Related papers: Mesoscale dynamics on the Sun's surface from HINOD…
Using time-distance local helioseismology flow maps within 1 Mm of the solar photosphere, we detect inflows toward activity belts that contribute to solar cycle scale variations in near-surface meridional flow. These inflows stretch out as…
Recent analysis revealed that supergranules (convection cells seen at the Sun's surface) are advected by the zonal flows at depths equal to the widths of the cells themselves. Here we probe the structure of the meridional circulation by…
One of the most striking manifestations of orderly behavior emerging out of complex interactions in any astrophysical system is the 11-year cycle of sunspots. However, direct sunspot observations and reconstructions of long-term solar…
The solar dynamo problem is the question of how the cyclic variation in the solar magnetic field is maintained. One of the important processes is the transport of magnetic flux by surface convection. To reveal this process, the dependence…
Two well known turbulent dynamo and MHD oscillation mechanisms are critically examined and fundamental difficulties are presented. Following new ideas on the genesis of the solar cycle and activity phenomena are presented. Inevitability of…
It is well known that the dominant frequency of oscillations in the solar photosphere is $\approx$3 mHz, which is the result of global resonant modes pertaining to the whole stellar structure. However, analyses of the horizontal motions of…
We report the discovery of isolated, small-scale emerging magnetic fields in a plage region with the Solar Optical Telescope aboard Hinode. Spectro-polarimetric observations were carried out with a cadence of 34 seconds for the plage region…
We study the relation between mesogranular flows, convectively driven sinks and magnetic fields using high spatial resolution spectropolarimetric data acquired with the Imaging Magnetograph eXperiment on board Sunrise. We obtain the…
Using a numerical simulation of compressible convection with radiative transfer mimicking the solar photosphere, we compare the velocity field derived from granule motions to the actual velocity field of the plasma. We thus test the idea…
The correlation between geomagnetic activity and the sunspot number in the 11-year solar cycle exhibits long-term variations due to the varying time lag between the sunspot-related and non-sunspot related geomagnetic activity, and the…
The existence of a turbulent small-scale solar surface dynamo is likely, considering existing numerical and laboratory experiments, as well as comparisons of a small-scale dynamo in MURaM simulations with Hinode observations. We find the…
The tilt angle, current helicity and twist of solar magnetic fields can be observed in solar active regions. We carried out estimates of these parameters by two ways. Firstly, we consider the model of turbulent convective cells…
We determine magnetic fields from the photosphere to the upper chromosphere combining data from the Hinode satellite and the CLASP2.1 sounding rocket experiment. CLASP2.1 provided polarization profiles of the Mg~{|sc ii} $h$ and $k$ lines,…
Three-dimensional numerical simulations of solar surface magnetoconvection using realistic model physics are conducted. The thermal structure of convective motions into the upper radiative layers of the photosphere, the main scales of…
In this thesis, various studies are performed leading to better understanding of the 11-year solar cycle and its theoretical modeling with the flux transport dynamo model. Although this is primarily a theoretical thesis, there is a part…
The ubiquitousness of solar inter-network horizontal magnetic field has been revealed by the space-borne observations with high spatial resolution and polarization sensitivity. However, no consensus has been achieved on the origin of the…
Results from initial helioseismic observations by Solar Optical Telescope onboard Hinode are reported. It has been demonstrated that intensity oscillation data from Broadband Filter Imager can be used for various helioseismic analyses. The…
Although the magnetic fields in the quiet Sun account for the majority of the magnetic energy in the solar photosphere, inferring their exact spatial distribution, origin, and evolution poses an important challenge because the signals lie…
Using images from the Helioseismic and Magnetic Imager aboard the \textit{Solar Dynamics Observatory} (SDO/HMI), we extract the radial-velocity (RV) signal arising from the suppression of convective blue-shift and from bright faculae and…
Three-dimensional magnetohydrodynamical large eddy simulations of solar surface convection using realistic model physics is conducted. The effects of magnetic fields on thermal structure of convective motions into radiative layers, the…