Abstract
The results of analyzing variations in the line-of-sight (LOS) velocities in the solar loop at photospheric and chromospheric levels in the region of emerging magnetic flux for the evolving active region NOAA 11024 are reported. The analysis combines the data of multiwave spectropolarimetric observations that were carried out on July 4, 2009, (Tenerife, Spain) using THEMIS solar telescope and the data obtained with GOES, SOHO, and STEREO cosmic satellites. A complex sequence of active events has been studied: formation of the Ellerman bomb, B1 X-ray microflare, and four chromospheric surges that were formed as a result of magnetic reconnection caused by new emerging magnetic flux. The Ellerman bomb was formed in the vicinity of a growing pore. Variations in the velocity V LOS of the EB had an oscillation character for chromosphere and photosphere. Before the microflare, the average velocities of the upward and downward plasma fluxes in one leg of the magnetic loop were nearly the same—26 km/s. During the microflare, the velocity V LOS of the ascending and descending flows increased up to −33 and 50 km/s, respectively. Variations in line-of-sight velocity of a plasma in the second leg of the magnetic loop correlated well with variations of V LOS in the region of microflare, but they occurred 1.5 minutes later. During the time of observations, four chromospheric ejections of matter were formed and three of them occurred in the region of Ellerman’s bomb formation. Sharp variations in the soft X-ray intensity occurred during these ejections. At photospheric level, variations in the line-of-sight velocity of plasma in the legs of the loop occurred in the opposite direction. In the region of the first leg, velocity V LOS diminished from −1.8 to −0.4 km/s, while the velocity increased from −0.6 to −2.6 km/s in the region of the second leg.
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References
E. A. Gurtovenko and R. I. Kostyk, Fraunhofer spectrum and a system of solar oscillator forces (Naukova Dumka, Kiev, 1989) [in Russian].
M. N. Pasechnik and S. N. Chornogor, “Dynamics of the atmoshere of active region during two chromospheric surges,” Visn. Kiev Nats. Un. Tarasa Shevchenka. Astronomiya No. 48, 22–26 (2012).
S. N. Chornogor and K. V. Alikaeva, “Line-of-sight velocity field in the Hα-loops in a course of the bright solar flare,” Kinematika Fiz. Nebes. Tel 19(5), 417–430 (2003).
N. S. Shilova and L. I. Starkova, “3D structure and matter motion velocities in dark loops of the near-limb Hα flares,” Kinematika Fiz. Nebes. Tel 3(6), 28–35 (1987).
V. Archontis, “Flux emergence and associated dynamic events in the sun,” in ASP Conf. Ser., Ed. by K. Tsinganos, D. Hatzidimitriou, and T. Matsakos, 424, 3 (2010).
V. Archontis, F. Moreno-Insertis, K. Galsgaard, et al., “Emergence of magnetic flux from the convection zone into the corona,” Astron. Astrophys. 426, 1047–1063 (2004).
S. Berkebile-Stoiser, P. Gomory, and A. M. Veronig, “Multiwavelength fine structure and mass flows in solar microflares,” Astron. Astrophys. 505(2), 811–823 (2009).
J. W. Brasius and G. D. Holman, “Early chromospheric response during a solar microflare observed with SOHO’S CDS and RHESSI,” Astrophys. J. 720, 1472–1482 (2010).
G. Cauzzi, A. Falchi, and R. Falciani, “Mass motions in young active region,” Mem. S. A. It. 74, 659–662 (2003).
J. Chae, J. Qiu, H. Wang, and P. R. Goode, “Extreme-ultraviolet jets and Hα surges in solar microflares,” Astrophys. J. 513(1), L75–L78 (1999).
S. V. Dominguez, L. van Driel-Gesztelyi, and L. R. Bellot Rubio, “Granular-scale elementary flux emergence episodes in a solar active region,” Solar Phys. 278(1), 99–120 (2012).
T. Emonet and F. Moreno-Insertis, “The physics of twisted magnetic tubes rising in a stratified medium: twodimensional results-1998,” Astrophys. J. 492, 804–821 (1998).
A. J. Engell, M. Siarkowski, M. Gryciuk, et al., “Flares and their underlying magnetic complexity,” Astrophys. J. 726, 12–20 (2011).
G. H. Fisher, “Dynamics of flare-driven chromospheric condensation,” Astrophys. J. 346(2), 1019–1029 (1989).
L. V. Ermakova and A. I. Khlystova, “Emergence of magnetic flux at the solar surface and the origin of active regions,” Astron. Rep. 53(9), 869–878 (2009).
L. V. Ermakova and A. I. Khlystova, “The dynamics of photospheric line-of-sight velocities in emerging active regions,” Astron. Rep. 55(29), 163–173 (2011).
S. L. Guglielmino, L. R. Bellot Rubio, F. Reale, and M. Carlsson, F. Zuccarello, et al., “Multiwavelength observations of small-scale reconnection events triggered by magnetic flux emergence in the solar atmosphere,” Astrophys. J. 724, 1083–1098 (2010).
M. Gupta, J. Rajmal, T. Jayshree, et al., “Microflares as possible sources for coronal heating,” J. Astrophys. Astron. 29, 171–177 (2008).
A. W. Hood, V. Archontis, K. Galsgaard, et al., “The emergence of toroidal flux tubes from beneath the solar photosphere,” Astron. Astrophys. 503, 999–1011 (2009).
D. B. Jess, M. Mathioudakis, P. K. Browning, et al., “Microflare activity driven by forced magnetic reconnection,” Astrophys. J. Lett. 712, L111–L115 (2010).
R. L. Jiang, C. Fang, and P. F. Chen, “Numerical simulations of chromospheric microflares,” Astrophys. J. 710, 1387–1394 (2010).
N. N. Kondrashova, M. N. Pasechnik, S. N. Chornogor, et al., “Atmosphere dynamics of the active region NOAA 11024,” Solar Phys. 284(2), 499–513 (2013).
H. Kozu, R. Kitai, D. H. Brooks, et al., “Horizontal and vertical flow structure in emerging flux regions,” Publ. Astron. Soc. Jpn. 58, 407–421 (2006).
A. Lagg, J. Woch, S. K. Solanki, et al., “Supersonic downflows in the vicinity of a growing pore. Evidence of unresolved magnetic fine structure at chromospheric heights,” Astron. Astrophys. 462, 1147–1155 (2007).
B. W. Lites, A. Skumanich, and PilletV. Martinez, “Vector magnetic fields of emerging solar flux I. Properties at the site of emergence,” Astron. Astrophys. 333, 1053–1068 (1998).
Ch. Liu, J. Qiu, D. E. Gary, et al., “Studies of microflares in RHESSI hard X-ray, Big Bear Solar Observatory Hα, and Michelson Doppler imager magnetograms,” Astrophys. J. 604, 442–448 (2004).
Yu. Liu and H. Kurokawa, “On a surge: properties of emerging flux region,” Astrophys. J. 610, 1136–1147 (2004).
D. W. Longcop, G. H. Fisher, and S. Arendt, “The evolution and fragmentation of rising magnetic flux tubes,” Astrophys. J. 464, 999–1011 (1996).
M. L. Luoni, P. Demoulin, C. H. Mandrini, et al., “Twisted flux tube emergence evidenced in longitudinal magnetograms: magnetic tongues,” Solar Phys. 270(1), 45–74 (2011).
M. S. Madjarska, J. G. Doyle, and B. de Pontieu, “Explosive events associated with a surge,” Astrophys. J. 701, 253–259 (2009).
R. Schlichenmaier, R. Rezaei, and N. Bello Gonzalez, “On the formation of penumbrae as observed with the German VTT, SOHO/MDI, and SDO/HMI,” in Hinode-4. Astron. Soc. Pacif., Ed. by L. R. Bellot Rubio, F. Reale, and M. Carlsson, CS-455, 2012.
W. Schmidt, K. Muglach, and M. Knolker, “Free-fall downflow observed in He I 1083.0 nanometers and Hα,” Astrophys. J. 544, 567–571 (2000).
B. Schmieder, G. Peres, S. Enome, et al., “Energy transport and dynamics,” Solar Phys. 153, 55–72 (1994).
B. Schmieder, D. M. Rust, and M. K. Georgoulis, “Emerging flux and the heating of coronal loops,” Astrophys. J. 601, 530–545 (2004).
D. Spadaro, S. Billotta, L. Contarino, et al., “AFS dynamic evolution during the emergence of an active region,” Astron. Astrophys. 425, 309–319 (2004).
L. H. Strous and C. Zwaan, “Phenomena in emerging active region. II. Properties of the dynamic small-scale structure,” Astrophys. J. 527, 435–444 (1999).
B. Sylwester, J. Sylwester, M. Siarkowski, et al., “Physical characteristics of AR 11024 plasma based on SphinX and XRT Data,” Cent. Eur. Astrophys. Bull. 35, 171–180 (2011).
G. Valori, L. M. Green, P. Demouli, et al., “Nonlinear force-free extrapolation of emerging flux with a global twist and serpantine fine structures,” Solar Phys. 278(1), 73–97 (2012).
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Original Russian Text © M.N. Pasechnik, 2014, published in Kinematika i Fizika Nebesnykh Tel, 2014, Vol. 30, No. 4, pp. 3–22.
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Pasechnik, M.N. Plasma motions in the solar loop of emerging magnetic flux. Kinemat. Phys. Celest. Bodies 30, 161–172 (2014). https://doi.org/10.3103/S0884591314040047
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DOI: https://doi.org/10.3103/S0884591314040047