Abstract and keywords
Abstract (English):
We have studied Ca II K line profiles, using two time series of spectrograms taken in two regions near the solar disk center. In each of the regions, the spectrograph slit cut out several areas of the quiet region and a plage. For the selected chromospheric structures, we have derived K line profiles and have defined a number of parameters that characterize the spatial and temporal variations of the profiles. The analysis of profile shapes in different structures belonging to the same moment of time has shown that there are structures whose profiles differ only slightly from each other in the photosphere, but differ dramatically in the chromosphere. The structures begin to differ from the level of formation of K1 and continue to differ further in the chromosphere. There are, however, structures which begin to differ at the level of the photosphere and continue to differ in the chromosphere. The difference between profile shapes in different structures is likely to be associated both with different thermodynamic conditions and with different magnetic field topology at a given point at a given time. We have examined temporal variations of the K Ca II line profiles in structural chromospheric elements, which are caused by the process of K2v-grains. In most of the studied areas of the chromospheric structures, the brightening of the K2v peak develops according to the “common” scenario: at the time of maximum bright-ness, the line shifts toward the red side. There are, however, cases when the brightening of the K2v peak occurs with a shift of the line to the violet side or with no shift at all. We have constructed scatter plots for some pairs of profile parameters related to intensities at characteristic points of the profile and their shifts. A correlation has been found between intensities in the center and wings of the K line. The correlation between shifts of the K2v and K2r peaks is very weak or completely absent.

chromosphere, K Ca II profiles, K2v grains
Publication text (PDF): Read Download


Благодаря развитию наблюдательной техники и теоретических методов накоплен большой объем знаний о хромосфере Солнца, однако ряд вопросов, связанных с физическими процессами, происходя-щими в этом слое, нуждается в дальнейшем уточнении. В этом контексте представляют интерес результаты, которые могут подтвердить уже полученные ранее и добавить уверенности в достоверности последних.

Данная работа является продолжением предыдущей работы авторов [Grigoryeva et al., 2016] по исследованию линий Ca II, основанной на наблюдениях двух областей, расположенных в основании корональной дыры. Каждая область включает уча-сток спокойной хромосферы с яркими и темными структурами и флоккул.

Цель работы — исследовать некоторые особенности пространственных и временных вариаций контуров линии K Ca II в различных хромосферных структурах.


Работа выполнена в рамках базового финансирования программы ФНИ II.16. Результаты получены с использованием оборудования Центра коллективного пользования «Ангара»,


1. Bappu M.K.V., Sivaraman K.R. K emission-line widths and the solar chromosphere. Solar Phys. 1971, vol. 17, pp. 316–330.

2. Beck C., Schmidt W., Rezaei R., Rammacher W. The signature of chromospheric heating in Ca II H spectra. Astron. Astrophys. 2008, vol. 479, pp. 213–227. DOI: 10.1051/0004-6361:20078410.

3. Beck C., Khomenko E., Rezaei R., Collados M. The energy of waves in the photosphere and lower chromosphere I. Velocity statistics. Astron. Astrophys. 2009, vol. 507, pp. 453–467. DOI: 10.1051/0004-6361/200911851.

4. Bjørgen J.P., Sukhorukov A.V., Leenaarts J., Carlsson M., de la Cruz Rodríguez, J., Scharmer G.B., Hansteen V.H. Three-dimensional modeling of the Ca II H&K lines in the solar atmosphere. ArXiv:1712.01045v1 [astro-ph.SR]. 2017.

5. Carlsson M., Stein R.F. Formation of solar calcium H and K bright grains. Astrophys. J. 1997, vol. 481, pp. 500–514.

6. Cram L.E. High resolution spectroscopy of the disk chromospheres. Solar Phys. 1974, vol. 37, pp. 75–83.

7. Cram L.E., Damé L. High spatial and temporal resolution observations of the solar Ca II H line. Astrophys. J. 1983, vol. 272, pp. 355–361.

8. Cram L.E., Brown D.R., Beckers J.M. High resolution spectroscopy of the disk chromospheres. V. Space-time variations observed simultaneously in seven lines. Astron. Astrophys. 1977, vol. 57, pp. 211–220.

9. Fontenla J.M., Curdt W., Haberreiter M., Harder J., Tian H. Semiempirical models of the solar atmosphere. III. Set of non-LTE models for far-ultraviolet/extreme- ultraviolet irradiance computation. Astrophys. J. 2009, vol. 707, pp. 482–502.

10. Grigoryeva S.A., Turova I.P., Ozhogina O.A. Studying Ca II K line profile shapes and dynamic processes in the solar chromosphere at the base of a coronal hole. Solar Phys. 2016, vol. 291, pp. 1977–2002. DOI: 10.1007/s11207-016-0951-9.

11. Grossmann-Doerth U., Kneer F., von Uexküll M. Properties of the solar Ca II K-line at high spatial resolution. Solar Phys. 1974, vol. 37, pp. 85–94.

12. Holweger H., Müller E.A. The photospheric barium spectrum: solar abundance and collision broadening of Ba II lines by hydrogen. Solar Phys. 1974, vol. 39, pp. 19–30.

13. Kalkofen W. Chromospheric oscillations in K2v bright points. Astrophys. J. 1996, vol. 468, L. 69–72.

14. Kalkofen W. Oscillations in chromospheric network bright points. Astrophys. J. 1997, vol. 486, L. 145–148.

15. Kamio S., Kurokawa H. The relation between Ca bright grains and oscillations in the photosphere. Astron. Astrophys. 2006, vol. 450, pp. 351–358. DOI: 10.1051/0004-6361:20054174.

16. Lites B.W., Rutten R.J., Kalkofen W. Dynamics of the solar chromospheres. I. Long-period network oscillations. Astrophys. J. 1993, vol. 414, pp. 345–356.

17. Lites B.W., Rutten R.J., Berger T.E. Dynamics of the solar chromospheres. II. Ca II H2v and K2v grains versus internetwork fields. Astrophys. J. 1999, vol. 517, pp. 1013–1033.

18. Liu S.-Y. Direct observational evidence for the propagation and dissipation of energy in the chromospheres. Astrophys. J. 1974, vol. 189, pp. 359–365.

19. Liu S.-Y., Skumanich A. An empirical interpretation for the time evolution of the Ca II line. Solar Phys. 1974, vol. 38, pp. 109–115.

20. Löfdahl M.G., Hillberg T., de la Cruz Rodriguez J., Vissers G., Scharmer G.B., Hagfors Haugan S.V., Fredvik T. A data-processing and metadata-generating pipeline for CHROMIS and CRISP // ArXiv:1804.03030v1 [astro-ph.IM]. 2018, pp. 1–17.

21. Pasachoff J.M. Fine structure in Ca II on the solar disk. Solar Phys. 1970, vol. 12, pp. 202–215.

22. Reardon K.P., Lepreti F., Carbone V., Vecchio A. Evidence of shock-driven turbulence in the solar chromospheres. Astrophys. J. 2008, vol. 683, L. 207–210. DOI: 10.1086/591790.

23. Reardon K.P., Uitenbroek K., Cauzzi G. The solar chromospheres at high resolution with IBIS III. Comparison of Ca II K and Ca II 854.2 nm imaging. Astron. Astrophys. 2009, vol. 500, pp. 1239–1247. DOI: 10.1051/0004-6361:200811223.

24. Rezaei R., Schlichenmaier R., Beck C.A.R., Bruls J.H.M.J., Schmidt W. Relation between photospheric magnetic field and chromospheric emission. Astron. Astrophys. 2007, vol. 466, pp. 1131–1144. DOI: 10.1051/0004-6361:20067017.

25. Rezaei R., Bruls J.H.M.J., Schmidt W., Beck C., Kalkofen W., Schlichenmaier R. Reversal-free Ca II H profiles: a challenge for solar chromosphere modeling in quiet inter-network. Astron. Astrophys. 2008, vol. 484, pp. 503–509. DOI: 10.1051/0004-6361:20079050.

26. Rutten R.J., Uitenbroek H. Ca II H2v and K2v cell grains. Solar Phys. 1991, vol. 134, pp. 15–21.

27. Vecchio A., Cauzzi G., Reardon K.P. The solar chromospheres at high resolution with IBIS. II. Acoustic shocks in the quiet internetwork and the role of magnetic fields. Astron. Astrophys. 2009, vol. 494, pp. 269–286. DOI: 10.1051/0004-6361:200810694.

28. URL: (accessed March 20, 2018).

Login or Create
* Forgot password?