THE ROLE OF MHD WAVES IN HEATING OF THE SOLAR CORONA
Year 2023,
Issue: 053, 97 - 117, 30.06.2023
Ebru Baş
,
Dicle Zengin Çamurdan
Abstract
Observations in the Solar North Polar Coronal Hole (NPCH) show that this region has high temperature values (10^6-10^8 K). At this temperature, the coronal plasma loses energy to the transition region below through heat conduction and optically thin emission. It is still a matter of debate how to replace this lost energy in the solar corona and how to maintain the observed temperature values. In this study, we aimed to study the wave theory, which is an important model proposed for the heating problem of the solar corona in NPCH. We assumed a model based on Alfvén/ion cyclotron resonance process with O VI ions by using quasi-linear approximation in NPCH and solve the magnetohydrodynamic (MHD) equations for O VI assuming that the non-thermal contribution to the temperature. Using a Matlab code, we performed 3D MHD numerical solutions of Alfvén waves. Our results show that the damping length scales (0.2-1.8 R) and energy flux densities (10^5-10^7 erg/cm^2 s) of Alfvén waves are similar for both plumes and interplumes in NPCH. As a result of our study, we present the contribution of MHD waves that will cause the acceleration of the solar wind and the heating of the solar corona.
References
- [1] Wedemeyer-Böhm, S., Lagg, A. , Nordlund, A., (2009), The Origin and Dynamics of Solar Magnetism, Space Sciences Series of ISSI, Volume 32. ISBN 978-1-4419-0238-2, Springer New York, p. 317.
- [2] Ofman, L., Davila, J. M., Steinolfson, R. S.,(1994), Nonlinear studies of coronal heating by the resonant absorption of Alfvén waves, Geophysical Research Letters, Volume 21, Issue 20, p. 2259-2262.
- [3] Pagano, P., De Moortel, I., (2017), Contribution of mode-coupling and phase-mixing of Alfvén waves to coronal heating, Astronomy & Astrophysics, Volume 601, id.A107, 13 pp.
- [4] Pagano, P., Pascoe, D. J., De Moortel, I., (2018), Contribution of phase-mixing of Alfvén waves to coronal heating in multi-harmonic loop oscillations, Astronomy & Astrophysics, Volume 616, id.A125, 12 pp.
- [5] Cargill, Peter J., Klimchuk, James A., (2004), Nanoflare Heating of the Corona Revisited, The Astrophysical Journal, Volume 605, Issue 2, pp. 911-920.
- [6] Klimchuk, J. A., (2006), On Solving the Coronal Heating Problem, Solar Physics, Volume 234, Issue 1, pp.41-77.
- [7] Chitta, L. P., Peter, H., Solanki, S. K., (2018), Nature of the energy source powering solar coronal loops driven by nanoflares, Astronomy & Astrophysics, Volume 615, id.L9, 6 pp.
- [8] Cranmer, S. R., Winebarger, A. R., (2019), The Properties of the Solar Corona and Its Connection to the Solar Wind, Annual Review of Astronomy and Astrophysics, vol. 57, p.157-187.
- [9] Viall, N. M., De Moortel, I.,Downs, C., Klimchuk, J. A., Parenti, S., Reale, F., (2021), The Heating of the Solar Corona, Space Physics and Aeronomy, Volume 1, Solar Physics and Solar Wind, Geophysical Monograph Series, Vol. 258. ISBN: 978-1-119-50753-6, 320 pp. American Geophysical Union, Wiley, 2021, p.35.
- [10] Tomczyk, S., McIntosh, S. W., Keil, S. L., Judge, P. G., Schad, T., Seeley, D. H., Edmondson, J., (2007), Alfvén Waves in the Solar Corona, Science, Volume 317, Issue 5842, pp. 1192.
- [11] Landi, E., Cranmer, S. R., (2009), Ion Temperatures in the Low Solar Corona: Polar Coronal Holes at Solar Minimum, The Astrophysical Journal, Volume 691, Issue 1, pp. 794-805.
- [12] Gupta, G. R., Banerjee, D., Teriaca, L., Imada, S., Solanki, S, (2010), Accelerating Waves in Polar Coronal Holes as Seen by EIS and SUMER, The Astrophysical Journal, Volume 718, Issue 1, pp. 11-22.
- [13] Bemporad, A., Abbo, L., (2012), Spectroscopic Signature of Alfvén Waves Damping in a Polar Coronal Hole up to 0.4 Solar Radii, The Astrophysical Journal, Volume 751, Issue 2, 110, 13 pp.
- [14] Cranmer, S. R., Gibson, S. E., Riley, P., (2017), Origins of the Ambient Solar Wind: Implications for Space Weather, Space Science Reviews, Volume 212, Issue 3-4, pp. 1345-1384.
- [15] Doyle J., Teriaca L., Banerjee D., (1999), Coronal hole diagnostics out to 8 R. Astronomy and Astrophysics, 349, 956.
- [16] Hassler D. M., Rottman G. J., Shoub E. C., Holzer T. E., (1990), Line broadening of MG X 609 and 625 A coronal emission lines observed above the solar limb. The Astrophysical Journal, 348, L77-80.
- [17] Saba J. L., Strong K. T., 1991. Coronal dynamics of a quiescent active region. The Astrophysical Journal, 375, 789-799.
- [18] Patsourakos, S., Klimchuk, J. A., (2006), Nonthermal Spectral Line Broadening and the Nanoflare Model, The Astrophysical Journal, Volume 647, Issue 2, pp. 1452-1465.
- [19] van Ballegooijen, A. A., Asgari-Targhi, M., Voss, A., (2017), The Heating of Solar Coronal Loops by Alfvén Wave Turbulence, The Astrophysical Journal, Volume 849, Issue 1, article id. 46, 23 pp.
- [20] Brooks, David H., Warren, Harry P., (2016), Measurements of Non-thermal Line Widths in Solar Active Regions, The Astrophysical Journal, Volume 820, Issue 1, article id. 63, 14 pp.
- [21] Ofman L., Nakariakov V., Sehgal N., (2000) Dissipation of slow magnetosonic waves in coronal plumes. The Astrophysical Journal, 533, 1071.
- [22] Nakariakov V. M., Ofman L., Arber T. D., (2000), Nonlinear dissipative spherical Alfvén waves in solar coronal holes. The Astronomy and Astrophysics, 353, 741-748.
- [23] Banerjee D., Gupta G. R., Teriaca L., (2011) Propagating MHD Waves in Coronal Holes. Space Science Reviews, 158, 267-288.
- [24] Wilhelm K., Marsch E., Dwivedi B. N., Hassler D. M., Lemaire P., Gabriel A. H., Huber M. C., (1998), The solar corona above polar coronal holes as seen by SUMER on SOHO. The Astrophysical Journal, 500, 1023.
- [25] Ruderman, M. S., Oliver, R., Erdélyi, R., Ballester, J. L., Goossens, M., (2000), Slow surface wave damping in plasmas with anisotropic viscosity and thermal conductivity, Astronomy and Astrophysics, v.354, p.261-276.
- [26] Banerjee, D., Pérez-Suárez, D., Doyle, J. G., (2009), Signatures of Alfvén waves in the polar coronal holes as seen by EIS/Hinode, Astronomy and Astrophysics, Volume 501, Issue 3, 2009, pp.L15-L18.
- [27] Morton R., Tomczyk S., Pinto R., 2015. Investigating Alfvénic wave propagation in coronal open-field regions. Nature Communications, 6, 1-12.
- [28] Pekünlü E. R., Bozkurt Z., Afsar M., Soydugan E., Soydugan F., (2002), Alfvén waves in the inner polar coronal hole. Monthly Notices of the Royal Astronomical Society, 336, 1195-1200.
- [29] Fisher R., Guhathakurta M., (1995), Physical properties of polar coronal rays and holes as observed with the Spartan 201-01 coronagraph. The Astrophysical Journal Letters, 447, L139.
- [30] Guhathakurta M., Fisher R., (1998), Solar Wind Consequences of a Coronal Hole Density Profile: Spartan 201-03 Coronagraph and Ulysses Observations from 1.15 R to 4 AU. The Astrophysical Journal Letters, 499, L215.
- [31] Banerjee D., Teriaca L., Doyle J., Wilhelm K., (1998), Broadening of SI VIII lines observed in the solar polar coronal holes. Astronomy and Astrophysics, 339, 208-214.
- [32] Doschek G., Warren H., Laming J., Mariska J., Wilhelm K., Lemaire P., Schühle U., Moran T., (1997), Electron densities in the solar polar coronal holes from density-sensitive line ratios of Si VIII and Sx. The Astrophysical Journal Letters, 482, L109.
- [33] Wilhelm K., Abbo, L., Aucre, F., and et al., (2011), Morphology, dynamics and plasma parameters of plumes and inter-plume regions in solar coronal holes. The Astronomy and Astrophysics Review, 19, 35.
- [34] Priest E., Kirk J., Melrose D., (1994), Plasma astrophysics. Berlin: Springer-Verlag.
- [35] Marsch E., (1999), Solar wind models from the Sun to 1 AU: Constraints by in situ and remote sensing measurements. Coronal holes and solar wind acceleration, 1–24.
- [36] Endeve E., Leer E., (2001), Coronal heating and solar wind acceleration; gyrotropic electron-proton solar wind. Solar Physics, 200, 235-250.
- [37] Voitenko Y., Goossens M., (2002), Excitation of high-frequency Alfvén waves by plasma outflows from coronal reconnection events. Solar Physics, 206, 285-313.
- [38] Cranmer S. R., Kohl, J.L. and Noci, G. And et al., (1999), An empirical model of a polar coronal hole at solar minimum. The Astrophysical Journal, 511, 481.
- [39] Devlen E., Pekünlü E. R., (2010), MHD waves in the solar north polar coronal hole. Astronomische Nachrichten, 331, 716-724.
- [40] Raymond, J. C., Kohl, J. L., Noci, G., et al., (1997), Composition of Coronal Streamers from the SOHO Ultraviolet Coronagraph Spectrometer, Solar Physics, Volume 175, Issue 2, pp 645–665.
- [41] Cranmer S. R., Panasyuk A. V., Kohl J. L., (2008), The Astrophysical Journal, 678, 1480.
- [42] Wilhelm K., Marsch E., Dwivedi B. N., Hassler D. M., Lemaire P., Gabriel A. H., Huber M. C., (1998) The solar corona above polar coronal holes as seen by SUMER on SOHO. The Astrophysical Journal, 500, 1023.
- [43] Kohl J., Noci, G. and Antonucci, E., et al., (1997), The First Results from SOHO. Springer, pp 613–644.
- [44] Cranmer S. R., Panasyuk A. V., Kohl J. L., (2008), The Astrophysical Journal, 678, 1480.
- [45] Esser R., Fineschi S., Dobrzycka D., Habbal S. R., Edgar R. J., Raymond J. C., Kohl J. L., Guhathakurta M., 1998. Plasma properties in coronal holes derived from measurements of minor ion spectral lines and polarized white light intensity. The Astrophysical Journal Letters, 510, L63.
- [46] Devlen E., Zengin Çamurdan D., Yardımcı M., Pekünlü E. R., (2017), A new model for heating of the Solar North Polar Coronal Hole. Monthly Notices of the Royal Astronomical Society, 467, 133-144.
- [47] Hollweg J. V., 1999. Kinetic Alfvén wave revisited. Journal of Geophysical Research: Space Physics, 104, 14811-14819.
- [48] Priest E. R., 1987. Solar magneto-hydrodynamics. D. Reidel Pub. Co.
- [49] Spitzer Jr L., 1962. Physics of Fully Ionized Gases 2nd edition Interscience. New York.
- [50] Doğan, S., Pekünlü, E. R., (2012), Ion-cyclotron waves in solar coronal hole, New Astronomy, Volume 17, Issue 3, p. 316-324.
- [51] Hollweg, J. V., (1986), Transition region, corona, and solar wind in coronal holes, Journal of Geophysical Research, Volume 91, Issue A4, p. 4111-4125.
- [52] Hollweg J. V., Johnson W., 1988. Transition region, corona, and solar wind in coronal holes: Some two-fluid models. Journal of Geophysical Research: Space Physics, 93, 9547-9554.
- [53] Withbroe G. L., Noyes R. W., 1977. Mass and energy flow in the solar chromosphere and corona. Annual review of astronomy and astrophysics, 15, 363-387.
- [54] McIntosh, S. W., de Pontieu, B., Carlsson, M., Hansteen, V., Boerner, P., Goossens, M., (2011), Alfvénic waves with sufficient energy to power the quiet solar corona and fast solar wind, Nature, Volume 475, Issue 7357, pp. 477-480.
- [55] Cranmer, S. R., Matthaeus, W. H., Breech, B. A., Kasper, J. C., (2009), Empirical Constraints on Proton and Electron Heating in the Fast Solar Wind, The Astrophysical Journal, Volume 702, Issue 2, pp. 1604-1614.
- [56] Hahn, M., Landi, E., Savin, D. W., (2012), Evidence of Wave Damping at Low Heights in a Polar Coronal Hole, The Astrophysical Journal, Volume 753, Issue 1, article id. 36, 9 pp.
- [57] Hahn, M., Savin, D. W., (2013), Observational Quantification of the Energy Dissipated by Alfvén Waves in a Polar Coronal Hole: Evidence that Waves Drive the Fast Solar Wind, The Astrophysical Journal, Volume 776, Issue 2, article id. 78, 10 pp.
- [58] Antonucci E., Dodero M. A., Giordano S., 2000. Oxygen temperature anisotropy and solar wind heating above coronal holes out to 5 R. Solar Physics, 197, 115-134.
- [59] Telloni D., Antonucci E., Dodero M. A., 2007. Oxygen temperature anisotropy and solar wind heating above coronal holes out to 5 R. The Astronomy and Astrophysics, 476, 1341-1346.
Year 2023,
Issue: 053, 97 - 117, 30.06.2023
Ebru Baş
,
Dicle Zengin Çamurdan
References
- [1] Wedemeyer-Böhm, S., Lagg, A. , Nordlund, A., (2009), The Origin and Dynamics of Solar Magnetism, Space Sciences Series of ISSI, Volume 32. ISBN 978-1-4419-0238-2, Springer New York, p. 317.
- [2] Ofman, L., Davila, J. M., Steinolfson, R. S.,(1994), Nonlinear studies of coronal heating by the resonant absorption of Alfvén waves, Geophysical Research Letters, Volume 21, Issue 20, p. 2259-2262.
- [3] Pagano, P., De Moortel, I., (2017), Contribution of mode-coupling and phase-mixing of Alfvén waves to coronal heating, Astronomy & Astrophysics, Volume 601, id.A107, 13 pp.
- [4] Pagano, P., Pascoe, D. J., De Moortel, I., (2018), Contribution of phase-mixing of Alfvén waves to coronal heating in multi-harmonic loop oscillations, Astronomy & Astrophysics, Volume 616, id.A125, 12 pp.
- [5] Cargill, Peter J., Klimchuk, James A., (2004), Nanoflare Heating of the Corona Revisited, The Astrophysical Journal, Volume 605, Issue 2, pp. 911-920.
- [6] Klimchuk, J. A., (2006), On Solving the Coronal Heating Problem, Solar Physics, Volume 234, Issue 1, pp.41-77.
- [7] Chitta, L. P., Peter, H., Solanki, S. K., (2018), Nature of the energy source powering solar coronal loops driven by nanoflares, Astronomy & Astrophysics, Volume 615, id.L9, 6 pp.
- [8] Cranmer, S. R., Winebarger, A. R., (2019), The Properties of the Solar Corona and Its Connection to the Solar Wind, Annual Review of Astronomy and Astrophysics, vol. 57, p.157-187.
- [9] Viall, N. M., De Moortel, I.,Downs, C., Klimchuk, J. A., Parenti, S., Reale, F., (2021), The Heating of the Solar Corona, Space Physics and Aeronomy, Volume 1, Solar Physics and Solar Wind, Geophysical Monograph Series, Vol. 258. ISBN: 978-1-119-50753-6, 320 pp. American Geophysical Union, Wiley, 2021, p.35.
- [10] Tomczyk, S., McIntosh, S. W., Keil, S. L., Judge, P. G., Schad, T., Seeley, D. H., Edmondson, J., (2007), Alfvén Waves in the Solar Corona, Science, Volume 317, Issue 5842, pp. 1192.
- [11] Landi, E., Cranmer, S. R., (2009), Ion Temperatures in the Low Solar Corona: Polar Coronal Holes at Solar Minimum, The Astrophysical Journal, Volume 691, Issue 1, pp. 794-805.
- [12] Gupta, G. R., Banerjee, D., Teriaca, L., Imada, S., Solanki, S, (2010), Accelerating Waves in Polar Coronal Holes as Seen by EIS and SUMER, The Astrophysical Journal, Volume 718, Issue 1, pp. 11-22.
- [13] Bemporad, A., Abbo, L., (2012), Spectroscopic Signature of Alfvén Waves Damping in a Polar Coronal Hole up to 0.4 Solar Radii, The Astrophysical Journal, Volume 751, Issue 2, 110, 13 pp.
- [14] Cranmer, S. R., Gibson, S. E., Riley, P., (2017), Origins of the Ambient Solar Wind: Implications for Space Weather, Space Science Reviews, Volume 212, Issue 3-4, pp. 1345-1384.
- [15] Doyle J., Teriaca L., Banerjee D., (1999), Coronal hole diagnostics out to 8 R. Astronomy and Astrophysics, 349, 956.
- [16] Hassler D. M., Rottman G. J., Shoub E. C., Holzer T. E., (1990), Line broadening of MG X 609 and 625 A coronal emission lines observed above the solar limb. The Astrophysical Journal, 348, L77-80.
- [17] Saba J. L., Strong K. T., 1991. Coronal dynamics of a quiescent active region. The Astrophysical Journal, 375, 789-799.
- [18] Patsourakos, S., Klimchuk, J. A., (2006), Nonthermal Spectral Line Broadening and the Nanoflare Model, The Astrophysical Journal, Volume 647, Issue 2, pp. 1452-1465.
- [19] van Ballegooijen, A. A., Asgari-Targhi, M., Voss, A., (2017), The Heating of Solar Coronal Loops by Alfvén Wave Turbulence, The Astrophysical Journal, Volume 849, Issue 1, article id. 46, 23 pp.
- [20] Brooks, David H., Warren, Harry P., (2016), Measurements of Non-thermal Line Widths in Solar Active Regions, The Astrophysical Journal, Volume 820, Issue 1, article id. 63, 14 pp.
- [21] Ofman L., Nakariakov V., Sehgal N., (2000) Dissipation of slow magnetosonic waves in coronal plumes. The Astrophysical Journal, 533, 1071.
- [22] Nakariakov V. M., Ofman L., Arber T. D., (2000), Nonlinear dissipative spherical Alfvén waves in solar coronal holes. The Astronomy and Astrophysics, 353, 741-748.
- [23] Banerjee D., Gupta G. R., Teriaca L., (2011) Propagating MHD Waves in Coronal Holes. Space Science Reviews, 158, 267-288.
- [24] Wilhelm K., Marsch E., Dwivedi B. N., Hassler D. M., Lemaire P., Gabriel A. H., Huber M. C., (1998), The solar corona above polar coronal holes as seen by SUMER on SOHO. The Astrophysical Journal, 500, 1023.
- [25] Ruderman, M. S., Oliver, R., Erdélyi, R., Ballester, J. L., Goossens, M., (2000), Slow surface wave damping in plasmas with anisotropic viscosity and thermal conductivity, Astronomy and Astrophysics, v.354, p.261-276.
- [26] Banerjee, D., Pérez-Suárez, D., Doyle, J. G., (2009), Signatures of Alfvén waves in the polar coronal holes as seen by EIS/Hinode, Astronomy and Astrophysics, Volume 501, Issue 3, 2009, pp.L15-L18.
- [27] Morton R., Tomczyk S., Pinto R., 2015. Investigating Alfvénic wave propagation in coronal open-field regions. Nature Communications, 6, 1-12.
- [28] Pekünlü E. R., Bozkurt Z., Afsar M., Soydugan E., Soydugan F., (2002), Alfvén waves in the inner polar coronal hole. Monthly Notices of the Royal Astronomical Society, 336, 1195-1200.
- [29] Fisher R., Guhathakurta M., (1995), Physical properties of polar coronal rays and holes as observed with the Spartan 201-01 coronagraph. The Astrophysical Journal Letters, 447, L139.
- [30] Guhathakurta M., Fisher R., (1998), Solar Wind Consequences of a Coronal Hole Density Profile: Spartan 201-03 Coronagraph and Ulysses Observations from 1.15 R to 4 AU. The Astrophysical Journal Letters, 499, L215.
- [31] Banerjee D., Teriaca L., Doyle J., Wilhelm K., (1998), Broadening of SI VIII lines observed in the solar polar coronal holes. Astronomy and Astrophysics, 339, 208-214.
- [32] Doschek G., Warren H., Laming J., Mariska J., Wilhelm K., Lemaire P., Schühle U., Moran T., (1997), Electron densities in the solar polar coronal holes from density-sensitive line ratios of Si VIII and Sx. The Astrophysical Journal Letters, 482, L109.
- [33] Wilhelm K., Abbo, L., Aucre, F., and et al., (2011), Morphology, dynamics and plasma parameters of plumes and inter-plume regions in solar coronal holes. The Astronomy and Astrophysics Review, 19, 35.
- [34] Priest E., Kirk J., Melrose D., (1994), Plasma astrophysics. Berlin: Springer-Verlag.
- [35] Marsch E., (1999), Solar wind models from the Sun to 1 AU: Constraints by in situ and remote sensing measurements. Coronal holes and solar wind acceleration, 1–24.
- [36] Endeve E., Leer E., (2001), Coronal heating and solar wind acceleration; gyrotropic electron-proton solar wind. Solar Physics, 200, 235-250.
- [37] Voitenko Y., Goossens M., (2002), Excitation of high-frequency Alfvén waves by plasma outflows from coronal reconnection events. Solar Physics, 206, 285-313.
- [38] Cranmer S. R., Kohl, J.L. and Noci, G. And et al., (1999), An empirical model of a polar coronal hole at solar minimum. The Astrophysical Journal, 511, 481.
- [39] Devlen E., Pekünlü E. R., (2010), MHD waves in the solar north polar coronal hole. Astronomische Nachrichten, 331, 716-724.
- [40] Raymond, J. C., Kohl, J. L., Noci, G., et al., (1997), Composition of Coronal Streamers from the SOHO Ultraviolet Coronagraph Spectrometer, Solar Physics, Volume 175, Issue 2, pp 645–665.
- [41] Cranmer S. R., Panasyuk A. V., Kohl J. L., (2008), The Astrophysical Journal, 678, 1480.
- [42] Wilhelm K., Marsch E., Dwivedi B. N., Hassler D. M., Lemaire P., Gabriel A. H., Huber M. C., (1998) The solar corona above polar coronal holes as seen by SUMER on SOHO. The Astrophysical Journal, 500, 1023.
- [43] Kohl J., Noci, G. and Antonucci, E., et al., (1997), The First Results from SOHO. Springer, pp 613–644.
- [44] Cranmer S. R., Panasyuk A. V., Kohl J. L., (2008), The Astrophysical Journal, 678, 1480.
- [45] Esser R., Fineschi S., Dobrzycka D., Habbal S. R., Edgar R. J., Raymond J. C., Kohl J. L., Guhathakurta M., 1998. Plasma properties in coronal holes derived from measurements of minor ion spectral lines and polarized white light intensity. The Astrophysical Journal Letters, 510, L63.
- [46] Devlen E., Zengin Çamurdan D., Yardımcı M., Pekünlü E. R., (2017), A new model for heating of the Solar North Polar Coronal Hole. Monthly Notices of the Royal Astronomical Society, 467, 133-144.
- [47] Hollweg J. V., 1999. Kinetic Alfvén wave revisited. Journal of Geophysical Research: Space Physics, 104, 14811-14819.
- [48] Priest E. R., 1987. Solar magneto-hydrodynamics. D. Reidel Pub. Co.
- [49] Spitzer Jr L., 1962. Physics of Fully Ionized Gases 2nd edition Interscience. New York.
- [50] Doğan, S., Pekünlü, E. R., (2012), Ion-cyclotron waves in solar coronal hole, New Astronomy, Volume 17, Issue 3, p. 316-324.
- [51] Hollweg, J. V., (1986), Transition region, corona, and solar wind in coronal holes, Journal of Geophysical Research, Volume 91, Issue A4, p. 4111-4125.
- [52] Hollweg J. V., Johnson W., 1988. Transition region, corona, and solar wind in coronal holes: Some two-fluid models. Journal of Geophysical Research: Space Physics, 93, 9547-9554.
- [53] Withbroe G. L., Noyes R. W., 1977. Mass and energy flow in the solar chromosphere and corona. Annual review of astronomy and astrophysics, 15, 363-387.
- [54] McIntosh, S. W., de Pontieu, B., Carlsson, M., Hansteen, V., Boerner, P., Goossens, M., (2011), Alfvénic waves with sufficient energy to power the quiet solar corona and fast solar wind, Nature, Volume 475, Issue 7357, pp. 477-480.
- [55] Cranmer, S. R., Matthaeus, W. H., Breech, B. A., Kasper, J. C., (2009), Empirical Constraints on Proton and Electron Heating in the Fast Solar Wind, The Astrophysical Journal, Volume 702, Issue 2, pp. 1604-1614.
- [56] Hahn, M., Landi, E., Savin, D. W., (2012), Evidence of Wave Damping at Low Heights in a Polar Coronal Hole, The Astrophysical Journal, Volume 753, Issue 1, article id. 36, 9 pp.
- [57] Hahn, M., Savin, D. W., (2013), Observational Quantification of the Energy Dissipated by Alfvén Waves in a Polar Coronal Hole: Evidence that Waves Drive the Fast Solar Wind, The Astrophysical Journal, Volume 776, Issue 2, article id. 78, 10 pp.
- [58] Antonucci E., Dodero M. A., Giordano S., 2000. Oxygen temperature anisotropy and solar wind heating above coronal holes out to 5 R. Solar Physics, 197, 115-134.
- [59] Telloni D., Antonucci E., Dodero M. A., 2007. Oxygen temperature anisotropy and solar wind heating above coronal holes out to 5 R. The Astronomy and Astrophysics, 476, 1341-1346.