Midlatitude ionospheric disturbances during magnetic storms and substorms

[1] We present periodic (∼2 hour) magnetospheric and ionospheric oscillations observed with multiple space-based and ground-based instruments during the severe magnetic storm of 25 September 1998. Periodic particle injections were observed at geosynchronous orbit. Ground magnetometers registered very large, as high as 3000 nT, magnetic deviations in the nightside auroral zone. The Millstone Hill incoherent scatter radar at magnetic latitude 55° measured periodic enhancements of ionospheric eastward ion velocity from midnight to ∼1000 MLT. The periodic variations in the magnetometers and Millstone Hill radar were well correlated with the magnetospheric particle injections. The observations are consistent with the occurrence of periodic magnetospheric substorms during a magnetic storm. During each substorm cycle the ionospheric auroral zone expanded to the latitude of the Millstone Hill radar, so the radar was periodically within the auroral zone and detected the auroral plasma return flows. After substorm activity stopped, the Millstone Hill radar measured near-noon in-phase periodic oscillations of the ionospheric F-region electron density and temperature, which may be due to particle precipitation from the ring current and/or plasmasphere into the midlatitude ionosphere. We suggest that magnetospheric substorms during magnetic storms have a cycle time of ∼2 hours. The magnetosphere can sustain similar oscillations for several cycles even though the substorm activity has stopped. All the observed periodic variations in the geosynchronous particle injections, in the auroral magnetic deviations, and in the ionospheric ion velocity are related to the periodic magnetospheric substorms and oscillations.

[1]  P. Erickson,et al.  Effects of solar wind variations on the midlatitude ionosphere , 2002 .

[2]  J. Foster,et al.  Westward plasma drift in the midlatitude ionospheric F region in the midnight‐dawn sector , 2001 .

[3]  J. Foster,et al.  Variations of midlatitude ionospheric plasma density in response to an interplanetary shock , 2001 .

[4]  John D. Craven,et al.  Negative ionospheric storm coincident with DE 1-observed thermospheric disturbance on October 14, 1981 , 2001 .

[5]  G. Reeves,et al.  Multisatellite comparisons of the radiation belt response to the Geospace Environment Modeling (GEM) magnetic storms , 2001 .

[6]  K. Morzinski,et al.  Two-satellite observations of substorm injections at geosynchronous orbit , 2001 .

[7]  R. McPherron,et al.  Timing of substorm signatures during the November 24, 1996, Geospace Environment Modeling event , 2001 .

[8]  W. J. Burke,et al.  Ionospheric disturbances observed by DMSP at middle to low latitudes during the magnetic storm of June 4–6, 1991 , 2000 .

[9]  V. Angelopoulos,et al.  Plasmaspheric depletion and refilling associated with the September 25, 1998 magnetic storm observed by ground magnetometers at L = 2 , 2000 .

[10]  G. Parks,et al.  Magnetospheric and ionospheric response to a substorm : Geotail HEP-LD and Polar PIXIE observations , 1999 .

[11]  B. Reinisch,et al.  Coordinated incoherent scatter radar study of the January 1997 storm , 1999 .

[12]  V. Jordanova,et al.  Ring current activity during the early Bz < 0 phase of the January 1997 magnetic cloud , 1999 .

[13]  M. Buonsanto.  Ionospheric Storms — A Review , 1999 .

[14]  J. Foster,et al.  Prompt midlatitude electric field effects during severe geomagnetic storms , 1998 .

[15]  H. Mayr,et al.  Storm‐time penetration to low latitudes of magnetospheric‐ionospheric convection and convection‐driven thermospheric winds , 1998 .

[16]  B. Wilken,et al.  Substorm activity on January 11, 1994: Geotail observations in the distant tail during the leading phase of a corotating interaction region , 1998 .

[17]  T. Fuller‐Rowell,et al.  How Does the Thermosphere and Ionosphere React to a Geomagnetic Storm , 2013 .

[18]  P. Richards,et al.  Comparison of techniques for derivation of neutral meridional winds from ionospheric data , 1997 .

[19]  R. D. Belian,et al.  Observations of magnetospheric substorms occurring with no apparent solar wind/IMF trigger , 1996 .

[20]  M. Buonsanto.  A case study of the ionospheric storm dusk effect , 1995 .

[21]  J. Holt,et al.  Measurements of gradients in ionospheric parameters with a new nine-position experiment at Millstone Hill , 1995 .

[22]  M. Buonsanto.  Millstone Hill incoherent scatter F region observations during the disturbances of June 1991 , 1995 .

[23]  M. Mendillo,et al.  Coordinated stable auroral red arc observations: Relationship to plasma convection , 1994 .

[24]  J. Foster,et al.  Effects of magnetospheric electric fields and neutral winds on the low‐middle latitude ionosphere during the March 20‐21, 1990, storm , 1993 .

[25]  Xiaoqing Pi,et al.  Diurnal double maxima patterns in the F region ionosphere: Substorm-related aspects , 1993 .

[26]  Joseph E. Borovsky,et al.  The occurrence rate of magnetospheric‐substorm onsets: Random and periodic substorms , 1993 .

[27]  J. Foster.  Storm time plasma transport at middle and high latitudes , 1993 .

[28]  Gerd W. Prölss,et al.  On explaining the local time variation of ionospheric storm effects , 1993 .

[29]  J. Foster,et al.  Observations from Millstone Hill during the geomagnetic disturbances of March and April 1990 , 1992 .

[30]  J. Foster,et al.  Storm-time electric-field penetration observed at mid-latitude , 1991 .

[31]  P. Anderson,et al.  The ionospheric signatures of rapid subauroral ion drifts , 1991 .

[32]  J. Foster,et al.  Neutral winds and thermosphere/ionosphere coupling and energetics during the geomagnetic disturbances of March 6–10, 1989 , 1990 .

[33]  R. D. Belian,et al.  Multi‐satellite measurements of the substorm injection region , 1990 .

[34]  Michael C. Kelley,et al.  The Earth's Ionosphere : Plasma Physics and Electrodynamics , 1989 .

[35]  R. Hunsucker,et al.  An observation of atmospheric gravity wave cause and effect during the October 1985 WAGS campaign , 1988 .

[36]  Y. Kamide,et al.  Interplanetary magnetic field control of high-latitude electric fields and currents determined from Greenland Magnetometer Data , 1985 .

[37]  V. Ponomarev,et al.  Plasma convection in polar ionosphere , 1974 .

[38]  Robert L. McPherron,et al.  Satellite studies of magnetospheric substorms on August 15, 1968. IX - Phenomenological model for substorms. , 1973 .

[39]  C. Meng,et al.  Vertical motions of the midlatitude F 2 layer during magnetospheric substorms , 1971 .