Case studies of the storm time variation of the polar cusp

The latitudinal variations of the polar cusp region were examined during three intense geomagnetic storms. The variations were compared with the intensity of storm time ring current inferred from the Dst index, with the magnitude of the north-south component B/sub z/ of the interplanetary magnetic field and with substorm activity. The common feature is that the rapid equatorward shift occurred during the increase of the ring current growth and during the southward turning of the interplanetary magnetic field orientation. The equatorwardmost latitude of the cusp was reached before the peak of the ring current intensity, by a few to several hours, coinciding with the occurrence of the largest magnitude of the southward interplanetary magnetic field component. However, details of the polar cusp latitudinal movement differ from storm to storm. During the three storms studied, the poleward recovery commenced at the peak magnitude of the negative IMF B/sub z/ component, but the recovery proceeded without a clear relation to variations of the interplanetary B/sub z/ component, to the ring current intensity, or to the substorm activity. The lowest cusp latitude observed was at approx.61.7/sup 0/, and the magnitude of this shift seems to be related to the magnitudes of -B/sub z/.more » It is further observed that the approximate rates of the cusp macroscopic equatorward and poleward movements are about 3/sup 0/ and 1.5/sup 0/ per hour, respectively.« less

[1]  C. Meng.  Latitudinal variation of the polar cusp during a geomagnetic storm , 1982 .

[2]  C. Meng.  Electron precipitation in the midday auroral oval , 1981 .

[3]  D. Covey,et al.  Equatorward shift of the cusp during magnetospheric substorms , 1981 .

[4]  C. P. Pike,et al.  Looking down on the aurora from space , 1981 .

[5]  J. Sauvaud,et al.  Spatial inhomogeneity of magnetosheath proton precipitation along the dayside cusp from the Arcad Experiment , 1980 .

[6]  R. Eather.  Reply [to “Comment on ‘Dayside aurora and relevance to substorm current systems and dayside merging’ by R. H. Eather, S. B. Mende, and E. J. Weber”] , 1980 .

[7]  G. Shepherd.  Dayside cleft aurora and its ionospheric effects , 1979 .

[8]  V. Vasyliūnas.  Interaction between the magnetospheric boundary layers and the ionosphere , 1979 .

[9]  Gussenhoven,et al.  The precipitating electron detectors (SSJ/3) for the block 5D/flights 2-5 DMSP satellites: calibration and data presentation. Final report, 1 January 1977-30 September 1978. [Data taken 1972-1975] , 1979 .

[10]  S. Mende,et al.  Dayside aurora and relevance to substorm current systems and dayside merging , 1979 .

[11]  G. Siscoe.  A Dst contribution to the equatorward shift of the aurora , 1979 .

[12]  James A. Slavin,et al.  A correlative study of magnetic flux transfer in the magnetosphere , 1979 .

[13]  J. Burch.  Effects of the interplanetary magnetic field on the auroral oval and plasmapause , 1979 .

[14]  Nancy U. Crooker,et al.  Dayside merging and cusp geometry , 1979 .

[15]  C. Meng.  Polar Cap Variations and the Interplanetary Magnetic Field , 1979 .

[16]  C. Russell.  The control of the magnetopause by the interplanetary magnetic field , 1979 .

[17]  J. Craven,et al.  Energization of polar-cusp electrons at the noon meridian , 1978 .

[18]  J. P. Doering,et al.  Low‐energy particle observations in the quiet dayside cusp from AE‐C and AE‐D , 1977 .

[19]  D. Fairfield.  Electric and magnetic fields in the high‐latitude magnetosphere , 1977 .

[20]  N. D’angelo.  Plasma waves and instabilities in the polar cusp: A review , 1977 .

[21]  S. Akasofu,et al.  The response of the dayside aurora to sharp northward and southward transitions of the interplanetary magnetic field and to magnetospheric substorms , 1977 .

[22]  G. S. Stiles,et al.  Ionosonde observations of the northern magnetospheric cleft during December 1974 and January 1975 , 1977 .

[23]  Y. Feldstein,et al.  The auroral oval during the substorm development , 1976 .

[24]  R. Heelis,et al.  Ion convection velocity reversals in the dayside cleft , 1976 .

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

[26]  Y. Kamide,et al.  Dependence of the latitude of the cleft on the interplanetary magnetic field and substorm activity , 1976 .

[27]  C. Russell,et al.  The Terrestrial Magnetosphere: A Half-Wave Rectifier of the Interplanetary Electric Field , 1975, Science.

[28]  B. Thomas,et al.  HEOS Observations of the Configuration of the Magnetosphere , 1975 .

[29]  Y. Feldstein,et al.  Dynamics of day and night aurora during substorms , 1975 .

[30]  C. P. Pike,et al.  Observed correlations between interplanetary magnetic field variations and the dynamics of the auroral oval and the high-latitude ionosphere , 1974 .

[31]  J. Burch.  Observations of interactions between interplanetary and geomagnetic fields , 1974 .

[32]  J. Winningham,et al.  Equatorward shift of the cleft during magnetospheric substorms as observed by Isis 1 , 1973 .

[33]  J. Burch.  Rate of erosion of dayside magnetic flux based on a quantitative study of the dependence of polar cusp latitude on the interplanetary magnetic field , 1973 .

[34]  R. Hoffman.  Properties of low energy particle impacts in the polar domain in the dawn and dayside hours. , 1973 .

[35]  C. P. Pike.  Equatorward shift of the polar F layer irregularity zone as a function of the Kp index , 1972 .

[36]  J. L. Burch,et al.  Precipitation of low‐energy electrons at high latitudes: Effects of interplanetary magnetic field and dipole tilt angle , 1972 .

[37]  S. Akasofu.  Midday auroras at the South Pole during magnetospheric substorms , 1972 .

[38]  J. Burrows,et al.  Solar particles and the dayside limit of closed field lines , 1972 .

[39]  N. Ness,et al.  IMP 5 magnetic field measurements in the high latitude outer magnetosphere near the noon meridian , 1972 .

[40]  S. Akasofu.  Midday auroras and magnetospheric substorms. , 1972 .

[41]  J. Winningham.  Characteristics of Magnetosheath Plasma Observed at Low Altitudes in the Dayside Magnetospheric Cusps , 1972 .

[42]  Y. Feldstein.  Auroras and Associated Phenomena , 1972 .

[43]  C. Russell,et al.  Ogo 5 observations of the polar cusp on November 1, 1968 , 1971 .

[44]  L. Frank.  Plasma in the Earth's polar magnetosphere , 1971 .

[45]  J. Winningham,et al.  Penetration of magnetosheath plasma to low altitudes through the dayside magnetospheric cusps , 1971 .

[46]  Talbot A. Chubb,et al.  Observations of the aurora in the far ultraviolet from OGO 4 , 1970 .

[47]  S. Chapman,et al.  A model midnight meridian magnetospheric field. , 1969 .

[48]  G. Mead.  DEFORMATION OF THE GEOMAGNETIC FIELD BY THE SOLAR WIND , 1964 .

[49]  David B. Beard,et al.  Shape of the geomagnetic field solar wind boundary , 1964 .

[50]  S. Akasofu.  DEFORMATION OF MAGNETIC SHELLS DURING MAGNETIC STORMS , 1963 .

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

[52]  S. Chapman,et al.  A new theory of magnetic storms , 1931 .