Cusp structures: combining multi-spacecraft observations with ground-based observations

Recent simultaneous observations of cusp structures with Polar, FAST and Interball revealed remarkably similar features at spacecraft crossing the cusp. Such stable cusp structures could be observed up to several hours only during stable solar wind conditions. Their similarities led to the conclusion that for such conditions large-scale cusp structures are spatial structures related to a global ionospheric convection pattern and not the result of temporal variations in reconnection parameters. With the launch of the Cluster fleet we are now able to observe precipitating ion structures in the cusp with three spacecraft and identical instrumentation. The orbit configuration of the Cluster spacecraft allows for delay times between spacecraft of about 45 min in crossing the cusp. The compact configuration of three spacecraft at about the same altitude allows for the analysis of cusp structures in great de-tail and during changing solar wind conditions. Cluster observations on 25 July 2001 are combined with SuperDARN radar observations that are used to derive a convection pattern in the ionosphere. We found that large-scale cusp structures for this Cluster cusp crossing are in agreement with structures in the convection pattern and conclude that major cusp structures can be consistent with a spatial phenomenon.

[1]  S. Fuselier,et al.  Spatial features observed in the cusp under steady solar wind conditions , 2002 .

[2]  D. Klumpar,et al.  Temporal versus spatial interpretation of cusp ion structures observed by two spacecraft , 2002, Journal of Geophysical Research.

[3]  H. Spence,et al.  Investigation of magnetopause reconnection models using two colocated, low‐altitude satellites: A unifying reconnection geometry , 2001 .

[4]  Simon Wing,et al.  Double cusp: Model prediction and observational verification , 2001 .

[5]  I. Papamastorakis,et al.  First multispacecraft ion measurements in and near the Earth's magnetosphere with the identical Cluster ion spectrometry (CIS) experiment , 2001 .

[6]  T. Yeoman,et al.  Two-dimensional electric field measurements in the ionospheric footprint of a flux transfer event , 2000 .

[7]  Stanley W. H. Cowley,et al.  Convection and auroral response to a southward turning of the IMF : Polar UVI, CUTLASS, and IMAGE signatures of transient magnetic flux transfer at the magnetopause , 2000 .

[8]  J. Sauvaud,et al.  On spatial and temporal structures in the cusp , 1999 .

[9]  C. J. Owen,et al.  A flux transfer event observed at the magnetopause by the Equator-S spacecraft and in the ionosphere by the CUTLASS HF radar , 1999 .

[10]  J. M. Ruohoniemi,et al.  Large-scale imaging of high-latitude convection with Super Dual Auroral Radar Network HF radar observations , 1998 .

[11]  M. Lockwood,et al.  Modelling signatures of pulsed magnetopause reconnection in cusp ion dispersion signatures seen at middle altitudes , 1998 .

[12]  P. Anderson,et al.  Opposite ion dispersions observed quasi‐simultaneously in the polar cusp by the DE‐2 and AUREOL‐3 satellites , 1997 .

[13]  Raymond A. Greenwald,et al.  Statistical patterns of high‐latitude convection obtained from Goose Bay HF radar observations , 1996 .

[14]  M. Lockwood,et al.  On the longitudinal extent of magnetopause reconnection pulses , 1996 .

[15]  M. Lockwood,et al.  Location and characteristics of the reconnection X line deduced from low‐altitude satellite and ground‐based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data , 1995 .

[16]  C. Meng,et al.  Cusp low‐energy ion cutoffs: A survey and implications for merging , 1995 .

[17]  M. Lockwood.  Location and characteristics of the reconnection X line deduced from low‐altitude satellite and ground‐based observations: 1. Theory , 1995 .

[18]  T. Onsager,et al.  Low-altitude observations and modeling of quasi-steady magnetopause reconnection , 1995 .

[19]  Raymond A. Greenwald,et al.  HF radar signatures of the cusp and low-latitude boundary layer , 1995 .

[20]  H. Carlson,et al.  Flow-aligned jets in the magnetospheric cusp: Results from the Geospace Environment Modeling Pilot Program , 1995, Journal of Geophysical Research.

[21]  A. Mavretic,et al.  SWE, a comprehensive plasma instrument for the WIND spacecraft , 1995 .

[22]  T. B. Jones,et al.  DARN/SuperDARN , 1995 .

[23]  C. Russell,et al.  Determining the standoff distance of the bow shock: Mach number dependence and use of models , 1994 .

[24]  M. Lockwood,et al.  Comment on “By fluctuations in the magnetosheath and azimuthal flow velocity transients in the dayside ionosphere” by Newell and Sibeck , 1994 .

[25]  M. Smith,et al.  Low and middle altitude cusp particle signatures for general magnetopause reconnection rate variations: 1. Theory , 1994 .

[26]  P. Newell,et al.  Upper limits on the contribution of flux transfer events to ionospheric convection , 1993 .

[27]  P. Newell,et al.  By fluctuations in the magnetosheath and azimuthal flow velocity transients in the dayside ionosphere , 1993 .

[28]  R. Elphic,et al.  Well‐resolved observations by ISEE 2 of ion dispersion in the magnetospheric cusp , 1993 .

[29]  T. Onsager,et al.  Model of magnetosheath plasma in the magnetosphere: Cusp and mantle particles at low‐altitudes , 1993 .

[30]  W. F. Denig,et al.  Ionospheric signatures of pulsed reconnection at the Earth's magnetopause , 1993, Nature.

[31]  P. Anderson,et al.  Staircase ion signature in the polar cusp: A case study , 1992 .

[32]  M. Smith,et al.  The statistical cusp: a flux transfer event model , 1992 .

[33]  Mike Lockwood,et al.  Excitation and decay of solar-wind driven flows in the magnetosphere-ionosphere system , 1992 .

[34]  M. Freeman,et al.  The ionospheric signature of flux transfer events , 1991 .

[35]  C. Meng,et al.  Ion acceleration at the equatorward edge of the cusp: Low altitude observations of patchy merging , 1991 .

[36]  D. Klumpar,et al.  Ion Reflection and transmission during reconnection at the Earth's subsolar magnetopause , 1991 .

[37]  R. Greenwald,et al.  Simultaneous HF-radar and DMSP observations of the cusp , 1990 .

[38]  P. Newell.  Comment on “Low‐altitude signatures of the cusp and flux transfer events” by Lockwood and Smith , 1990 .

[39]  M. Smith,et al.  Low-altitude signatures of the cusp and flux transfer events , 1989 .

[40]  M. S. Gussenhoven,et al.  Statistical and functional representations of the pattern of auroral energy flux, number flux, and conductivity , 1987 .

[41]  C. Russell,et al.  Patterns of potential magnetic field merging sites on the dayside magnetopause , 1984 .

[42]  S. Cowley.  The causes of convection in the Earth's magnetosphere: A review of developments during the IMS , 1982 .

[43]  I. Papamastorakis,et al.  Evidence for magnetic field reconnection at the Earth's magnetopause , 1981 .

[44]  I. Papamastorakis,et al.  Plasma acceleration at the Earth's magnetopause: evidence for reconnection , 1979, Nature.

[45]  T. Hill,et al.  Solar wind plasma injection at the dayside magnetospheric cusp , 1977 .

[46]  E. Shelley,et al.  He ++ and H + Flux Measurements in the Day Side Cusp: Estimates of Convection El , 1976 .

[47]  H. Rosenbauer,et al.  Heos 2 plasma observations in the distant polar magnetosphere: The plasma mantle , 1975 .

[48]  S. Petrinec,et al.  Cusp observations of high- and low-latitude reconnection for northward interplanetary magnetic field , 2000 .

[49]  C. Russell,et al.  Near-Earth magnetotail shape and size as determined from the magnetopause flaring angle , 1996 .

[50]  J. Luhmann,et al.  Magnetopause merging site asymmetries , 1985 .

[51]  Comment on “ B _ y fluctuations in the magnetosheath and azimuthal flow velocity transients in the dayside ionosphere , 2022 .