Related papers: Solar Activity Studies using Microwave Imaging Obs…
Over the past five years, 2010-2015, we have observed, in the near infrared (IR), the maximum magnetic field strengths for 4145 sunspot umbrae. Herein we distinguish field strengths from field flux. (Most solar magnetographs measure flux).…
Intense solar energetic particle (SEP) events data, associated with ground level enhancements (GLEs), occurred during 1989 to 2006 have been obtained from the spectrometers on board GOES spacecraft in the energy range 10-100 MeV. The…
Using high-cadence extreme-ultraviolet (EUV) images obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, we investigate the solar sources of 26 $^{3}$He-rich solar energetic particle (SEP) events at…
Variations of the weak magnetic fields of the photosphere with periods of the order of the solar magnetic cycle were investigated. Synoptic maps of the photospheric magnetic field produced by NSO Kitt Peak for the period from 1978 to 2016…
Synoptic magnetograms and relevant proxy data were analyzed to study the evolution of the Sun's polar magnetic fields. Time-latitude analysis of large-scale magnetic fields demonstrates cyclic changes in their zonal structure and the…
We investigate the occurrence of the "extended solar cycle" (ESC) as it occurs in a host observational data spanning 140 years. Investigating coronal, chromospheric, photospheric and interior diagnostics we develop a consistent picture of…
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…
In this paper, we have made a statistical analysis of solar H$\alpha$ flares that occurred during the period 1996 to 2005 to investigate their spatial distribution with respect to northern and southern hemispheres of the Sun. The analysis…
The Sun's variability is controlled by the progression and interaction of the magnetized systems that form the 22-year magnetic activity cycle (the "Hale Cycle'') as they march from their origin at $\sim$55 degrees latitude to the equator,…
Motivated by the need to improve the ability to forecast whether a certain coronal mass ejection (CME) is to impact Earth, and by the insufficiency of statistical studies that analyze the whole erupting system with the focus on the…
We present the results of a detailed analysis of multi-wavelength observations of a very impulsive solar flare 1B/M6.7, which occurred on 10 March, 2001 in NOAA AR 9368 (N27 W42). The observations show that the flare is very impulsive with…
This work is a continuation of Paper I [Sharykin et al., 2018] devoted to analysis of nonthermal electron dynamics and plasma heating in the confined M1.2 class solar flare SOL2015-03-15T22:43 revealing energy release in the highly sheared…
Longitudinal distributions of the photospheric magnetic field studied on the base of National Solar Observatory (Kitt Peak) data (1976 - 2003) displayed two opposite patterns during different parts of the 11-year solar cycle.…
Here we present the results of the study of the north-south (N-S) distribution and asymmetry of GOES soft X-ray (SXR) flares during solar cycle 24. The period of study includes ascending, maximum and descending phases of the cycle. During…
Quasi-biennial oscillation (QBO) of solar magnetic activities is intrinsic to dynamo mechanism, but still far from fully understood. In this work, the phase and amplitude asymmetry of solar QBO of Halpha flare activity in the northern and…
It has been found that photospheric magnetic fields can change in accordance with the three-dimensional magnetic field restructuring following solar eruptions. Previous studies mainly use vector magnetic field data taken for events near the…
Research results from solar-dynamo models show the northern and southern hemispheres may evolve separately throughout the solar cycle. The observed phase lag between the hemispheres provides information regarding the strength of hemispheric…
After decades of effort, the solar activity cycle is exceptionally well characterized but it remains poorly understood. Pioneering work at the Mount Wilson Observatory demonstrated that other sun-like stars also show regular activity…
The present study examines the response of the terrestrial magnetosphere to the long-term steady declining trends observed in solar magnetic fields and solar wind micro-turbulence levels since mid-1990's that has been continuing beyond the…
Photospheric magnetic fields were studied using the Kitt Peak synoptic maps for 1976-2003. Only strong magnetic fields (B>100 G) of the equatorial region were taken into account. The north-south asymmetry of the magnetic fluxes was…