employee from 01.01.2016 until now
Moscow, Russian Federation
Moscow, Russian Federation
Moscow, Russian Federation
Studying electric currents in solar active regions (AR) is an essential step in understanding solar activity in general and solar flares in particular. In this paper, we compare probability density functions of vertical electric current PDF(|jz|) in several active regions, using HMI/SDO and SOT/Hinode photospheric magnetic field data. We have established that at a high value (above the noise level of |jz| >9•10³ statampere/cm²) of current structures of ARs these functions are nearly identical. The main difference in PDFs for low (noise) jz≤9•10³ statampere/cm² is due to differences in sensitivity of these two instruments. We have also found that the criterion of pixel selection from magnetic field strength is inapplicable, and the similarity between PDFs is determined by high jz. For all PDF(|jz|) under study we have calculated the power law exponent of the PDF tail for the two instruments, which coincide within their errors for the current structures with current values above noise level. Thus there is no significant difference as to which instrument is used for analyzing probability density functions in high current parts of ARs where flares are localized.
solar active regions, magnetic field, electric currents, solar flares
1. Abramenko V.I., Gopasiuk S.I., Ogir' M.B. The variety of solar flares revealed on the basis of the electric currents investigation. Izvestiya Krymskoi Astrofizicheskoi Observatorii [Bulletin of the Crimean Astrophysical Observatory]. 1990, vol. 81, pp. 8-13. (In Russian).
2. Barnes G., Leka K.D. Inferring currents from the Zeeman effect at the solar surface. Electric Currents in Geospace and Beyond. 2018. P. 81-91. (Geophys. Mon. Ser., vol. 235). DOI:https://doi.org/10.1002/9781119324522.ch5.
3. Fursyak Y.A. Vertical Electric currents in active regions: Calculation methods and relation to the flare index. Geomagnetism and Aeronomy. 2018, vol. 58, pp. 1129-1135. DOI:https://doi.org/10.1134/S0016793218080078.
4. Fursyak Y.A., Abramenko V.I. Possibilities for estimating horizontal electrical currents in active regions on the Sun. Astrophys. 2017, vol. 60, pp. 544-552. DOI:https://doi.org/10.1007/s10511-017-9505-6.
5. Hoeksema J.T., Liu Y., Hayashi K., Sun X., Schou J., Couvidat S., Norton A., Bobra M., Centeno R., Leka K.D., Barnes G., Turmon M. The Helioseismic and Magnetic Imager (HMI) vector magnetic field pipeline: Overview and performance. Solar Phys. 2014, vol. 289, pp. 3483-3530. DOI:https://doi.org/10.1007/s11207-014-0516-8.
6. Kontogiannis I., Georgoulis M.K., Park S.H., Guerra J.A. Non-neutralized electric currents in solar active regions and flare productivity. Solar Phys. 2017, vol. 292, p. 159. DOI:https://doi.org/10.1007/s11207-017-1185-1.
7. Löhner-Böttcher J., Schmidt W., Schlichenmaier R., Steinmetz T., Holzwarth R. Convective blueshifts in the solar atmosphere. III. High-accuracy observations of spectral lines in the visible. Astron. Astrophys. 2019, vol. 624, p. A57. DOI:https://doi.org/10.1051/0004-6361/201834925.
8. Nechaeva A.B., Sharykin I.N., Zimovets I.V., Chen F. Relationship between the horizontal gradient of the vertical magnetic field and the horizontal electric current on the photosphere in a model active region of the Sun. Geomagnetism and Aeronomy. 2021, vol. 61, pp. 956-963. DOI:https://doi.org/10.1134/S0016793221070148.
9. Puschmann K.G., Ruiz C.B., Martínez P.V. The electrical current density vector in the inner penumbra of a sunspot. Astrophys. J. Lett.. 2010, vol. 721, no. 1. DOI:https://doi.org/10.1088/2041-8205/721/1/L58.
10. Scherrer P.H., Schou J., Bush R.I., Kosovichev A.G., Bogart R.S., Hoeksema J.T., Liu Y., Duvall Jr. T.L., et al. The Helioseismic and Magnetic Imager (HMI) investigation for the Solar Dynamics Observatory (SDO). Solar Phys. 2012, vol. 275, pp. 207-227. DOI:https://doi.org/10.1007/s11207-011-9834-2.
11. Severny A.B. Nekotorye problemy fiziki Solntsa. [Some Problems in Solar Physics]. Moscow, Nauka, 1988. 224 p. (In Russian).
12. Tsuneta S., Ichimoto K., Katsukawa Y., Nagata S., Otsubo M., Shimizu T., Suematsu Y., Nakagiri M., et al. The Solar Optical Telescope for the Hinode Mission: An overview. Solar Phys. 2008, vol. 249, pp. 167-196. DOI:https://doi.org/10.1007/s11207-008-9174-z.
13. Watanabe K., Masuda S., Segawa T. Hinode Flare Catalogue. Solar Phys. 2012, vol. 279, pp. 317-322. DOI:https://doi.org/10.1007/s11207-012-9983-y.
14. Zimovets I.V., Nechaeva A.B., Sharykin I.N., Gan W.Q. Density distribution of photospheric vertical electric currents in flare-active regions of the Sun. Astrophys. 2020a, vol. 63, pp. 408-420. DOI:https://doi.org/10.1007/s10511-020-09645-0.
15. Zimovets I.V., Sharykin I.N., Gan W.Q. Relationships between photospheric vertical electric currents and hard X-ray sources in solar flares: Statistical study. Astrophys. J. 2020b, vol. 891, no. 2. DOI:https://doi.org/10.3847/1538-4357/ab75be
