Annales Geophysicae www.ann-geophys.net 0992-7689 1432-0576 27 1 2009 10.5194/angeo-27-357-2009 http://www.ann-geophys.net/27/357/2009/ http://www.ann-geophys.net/27/357/2009/angeo-27-357-2009.html http://www.ann-geophys.net/27/357/2009/angeo-27-357-2009.pdf 357 371 2009-01-22 First simultaneous measurements of waves generated at the bow shock in the solar wind, the magnetosphere and on the ground L. B. N. Clausen lbnc1@ion.le.ac.uk T. K. Yeoman R. C. Fear R. Behlke E. A. Lucek M. J. Engebretson Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK Department of Physics, University of Tromsø, 9037 Tromsø, Norway Department of Physics, Imperial College London, London SW7 2AZ, UK Augsburg College, Minneapolis, Minnesota, USA On 5 September 2002 the Geotail satellite observed the cone angle of the Interplanetary Magnetic Field (IMF) change to values below 30&deg; during a 56 min interval between 18:14 and 19:10 UT. This triggered the generation of upstream waves at the bow shock, 13 <I>R_E</I> downstream of the position of Geotail. Upstream generated waves were subsequently observed by Geotail between 18:30 and 18:48 UT, during times the IMF cone angle dropped below values of 10&deg;. At 18:24 UT all four Cluster satellites simultaneously observed a sudden increase in wave power in all three magnetic field components, independent of their position in the dayside magnetosphere. We show that the 10 min delay between the change in IMF direction as observed by Geotail and the increase in wave power observed by Cluster is consistent with the propagation of the IMF change from the Geotail position to the bow shock and the propagation of the generated waves through the bow shock, magnetosheath and magnetosphere towards the position of the Cluster satellites. We go on to show that the wave power recorded by the Cluster satellites in the component containing the poloidal and compressional pulsations was broadband and unstructured; the power in the component containing toroidal oscillations was structured and shows the existence of multi-harmonic Alfvénic continuum waves on field lines. Model predictions of these frequencies fit well with the observations. An increase in wave power associated with the change in IMF direction was also registered by ground based magnetometers which were magnetically conjunct with the Cluster satellites during the event. To the best of our knowledge we present the first simultaneous observations of waves created by backstreaming ions at the bow shock in the solar wind, the dayside magnetosphere and on the ground. Arthur, C W. and McPherron, R L.: Interplanetary magnetic field conditions associated with synchronous orbit observations of Pc3 magnetic pulsations, J. Geophys. Res., 82, 5138–5142, 1977. Chi, P J. and Russell, C T.: Phase skipping and Poynting flux of continuous pulsations, J. Geophys. Res., 103, 29479–29492, \doi10.1029/98JA02101, 1998. Chi, P J., Russell, C T., Raeder, J., Zesta, E., Yumoto, K., Kawano, H., Kitamura, K., Petrinec, S M., Angelopoulos, V., Le, G., and Moldwin, M B.: Propagation of the preliminary reverse impulse of sudden commencements to low latitudes, J. Geophys. Res., 106, 18857–18864, \doi10.1029/2001JA900071, 2001. Denton, R E., Goldstein, J., Menietti, J D., and Young, S L.: Magnetospheric electron density model inferred from Polar plasma wave data, J. Geophys. Res., 107, 25–1, \doi10.1029/2001JA009136, 2002. Dunlop, M W., Lavraud, B., Cargill, P., Taylor, M G G T., Balogh, A., Réme, H., Decreau, P., Glassmeier, K.-H., Elphic, R C., Bosqued, J.-M., Fazakerley, A N., Dandouras, I., Escoubet, C P., Laakso, H., and Marchaudon, A.: Cluster Observations of the CUSP: Magnetic Structure and Dynamics, Surv. Geophys., 26, 5–55, \doi10.1007/s10712-005-1871-7, 2005. Engebretson, M J., Zanetti, L J., Potemra, T A., and Acuna, M H.: Harmonically structured ULF pulsations observed by the AMPTE CCE magnetic field experiment, Geophys. Res. Lett., 13, 905–908, 1986. Feldstein, Y I. and Starkov, G V.: Dynamics of auroral belt and polar geomagnetic disturbances, Planet. Space Sci., 15, 209–229, 1967. Greenstadt, E W., McPherron, R L., and Takahashi, K.: Solar wind control of daytime, midperiod geomagnetic pulsations, pp. 89–110, ULF pulsations in the magnetosphere,~A82-37426 18-46, Tokyo, Center for Academic Publications Japan, D Reidel Publishing Co., Dordrecht, p 89–110, 1981. Khan, H. and Cowley, S. W. H.: Observations of the response time of high-latitude ionospheric convection to variations in the interplanetary magnetic field using EISCAT and IMP-8 data, Ann. Geophys., 17, 1306–1335, 1999. Krauss-Varban, D.: Bow Shock and Magnetosheath Simulations: Wave Transport and Kinetic Properties, in: Solar Wind Sources of Magnetospheric Ultra-Low-Frequency Waves, edited by: Engebretson, M J., Takahashi, K., and Scholer, M., pp. 121–134, 1994. Le, G. and Russell, C T.: A study of ULF wave foreshock morphology-I: ULF foreshock boundary, Planet. Space Sci., 40, 1203–1213, \doi10.1016/0032-0633(92)90077-2, 1992a. Le, G. and Russell, C T.: A study of ULF wave foreshock morphology-II: spatial variation of ULF waves, Planet. Space Sci., 40, 1215–1225, \doi10.1016/0032-0633(92)90078-3, 1992b. Odera, T J.: Solar wind controlled pulsations: a review., Rev. Geophys., 24, 55–74, 1986. Peredo, M., Slavin, J A., Mazur, E., and Curtis, S A.: Three-dimensional position and shape of the bow shock and their variation with Alfvenic, sonic and magnetosonic Mach numbers and interplanetary magnetic field orientation, J. Geophys. Res., 100, 7907–7916, 1995. Schulz, M.: Eigenfrequencies of geomagnetic field lines and implications for plasma-density modeling, J. Geophys. Res., 101, 17385–17398, \doi10.1029/95JA03727, 1996. Shue, J.-H., Chao, J K., Fu, H C., Russell, C T., Song, P., Khurana, K K., and Singer, H J.: A new functional form to study the solar wind control of the magnetopause size and shape, J. Geophys. Res., 102, 9497–9512, \doi10.1029/97JA00196, 1997. Takahashi, K., McPherron, R L., and Terasawa, T.: Dependence of the spectrum of Pc 3-4 pulsations on the interplanetary magnetic field, J. Geophys. Res., 89, 2770–2780, 1984. Troitskaya, V A., Plyasova-Bakunina, T A., and Gul'elmi, A V.: Relationship between Pc 2-4 pulsations and the interplanetary field, Dokl. Akad. Nauk. SSSR, 197, 1313–?, 1971. Trotignon, J. G., Décréau, P. M. E., Rauch, J. L., Randriamboarison, O., Krasnoselskikh, V., Canu, P., Alleyne, H., Yearby, K., Le Guirriec, E., Séran, H. C., Sené, F. X., Martin, Ph., Lévêque, M., and Fergeau, P.: How to determine the thermal electron density and the magnetic field strength from the Cluster/Whisper observations around the Earth, Ann. Geophys., 19, 1711–1720, 2001. Tsyganenko, N A.: Modeling the Earth's magnetospheric magnetic field confined within a realistic magnetopause, J. Geophys. Res., 100, 5599–5612, 1995. Waters, C L., Menk, F W., and Fraser, B J.: The resonance structure of low latitude Pc3 geomagnetic pulsations, Geophys. Res. Lett., 18, 2293–2296, 1991. Webb, D. and Orr, D.: Geomagnetic pulsations (5-50 mHz) and the interplanetary magnetic field, J. Geophys. Res., 81, 5941–5947, 1976.