The Vertical Component of the Supergranular Convection
Abstract
Proper motion measurements of solar granulation made by local cross-correlation analysis of a 190 minute time series of white-light images reveal persistent flows with scales of 5-50 Mm. The two-dimensional horizontal flow shows mainly the horizontal supergranulation, and the divergence of the flow, of the 5-10 Mm mesogranulation. Time-averaged Doppler vertical velocities in the photospheric Fe I 5576 A and in the temperature minimum Mg I b2 5173 A lines are correlated with the flow divergence. The time-averaged chromospheric intensity in Mg I b2 is correlated with the flow divergence. Fourier spectrum and autocorrelation analyses of the flow divergence gives a measure of 6.6 Mm in the principal component and indicates little power at scales larger than 15 Mm.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1989
- DOI:
- 10.1086/167818
- Bibcode:
- 1989ApJ...344..494N
- Keywords:
-
- Benard Cells;
- Convection Currents;
- Solar Granulation;
- Autocorrelation;
- Chromosphere;
- Cross Correlation;
- Doppler Effect;
- Solar Physics;
- SUN: ATMOSPHERIC MOTIONS;
- SUN: GRANULATION