Иркутск, Россия
Иркутск, Россия
Using data on three superstorms, we study new features of the saturation of the polar cap area when the solar wind (SW) increases. The polar cap saturation is shown to occur when the SW dynamic pressure and southward vertical (IMF) component rise. The saturation is realized not only during the passage of interplanetary magnetic clouds, but also at significant enhancement of SW density when the SW thermal pressure is comparable with the pressure of the interplanetary magnetic field. We assume that under such conditions the saturation is caused not only by a decrease in the efficiency of reconnection at the dayside magnetopause, but mainly by finite magnetosphere compressibility — stopping the magnetopause compression due to a rapid earthward growth of the geomagnetic field, i.e. the inner magnetospheric structure of the geomagnetic field. We have found signs of saturation depending on the northward IMF component. We assume that the IMF-dependent saturation exists for both signs of its vertical component due to an increase in the total pressure in the magnetosheath. Moreover, when penetrating into the magnetosphere, the southward IMF component reduces the geomagnetic field and thereby causes additional compression of the magnetopause and, accordingly, an increase in the saturation level of the polar cap area.
magnetosphere, solar wind, polar cap, magnetic flux
1. Alex S., Mukherjee S., Lakhina G.S. Geomagnetic signatures during the intense geomagnetic storms of 29 October and 20 November 2003. J. Atmos. Sol. Terr. Phys. 2006, vol. 68, no. 7. pp. 769–780. DOI: 10.1016/j.jastp.2006.01.003.
2. Bazarshapov A.D., Mishin V.M., Shpynev G.B. A Mathematical Analysis of Geomagnetic Variation Fields. Gerlands Beitr. Geophysik. 1976, vol. 85, no. 1, pp. 76–82.
3. Borovsky J.E., Lavraud B., Kuznetsova M.M. Polar cap potential saturation, dayside reconnection, and changes to the magnetosphere. J. Geophys. Res. 2009, vol. 114, A03224. DOI: 10.1029/2009JA014058.
4. Dmitriev A., Suvorova A., Chao J.-K. A predictive model of geosynchronous magnetopause crossings. J. Geophys. Res. 2011, vol. 116, A05208. DOI: 10.1029/2010JA016208.
5. Dmitriev A.V., Suvorova A.V., Chao J.-K., Wang C.B., Rastaetter L., Panasyuk M.I., Lazutin L.L., Kovtyukh A.S., Veselovsky I.S., Myagkova I.N. Anomalous dynamics of the extremely compressed magnetosphere during 21 January 2005 magnetic storm. J. Geophys. Res. 2014, vol. 119, no. 2, pp. 877–896. DOI: 10.1002/2013JA019534.
6. Gao Y., Kivelson M.G., Walker R.J. Two models of cross polar cap potential saturation compared: Siscoe-Hill model versus Kivelson-Ridley model. J. Geophys. Res. Space Physics. 2013, vol. 118, no. 2, pp. 794–803.
7. Huttunen K.E.J., Koskinen H.E.J., Pulkkinen T.I., Pulkkinen A., Palmroth M., Reeves G.D., Singer H.J. April 2000 magnetic storm: Solar wind driver and magnetospheric response. J. Geophys. Res. 2002, vol. 107, no. A12, p. 1440.
8. Iijima T., Potemra T.A. Large-scale characteristics of field-aligned currents associated with substorms. J. Geophys. Res. 1978, vol. 83, no. A2, pp. 599–615.
9. Kalegaev V.V., Makarenkov E.V. Relative importance of ring and tail currents to Dst under extremely disturbed conditions. J. Atmos. Solar-Terr. Phys. 2008, vol. 70, p. 519.
10. Kan J., Lee L. Energy coupling function and solar wind magnetosphere dynamo. Geophys. Res. Lett. 1979, vol. 6, pp. 577–580.
11. Kan J.R., Li H., Wang C., Tang B.B., Hu Y.Q. Saturation of polar cap potential: Nonlinearity in quasi-steady solar wind–magnetosphere–ionosphere coupling. J. Geophys. Res. 2010, vol. 115, no. A8, pp. A08226. DOI: 10.1029/2009JA014389.
12. Karavaev Yu.A., Shapovalova A.A., Mishin V.M., Mishin V.V. The superstorm on 20.11.2003: Identification of hidden dependencies of the tail lobe magnetic flux on the solar wind dynamic pressure. Proc. 9th International Conference “Problems of Geocosmos”, St. Petersburg, Petrodvorets, Russia, October. 2012a, pp. 245–250.
13. Karavaev Y.A., Shapovalova A.A., Mishin V.M., Mishin V.V. Super-storm 24-25.09.1998: identification of hidden dependencies of the tail lobe magnetic flux on the solar wind dynamic pressure. Proc. 9th International Conference “Problems of Geocosmos”, St. Petersburg, Petrodvorets, Russia, October 2012b, pp. 251–255.
14. Kivelson M.G., Ridley A.J. Saturation of the polar cap potential: Inference from Alfven wing arguments. J. Geophys. Res. 2008, vol. 113, DOI: 10.1029/2007ja012302.
15. Kovner M.S., Feldstein Ya.I. On solar wind interaction with the Earth’s magnetosphere. Planet. Space Sci. 1973, vol. 21, pp. 1191–1211.
16. Kuznetsov S.N., Suvorova A.V. Solar wind magnetic field and plasma during magnetopause crossings at geosynchronous orbit. Adv. Space Res. 1998, vol. 22, no. 1, pp. 63–66.
17. Lavraud B., Borovsky J.E. Altered solar wind-magnetosphere interaction at low Mach numbers: Coronal mass ejections. J. Geophys. Res. 2008, vol. 113, A00B08. DOI: 10.1029/2008JA013192.
18. Lopez R.E., Bruntz R., Mitchell E.J., Wiltberger M., Lyon J.G., Merkin V.G. Role of magnetosheath force balance in regulating the dayside reconnection potential. J. Geophys. Res. 2010, vol. 115, A12216. DOI: 10.1029/2009JA014597.
19. Lyatsky W., Khazanov G.V., Slavin J.A. Saturation of the electric field transmitted to the magnetosphere. J. Geophys. Res. 2010, vol. 115, no. A8, pp. A08221. DOI: 10.1029/ 2009JA015091.
20. Maltsev Yu.P, Lyatsky W.B. Field-aligned currents and erosion of dayside magnetosphere. Planet. Space Sci. 1975, vol. 23, pp. 1257–1261.
21. Merkin V.G., Goodrich C.C. Does the polar cap area saturate? Geophys. Res. Lett. 2007, vol. 34, no. 9, p. L09107.
22. Mishin V.M. The magnetogram inversion technique and some applications. Space Sci Rev. 1990, vol. 53, no. 1, pp. 83–163.
23. Mishin V.M. The Magnetogram Inversion Technique — Applications to the Problem of Magnetospheric Substorms. Space Sci Rev. 1991, vol. 57, no. 3–4. pp. 237–337.
24. Mishin V.M., Russell C.T., Saifudinova T.I., Bazarzha-pov A.D. Study of weak substorms observed during December 8, 1990, Geospace Environment Modeling campaign: Timing of different types of substorm onsets. J. Geophys. Res. 2000, vol. 105, no. A10, pp. 23263–23276. DOI: 10.1029/ 1999ja900495.
25. Mishin V.M., Förster M., Kurikalova M.A., Mishin V.V. The generator system of field-aligned currents during the April 06, 2000, superstorm. Adv. Space Res. 2011, vol. 48, no. 7, pp. 1172–1183.
26. Mishin V.V., Mishin V.M., Pu Z., Lunyushkin S.B., Sapronova L.A., Sukhbaatar U., Baishev D.G. Old tail lobes effect on the solar wind — magnetosphere energy transport for the 27 August 2001 substorm. Adv. Space Res. 2014, vol. 54, no. 12, pp. 2540–2548. DOI: 10.1016/j.asr.2014.09.013.
27. Mishin V.V., Karavaev Y., Han J.P., Wang C. The saturation effect of the Poynting flux into the magnetosphere during superstorms: results of mit and the global PPMLR-MHD model... “Physics of Auroral Phenomena”. Proc. XXXVIII Annual Seminar, Apatity. A.G. Yahnin. Apatity, Kola Science Centre, Russian Academy of Science. 2015, pp. 40–43.
28. Mishin V.V., Mishin V.M., Karavaev Y., Han J.P., Wang C. Saturation of superstorms and finite compressibility of the magnetosphere: Results of the magnetogram inversion technique and global PPMLR-MHD model. Geophys. Res. Lett. 2016, vol. 43, no. 13, pp. 6734–6741. DOI: 10.1002/2016 GL069649.
29. Perreault P., Akasofu S.I. A study of geomagnetic storms. Geophys. J. R. Astr. Soc. 1978, vol. 54, no. 3, pp. 547–573. DOI: 10.1111/j.1365-246X.1978.tb05494.x.
30. Pulkkinen T.I., Dimmock A.P., Lakka A., Osmane A., Kilpua E., Myllys M., Tanskanen E.I., Viljanen A. Magnetosheath control of solar wind–magnetosphere coupling efficiency. J. Geophys. Res. Space Phys. 2016, vol. 121, pp. 8728–8739. DOI: 10.1002/2016JA023011.
31. Russell C.T., Wang Y.L., Raeder J., Tokar R.L., Smith C.W., Ogilvie K.W., Lazarus A.J., Lepping R.P., Szabo A., Kawano H., Mukai T., Savin S., Yermolaev Y.I., Zhou X.-Y., Tsurutani B.T. The interplanetary shock of September 24, 1998: Arrival at Earth. J. Geophys. Res. 2000, vol. 105, no. A11, pp. 25143–25154. DOI: 10.1029/ 2000ja900070.
32. Shue J.H., Chao J.K., Fu H.C., Russell C.T., Song P., Khurana K. K., Singer H. A new functional form to study the control of the magnetopause size and shape. J. Geophys. Res. 1997, vol. 102, p. 9497.
33. Shue J.H., Song P., Russell C.T., Khurana K.K., Russell C.T., Singer H.J., Song P. Magnetopause location under extreme solar wind conditions. J. Geophys. Res. 1998, vol. 103, no. A8, pp. 17691–17700.
34. Siscoe G.L., Crooker N.U., Siebert K.D. Transpolar potential saturation: Roles of region 1 current system and solar wind ram pressure. J. Geophys. Res. 2002, vol. 107, no. A10, p. 1321.
35. Suvorova A., Dmitriev A., Chao J.-K., Thomsen M., Yang Y.-H. Necessary conditions for geosynchronous magnetopause crossings. J. Geophys. Res. 2005, vol. 110, A01206. DOI: 10.1029/2003JA010079.
36. Wilder F.D., Clauer C.R., Baker J., Cousins E.P., Hairston M.R. The nonlinear response of the polar cap potential under southward IMF: A statistical view. J. Geophys. Res. 2011, vol. 116, no. A12, p. A12229.
37. URL: http.gsfc.cdaw.gov (accessed April 14, 2017).
