The structure and evolution of the photospheric velocity and intensity field, lying in the convective overshooting region, are investigated on the basis of monochromatic and large bandwidth solar granulation images. The time series of a quiet granulation field, at the Sun center, have been acquired with the IPM Monochromator mounted at the THEMIS telescope in Tenerife (Spain) in July 1999. In specific we investigate both the stratification of relative temperature fluctuations and the evolution of fragmenting granules. The main results that the present analysis seem to suggest are: a) The presence of two photospheric heights at which the intensity (then the temperature) change sign. b) The existence of a deceleration of upward flow, and the following upset of a downflow, in the center of exploding granules near the peak of corresponding large bandwidth intensity profiles.
Solar granulation: properties of velocity fields from THEMIS-IPM observations
PIETROPAOLO, Ermanno
2001-01-01
Abstract
The structure and evolution of the photospheric velocity and intensity field, lying in the convective overshooting region, are investigated on the basis of monochromatic and large bandwidth solar granulation images. The time series of a quiet granulation field, at the Sun center, have been acquired with the IPM Monochromator mounted at the THEMIS telescope in Tenerife (Spain) in July 1999. In specific we investigate both the stratification of relative temperature fluctuations and the evolution of fragmenting granules. The main results that the present analysis seem to suggest are: a) The presence of two photospheric heights at which the intensity (then the temperature) change sign. b) The existence of a deceleration of upward flow, and the following upset of a downflow, in the center of exploding granules near the peak of corresponding large bandwidth intensity profiles.Pubblicazioni consigliate
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