Atmosphere Dynamics of the Active Region NOAA 11024

• Published in: Solar physics 2013-06, Vol.284 (2), p.499-513
• Main Authors: Kondrashova, N. N., Pasechnik, M. N., Chornogor, S. N., Khomenko, E. V.
• Format: Article
• Language: English
• Subjects: Advances in European Solar Physics; Astrophysics and Astroparticles; Atmosphere; Atmospheric Sciences; Magnetic fields; Physics; Physics and Astronomy; Solar physics; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics
• ISSN: 0038-0938; 1573-093X
• DOI: 10.1007/s11207-012-0212-5

We present results of the study of chromospheric and photospheric line-of-sight velocity fields in the young active region NOAA 11024. Multi-layer, multi-wavelength observational data were used for the analysis of the emerging flux in this active region. Spectropolarimetric observations were carried out with the telescope THEMIS on Tenerife (Canary Islands) on 4 July 2009. In addition, space-borne data from SOHO/MDI, STEREO and GOES were also considered. The combination of data from ground- and space-based telescopes allowed us to study the dynamics of the lower atmosphere of the active region with high spatial, spectral, and temporal resolutions. THEMIS spectra show strong temporal variations of the velocity in the chromosphere and photosphere for various activity features: two pores, active and quiet plage regions, and two surges. The range of variations of the chromospheric line-of-sight velocity at the heights of the formation of the Hα core was extremely large. Both upward and downward motions were observed in these layers. In particular, a surge with upward velocities up to −73 km s −1 was detected. In the photosphere, predominantly upward motions were found, varying from −3.1 km s −1 upflows to 1.4 km s −1 downflows in different structures. The velocity variations at different levels in the lower atmosphere are compatible with the emergence of magnetic flux.