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The height variation of supergranular velocity fields determined from simultaneous OSO 8 satellite and ground-based observationsResults are reported for simultaneous satellite and ground-based observations of supergranular velocities in the sun, which were made using a UV spectrometer aboard OSO 8 and a diode-array instrument operating at the exit slit of an echelle spectrograph attached to a vacuum tower telescope. Observations of the steady Doppler velocities seen toward the limb in the middle chromosphere and the photosphere are compared; the observed spectral lines of Si II at 1817 A and Fe I at 5576 A are found to differ in height of formation by about 1400 km. The results show that supergranular motions are able to penetrate at least 11 density scale heights into the middle chromosphere, that the patterns of motion correlate well with the cellular structure seen in the photosphere, and that the motion increases from about 800 m/s in the photosphere to at least 3000 m/s in the middle chromosphere. These observations imply that supergranular velocities should be evident in the transition region and that strong horizontal shear layers in supergranulation should produce turbulence and internal gravity waves.
Document ID
19790039195
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
November, L. J.
(Colorado Univ. Boulder, CO, United States)
Toomre, J.
(Colorado, University; Joint Institute for Laboratory Astrophysics, Boulder, Colo., United States)
Gebbie, K. B.
(Colorado, University; Joint Institute for Laboratory Astrophysics; National Bureau of Standards, Boulder, Colo., United States)
Simon, G. W.
(Sacramento Peak Observatory Sunspot, N. Mex., United States)
Date Acquired
September 3, 2013
Publication Date
January 15, 1979
Publication Information
Publication: Astrophysical Journal
Subject Category
Solar Physics
Report/Patent Number
PB-294163
Accession Number
79A23208
Funding Number(s)
CONTRACT_GRANT: F19628-77-C-0104
CONTRACT_GRANT: NGL-06-003-057
Distribution Limits
Public
Copyright
Other

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