Kazuyuki Hakamada

TL;DR: In this paper, the authors investigated the origin of low-speed winds observed in association with active regions near the equator at times of solar activity minimum and found that slow solar wind does not arise from closed magnetic loops above an active region, but instead the low speed stream originates from the vicinity of one polarity side of the active region.

TL;DR: In this article, the authors constructed a synoptic map of the solar wind speed (SWS) estimated by the computer-assisted tomography (CAT) method with interplanetary scintillation observations for the 1909 Carrington rotation.

TL;DR: In this article, the authors investigated the relation between coronal hole (CH) areas and solar wind speeds using the potential field (PF) model analysis of magnetograph observations and interplanetary scintillation (IPS) observations by the Institute for Space-Earth Environmental Research (formerly Solar-Terrestrial Environment Laboratory) of Nagoya University.

TL;DR: In this paper, the authors developed an automated prediction technique for coronal holes using potential magnetic field extrapolation in the solar corona to construct a database of CORONA holes appearing from 1975 February to 2015 July (Carrington rotations from 1625 to 2165).

TL;DR: In this article, the relationship between the solar-wind speed and the coronal magnetic-field properties (a fluxexpansion factor [676] and photospheric magnetic field strength [B_{\mathrm{S}}$� ]) at all latitudes using data of interplanetary scintillation and solar magnetic field obtained for 24 years from 1986 to 2009.