GONG Observations of Solar Surface Flows

• Published in: Science (American Association for the Advancement of Science) Vol. 272; no. 5266; pp. 1306 - 1309
• Main Authors: Hathaway, D. H., Gilman, P. A., Harvey, J. W., Hill, F., Howard, R. F., Jones, H. P., Kasher, J. C., Leibacher, J. W., Pintar, J. A., Simon, G. W.
• Format: Journal Article
• Language: English
• Published: United States American Society for the Advancement of Science 31.05.1996; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Astrophysics; Doppler effect; Flow distribution; Flow velocity; Giant cells; Gong Helioseismology; Gongs; Magnetic fields; Meridional flow; Motion; Networks; Observational research; Observations; Photosphere; Solar observatories; Solar oscillations; Solar photosphere; Solar surface; Spherical harmonics; Sun; Surface
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.272.5266.1306

Doppler velocity observations obtained by the Global Oscillation Network Group (GONG) instruments directly measure the nearly steady flows in the solar photosphere. The sun's differential rotation is accurately determined from single observations. The rotation profile with respect to latitude agrees well with previous measures, but it also shows a slight north-south asymmetry. Rotation profiles averaged over 27-day rotations of the sun reveal the torsional oscillation signal-weak, jetlike features, with amplitudes of 5 meters per second, that are associated with the sunspot latitude activity belts. A meridional circulation with a poleward flow of about 20 meters per second is also evident. Several characteristics of the surface flows suggest the presence of large convection cells.