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The interpretation of velocity filtergrams

III: Velocities inside solar granules


From simultaneous filtergrams taken in opposite wings of the λ6569.2 solar absorption line we derive the velocity profile of an average solar granule. We definitely established the existence of the horizontal outflow in a granule in addition to the vertical upflow at the granule center. The magnitude of this outflow is strongly dependent on the influence of instrumental and atmospheric smoothing and on the effective height in the solar atmosphere at which the velocity is measured. The maximum upflow (at the granule center) equals 0.4 km/sec, the maximum outflow (500 km from the granule center) equals 0.25 km/sec.

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Part of the research reported here was carried out while the author was at the High Altitude Observatory, Boulder, Colorado.

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Beckers, J.M., Morrison, R.A. The interpretation of velocity filtergrams. Sol Phys 14, 280–293 (1970).

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  • Atmosphere
  • Velocity Profile
  • Absorption Line
  • Solar Atmosphere
  • Solar Absorption