Solar wind speed and He I (1083 nm) absorption line intensity

Journal Article · Mon Apr 01 00:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JA02445· OSTI ID:5261766

Hakamada, Kazuyuki ^[1]; Kojima, Masayoshi; Kakinuma, Takakiyo ^[2]

---

1. Chubu Univ., Aichi (Japan)
2. Nagoya Univ., Aichi (Japan)

Since the pattern of the solar wind was relatively steady during Carrington rotations 1,748 through 1,752 in 1984, an average distribution of the solar windspeed on a so-called source surface can be constructed by superposed epoch analysis of the wind values estimated by the interplanetary scintillation observations. The average distribution of the solar wind speed is then projected onto the photosphere along magnetic field lines computed by a so-called potential model with the line-of-sight components of the photospheric magnetic fields. The solar wind speeds projected onto the photosphere are compared with the intensities of the He I (1,083 nm) absorption line at the corresponding locations in the chromosphere. The authors found that there is a linear relation between the speeds and the intensities. Since the intensity of the He I (1,083 nm) absorption line is coupled with the temperature of the corona, this relation suggests that some physical mechanism in or above the photosphere accelerates coronal plasmas to the solar wind speed in regions where the temperature is low. Further, it is suggested that the efficiency of the solar wind acceleration decreases as the coronal temperature increases.

• OSTI ID: 5261766
• Journal Information: Journal of Geophysical Research; (United States), Vol. 96:A4; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
SOLAR WIND
ORIGIN
VELOCITY
ABSORPTION SPECTRA
CHROMOSPHERE
COMPARATIVE EVALUATIONS
MAGNETIC FIELDS
MASS TRANSFER
PHOTOSPHERE
PLASMA ACCELERATION
SCINTILLATIONS
SOLAR CORONA
ACCELERATION
ATMOSPHERES
EVALUATION
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SPECTRA
STELLAR ATMOSPHERES
STELLAR CORONAE
640104* - Astrophysics & Cosmology- Solar Phenomena