Related papers: Solar cycle dependence of spatial correlation in t…
Solar variability occurs over a broad range of spatial and temporal scales, from the Sun's brightening over its lifetime to the fluctuations commonly associated with magnetic activity over minutes to years. The latter activity includes most…
This paper presents the analysis of 3D evolution of solar wind density turbulence and speed at various levels of solar activity between solar cycles 22 and 24. The solar wind data has been obtained from interplanetary scintillation (IPS)…
Mapping of magnetic field lines is important for studies of the solar wind and the sources and propagation of energetic particles between the Sun and observers. A recently developed mapping approach is generalised to use a more advanced…
We investigate the dependence of solar wind fluctuations measured by the Wind spacecraft on scale and on the degree of alignment between oppositely directed Elsasser fields. This alignment controls the strength of the non-linear…
The velocity field in the lower solar atmosphere undergoes strong interactions with magnetic fields. Many authors have pointed out that power is reduced by a factor between two and three within magnetic regions, depending on frequency,…
The interplanetary magnetic field near has a characteristic "sector" structure that reflects its polarity relative to the solar direction. Typically we observe large-scale coherence in these directions, with two or four "away" or "towards"…
As a star spins-down during the main sequence, its wind properties are affected. In this work, we investigate how the Earth's magnetosphere has responded to the change in the solar wind. Earth's magnetosphere is simulated using 3D…
The meridional circulation of the solar magnetic fields in Solar Cycles 21-24 was considered. Data from both ground-based and space observatories were used. Three types of time-latitude distributions of photospheric magnetic fields and…
In this work, we perform a statistical study of magnetic field fluctuations in the solar wind at 1 au using permutation entropy and complexity analysis, and the investigation of the temporal variations of the Hurst exponents. Slow and fast…
The maximum amplitude (Rm) of a solar cycle, in the term of mean sunspot numbers, is well-known to be positively correlated with the preceding minimum (Rmin). So far as the long term trend is concerned, a low level of Rmin tends to be…
Observations show that the solar p-mode frequencies change with the solar cycle. The horizontal-phase-velocity dependence of the relative frequency change, scaled by mode mass, provides depth information on the perturbation in the solar…
In-situ measurements by several spacecraft have revealed that the solar wind is frequently perturbed by transient structures (magnetic folds, jets, waves, flux-ropes) that propagate rapidly away from the Sun over large distances. Parker…
Alfv\'enicity is a well-known property, common in the solar wind, characterized by a high correlation between magnetic and velocity fluctuations. Data from the Parker Solar Probe (PSP) enable the study of this property closer to the Sun…
AIM: To study the variation of the angular momentum and the rotational kinetic energy of the Sun, and associated variations in the gravitational multipole moments, on a timescale of the solar cycle. METHOD: Inverting helioseismic rotational…
As the global magnetic field of the Sun has an activity cycle, one expects to observe some variation of the dynamical properties of the flows visible in the photosphere. We investigate the flow field during the solar cycle by analysing…
Variations in the solar wind (SW) parameters with scales of several years are an important characteristic of solar activity and the basis for a long-term space weather forecast. We examine the behavior of interplanetary parameters over…
We investigated the behavior of the spectral slope of interplanetary magnetic field fluctuations at proton scales for selected high resolution time intervals from WIND and MESSENGER spacecraft at $1$ AU and $0.56$ AU, respectively. The…
We investigate the spatial and temporal variations of the high-degree mode frequencies calculated over localized regions of the Sun during the extended minimum phase between solar cycles 23 and 24. The frequency shifts measured relative to…
I study the sunspot area fluctuations over the epoch of 12 solar cycles (12-23). Lately, I found three significant quasi-periodicities at 10, 17 and 23 solar rotations, but two longer periods could be treated as subharmonics of the…
The solar activity displays variability and periodic behaviours over a wide range of timescales, with the presence of a most prominent cycle with a mean length of 11 years. Such variability is transported within the heliosphere by solar…