Solar-Terrestrial Physics, 2016. Vol. 3. Iss. 2, pp. 25–33, DOI: 10.12737/stp-3220175. © INFRA-M Academic Publishing House Original Russian version D.G. Baishev, S.N. Samsonov, A.V. Moiseev, R.N. Boroyev, A.E. Stepanov, V.I. Kozlov, A.A. Korsakov, A.A. Toropov et al., published in Solnechno-Zemnaya Fizika, 2017, vol. 3, iss. 2, pp. 27–35, DOI: 10.12737/22607 MONITORING AND INVESTIGATING SPACE WEATHER EFFECTS WITH MERIDIONAL CHAIN OF INSTRUMENTS IN YAKUTIA: A BRIEF OVERVIEW D.G. Baishev V.I. Kozlov Yu.G. Shafer Institute of Cosmophysical Research Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy SB RAS, and Aeronomy SB RAS, Yakutsk, Russia, [email protected] Yakutsk, Russia S.N. Samsonov A.A. Korsakov Yu.G. Shafer Institute of Cosmophysical Research Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy SB RAS, and Aeronomy SB RAS, Yakutsk, Russia Yakutsk, Russia A.V. Moiseev A.A. Toropov Yu.G. Shafer Institute of Cosmophysical Research Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy SB RAS, and Aeronomy SB RAS, Yakutsk, Russia Yakutsk, Russia R.N. Boroyev A. Yoshikawa Yu.G. Shafer Institute of Cosmophysical Research International Center for Space Weather Science and Aeronomy SB RAS, and Education, Kyushu University, Yakutsk, Russia Fukuoka, Japan A.E. Stepanov K. Yumoto Yu.G. Shafer Institute of Cosmophysical Research International Center for Space Weather Science and Aeronomy SB RAS, and Education, Kyushu University, Yakutsk, Russia Fukuoka, Japan Abstract. The Yakutsk Meridional Chain (YMC) of magnetosphere system. In addition, long-term experi- IKFIA SB RAS, located along the 190° magnetic merid- mental research into space weather effects on human ian, is equipped with geophysical and radiophysical health is conducted at Tixie and Yakutsk. The report instruments for monitoring space weather in northeast- describes the meridional chain of instruments at subau- ern Russia. YMC includes four basic stations in Ya- roral and auroral latitudes and gives a brief overview of kutsk, Tixie, Zhigansk, and Maymaga, and six addition- scientific results of monitoring and investigation into al observation sites in Neryungri, Zyryanka, Kystatyam, space weather effects in Yakutia. It also observes partic- Dzhardzhan, Chokurdakh, and Kotelny Island. It pro- ipation of IKFIA SB RAS in international projects (In- vides continuous monitoring of near-Earth space in termagnet, MAGDAS, GIRO). order to obtain data on magnetic field variations, cosmic radio noise, VLF radiation, and ionospheric parameters Keywords: meridional chain, magnetometer, in the complex upper atmosphere – ionosphere – digisonde, space weather. INTRODUCTION ditions in near-Earth space and their impact on the hu- The widely used term “space weather” introduced in man environment, as well as at the study of global cli- recent years denotes environmental conditions in near- matic changes on Earth – International Living with a Earth space. Space weather is the main object of aero- Star (ILWS) Program, Climate and Weather of the Sun– nomy research conducted by IKFIA SB RAS. Environ- Earth System (CAWSES), International Space Weather mental conditions comprise interrelated physical pro- Initiatives (ISWI), and others. cesses in different regions of near-Earth space, which In this paper, we present a review of the space are driven by solar activity. weather research and results obtained at IKFIA SB RAS There are diverse manifestations of these processes in Russia. The Yakutsk Meridional Chain (YMC) and in the upper atmosphere and near-Earth space. The the main instrumentation are described in Section study of regularities of space weather formation relies “Methods and Instrumentation”. New results of optical, on the fact that space weather affects meteorological ionospheric, VLF emissions, atmospheric electricity, processes in the lower and middle atmosphere, the reli- cosmic noise absorption, and multi-instrumental obser- ability of operation of different technical systems in vations in Yakutia are given in Section “Results from space and on Earth, and human health. the Yakutsk Meridional Chain”. Participation of IKFIA Many countries have now enacted a national pro- SB RAS in international projects through the applica- gram to study space weather effects. A number of inter- tion of available multi-instrumental base is described in national programs are aimed at in-depth studies of con- Section “International Cooperation”. 25 D.G. Baishev, S.N. Samsonov, A.V. Moiseev, R.N. Boroyev, A.E. Stepanov, V.I. Kozlov, A.A. Korsakov, A.A. Toropov, A. Yoshikawa, K. Yumoto METHODS Two all-sky TV cameras with a temporal resolution AND INSTRUMENTATION of 4 s were installed in Tixie (71.6 N, 128.9 E) in Space weather manifests itself in many different 1994 and Zhigansk (66.8 N, 123.4 E) in 1995. An all- ways such as changes in the complex and dynamic sky TV camera was described in [Shiokawa et al., magnetosphere–ionosphere system, generation of geo- 1996]. Archive of optical observations until 2013 is magnetic pulsations in a wide frequency range, precipi- stored on 8-mm cassette tapes, and most auroral events tation of energetic particles, influences on pipelines and are digitized by 240×320 pixel frames in MOV or AVI human health during geomagnetic storms and magneto- video formats. spheric substorms. The Digisonde Portable Sounder (DPS) [Reinisch et IKFIA SB RAS carry out experimental studies of al., 1997] produced by the University of Massachusetts processes in near-Earth space and in the upper atmos- Lowell’s Center for Atmospheric Research (UMLCAR) phere, using magnetic, optical, and radiophysical meas- (http://ulcar.uml.edu/) consists of the main unit, moni- urements. tor, two transmitter antennas, four crossed magnetic The main tasks of aeronomy research are: dipole receiver antennas, GPS receiver, and battery backup power. The main unit includes two computers, a a comprehensive study of wave activity during periods of magnetospheric disturbances based on global transmitter, four receivers, and a signal processor. The geomagnetic observations, optical and radiophysical digisonde DPS-4 has a number of distinctive features measurements made at YMC (see Figure 1); that make this device unique. Technical features of the digisonde are its low radiation (the power of two trans- a study of thermal regime, large-scale circula- tion, and wave disturbances in the high-latitude thermo- mitters is 150 W each) and special methods of signal sphere and mesosphere; processing (polarization matching, coherent processing, coherent accumulation) [Reinisch et al., 1997]. Iono- a study of atmospheric electrodynamic processes, their relationship to solar activity, ionospheric and mag- spheric sounding is conducted by a similar digisonde netospheric processes. DPS-4 at Yakutsk and Zhigansk in the range from 1 to The Yakutsk meridional chain of geophysical and 12 MHz for the standard 15-minute program. Digital radiophysical stations of IKFIA SB RAS (Figure 1), ionospheric data in SAO formats are stored for Yakutsk which are located along the 190° magnetic meridian, is from November 2002 to the present day and for Zhi- the most appropriate for the study of magnetosphere– gansk from November 2003 to December 2016 on CD- ionosphere interactions in the vicinity of the plasma ROM disks and external hard drive. sheet of the magnetosphere, the boundary of the ring We describe the instrumentation for VLF emission current, and the plasmapause. YMC is placed in the and riometer observations in the next sections. northeastern region of Russia with a large difference between geographic and geomagnetic coordinates, RESULTS FROM THE YAKUTSK where longitudinal effects in spatial distribution of geo- MERIDIONAL CHAIN physical parameters are most pronounced [Mamrukov, Optical observations Filippov, 1988; Solovyev et al., 2002]. A research team led by Prof. S.I. Solovyev has ana- The main instrumentation for monitoring and inves- lyzed spatial-temporal characteristics of geomagnetic tigating space weather effects in Yakutia are described pulsations and non-stationary structures of auroral lumi- on the IKFIA website in Section “Experimental base” nosity during magnetic disturbances until 2010 at (http://ikfia.ysn.ru/en/experimental-base.html). IKFIA SB RAS. Then these investigations were contin- Absolute magnetic data from the Yakutsk observato- ry allow us to study both fast changes (geomagnetic ued by D.G. Baishev. pulsations, substorms, magnetic storms) and slow, so- Baishev et al. [2012] described some results of sta- called secular changes of the geomagnetic field with a tistical studies of large-scale undulations observed for period over 1 year. Digital data (one-minute absolute 15 years (1994–2008) at Tixie and Zhigansk. For the magnetic field values and K indices) are available since first time it was shown that undulations registered in the 2007. During that year, the observatory was equipped evening sector (17–23 LT) occurred during magnetic with modern instruments in the context of cooperation storms (22 events) and in the absence of magnetic between IKFIA SB RAS and GeoForschungsZentrum storms (32 events). (Potsdam, Germany); the observatory equipment is de- Figure 2 exemplifies simultaneous observations of scribed in [Moiseev et al., 2011]. large-scale undulations made with the DMSP F15 satel- The MAGDAS-9 fluxgate magnetometer furnishes lite and all-sky TV camera at Tixie between 09:48– measurements of H, D, Z magnetic field components 09:52 UT on December 25, 2005. Referring to Figure 2, b, with an accuracy of 0.01 nT in a range of ±70000 nT five diffuse “tongues” or large-scale undulations in the and a sampling rate up to 10 Hz [Yumoto et al., 2006]. evening sector (~19–21 MLT) were observed on the Digital magnetic data from six stations (Kotelny Island – equatorward boundary of diffuse aurora. Discrete auro- KTN, Tixie – TIX, Chokurdakh – CHD, Zhigansk – ral structures of various shapes and dimensions were ZGN, Zyryanka – ZYK, and Yakutsk – YAK) acquired registered northward of this boundary. The DMSP F15 in September 2011 (except for Zyryanka, September 2013) satellite flew almost over Tixie at ~09:48 UT.