Main Objective: Measure Doppler velocity, temperature, density, and abundance in a polar coronal hole, Quiet Sun, and their boundary to be compared with the density, temperature, and speed in the extended solar corona seen in coronagraphic images.
Scientific Justification: The solar atmosphere is highly structured due to the complexity of coronal magnetic fields. Such complex structures result in differences in temperature and speed of the solar wind. To understand the physical processes of the coronal heating and solar wind acceleration, we investigate the physical characteristics of various chromosphere, transition region, and coronal structures. It includes (1) the footpoints of plumes and inter-plumes in a polar coronal hole, (2) Quiet Sun adjacent to the coronal hole where the plumes originate from, and (3) the boundary of the coronal hole and the Quiet Sun, which is likely to be the boundary of coronal streamers. Hinode/EIS determines the mass of outflows, temperature, and abundance, as well as the properties of waves and shocks, if any. EUV and coronagraphic images are used to see the upper atmospheric response of these coronal base features. To pinpoint such specific regions listed above, we use the most recent EUV images taken from SDO AIA, SOHO, EIT, and STEREO EUVI, as well as coronagraphic images obtained from SOHO LASCO C2/C2 and STEREO COR1/COR2.
This coordinated observation consists of BITSE (Balloon-borne Investigation of Temperature and Speed of Electrons in the corona), BBSO (Big Bear Solar Observatory) GST (Goode Solar Telescope), IRIS, and Hinode/EIS. BITSE will provide coronagraphic images, which enable to measure the electron density, temperature, and speed in the extended solar corona from 3.5 to 8 solar radii. BBSO/GST and IRIS will probe into the chromospheric outflows associated with the structures observed in coronagraphic images (polar plumes, inter-plumes, and streamers). Hinode/EIS will fill up the gap between the outflows and the solar wind properties. The STEREO Ahead observations will provide an additional viewing perspective and help associate the Hinode/BBSO/IRIS observations with the ones in the extended solar corona. |
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