74 citations · 297 across the 11 of their papers we have counts for
12 papers
Comparative Study of Microwave Polar Brightening, Coronal Holes, and Solar Wind Over the Solar Poles
Ken'ichi Fujiki, Kiyoto Shibasaki, Seiji Yashiro +3
We comparatively studied the long-term variation (1992-2017) in polar brightening observed with the Nobeyama Radioheliograph, the polar solar wind velocity with interplanetary scin…
Solar cycle indices from the photosphere to the corona: measurements and underlying physics
Ilaria Ermolli, Kiyoto Shibasaki, Andrey Tlatov +1
A variety of indices have been proposed in order to represent the many different observables modulated by the solar cycle. Most of these indices are highly correlated with each oth…
Chromospheric sunspots in the millimeter range as observed by the Nobeyama Radioheliograph
Kazumasa Iwai, Hideki Koshiishi, Kiyoto Shibasaki +3
We investigate the upper chromosphere and the transition region of the sunspot umbra using the radio brightness temperature at 34 GHz (corresponding to 8.8-mm observations) as obse…
Coronal Magnetic Fields Derived from Simultaneous Microwave and EUV Observations and Comparison with the Potential Field Model
Shun Miyawaki, Kazumasa Iwai, Kiyoto Shibasaki +2
We estimated the accuracy of coronal magnetic fields derived from radio observations by comparing them to potential field calculations and the DEM measurements using EUV observatio…
Coronal magnetic field and the plasma beta determined from radio and multiple satellite observations
Kazumasa Iwai, Kiyoto Shibasaki, Satoshi Nozawa +5
We derived the coronal magnetic field, plasma density, and temperature from the observation of polarization and intensity of radio thermal free-free emission using the Nobeyama Rad…
The 17 GHz active region number
C. L. Selhorst, J. E. R. Costa, C. G. Giménez de Castro +3
We report the statistics of the number of active regions (NAR) observed at 17 GHz with the Nobeyama Radioheliograph between 1992, near the maximum of cycle 22, and 2013, that also…
Synoptic solar radio observations as proxies for upper atmosphere modelling
Thierry Dudok de Wit, Sean Bruinsma, Kiyoto Shibasaki
The specification of the upper atmosphere strongly relies on solar proxies that can properly reproduce the solar energetic input in the UV. Whilst the microwave flux at 10.7 cm (al…
Systematic Microwave Source Motions along Flare-arcade Observed by Nobeyama Radioheliograph and AIA/SDO
Sujin Kim, Kiyoto Shibasaki, Satoshi Masuda
We found systematic microwave source motions along a flare-arcade using Nobeyama Radioheliograph (NoRH) 17 GHz images. The motions were associated with a X-class disk flare which o…
Measurements of Coronal and Chromospheric Magnetic Fields using Polarization Observations by the Nobeyama Radioheliograph
Kazumasa Iwai, Kiyoto Shibasaki
Coronal and chromospheric magnetic fields are derived from polarization and spectral observations of the thermal free-free emission using the Nobeyama Radioheliograph (NoRH). In ma…
Microwave Emission of Supra-arcade Structure associated with M1.6 Limb Flare
Sujin Kim, Hazel Bain, Kiyoto Shibasaki +1
We have investigated a supra-arcade structure, associated with an M1.6 flare, which occurred on the south-east limb on 4th of November 2010. It is observed in microwaves at 17 GHz…
Behavior of Solar Cycles 23 and 24 Revealed by Microwave Observations
N. Gopalswamy, S. Yashiro, P. Mäkelä +3
Using magnetic and microwave butterfly diagrams, we compare the behavior of solar polar regions to show that (i) the polar magnetic field and the microwave brightness temperature d…
The slow magnetoacoustic mode in the flaring loop
Veronika Reznikova, Kiyoto Shibasaki
We studied long duration flare observed with Nobeyama Radioheliograph at frequencies 17 and 34 GHz and with Ramaty High Energy Solar Spectroscopic Imager at 25-50 keV. We found tha…