Institute of Terrestrial Magnetism

Saint Petersburg, Russia

Institute of Terrestrial Magnetism

Saint Petersburg, Russia
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Paschalis P.,National and Kapodistrian University of Athens | Mavromichalaki H.,National and Kapodistrian University of Athens | Yanke V.,Institute of Terrestrial Magnetism | Belov A.,Institute of Terrestrial Magnetism | And 3 more authors.
Journal of Physics: Conference Series | Year: 2013

One of the most important data corrections related to the primary data processing of the neutron monitors is the pressure correction due to the barometric effect. This effect induces considerable variation in the counting rate of a cosmic ray detector which is not related to the real variation of the cosmic rays flux but only to the local atmospheric pressure of the station. In order to provide the worldwide neutron monitor network with good quality data, a correction has to be made that requires the calculation of the barometric coefficient. A new method that effectively calculates the barometric coefficient for a station using data of a reference station in order to subtract the primary variations of cosmic rays is presented in this work. Moreover, this method is the prototype of an online tool that uses data of the NMDB stations and calculates the barometric coefficient for any available station. This tool is also presented.


Paschalis P.,National and Kapodistrian University of Athens | Mavromichalaki H.,National and Kapodistrian University of Athens | Yanke V.,Institute of Terrestrial Magnetism | Belov A.,Institute of Terrestrial Magnetism | And 3 more authors.
New Astronomy | Year: 2013

The primary processing of the neutron monitor data includes all the necessary actions and procedures that each cosmic ray station follows in order to provide the worldwide neutron monitor network with good quality data. One of the main corrections of the primary data is the pressure correction due to the barometric effect. The barometric effect induces variations to the measured data of the neutron monitors which are related to the variations of the local atmospheric pressure of the stations. This correction requires the definition of the barometric coefficient which is calculated experimentally. The accurate calculation of the coefficient is a prerequisite for the quality of the data. This paper presents the implementation of an online tool which calculates the barometric coefficient of a cosmic ray station, by taking advantage of the fact that most stations publish their data on the Neutron Monitor Data Base. © 2012 Elsevier B.V. All rights reserved.


Ganeva M.,University of Greifswald | Peglow S.,University of Greifswald | Hippler R.,University of Greifswald | Berkova M.,Institute of Terrestrial Magnetism | Yanke V.,Institute of Terrestrial Magnetism
Journal of Physics: Conference Series | Year: 2013

A research of the temperature effect of the muon cosmic ray (CR) component on the MuSTAnG super telescope data (Greifswald, Germany) for the whole period of its work (from 2007) was carried out. The primary hourly telescope's data were corrected for the temperature effect, using vertical temperature atmospheric profile at the standard isobaric levels obtained from the GFS model. To estimate the model accuracy and applicability the air sounding data for some years were used.


Vernova E.S.,Institute of Terrestrial Magnetism | Tyasto M.I.,Institute of Terrestrial Magnetism | Baranov D.G.,RAS Ioffe Physical - Technical Institute
Geomagnetism and Aeronomy | Year: 2010

Synoptic maps for 1976-2003 obtained at the Kitt Peak National Solar Observatory are used to analyze the longitudinal distribution of the solar photospheric magnetic field. The superposition of synoptic maps gives different pictures for the rise-maximum phase and the decline-minimum phase. Two characteristic periods correspond to different situations in the 22-year solar magnetic cycle in the course of which both the global magnetic field and the magnetic field of the leading sunspot in a group change their sign. © Pleiades Publishing, Ltd., 2009.


Karlachev A.T.,Institute of Terrestrial Magnetism | Zhbankov G.A.,Southern Federal University | Telegin V.A.,Institute of Terrestrial Magnetism
Geomagnetism and Aeronomy | Year: 2014

Unusual complex ionograms obtained by the Intercosmos-19 satellite are considered, in which four diffuse clouds with a characteristic shape are strung like pearls on the main path of the reflected signal. Ray tracing has been used to show that they are associated with 26 layers of irregularities located at altitudes from hmFs2 up to ~900 km. The sizes of the irregularities range from a few kilometers to 100 kilometers, and the intensity of δNe reaches 100%. The heights of irregular layers increase towards the equator, together with a rise of the F2 layer, and are not associated with magnetic field lines. Complex ionograms have been observed on the outer slope and at the top of the crest of the equatorial anomaly. They are probably caused by the processes occurring in the equatorial ionosphere. © 2014 Pleiades Publishing, Ltd.


Edemsky F.,Institute of Terrestrial Magnetism | Popov A.,Institute of Terrestrial Magnetism | Zapunidi S.,Institute of Terrestrial Magnetism
International Journal of Electronics and Telecommunications | Year: 2011

The problem of transient EM radiation by a linear current source placed on the ground-air interface is analytically studied. We derive a self-modeling exact solution for the interfacial Green function. The spatio-temporal radiation pattern is constructed by means of the Duhamel integral. An inverse problem of antenna current reconstruction from the measured waveform of direct surface wave is solved analytically. An example of real GPR data deconvolution is given.


Gulyaeva T.L.,Institute of Terrestrial Magnetism
Journal of Geophysical Research: Space Physics | Year: 2012

An empirical model of storm-time behavior of the ionospheric peak height hmF2 associated with changes of peak electron density NmF2 is inferred from the topside true-height profiles provided by ISIS 1, ISIS 2, IK-19, and Cosmos-1809 satellites for the period of 1969-1987. The topside-derived quiet-time models of the ionospheric peak height hqF2 and peak electron density NqF2 are used as a frame of reference. To harmonize the model with storm and substorm effects induced by large-scale traveling ionospheric disturbances (LSTIDs), constraints are applied to the topside data, excluding their changes deviating above LSTID extreme limits. The degree of disturbance is estimated by the ionospheric weather W index; then, the least squares fitting is applied to the median of log(hm/hq) versus log(Nm/N q). Anticorrelation between instant changes of hmF 2 and NmF2 has a particular seasonal-magnetic latitude structure varying with solar activity that is used for the buildup of the analytical model. The model allows the deduction of the instantaneous h mF2 associated with the assessment or forecast of the respective NmF2. The model is validated with the data of five ground-based ionosondes during severe space weather storms at times of high solar activity (2000) and low solar activity (2006), and results agree reasonably well with the peak parameters derived from an ionogram. The model is incorporated into the coupled International Reference Ionosphere-Plasmasphere (IRI-Plas) code, used in the assimilative mode as the three-dimensional (3-D) interpolator of the GPS-derived total electron content, TECgps. © Copyright 2012 by the American Geophysical Union.


Sidorova L.N.,Institute of Terrestrial Magnetism | Filippov S.V.,Institute of Terrestrial Magnetism
Geomagnetism and Aeronomy | Year: 2013

This work presents a new examination of the hypothesis regarding the equatorial origin of low He+ density plasma depletions (or subtroughs). For this purpose, we have conducted a detailed comparative analysis of longitudinal variations in the occurrence probabilities of subtroughs in both hemispheres and variations in the occurrence probabilities of equatorial F-region irregularities (EFIs), equatorial spread F (RFS and ESF), and equatorial plasma bubbles (EPBs). Taking into consideration the seasonal dependence and some peculiarities of magnetic field variations in different hemispheres, a conclusion has been reached regarding the similarity between longitudinal statistical occurrences of subtroughs and equatorial ionospheric F-region irregularities. In addition, another piece of evidence in favor of the similarity of the nature of the above-mentioned phenomena has been obtained. We have got a confirmation once again that low He+ density depletions (or subtroughs) can be rightfully considered as equatorial plasma "bubbles," which can be observed at altitudes of the topside ionosphere as depletions in the He+ density. © 2013 Pleiades Publishing, Ltd.


Zirakashvili V.N.,Institute of Terrestrial Magnetism
AIP Conference Proceedings | Year: 2011

Cosmic ray acceleration and magnetic amplification in supernova remnants is shortly reviewed. The results on the modeling of broadband electromagnetic emission from supernova remnants are presented. © 2011 American Institute of Physics.


Deminov M.G.,Institute of Terrestrial Magnetism | Deminova G.F.,Institute of Terrestrial Magnetism
Geomagnetism and Aeronomy | Year: 2016

On the basis of the F2-layer critical frequency foF2 for the noon at some European stations for 1958–2005, it is found that the geomagnetic activity corresponding to the foF2 median is systematically lower than that averaged over the month; the difference increases with an increase in latitude. Moreover, the dispersion of geomagnetic activity for the foF2 median at relatively high latitudes is lower than at middle latitudes. These regularities are related to the fact that high geomagnetic activity usually leads to a distinct deviation of foF2 from the typical average value, i.e., from the foF2 median, and such deviation is more substantial at relatively high latitudes. That is why the geomagnetic activity for the foF2 median is lower at relatively high latitudes than at middle latitudes. © 2016, Pleiades Publishing, Ltd.

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