Midday magnetopause shifts earthward of geosynchronous orbit during geomagnetic superstorms with Dst ≤ −300 nT

[1] Geomagnetic storm intensity, as measured by the Dst (SYMH) index, shows no limit as the solar wind dawn-to-dusk electric field increases. We show that the magnetopause around noon erodes earthward with increasing storm intensity. The panoramic geosynchronous B Z signatures for the magnetic storm groups with different intensity are differ significantly from each other. For superstorms with SYMH ≤ -300 nT, the magnetopause around noon erodes to inside the geosynchronous orbit, which causes the B Z reversal near local noon. The necessary conditions for superstorms with SYMH ≤ -300 nT to occur include the following: (I) interplanetary magnetic field (IMF) B Z ~ 12 nPa; (3) the projected interplanetary electric field, E K - L > ~30 mV/m.

[1]  Z. Y. Li,et al.  Precursor activation and substorm expansion associated with observations of a dipolarization front by Thermal Emission Imaging System (THEMIS) , 2010 .

[2]  Christopher Portier,et al.  Risk factors for childhood leukaemia. Discussion and summary. , 2008, Radiation protection dosimetry.

[3]  Ezequiel Echer,et al.  Interplanetary conditions causing intense geomagnetic storms (Dst ≤ −100 nT) during solar cycle 23 (1996–2006) , 2008 .

[4]  R. Bruntz,et al.  Why doesn't the ring current injection rate saturate? , 2008 .

[5]  M. Hairston,et al.  Saturation of the ionospheric polar cap potential during the October–November 2003 superstorms , 2005 .

[6]  J. Sauvaud,et al.  Statistical studies of geomagnetic storm dependencies on solar and interplanetary events: a review , 2005 .

[7]  R. Tozzi,et al.  Geomagnetic storms, dependence on solar and interplanetary phenomena: a review , 2005 .

[8]  P. Venkatakrishnan,et al.  Solar and interplanetary sources of major geomagnetic storms during 1996–2002 , 2004 .

[9]  Yuming Wang,et al.  An empirical formula relating the geomagnetic storm's intensity to the interplanetary parameters: − and Δt , 2003 .

[10]  A. Dmitriev,et al.  Saturation of IMF Bz influence on the position of dayside magnetopause , 2003 .

[11]  G. Siscoe,et al.  Transpolar potential saturation: Roles of region 1 current system and solar wind ram pressure , 2002 .

[12]  B. Tsurutani,et al.  Interplanetary phenomena associated with very intense geomagnetic storms , 2002 .

[13]  W. Gonzalez,et al.  Solar and interplanetary causes of very intense geomagnetic storms , 2001 .

[14]  W. J. Burke,et al.  Geoeffective interplanetary scale sizes derived from regression analysis of polar cap potentials , 1999 .

[15]  B. Tsurutani,et al.  Interplanetary causes of great and superintense magnetic storms , 1999 .

[16]  Hideaki Kawano,et al.  Magnetopause location under extreme solar wind conditions , 1998 .

[17]  A. Ridley,et al.  A statistical study of the ionospheric convection response to changing interplanetary magnetic field conditions using the assimilative mapping of ionospheric electrodynamics technique , 1998 .

[18]  Bruce T. Tsurutani,et al.  The Interplanetary Causes of Magnetic Storms: A Review , 2013 .

[19]  H. W. Kroehl,et al.  What is a geomagnetic storm , 1994 .

[20]  J. Slavin,et al.  Solar wind-magnetosphere coupling , 1985 .

[21]  Lou‐Chuang Lee,et al.  Energy coupling function and solar wind‐magnetosphere dynamo , 1979 .

[22]  L. J. Cahill,et al.  Transition region magnetic field and polar magnetic disturbances. , 1966 .

[23]  U. R. Rao,et al.  The solar wind velocity and its correlation with cosmic-ray variations and with solar and geomagnetic activity , 1963 .

[24]  C. O. Hines,et al.  A UNIFYING THEORY OF HIGH-LATITUDE GEOPHYSICAL PHENOMENA AND GEOMAGNETIC STORMS , 1961 .

[25]  J. Dungey.  Interplanetary Magnetic Field and the Auroral Zones , 1961 .