

The lab is a participant of the international project “Disturbances of the polar atmosphere and ionosphere” of PGI and the Institute of space physics of the Swedish academy of sciences (Kiruna, Sweden).

Plans for the nearest future

• Upgrading of the physical-chemical model of the lower ionosphere
• Improvement of the equipment and algorithms for the ionosphere researches by the partial reflection method

Principal publications

Brunelli B.E., Kochkin M.I., Presnyakov I.N., Tereshchenko E.D., Tereshchenko V. D. The method of incoherent scattering of radiowaves. L.: Nauka, 1979. – 188 p

Suni A.L., Tereshchenko V.D., Tereshchenko E.D., Khudukon B. Z. Incoherent scattering of radiowaves in the high-latitude ionosphere. – Apatity: Kola Science Center AS USSR, 1989. – P. 184.

Belikovich V.V., Vyakhirev V.D., Kalinin Е.Е., Tereshchenko V.D., Ogloblina O.F., Tereshchenko V.A. Research of the D region of the ionosphere by the method of partial reflections at middle latitudes and in the auroral zone // Proc. of Higher School. Radiophysics. – 2003. – V. 46, N 3. – P. 181-191.

Tereshchenko V.D., Vasil ` ev E.B., Ogloblina O.F., Tereshchenko V.A., Chernyakov S.M. Studies of the structure and dynamics of the D region of the polar ionosphere during solar flares in April 2004 // Geomagnetism and Aeronomy International. V. 6, GI 2004, doi: 10.1029/2005 GI000107. 2006.

Tereshchenko V.D., Vasiljev E.B., Ogloblina O.F., Tereshchenko V.A. Behavior of the polar lower ionosphere during solar flares in January, 2005 according to the method of partial reflections // Geomagnetism and Aeronomy.-2006.-V. 46, N 5.-P. 698-703.

Belikovich V.V., Vyakhirev V.D., Kalinin Е.Е., Tereshchenko V.D., Ogloblina O.F., Tereshchenko V.A. Research of the D region of the ionosphere by the method of partial reflections in the spring of 2004 at middle and high latitudes // Geomagnetism and Aeronomy.-2006.-V. 46, N 2.-P. 229-233.

Tereshchenko V.D., Osepian A.P., Tereshchenko V.A. Modelling of behavior of the D region of the polar ionosphere during the solar flare on April, 5, 2004 // Geomagnetism and Aeronomy.-2007.-V. 47, N 4.-P. 528-533.

Belikovich V.V., Vyakhirev V.D., Kalinin Е.Е., Tereshchenko V.D., Chernyakov S.M., Tereshchenko V.A. Response of the ionosphere on the partial solar eclipse 29.03.2006 on observations in N.Novgorod and Murmansk // Geomagnetism and Aeronomy.-2008.-V. 48, N 1.-P. 103-108.

Osepian A.P., V.D. Tereshchenko, P.A. Dalin, S. Kirkwood. The role of atomic oxygen concentration in the ionization balance of the lower ionosphere during solar proton events // Annales Geophysicae. – 2008. – V. 26.-P. 131-143.

Tereshchenko V.D., Ogloblina O.F., Osepian A.P., Tereshchenko V. A. Response of the lower polar ionosphere on solar flares // Changes of natural environment and climate, natural and possible consequent human-induced catastrophes. V. 8. Solar activity and physical processes in the Sun-Earth system. – M.: ISTP SB RAS, IPE RAS, 2008. – P. 118-123.

Smirnova N.V., А.N. Lyakhov, Yu.I.Zetser, A.P. Osepian, Ch.-I. Meng, R. Smith, G. Nilsen. The role of precipitating protons in ionization of the polar ionosphere // Space Researches. – 2004. – V. 42, N3. – P.219-227.

Stebel K., U. Blum, K.-H. Fricke, S. Kirkwood, N. Mitchell, A. Osepian. Joint radar/lidar observations of possible aerosol layers in the winter mesosphere // J. Atmos. Solar-Terr. Phys. – 2004. – V.66, N 11. – P. 957-970.

Osepian A., S. Kirkwood. Cosmic radio-noise absorption bursts caused by solar wind shocks // Annales Geophys. – 2004. – V.22, N 8. – P.2973-2987.

Belova E., S. Kirkwood, J. Ekeberg, A. Osepian, I. Hдggstrцm, H. Nilsson, M. Rietveld. The dynamical background of Polar Mesosphere Winter Echoes from simultaneous EISCAT and ESRAD observations // Annales Geophys. – 2005. – V.23, N 8. – P.1239-1247.

Smirnova N.V., Ogloblina O.F., Vlaskov V.A. Modelling of the lower ionosphere // Pageoph. – 1988. – V. 127, N2/3. – P. 353-379.

Osepian A.P., Smirnova N.V. Modelling of absorption events // J. Atmos. Solar-Terr. Phys. – 1996. – V. 59, N 8. – P. 951-960.