arXiv subjects

R. Modzelewska

Publications and source records attributed to R. Modzelewska.

17 recordsLinked to original sources

arXiv2021

Temporal changes of near-surface air temperature in Poland for 1781-2016 and in Tbilisi (Georgia) for 1881-2016

Analyses of near-surface air temperature T in Poland for 1781-2016 and in Tbilisi (Georgia) for 1881-2016 have been carried out. We show that the centenary warming effect in Poland and in Tbilisi has almost the same peculiarities. An average centenary warming effect deltaT = (1.08+/-0.29) C is observed in Poland and in Tbilisi for 1881-2016. A warming effect is larger in winter season (deltaT = ~1.15 C) than in other seasons (average warming effect for these seasons deltaT = ~0.95 C). We show that a centenary warming is mainly related to the change of solar activity (estimated by sunspot numbers (SSN) and total solar irradiance (TSI)); particularly, a time interval about ~70 years (1890-1960), when a correlation coefficients between 11 years smoothed SSN and T, and TSI and T are high, r = 0.66+/-0.07 and r = 0.73+/-0.07 for Poland and r = 0.82+/-0.05 and r = 0.90+/-0.05 for Tbilisi, respectively; in this period solar activity contributes decisively in the global warming. We show that a global warming effect equals zero based on the temperature T data in Poland for period 1781-1880, when human activities were relatively less than in 1881-2016. We recognize a few feeble ~20+/-3 years disturbances in the temperature changes for period 1885-1980, most likely related with the fluctuations of solar magnetic cycles. We distinguish the fluctuations of ~7-8 years in Poland's T data, possibly connected with local effects of the North Atlantic Oscillation.

physics.ao-ph↗

arXiv2021

Recurrence of galactic cosmic rays intensity and anisotropy in solar minima 23/24 and 24/25 by ACE/CRIS, STEREO, SOHO/EPHIN and neutron monitors. Fourier and wavelet analysis. Dedicated to the Memory of Michael Alania

Aims. We study the 27-day variations of galactic cosmic rays (GCRs) based on neutron monitor (NM), ACE/CRIS, STEREO and SOHO/EPHIN measurements, in solar minima 23/24 and 24/25 characterized by the opposite polarities of solar magnetic cycle. Now there is an opportunity to reanalyze the polarity dependence of the amplitudes of the recurrent GCR variations in 2007-2009 for negative A < 0 solar magnetic polarity and to compare it with the clear periodic variations related to solar rotation in 2017-2019 for positive A > 0. Methods. We use the Fourier analysis method to study the periodicity in the GCR fluxes. Since the GCR recurrence is a consequence of solar rotation, we analyze not only GCR fluxes, but also solar and heliospheric parameters examining the relationships between the 27-day GCR variations and heliospheric, as well as, solar wind parameters. Results. We find that the polarity dependence of the amplitudes of the 27-day variations of the GCR intensity and anisotropy for NMs data is kept for the last two solar minima: 23/24 (2007-2009) and 24/25 (2017-2019) with greater amplitudes in positive A > 0 solar magnetic polarity. ACE/CRIS, SOHO/EPHIN and STEREO measurements are not governed by this principle of greater amplitudes in positive A > 0 polarity. GCR recurrence caused by the solar rotation for low energy (< 1GeV) cosmic rays is more sensitive to the enhanced diffusion effects, resulting in the same level of the 27-day amplitudes for positive and negative polarities. While high energy (> 1GeV) cosmic rays registered by NMs, are more sensitive to the large-scale drift effect leading to the 22-year Hale cycle in the 27-day GCR variation, with the larger amplitudes in the A > 0 polarity than in the A < 0.

astro-ph.SR↗

arXiv2021

Features of the Galactic Cosmic Ray Anisotropy in the Solar Cycle 24 and Solar Minima 23/24 and 24/25

We study the role of drift effect in the temporal changes of the anisotropy of galactic cosmic rays (GCRs) and the influence of the sector structure of the heliospheric magnetic field on it. We analyze the GCRs anisotropy in the Solar Cycle 24 and solar minimum 23_24 with negative polarity for the period of 2007-2009 and near minimum 24_25 with positive polarity in 2017-2018 using data of global network of Neutron Monitors. We use the harmonic analyses method to calculate the radial and tangential components of the anisotropy of GCRs for different sectors (plus corresponds to the positive and minus to the negative directions) of the heliospheric magnetic field. We compare the analysis of GCRs anisotropy using different evaluations of the mean GCRs rigidity related to Neutron Monitor observations. Then the radial and tangential components are used for characterizing the GCRs modulation in the heliosphere. We show that in the solar minimum 23_24 in 2007-2009 when negative, the drift effect is not visibly evident in the changes of the radial component, i.e. the drift effect is found to produce 4 % change in the radial component of the GCRs anisotropy for 2007-2009. Hence the diffusion dominated model of GCRs transport is more acceptable in 2007-2009. In turn, near the solar minimum 24_25 in 2017-2018 when positive, the drift effect is evidently visible and produce 40% change in the radial component of the GCRs anisotropy for 2017-2018. So in the period of 2017-2018 diffusion model with noticeably manifested drift is acceptable. The results of this work are in good agreement with the drift theory of GCRs modulation, according to which during negative (positive) polarity cycles, a drift stream of GCRs is directed toward (away from) the Sun, thus giving rise to a 22-year cycle variation of the radial GCRs anisotropy.

astro-ph.SR↗

arXiv2021

Quasi-periodic changes of three dimensional solar anisotropy of galactic cosmic rays for 1965-2014

We study features of the 3D anisotropy of galactic cosmic rays (GCR) for 1965-2014. We analyze the 27-day variations of the 2D GCR anisotropy in the ecliptic plane, and the north-south anisotropy normal to the ecliptic plane. We study the dependence of the 27-day variation of the 3D GCR anisotropy on the solar cycle and solar magnetic cycle. We demonstrate that the 27-day variations of the GCR intensity and anisotropy can be used as an important tool to study solar wind, solar activity and heliosphere. We use the components of the 3D GCR anisotropy found based on hourly data of neutron monitors (NMs) and muon telescopes (MTs) using the harmonic analyses and spectrographic methods. We correct 2D diurnal variation of the GCR intensity for the influence of the Earth magnetic field. We derive the north-south component of the GCR anisotropy based on the GG index calculated as the difference in GCR intensities of Nagoya multidirectional MTs. We show that behavior of the 27-variation of the 3D anisotropy verifies an existence of a stable long-lived active heliolongitudes on the sun. This finding illustrates usefulness of the 27-day variation of the GCR anisotropy as a unique proxy to study solar wind, solar activity and heliosphere. We distinguish a tendency of the 22-year changes of the amplitudes of the 27-day variation of the 2D anisotropy connected with the solar magnetic cycle. We demonstrate that the amplitudes of the 27-day variation of the north-south component of the anisotropy vary upon the 11 year solar cycle, however, a dependence of the solar magnetic polarity hardly can be recognized. We show that the 27-day recurrences of the $GG$ index and At component are in a high positive correlation, and both are highly correlated with By component of the heliospheric magnetic field.

astro-ph.SR↗

arXiv2021

Study of the 27-day variations in GCR fluxes during 2007-2008 based on PAMELA and ARINA observations

Using measurements from the PAMELA and ARINA spectrometers onboard the RESURS DK-1 satellite, we have examined the 27-day intensity variations in galactic cosmic ray (GCR) proton fluxes in 2007-2008. The PAMELA and ARINA data allow for the first time a study of time profiles and the rigidity dependence of the 27-day variations observed directly in space in a wide rigidity range from ~300 MV to several GV. We find that the rigidity dependence of the amplitude of the 27-day GCR variations cannot be described by the same power-law at both low and high energies. A flat interval occurs at rigidity R = <0.6-1.0> GV with a power-law index gamma = - 0.13+/-0.44 for PAMELA, whereas for R >= 1 GV the power-law dependence is evident with index gamma = - 0.51+/-0.11. We describe the rigidity dependence of the 27-day GCR variations for PAMELA and ARINA data in the framework of the modulation potential concept using the force-field approximation for GCR transport. For a physical interpretation, we have considered the relationship between the 27-day GCR variations and solar wind plasma and other heliospheric parameters. Moreover, we have discussed possible implications of MHD modeling of the solar wind plasma together with a stochastic GCR transport model concerning the effects of corotating interaction regions.

astro-ph.HE↗

arXiv2015

Numerical methods for solution of the stochastic differential equations equivalent to the non-stationary Parker's transport equation

We derive the numerical schemes for the strong order integration of the set of the stochastic differential equations (SDEs) corresponding to the non-stationary Parker transport equation (PTE). PTE is 5-dimensional (3 spatial coordinates, particles energy and time) Fokker- Planck type equation describing the non-stationary the galactic cosmic ray (GCR) particles transport in the heliosphere. We present the formulas for the numerical solution of the obtained set of SDEs driven by a Wiener process in the case of the full three-dimensional diffusion tensor. We introduce the solution applying the strong order Euler-Maruyama, Milstein and stochastic Runge-Kutta methods. We discuss the advantages and disadvantages of the presented numerical methods in the context of increasing the accuracy of the solution of the PTE.

astro-ph.SR↗

arXiv2015

Stochastic approach to the numerical solution of the non-stationary Parker's transport equation

We present the newly developed stochastic model of the galactic cosmic ray (GCR) particles transport in the heliosphere. Mathematically Parker transport equation (PTE) describing non-stationary transport of charged particles in the turbulent medium is the Fokker-Planck type. It is the second order parabolic time-dependent 4-dimensional (3 spatial coordinates and particles energy/rigidity) partial differential equation. It is worth to mention that, if we assume the stationary case it remains as the 3-D parabolic type problem with respect to the particles rigidity R. If we fix the energy it still remains as the 3-D parabolic type problem with respect to time. The proposed method of numerical solution is based on the solution of the system of stochastic differential equations (SDEs) being equivalent to the Parker's transport equation. We present the method of deriving from PTE the equivalent SDEs in the heliocentric spherical coordinate system for the backward approach. The obtained stochastic model of the Forbush decrease of the GCR intensity is in an agreement with the experimental data. The advantages and disadvantages of the forward and the backward solution of the PTE are discussed.

astro-ph.SR↗

arXiv2015

A stochastic method of solution of the Parker transport equation

We present the stochastic model of the galactic cosmic ray (GCR) particles transport in the heliosphere. Based on the solution of the Parker transport equation we developed models of the short-time variation of the GCR intensity, i.e. the Forbush decrease (Fd) and the 27-day variation of the GCR intensity. Parker transport equation being the Fokker-Planck type equation delineates non-stationary transport of charged particles in the turbulent medium. The presented approach of the numerical solution is grounded on solving of the set of equivalent stochastic differential equations (SDEs). We demonstrate the method of deriving from Parker transport equation the corresponding SDEs in the heliocentric spherical coordinate system for the backward approach. Features indicative the preeminence of the backward approach over the forward is stressed. We compare the outcomes of the stochastic model of the Fd and 27-day variation of the GCR intensity with our former models established by the finite difference method. Both models are in an agreement with the experimental data.

astro-ph.SR↗

arXiv2015

Annual Variations of the Galactic Cosmic Ray Intensity and Seasonal Distribution of the Cloudless Days and Cloudless Nights in Abastumani (41.75oN, 42.82oE; Georgia): (1) experimental study and (2) theoretical modeling

We study a possible relationships between seasonal distributions of the visually observed cloudless days (CD) and cloudless nights (CN) at Abastumani Astrophysical Observatory (41.75N, 42.82E; Georgia) in 1957-1993. The annual variations of monthly numbers of CD and CN have been observed, with maximum in August for CD and in September for CN. During geomagnetic disturbances it is also observed the growth of number of CD in September andMarch (equinoctial months), and for CN, together with September, in June, April and February. We assume that this phenomenon indicates an influence of cosmic factors on cloudiness, as well as the existence of semiannual and possibly shorter-periodicity variations. This cosmic factor can be the manifestation of different rates of the galactic cosmic rays (GCRs) flux variations in CD and CN periods. The influence of GCR flux on ionization of lower atmosphere and variations of density of cloud condensation nuclei also can be connected to the annual and seasonal changes of temperature at Earth surface of this region. To comprehend behaviors of the annual and semi-annual variations of the GCR intensity and their possible relationships with the seasonal distributions of CD and CN we compose and numerically solve two dimensional (2-D) time dependent transport equation including all important processes in the heliosphere. An analysis of experimentally observed and theoretically obtained results have been carried out.

astro-ph.SR↗

arXiv2015

27-day Variation of the Three Dimensional Solar Anisotropy of Galactic Cosmic Ray: 1965-2014

The temporal evaluation of the 27-day variation of the three dimensional (3D) galactic cosmic ray (GCR) anisotropy has been studied for 1965-2014. 3D anisotropy vector was obtained based on the neutron monitors and Nagoya muon telescopes data. We analyze the 27-day variation of the (1) two dimensional (2D) GCR anisotropy in the ecliptic plane, and (2) north-south anisotropy normal to the ecliptic plane. Studying the time line of the 27-day variation of the 2D GCR anisotropy, we confirm that the average amplitude in the minimum epoch of solar activity is polarity dependent, as it is expected from the drift theory. The amplitude in the negative polarity epochs is less as we had shown before. The feeble 11-year variation connected with solar cycle and strong 22-year pattern connected with solar magnetic cycle is visible in the 27-day variation of the 2D anisotropy for 1965-2014. We show that the 27-day variation of the GG index (being a measure of the north-south asymmetry) varies in accordance to solar cycle with a period of 11-years, being in good agreement with the 27-day variation of the At component of the GCR anisotropy calculated by the IZMIRAN group. Detailed analysis are presented for the solar minimum 2007-2008 of solar cycle no.23 and solar maximum 2013-2015 of solar cycle no 24. In the solar cycle no. 24 GG index, calculated by Nagoya telescopes data, is highly anticorrelated with By component of the interplanetary magnetic field (IMF) and shows a clear recurrent changes related to the Sun's rotation.

astro-ph.SR↗

arXiv2015

Three dimensional solar anisotropy of galactic cosmic rays near the recent solar minimum 23/24

Three dimensional (3D) galactic cosmic ray (GCR) anisotropy has been studied for 2006- 2012. The GCR anisotropy, both in the ecliptic plane and in polar direction, were obtained based on the neutron monitors (NMs) and Nagoya muon telescopes (MT) data. We analyze two dimensional (2D) GCR anisotropy in the ecliptic plane and north-south anisotropy normal to the ecliptic plane. We reveal quasi-periodicities - the annual and 27-days waves in the GCR anisotropy in 2006-2012. We investigate the relationship of the 27-day variation of the GCR anisotropy in the ecliptic plane and in the polar direction with the parameters of solar activity and solar wind.

astro-ph.SR↗

arXiv2015

27-day variation of the GCR intensity based on corrected and uncorrected for geomagnetic disturbances data of neutron monitors

We study 27-day variations of the galactic cosmic ray (GCR) intensity for 2005- 2008 period of the solar cycle #23. We use neutron monitors (NMs) data corrected and uncorrected for geomagnetic disturbances. Besides the limited time intervals when the 27-day variations are clearly established, always exist some feeble 27-day variations in the GCR 5 intensity related to the constantly present weak heliolongitudinal asymmetry in the heliosphere. We calculate the amplitudes of the 27-day variation of the GCR intensity based on the NMs data corrected and uncorrected for geomagnetic disturbances. We show that these amplitudes do not differ for NMs with cut-off rigidities smaller than 4-5 GV comparing with NMs of higher cut-off rigidities. Rigidity spectrum of the 27-day variation of the GCR intensity found in the uncorrected data is soft while it is hard in the case of the corrected data. For both cases exists definite tendency of softening the temporal changes of the 27-day variation's rigidity spectrum in period of 2005 to 2008 approaching the minimum of solar activity. We believe that a study of the 27-day variation of the GCR intensity based on the data uncorrected for geomagnetic disturbances should be carried out by NMs with cut-off rigidities smaller than 4-5 GV.

astro-ph.SR↗

arXiv2015

Pecularities of cosmic ray modulation in the solar minimum 23/24

We study changes of the galactic cosmic ray (GCR) intensity for the ending period of the solar cycle 23 and the beginning of the solar cycle 24 using neutron monitors experimental data. We show that an increase of the GCR intensity in 2009 is generally related with decrease of the solar wind velocity U, the strength B of the interplanetary magnetic field (IMF), and the drift in negative (Aneg) polarity epoch. We present that temporal changes of rigidity dependence of the GCR intensity variation before reaching maximum level in 2009 and after it, do not noticeably differ from each other. The rigidity spectrum of the GCR intensity variations calculated based on neutron monitors data (for rigidities greaten than 10 GV) is hard in the minimum and near minimum epoch. We do not recognize any non-ordinary changes in the physical mechanism of modulation of the GCR intensity in the rigidity range of GCR particles to which neutron monitors respond. We compose 2-D non stationary model of transport equation to describe variations of the GCR intensity for 1996-2012 including the Apos (1996-2001) and the Aneg (2002-2012) periods; diffusion coefficient of cosmic rays for rigidity 10-15 GV is increased by 30 percent in 2009 (Aneg) comparing with 1996 (Apos). We believe that the proposed model is relatively realistic and obtained results are satisfactorily compatible with neutron monitors data.

astro-ph.SR↗

arXiv2015

On the relationship of the 27-day variations of the solar wind velocity and galactic cosmic ray intensity in minimum epoch of solar activity

We study the relationship of the 27-day variation of the galactic cosmic ray intensity with similar changes of the solar wind velocity and the interplanetary magnetic field based on the experimental data for the Bartels rotation period 2379 of 23 November 2007-19 December 2007. We develop a three dimensional (3-D) model of the 27-day variation of galactic cosmic ray intensity based on the heliolongitudinally dependent solar wind velocity. A consistent, divergence-free interplanetary magnetic field is derived by solving Maxwells equations with a heliolongitudinally dependent 27-day variation of the solar wind velocity reproducing in situ observations. We consider two types of 3-D models of the 27-day variation of galactic cosmic ray intensity - (1) with a plane heliospheric neutral sheet, and (2)- with the sector structure of the interplanetary magnetic field. The theoretical calculation shows that the sector structure does not influence significantly on the 27-day variation of galactic cosmic ray intensity as it was shown before based on the experimental data. Also a good agreement is found between the time profiles of the theoretically expected and experimentally obtained first harmonic waves of the 27-day variation of the galactic cosmic ray intensity (correlation coefficient equals 0.98 0.02). The expected 27-day variation of the galactic cosmic ray intensity is inversely correlated with the modulation parameter z (correlation coefficient equals -0.91 0.05) which is proportional to the product of the solar wind velocity V and the strength of the interplanetary magnetic field B (z VB). The high anticorrelation between these quantities indicates that the predictable 27-day variation of the galactic cosmic ray intensity mainly is caused by this basic modulation effect.

astro-ph.SR↗

arXiv2015

Modeling and experimental study of the 27-day variation of galactic cosmic-ray intensity for a solar-wind velocity depending on heliolongitude

We develop a three dimensional (3-D) model of the 27-day variation of galactic cosmic ray (GCR) intensity with a spatial variation of the solar wind velocity. A consistent, divergence-free interplanetary magnetic field is derived by solving the corresponding Maxwell equations with a variable solar wind speed, which reproduces in situ observed experimental data for the time interval to be analyzed (24 August 2007-28 February 2008). We perform model calculations for the GCR intensity using the variable solar wind and the corresponding magnetic field. Results are compatible with experimental data; the correlation coefficient between our model predictions and observed 27-day GCR variation is 0.80 0.05.

astro-ph.SR↗

arXiv2015

Dependence of the 27-Day Variation of Cosmic Rays on the Global Magnetic Field of the Sun

We show that the higher range of the heliolongitudinal asymmetry of the solar wind speed in the positive polarity period (Apos) than in the negative polarity period (Aneg) is one of the important reasons of the larger amplitudes of the 27-day variation of the galactic cosmic ray (GCR) intensity in the period of 1995-1997 (Apos) than in 1985-1987 (Aneg). Subsequently, different ranges of the heliolongitudinal asymmetry of the solar wind speed jointly with equally important corresponding drift effect are general causes of the polarity dependence of the amplitudes of the 27-day variation of the GCR intensity. At the same time, we show that the polarity dependence is feeble for the last unusual minimum epoch of solar activity 2007-2009 (Aneg); the amplitude of the 27-day variation of the GCR intensity shows only a tendency of the polarity dependence. We present a three dimensional (3-D) model of the 27-day variation of GCR based on the Parkers transport equation. In the 3-D model is implemented a longitudinal variation of the solar wind speed reproducing in situ measurements and corresponding divergence-free interplanetary magnetic field (IMF) derived from the Maxwells equations. We show that results of the proposed 3-D modeling of the 27-day variation of GCR intensity for different polarities of the solar magnetic cycle are in good agreement with the neutron monitors experimental data. To reach a compatibility of the theoretical modeling with observations for the last minimum epoch of solar activity 2007-2009 (Aneg) a parallel diffusion coefficient was increased by 40 percent

astro-ph.SR↗

arXiv2015

On the 27-day Variations of Cosmic Ray Intensity in Recent Solar Minimum 23/24

We have studied the 27-day variations and their harmonics of the galactic cosmic ray (GCR) intensity, solar wind velocity, and interplanetary magnetic field (IMF) components in the recent prolonged solar minimum 23 24. The time evolution of the quasi-periodicity in these parameters connected with the Suns rotation reveals that their synodic period is stable and is aprox 26-27 days. This means that the changes in the solar wind speed and IMF are related to the Suns near equatorial regions in considering the differential rotation of the Sun. However, the solar wind parameters observed near the Earths orbit provide only the conditions in the limited local vicinity of the equatorial region in the heliosphere (within in latitude). We also demonstrate that the observed period of the GCR intensity connected with the Suns rotation increased up to aprox 33-36 days in 2009. This means that the process driving the 27-day variations of the GCR intensity takes place not only in the limited local surroundings of the equatorial region but in the global 3-D space of the heliosphere, covering also higher latitude regions. A relatively long period ( aprox 34 days) found for 2009 in the GCR intensity gives possible evidence of the onset of cycle 24 due to active regions at higher latitudes and rotating slowly because of the Suns differential rotation. We also discuss the effect of differential rotation on the theoretical model of the 27-day variations of the GCR intensity.

astro-ph.SR↗