SOTSP: HOP 76 Equatorial Obs:
2008-09-05T22:19:00 to 2008-09-05T23:54:01
Science Goal: Observation of an equatorial coronal hole
Program: Fast map 164x164", Q65, 1 side
Target: Coronal Hole
xcen=406 ycen=-330
Instrument: SOTSP
HOP/JOP: 76
Description:
High-speed solar wind with velocity of about 700 km/s was detected by ACE from July 12 to 16, 2008. Just before, on July 10-12, an equatorial coronal hole had passed the central meridian. Various models (e.g. the Wang-Sheeley-Arge solar wind speed prediction model with potential field approximation and our MHD model) strongly suggest that the high-speed solar wind originated from this equatorial coronal hole. Because the global structure of the solar corona is simple and dipole-dominated during solar minimum, the sources of the solar wind is well determined. Most high speed streams originates in the polar regions that are difficult to observe. Because magnetic field in an equatorial coronal hole near the central meridian is almost aligned with the line-of-sight direction, this is a good opportunity to precisely measure the vector magnetic field and plasma properties in the source of high-speed solar wind. We would like to compare the Hinode observations to the solar-wind observations with near-Earth space probes (like ACE) or with IPS (interplanetary scintillation of radio waves). We are interested in the following two topics for solar wind. 1) To determine physical parameters (B, T, Ne and so on) in the coronal hole as a source of energy and momentum into the solar wind. 2) To find any quantitative relation between coronal-hole parameters and solar-wind parameters by the comparison between Hinode and solar-wind observations. It may be a very new finding to identify sources of the measured solar wind.
