Direct observations of the full Dungey convection cycle in the polar ionosphere for southward interplanetary magnetic field conditions

Tracking the formation and full evolution of polar cap ionization patches in the polar ionosphere, we directly observe the full Dungey convection cycle for southward interplanetary magnetic field (IMF) conditions. This enables us to study how the Dungey cycle influences the patches' evolution. The patches were initially segmented from the dayside storm enhanced density plume at the equatorward edge of the cusp, by the expansion and contraction of the polar cap boundary due to pulsed dayside magnetopause reconnection, as indicated by in situ Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations. Convection led to the patches entering the polar cap and being transported antisunward, while being continuously monitored by the globally distributed arrays of GPS receivers and Super Dual Auroral Radar Network radars. Changes in convection over time resulted in the patches following a range of trajectories, each of which differed somewhat from the classical twin‐cell convection streamlines. Pulsed nightside reconnection, occurring as part of the magnetospheric substorm cycle, modulated the exit of the patches from the polar cap, as confirmed by coordinated observations of the magnetometer at Tromsø and European Incoherent Scatter Tromsø UHF radar. After exiting the polar cap, the patches broke up into a number of plasma blobs and returned sunward in the auroral return flow of the dawn and/or dusk convection cell. The full circulation time was about 3 h.

[1]  D. Sibeck,et al.  Simultaneous Ground- and Space-Based Observations of the Plasmaspheric Plume and Reconnection , 2014, Science.

[2]  D. Baker,et al.  Prompt energization of relativistic and highly relativistic electrons during a substorm interval: Van Allen Probes observations , 2014 .

[3]  T. Karlsson,et al.  IMF dependence of the azimuthal direction of earthward magnetotail fast flows , 2013 .

[4]  Q.‐H. Zhang,et al.  Polar cap patch segmentation of the tongue of ionization in the morning convection cell , 2013 .

[5]  Hongqiao Hu,et al.  Direct Observations of the Evolution of Polar Cap Ionization Patches , 2013, Science.

[6]  L. Zanetti,et al.  Variation of the Auroral Birkeland Current Pattern Associated with the North‐South Component of the IMF , 2013 .

[7]  A. Coster,et al.  Direct observations of the role of convection electric field in the formation of a polar tongue of ionization from storm enhanced density , 2013 .

[8]  Mats Nilsson,et al.  Energy exchange and water budget partitioning in a boreal minerogenic mire , 2013 .

[9]  M. Lester,et al.  The Heppner‐Maynard Boundary measured by SuperDARN as a proxy for the latitude of the auroral oval , 2013 .

[10]  S. Milan,et al.  The IMF dependence of the local time of transpolar arcs: Implications for formation mechanism , 2012 .

[11]  Yongliang Zhang,et al.  Nightside polar rain aurora boundary gap and its applications for magnetotail reconnection , 2011 .

[12]  Q.‐H. Zhang,et al.  Extended magnetic reconnection across the dayside magnetopause. , 2011, Physical review letters.

[13]  Q.‐H. Zhang,et al.  On the importance of interplanetary magnetic field B on polar cap patch formation , 2011 .

[14]  Beichen Zhang,et al.  On the importance of interplanetary magnetic field ∣By∣ on polar cap patch formation , 2011 .

[15]  J. Moen,et al.  On the entry and transit of high-density plasma across the polar cap , 2010 .

[16]  Zejun Hu,et al.  Observation of a double-onset substorm during northward interplanetary magnetic field , 2010 .

[17]  S. E. Pryse,et al.  Modulation of nightside polar patches by substorm activity , 2009 .

[18]  H. Carlson,et al.  On the MLT distribution of F region polar cap patches at night , 2007 .

[19]  Peter. Dyson,et al.  A decade of the Super Dual Auroral Radar Network (SuperDARN): scientific achievements, new techniques and future directions , 2007 .

[20]  Stephen E. Milan,et al.  Magnetic flux transport in the Dungey cycle: A survey of dayside and nightside reconnection rates , 2007 .

[21]  J. Moen,et al.  Motion of the dayside polar cap boundary during substorm cycles: II. Generation of poleward-moving events and polar cap patches by pulses in the magnetopause reconnection rate , 2005 .

[22]  W. Rideout,et al.  Multiradar observations of the polar tongue of ionization , 2005 .

[23]  J. King,et al.  Solar wind spatial scales in and comparisons of hourly Wind and ACE plasma and magnetic field data , 2005 .

[24]  M. Dunlop,et al.  High‐altitude cusp flow dependence on IMF orientation: A 3‐year Cluster statistical study , 2005 .

[25]  H. Carlson,et al.  The dynamics and relationships of precipitation, temperature and convection boundaries in the dayside auroral ionosphere , 2004 .

[26]  Philip J. Erickson,et al.  Stormtime observations of the flux of plasmaspheric ions to the dayside cusp/magnetopause , 2004 .

[27]  D. Lorentzen,et al.  Drifting airglow patches in relation to tail reconnection , 2004 .

[28]  P. Reiff,et al.  IMF‐driven plasmasphere erosion of 10 July 2000 , 2003 .

[29]  John C. Foster,et al.  Monitoring Space Weather with GPS Mapping Techniques , 2003 .

[30]  C. Russell,et al.  Relationship between multiple substorm onsets and the IMF: A case study , 2002 .

[31]  William J. Burke,et al.  SAPS: A new categorization for sub‐auroral electric fields , 2002 .

[32]  C. Russell,et al.  Two distinct substorm onsets , 2001 .

[33]  J. Ruohoniemi,et al.  Electrostatic potential patterns in the high‐latitude ionosphere constrained by SuperDARN measurements , 2000 .

[34]  J. Moen,et al.  Plasma structure within poleward-moving cusp/cleft auroral transients: EISCAT Svalbard radar observations and an explanation in terms of large local time extent of events , 2000 .

[35]  S. Wing,et al.  Transformation of high-latitude ionospheric F region patches into blobs during the March 21, 1990, storm , 2000 .

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

[37]  M. Lockwood.  Relationship of dayside auroral precipitations to the open‐closed separatrix and the pattern of convective flow , 1997 .

[38]  R. Greenwald,et al.  A new mechanism for polar patch formation , 1994 .

[39]  R. Schunk,et al.  Modeling Polar Cap F-Region Patches Using Time Varying Convection , 1993 .

[40]  M. Lockwood.  Modelling high-latitude ionosphere for time-varying plasma convection , 1993 .

[41]  H. Carlson,et al.  Production of polar cap electron density patches by transient magnetopause reconnection , 1992 .

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

[43]  N. Maynard,et al.  Empirical high‐latitude electric field models , 1987 .

[44]  R. Robinson,et al.  Sources of F region ionization enhancements in the nighttime auroral zone , 1985 .

[45]  J. Foster,et al.  Plasma convection in the vicinity of the dayside cleft , 1984 .

[46]  G. Siscoe.  Energy coupling between regions 1 and 2 Birkeland current systems , 1982 .

[47]  E. W. Hones,et al.  Magnetotail plasma flow during substorms: A survey with Imp 6 and Imp 8 satellites , 1979 .

[48]  B. Fejer,et al.  An explanation for anomalous equatorial ionospheric electric fields associated with a northward turning of the interplanetary magnetic field , 1979 .

[49]  T. Potemra,et al.  Large‐scale characteristics of field‐aligned currents associated with substorms , 1978 .

[50]  C. Chappell.  Detached plasma regions in the magnetosphere , 1974 .

[51]  W. C. Knudsen.  Magnetospheric convection and the high‐latitude F 2 ionosphere , 1974 .

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

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

[54]  G. Siscoe,et al.  Polar cap inflation and deflation , 1985 .

[55]  C. Russell,et al.  The magnetotail and substorms , 1973 .