Hostname: page-component-8448b6f56d-sxzjt Total loading time: 0 Render date: 2024-04-23T10:56:11.783Z Has data issue: false hasContentIssue false

Polar magnetic fields and coronal holes during the recent solar minima

Published online by Cambridge University Press:  05 July 2012

Giuliana de Toma*
Affiliation:
High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 email: detoma@ucar.edu
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The slow decline of solar Cycle 23 combined with the slow rise of Cycle 24 resulted in a very long period of low magnetic activity during the years 2007–2009 with sunspot number reaching the lowest level since 1913. This long solar minimum was characterized by weak polar magnetic fields, smaller polar coronal holes, and a relatively complex coronal morphology with multiple streamers extending to mid latitudes. At the same time, low latitude coronal holes remained present on the Sun until the end of 2008 modulating the solar wind at the Earth in co-rotating, fast solar wind streams. This magnetic configuration was remarkably different from the one observed during the previous two solar minima when coronal streamers were confined near the equator and the fast solar wind was mainly originating from the large coronal holes around the Sun's poles. This paper presents the evolution of the polar magnetic fields and coronal holes during the past minimum, compare it with the previous minima, and discuss the implications for the solar wind near the Earth. It also considers the minimum of Cycle 23 in an historical perspective and, in particular, compares it to the long minima at the turn of the 19th century.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2012

References

Abramenko, V., Yurchyshyn, V., Linker, J., Mikić, Z., Luhmann, J. G., & Lee, C. O., 2010, ApJ, 712, 813CrossRefGoogle Scholar
Billings, D. E., 1966, A Guide to the Solar Corona, New York, Academic PressGoogle Scholar
DeRosa, M. L., Brun, A. S., & Hoeksema, J. T., 2011, Astrophysical Dynamics: From Stars to Galaxies, Proceedings of the International Astronomical Union, IAU Symposium 271, 94CrossRefGoogle Scholar
de Toma, G. & Arge, C. N., 2005, ASP Proceedings of the NSO Workshop 22: Large-Scale Structures and Their Role in Solar Activity, 251Google Scholar
de Toma, G. & Arge, C. N., 2010, Twelfth International Solar Wind Conference, AIP Conference Proceedings vol. 1216, 679Google Scholar
de Toma, G., Gibson, S. E., Emery, B. A., & Kozyra, J. U., 2010, Twelfth International Solar Wind Conference, AIP Conference Proceedings vol. 1216, 667Google Scholar
de Toma, G., Gibson, S. E., Emery, B. A., & Arge, C. N., 2010b, SOHO 23: Understanding a Peculiar Solar Minimum, ASP Conference Series vol. 428, 217Google Scholar
de Toma, G. 2010, Solar Phys., doi 10.1007/s11207-010-9677-2Google Scholar
Harvey, K. L. & Recely, F., 2002, Solar Phys., 211, 31CrossRefGoogle Scholar
Emery, B. A., Richardon, I. G., Evans, D. S., & Rich, F. J., 2009, J.A.S.T.P., 71, 1157Google Scholar
Emery, B. A., Richardson, I. G., Evans, D. S., Rich, F. J., & Wilson, G. R., 2010, Solar Phys., doi 10.1007/s11207-011-9758-x.Google Scholar
Fisher, R. R., Lee, R. H., MacQueen, R. M., & Poland, A. I., 1981, Applied Optics, 20, 1094CrossRefGoogle Scholar
Gibson, S. E., Kozyra, J. U., de Toma, G., Emery, B. A., & Onsager, T., Thompson, B. J., 2009, J. Geophys. Res., 114, A09105Google Scholar
Gibson, S. E., de Toma, G., Emery, B. A., Riley, P., Zhao, L., Elsworth, Y., Leamon, R. J., Lei, J., McIntosh, S., Mewaldt, R. A., Thompson, B. J., & Webb, D., 2011, Solar Phys., in pressGoogle Scholar
Issautier, K., Le Chat, G., Meyer-Vernet, N., Moncuquet, M., Hoang, S., MacDowall, R. J., & McComas, D. J., 2008, GRL 35, L19101CrossRefGoogle Scholar
Jian, L. K., Russell, C. T., & Luhmann, J. G., 2010, Solar Phys., doi 10.1007/s11207-011-9737-2Google Scholar
Judge, P. G., Burkepile, J., de Toma, G., & Druckmüller, M., 2010, SOHO 23: Understanding a Peculiar Solar Minimum, ASP Conference Series vol. 428, 171Google Scholar
Lee, C. O., Luhmann, J. G., Zhao, X. P., Liu, Y., Riley, P., Arge, C. N., Russell, C. T., & de Pater, I., 2009, Solar Phys., 256, 345CrossRefGoogle Scholar
Lei, J., Thayer, J. P., Wang, W., & McPherron, R. L., 2010, Solar Phys., doi 10.1007/s11207-010-9563Google Scholar
Luhmann, J. G., Lee, C. O., Li, Y., Arge, C. N., Galvin, A. B., Simunac, K., Russell, C. T., Howard, R. A., & Petrie, G., 2009, Solar Phys., 256, 285CrossRefGoogle Scholar
McComas, D. J., Ebert, R. W., Elliott, H. A., Goldstein, B. E., Gosling, J. T., Schwadron, N. A., & Skoug, R. M., 2008, GRL, 35, L18193Google Scholar
McIntosh, S. W., Leamon, R. J., Hock, R. A., Rast, M. P., & Ulrich, R. K., 2011, ApJ Lett., 730, L3CrossRefGoogle Scholar
Petrie, G. J. D., Canou, A., & Amari, T., 2010, Solar Phys., doi 10.1007/s11207-010-9687-0Google Scholar
Riley, P., Lionello, R., Linker, J. A., Mikić, Z., Luhmann, J. G., & Wijaya, J., 2010, Solar Phys., doi 10.1007/s11207-010-9698-xGoogle Scholar
Schrijver, C. J., Livingston, W. C., Woods, T. N., & Mewaldt, R. A., 2011, J. Geophys. Res., 38, CiteID L06701Google Scholar
Sheeley, N. R. 2008, ApJ, 680, 1553CrossRefGoogle Scholar
Smith, E. J. & Balogh, A., 2008, GRL, 35, L22103Google Scholar
Svalgaard, L. & Cliver, E. W., 2007, ApJ Lett., 661, L203CrossRefGoogle Scholar
Thayer, J. P., Lei, J., Forbes J. M., Sutton E. K., & Nerem, S. M., 2008 J. Geophys. Res., 113, CiteID A06307CrossRefGoogle Scholar
Tokumaru, M., Kojima, M., Fujiki, K., & Hayashi, K., 2009, GRL, 36, CiteID L09101CrossRefGoogle Scholar
Tokumaru, M., Kojima, M., & Fujiki, K., 2010, J. Geophys. Res., 115, CiteID A04102CrossRefGoogle Scholar
Tsurutani, B. T., Echer, E., Guarnieri, F. L., & Gonzalez, W. D., 2011, J.A.S.T.P., 73, 164Google Scholar
Wang, Y. M., Robbrecht, E., Sheeley, N. R., 2009, ApJ, 707, 1372CrossRefGoogle Scholar