Search Publications
Long-term solar activity studies using microwave imaging observations and prediction for cycle 25
Gopalswamy, N.; Yashiro, S.; Mäkelä, P. +1 more
We use microwave imaging observations from the Nobeyama Radioheliograph at 17 GHz for long-term studies of solar activity. In particular, we use the polar and low-latitude brightness temperatures as proxies to the polar and active-region magnetic fields, respectively. We also use the locations of prominence eruptions as a proxy to the filament loc…
Sun-to-earth propagation of the 2015 June 21 coronal mass ejection revealed by optical, EUV, and radio observations
Gopalswamy, N.; Yashiro, S.; Mäkelä, P. +3 more
We investigate the propagation of the 2015 June 21 CME-driven shock as revealed by the type II bursts at metric and longer wavelengths and coronagraph observations. The CME was associated with the second largest geomagnetic storm of solar cycle 24 and a large solar energetic particle (SEP) event. The eruption consisted of two M-class flares, with …
Multi-instrument view on solar eruptive events observed with the Siberian Radioheliograph: From detection of small jets up to development of a shock wave and CME
Grechnev, V. V.; Kochanov, A. A.; Uralov, A. M. +7 more
The first 48-antenna stage of the Siberian Radioheliograph (SRH) started single-frequency test observations early in 2016, and since August 2016 it routinely observes the Sun at several frequencies in the 4-8 GHz range with an angular resolution of 1-2 arc minutes and an imaging interval of about 12 s. With limited opportunities of the incomplete …
Detecting the solar new magnetic flux regions on the base of vector magnetograms
Golovko, A. A.; Salakhutdinova, I. I.
To understand better the origin of CME and other non-stationary processes, the detailed information about emerging flux regions must be known. The advanced method of mapping emerging magnetic flux regions through the multifractal segmentation of vector photospheric magnetograms, is created. It is free from influence of effects of projection. Maps …
Large-scale magnetic fields and anomalies of chemical composition of stellar coronae
Pipin, V. V.; Tomozov, V. M.
We present evidence that anomalies in abundance of the chemical admixtures with the low first ionization potential (FIP) in the low corona of the late-type stars can be related to a topology of the large-scale magnetic field. Observational data from Ulysses and the Stanford Solar Observatory reveal the high correlations between the FIP effect of t…
New estimation of non-thermal electron energetics in the giant solar flare on 28 October 2003 based on Mars Odyssey observations
Zimovets, I. V.; Mitrofanov, I. G.; Golovin, D. V. +5 more
A new estimation of the total number and energy of the non-thermal electrons produced in the giant (>X 17) solar flare on 2003 October 28 is presented based on the analysis of the observations of the hard X-ray (HXR) emission by the High Energy Neutron Detector (HEND) onboard the Mars Odyssey spacecraft orbiting Mars. Previous estimations of th…
A shear BY field in the Earth's magnetotail and its variations in the current sheet
Malova, Helmi V.; Grigorenko, Elena E.; Zelenyi, Lev M. +2 more
We use Cluster and THEMIS simultaneous observations to study the spatial distributions of a shear BY field in the Plasma Sheet (PS) of the Earth's magnetotail at -31 RE < X < -9 RE. The best correlation between the BY field in the PS (BY_PS) and the Y-component of the Interplanetary Magn…