References

ANGEO

Annales Geophysicae

ANGEO

Ann. Geophys.

1432-0576

Copernicus Publications

Göttingen, Germany

10.5194/angeo-32-157-2014

A model of the magnetosheath magnetic field during magnetic clouds

Turc

https://orcid.org/0000-0002-7576-3251

¹ Fontaine

https://orcid.org/0000-0002-4348-2623

¹ Savoini

¹ Kilpua

E. K. J.

Ecole Polytechnique, CNRS, Sorbonne Universités, UPMC Univ Paris 06, Univ Paris-Sud, UMR7648, Laboratoire de Physique des Plasmas, 91128, Palaiseau, France

Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland

21 02 2014

32 2 157 173

2014

This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/

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The full text article is available as a PDF file from https://angeo.copernicus.org/articles/32/157/2014/angeo-32-157-2014.pdf

Magnetic clouds (MCs) are huge interplanetary structures which originate from the Sun and have a paramount importance in driving magnetospheric storms. Before reaching the magnetosphere, MCs interact with the Earth's bow shock. This may alter their structure and therefore modify their expected geoeffectivity. We develop a simple 3-D model of the magnetosheath adapted to MCs conditions. This model is the first to describe the interaction of MCs with the bow shock and their propagation inside the magnetosheath. We find that when the MC encounters the Earth centrally and with its axis perpendicular to the Sun–Earth line, the MC's magnetic structure remains mostly unchanged from the solar wind to the magnetosheath. In this case, the entire dayside magnetosheath is located downstream of a quasi-perpendicular bow shock. When the MC is encountered far from its centre, or when its axis has a large tilt towards the ecliptic plane, the MC's structure downstream of the bow shock differs significantly from that upstream. Moreover, the MC's structure also differs from one region of the magnetosheath to another and these differences vary with time and space as the MC passes by. In these cases, the bow shock configuration is mainly quasi-parallel. Strong magnetic field asymmetries arise in the magnetosheath; the sign of the magnetic field north–south component may change from the solar wind to some parts of the magnetosheath. We stress the importance of the Bx component. We estimate the regions where the magnetosheath and magnetospheric magnetic fields are anti-parallel at the magnetopause (i.e. favourable to reconnection). We find that the location of anti-parallel fields varies with time as the MCs move past Earth's environment, and that they may be situated near the subsolar region even for an initially northward magnetic field upstream of the bow shock. Our results point out the major role played by the bow shock configuration in modifying or keeping the structure of the MCs unchanged. Note that this model is not restricted to MCs, it can be used to describe the magnetosheath magnetic field under an arbitrary slowly varying interplanetary magnetic field.

References 1

Bothmer, V. and Schwenn, R.: The structure and origin of magnetic clouds in the solar wind, Ann. Geophys., 16, 1–24, <a href="http://dx.doi.org/10.1007/s00585-997-0001-x">https://doi.org/10.1007/s00585-997-0001-x</a>, 1998.

Burlaga, L., Sittler, E., Mariani, F., and Schwenn, R.: Magnetic loop behind an interplanetary shock – Voyager, Helios, and IMP 8 observations, J. Geophys. Res., 86, 6673–6684, <a href="http://dx.doi.org/10.1029/JA086iA08p06673">https://doi.org/10.1029/JA086iA08p06673</a>, 1981.

Burlaga, L. F.: Magnetic clouds and force-free fields with constant alpha, J. Geophys. Res., 93, 7217–7224, 1988.

Chen, J., Slinker, S. P., and Triandaf, I.: Bayesian prediction of geomagnetic storms: Wind data, 1996–2010, Space Weather, 10, S04005, <a href="http://dx.doi.org/10.1029/2011SW000740">https://doi.org/10.1029/2011SW000740</a>, 2012.

Coleman, I. J.: A multi-spacecraft survey of magnetic field line draping in the dayside magnetosheath, Ann. Geophys., 23, 885-900, <a href="http://dx.doi.org/10.5194/angeo-23-885-2005">https://doi.org/10.5194/angeo-23-885-2005</a>, 2005.

Dungey, J. W.: Interplanetary Magnetic Field and the Auroral Zones, Phys. Rev. Lett., 6, 47–48, <a href="http://dx.doi.org/10.1103/PhysRevLett.6.47">https://doi.org/10.1103/PhysRevLett.6.47</a>, 1961.

Echer, E., Alves, M. V., and Gonzalez, W. D.: A statistical study of magnetic cloud parameters and geoeffectiveness, J. Atmos. Sol.-Terr. Phys., 67, 839–852, <a href="http://dx.doi.org/10.1016/j.jastp.2005.02.010">https://doi.org/10.1016/j.jastp.2005.02.010</a>, 2005.

Echer, E., Gonzalez, W. D., Tsurutani, B. T., and Gonzalez, A. L. C.: Interplanetary conditions causing intense geomagnetic storms (Dst ≤ −100 nT) during solar cycle 23 (1996–2006), J. Geophys. Res., 113, A05221, <a href="http://dx.doi.org/10.1029/2007JA012744">https://doi.org/10.1029/2007JA012744</a>, 2008.

Farris, M. H. and Russell, C. T.: Determining the standoff distance of the bow shock: Mach number dependence and use of models, J. Geophys. Res., 99, 17681, <a href="http://dx.doi.org/10.1029/94JA01020">https://doi.org/10.1029/94JA01020</a>, 1994.

Farris, M. H., Petrinec, S. M., and Russell, C. T.: The thickness of the magnetosheath – Constraints on the polytropic index, Geoph. Res. Lett., 18, 1821–1824, <a href="http://dx.doi.org/10.1029/91GL02090">https://doi.org/10.1029/91GL02090</a>, 1991.

Génot, V., Broussillou, L., Budnik, E., Hellinger, P., Trávníček, P. M., Lucek, E., and Dandouras, I.: Timing mirror structures observed by Cluster with a magnetosheath flow model, Ann. Geophys., 29, 1849–1860, <a href="http://dx.doi.org/10.5194/angeo-29-1849-2011">https://doi.org/10.5194/angeo-29-1849-2011</a>, 2011.

Gopalswamy, N., Akiyama, S., Yashiro, S., Michalek, G., and Lepping, R. P.: Solar sources and geospace consequences of interplanetary magnetic clouds observed during solar cycle 23, J. Atmos. Sol.-Terr. Phys., 70, 245–253, <a href="http://dx.doi.org/10.1016/j.jastp.2007.08.070">https://doi.org/10.1016/j.jastp.2007.08.070</a>, 2008

Huttunen, K. E. J., Schwenn, R., Bothmer, V., and Koskinen, H. E. J.: Properties and geoeffectiveness of magnetic clouds in the rising, maximum and early declining phases of solar cycle 23, Ann. Geophys., 23, 625–641, <a href="http://dx.doi.org/10.5194/angeo-23-625-2005">https://doi.org/10.5194/angeo-23-625-2005</a>, 2005.

Je\v ráb, M., N\v eme\v cek, Z., \v S}afránková, J., Jel{ínek, K., and M\v erka, J.: Improved bow shock model with dependence on the IMF strength, Planet. Space Sci., 53, 85–93, <a href="http://dx.doi.org/10.1016/j.pss.2004.09.032">https://doi.org/10.1016/j.pss.2004.09.032</a>, 2005.

Kallio, E. J. and Koskinen, H. E. J.: A semiempirical magnetosheath model to analyze the solar wind-magnetosphere interaction, J. Geophys. Res., 105, 27469–27480, <a href="http://dx.doi.org/10.1029/2000JA900086">https://doi.org/10.1029/2000JA900086</a>, 2000.

Kobel, E. and Flückiger, E. O.: A model of the steady state magnetic field in the magnetosheath, J. Geophys. Res., 99, 23617–23622, <a href="http://dx.doi.org/10.1029/94JA01778">https://doi.org/10.1029/94JA01778</a>, 1994.

Lavraud, B. and Borovsky, J. E.: Altered solar wind-magnetosphere interaction at low Mach numbers: Coronal mass ejections, J. Geophys. Res., 113, A00B08, <a href="http://dx.doi.org/10.1029/2008JA013192">https://doi.org/10.1029/2008JA013192</a>, 2008

Lavraud, B., Larroque, E., Budnik, E., Génot, V., Borovsky, J. E., Dunlop, M. W., Foullon, C., Hasegawa, H., Jacquey, C., Nykyri, K., Ruffenach, A., Taylor, M. G. G. T., Dandouras, I., and Rème, H.: Asymmetry of magnetosheath flows and magnetopause shape during low Alfvén Mach number solar wind, J. Geophys. Res., 118, 1089–1100, <a href="http://dx.doi.org/10.1002/jgra.50145">https://doi.org/10.1002/jgra.50145</a>, 2013.

Lepping, R. P., Berdichevsky, D. B., Wu, C.-C., Szabo, A., Narock, T., Mariani, F., Lazarus, A. J., and Quivers, A. J.: A summary of WIND magnetic clouds for years 1995–2003: model-fitted parameters, associated errors and classifications, Ann. Geophys., 24, 215–245, <a href="http://dx.doi.org/10.5194/angeo-24-215-2006">https://doi.org/10.5194/angeo-24-215-2006</a>, 2006.

Longmore, M., Schwartz, S. J., Geach, J., Cooling, B. M. A., Dandouras, I., Lucek, E. A., and Fazakerley, A. N.: Dawn-dusk asymmetries and sub-Alfvénic flow in the high and low latitude magnetosheath, Ann. Geophys., 23, 3351–3364, <a href="http://dx.doi.org/10.5194/angeo-23-3351-2005">https://doi.org/10.5194/angeo-23-3351-2005</a>, 2005.

Longmore, M., Schwartz, S. J., and Lucek, E. A.: Rotation of the magnetic field in Earth's magnetosheath by bulk magnetosheath plasma flow, Ann. Geophys., 24, 339–354, <a href="http://dx.doi.org/10.5194/angeo-24-339-2006">https://doi.org/10.5194/angeo-24-339-2006</a>, 2006.

M\v erka, J., Szabo, A., Narock, T. W., King, J. H., Paularena, K. I., and Richardson, J. D.: A comparison of IMP 8 observed bow shock positions with model predictions, J. Geophys. Res., 108, 1077, <a href="http://dx.doi.org/10.1029/2002JA009384">https://doi.org/10.1029/2002JA009384</a>, 2003.

Mulligan, T., Russell, C. T., and Luhmann, J. G.: Solar cycle evolution of the structure of magnetic clouds in the inner heliosphere, Geophys. Res. Lett., 25, 2959–2963, <a href="http://dx.doi.org/10.1029/98GL01302">https://doi.org/10.1029/98GL01302</a>, 1998.

Paschmann, G.: Recent in-situ observations of magnetic reconnection in near-Earth space, Geophys. Res. Lett., 35, 19109, <a href="http://dx.doi.org/10.1029/2008GL035297">https://doi.org/10.1029/2008GL035297</a>, 2008.

Richardson, I. G. and Cane, H. V.: Near-Earth Interplanetary Coronal Mass Ejections During Solar Cycle 23 (1996–2009): Catalog and Summary of Properties, Solar Phys., 264, 189–237, <a href="http://dx.doi.org/10.1007/s11207-010-9568-6">https://doi.org/10.1007/s11207-010-9568-6</a>, 2010.

Richardson, I. G., Cliver, E. W., and Cane, H. V.: Sources of geomagnetic storms for solar minimum and maximum conditions during 1972–2000, Geophys. Res. Lett., 28, 2569–2572, <a href="http://dx.doi.org/10.1029/2001GL013052">https://doi.org/10.1029/2001GL013052</a>, 2001.

Richardson, I. G., Cane, H. V., and Cliver, E. W.: Sources of geomagnetic activity during nearly three solar cycles (1972–2000), J. Geophys. Res., 107, 1187, <a href="http://dx.doi.org/10.1029/2001JA000504">https://doi.org/10.1029/2001JA000504</a>, 2002.

Romashets, E. P., Poedts, S., and Vandas, M.: Modeling of the magnetic field in the magnetosheath region, J. Geophys. Res., 113, A02203, <a href="http://dx.doi.org/10.1029/2006JA012072">https://doi.org/10.1029/2006JA012072</a>, 2008.

Russell, C. T., Luhmann, J. G., Odera, T. J., and Stuart, W. F.: The rate of occurrence of dayside Pc 3,4 pulsations – The L-value dependence of the IMF cone angle effect, Geophys. Res. Lett., 10, 663–666, <a href="http://dx.doi.org/10.1029/GL010i008p00663">https://doi.org/10.1029/GL010i008p00663</a>, 1983.

\v Safránková, J., Hayosh, M., Gutynska, O., N\v eme\v cek, Z., and P\v rech, L.: Reliability of prediction of the magnetosheath BZ component from interplanetary magnetic field observations, J. Geophys. Res., 114, A12213, <a href="http://dx.doi.org/10.1029/2009JA014552">https://doi.org/10.1029/2009JA014552</a>, 2009.

Shue, J.-H., Song, P., Russell, C. T., Steinberg, J. T., Chao, J. K., Zastenker, G., Vaisberg, O. L., Kokubun, S., Singer, H. J., Detman, T. R., and Kawano, H.: Magnetopause location under extreme solar wind conditions, J. Geophys. Res., 103, 17691–17700, <a href="http://dx.doi.org/10.1029/98JA01103">https://doi.org/10.1029/98JA01103</a>, 1998.

Soucek, J. and Escoubet, C. P.: Predictive model of magnetosheath plasma flow and its validation against Cluster and THEMIS data, Ann. Geophys., 30, 973–982, <a href="http://dx.doi.org/10.5194/angeo-30-973-2012">https://doi.org/10.5194/angeo-30-973-2012</a>, 2012.

Spreiter, J. R., Summers, A. L., and Alksne, A. Y.: Hydromagnetic flow around the magnetosphere, Planet. Space. Sci., 14, 223–250, <a href="http://dx.doi.org/10.1016/0032-0633(66)90124-3">https://doi.org/10.1016/0032-0633(66)90124-3</a>, 1966.

Spreiter, J. R. and Stahara, S. S.: Gasdynamic and magnetohydrodynamic modeling of the magnetosheath: A tutorial, Adv. Space Res., 14, 5–19, <a href="http://dx.doi.org/10.1016/0273-1177(94)90042-6">https://doi.org/10.1016/0273-1177(94)90042-6</a>, 1994.

Stahara, S. S.: Adventures in the magnetosheath: two decades of modeling and planetary applications of the Spreiter magnetosheath model, Planet. Space Sci., 50, 421–442, <a href="http://dx.doi.org/10.1016/S0032-0633(02)00023-5">https://doi.org/10.1016/S0032-0633(02)00023-5</a>, 2002

Tatrallyay, M., Russell, C. T., Luhmann, J. G., Barnes, A., and Mihalov, J. D.: On the proper Mach number and ratio of specific heats for modeling the Venus bow shock, J. Geophys. Res., 89, 7381–7392, <a href="http://dx.doi.org/10.1029/JA089iA09p07381">https://doi.org/10.1029/JA089iA09p07381</a>, 1984.

Tsyganenko, N. A.: Modeling the Earth's magnetospheric magnetic field confined within a realistic magnetopause, J. Geophys. Res., 100, 5599–5612, <a href="http://dx.doi.org/10.1029/94JA03193">https://doi.org/10.1029/94JA03193</a>, 1995.

Tsyganenko, N. A.: Effects of the solar wind conditions in the global magnetospheric configurations as deduced from data-based field models (Invited), International Conference on Substorms, ESA Special Publication, 389, Rolfe, E. J. and Kaldeich, B., 181 pp., 1996.

Turc, L., Fontaine, D., Savoini, P., Hietala, H., and Kilpua, E. K. J.: A comparison of bow shock models with Cluster observations during low Alfvén Mach number magnetic clouds, Ann. Geophys., 31, 1011–1019, <a href="http://dx.doi.org/10.5194/angeo-31-1011-2013">https://doi.org/10.5194/angeo-31-1011-2013</a>, 2013.

Walsh, B. M., Sibeck, D. G., Wang, Y., and Fairfield, D. H.: Dawn-dusk asymmetries in the Earth's magnetosheath, J. Geophys. Res., 117, A12211, <a href="http://dx.doi.org/10.1029/2012JA018240">https://doi.org/10.1029/2012JA018240</a>, 2012.

Wu, C.-C. and Lepping, R. P.: Statistical Comparison of Magnetic Clouds with Interplanetary Coronal Mass Ejections for Solar Cycle 23, Sol. Phys., 269, 141–153, <a href="http://dx.doi.org/10.1007/s11207-010-9684-3">https://doi.org/10.1007/s11207-010-9684-3</a>, 2011.

Yermolaev, Y. I., Nikolaeva, N. S., Lodkina, I. G., and Yermolaev, M. Y.: Geoeffectiveness and efficiency of CIR, sheath, and ICME in generation of magnetic storms, J. Geophys. Res., 117, A00L07, <a href="http://dx.doi.org/10.1029/2011JA017139">https://doi.org/10.1029/2011JA017139</a>, 2012

Zhang, J., Liemohn, M. W., Kozyra, J. U., Lynch, B. J., and Zurbuchen, T. H.: A statistical study of the geoeffectiveness of magnetic clouds during high solar activity years, J. Geophys. Res., 109, A09101, <a href="http://dx.doi.org/10.1029/2004JA010410">https://doi.org/10.1029/2004JA010410</a>, 2004.