Ionospheric Outflow During the Substorm Growth Phase: THEMIS Observations of Oxygen Ions at the Plasma Sheet Boundary

Ionospheric outflow is an important plasma source that feeds the near‐Earth magnetotail with heavy oxygen ions. Because these ions can significantly alter the structure and stability of the magnetotail current sheet, the characteristics of this outflow are important for accurate magnetosphere modeling, including modeling of substorms—a key element of magnetosphere dynamics. Using Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft measurements in the magnetotail (around the plasma sheet boundary), we investigate characteristics oxygen outflows observed during substorm growth phases. The observed oxygen ion temperature and flow energy indicate that the outflow is marginally stable to ion acoustic wave generation: The oxygen temperature is slightly lower than the electron temperature and slightly higher than the oxygen flow energy. Moreover, the observed outflows are accompanied by low frequency electrostatic waves that may contribute to outflow thermalization. The oxygen bulk velocity has a significant component directed toward the equatorial plane, originating from the cross‐field drift in the convection electric field. The estimated radial distances at which oxygen ions reach the plasma sheet are ∼20–40RE downtail, that is, outflows during substorm growth phases can alter current sheet characteristics around the potential magnetic reconnection region.

[1]  V. Angelopoulos,et al.  Contribution of Anisotropic Electron Current to the Magnetotail Current Sheet as a Function of Location and Plasma Conditions , 2020, Journal of Geophysical Research: Space Physics.

[2]  C. Norgren,et al.  The Impact of Oxygen on the Reconnection Rate , 2019, Geophysical Research Letters.

[3]  J. G. Sample,et al.  The Space Physics Environment Data Analysis System (SPEDAS) , 2019, Space Science Reviews.

[4]  C. Norgren,et al.  The Formation of an Oxygen Wave by Magnetic Reconnection , 2018, Journal of Geophysical Research: Space Physics.

[5]  H. Spence,et al.  Plasma Anisotropies and Currents in the Near‐Earth Plasma Sheet and Inner Magnetosphere , 2018, Journal of Geophysical Research: Space Physics.

[6]  P. Pritchett,et al.  Externally Driven Onset of Localized Magnetic Reconnection and Disruption in a Magnetotail Configuration , 2018 .

[7]  A. Schillings,et al.  Relative outflow enhancements during major geomagnetic storms – Cluster observations , 2017 .

[8]  Z. Pu,et al.  Plasma Sheet Pressure Variations in the Near‐Earth Magnetotail During Substorm Growth Phase: THEMIS Observations , 2017 .

[9]  A. Runov,et al.  Properties of the Equatorial Magnetotail Flanks ∼50–200 RE Downtail , 2017 .

[10]  M. Kuznetsova,et al.  On the origin of plasma sheet reconfiguration during the substorm growth phase , 2017 .

[11]  B. Anderson,et al.  Dominance of high‐energy (>150 keV) heavy ion intensities in Earth's middle to outer magnetosphere , 2017 .

[12]  A. Schillings,et al.  Quantification of the total ion transport in the near-Earth plasma sheet , 2017 .

[13]  Ying Lin,et al.  Hall effect control of magnetotail dawn‐dusk asymmetry: A three‐dimensional global hybrid simulation , 2016 .

[14]  A. Runov,et al.  Properties of current sheet thinning at x ∼− 10 to −12 RE , 2016 .

[15]  V. Angelopoulos,et al.  On the radial force balance in the quiet time magnetotail current sheet , 2016 .

[16]  L. Kistler,et al.  The inner magnetosphere ion composition and local time distribution over a solar cycle , 2016 .

[17]  G. Lapenta,et al.  Oxygen impacts on dipolarization fronts and reconnection rate , 2016 .

[18]  R. P. Singhal,et al.  Electron distribution function formation in regions of diffuse aurora , 2015 .

[19]  H. Karimabadi,et al.  The heavy ion diffusion region in magnetic reconnection in the Earth's magnetotail , 2015 .

[20]  L. Kistler,et al.  Journal of Geophysical Research: Space Physics Distribution of energetic oxygen and hydrogen in the near-Earth plasma sheet , 2016 .

[21]  G. Parks,et al.  Outflow of low-energy O + ion beams observed during periods without substorms , 2015 .

[22]  H. Nilsson,et al.  O + transport in the dayside magnetosheath and its dependence on the IMF direction , 2015 .

[23]  B. Klecker,et al.  Acceleration of O+ from the cusp to the plasma sheet , 2015 .

[24]  J. Eastwood,et al.  The location and rate of occurrence of near-Earth magnetotail reconnection as observed by Cluster and Geotail , 2014 .

[25]  J. Birn,et al.  Onset of reconnection in the near magnetotail: PIC simulations , 2014 .

[26]  M. Ashour‐Abdalla,et al.  Circulation of Heavy Ions and Their Dynamical Effects in the Magnetosphere: Recent Observations and Models , 2014 .

[27]  V. Angelopoulos,et al.  Properties of low‐latitude mantle plasma in the Earth's magnetotail: ARTEMIS observations and global MHD predictions , 2014 .

[28]  Wolfgang Baumjohann,et al.  Electron pitch angle/energy distribution in the magnetotail , 2014 .

[29]  H. Karimabadi,et al.  The scale of the magnetotail reconnecting current sheet in the presence of O+ , 2014 .

[30]  J. Lyon,et al.  Ionospheric control of magnetotail reconnection , 2014, Science.

[31]  L. Kistler,et al.  Spatial variation in the plasma sheet composition: Dependence on geomagnetic and solar activity , 2014 .

[32]  V. Angelopoulos,et al.  ARTEMIS observations of lunar pickup ions: Mass constraints on ion species , 2013 .

[33]  Kazue Takahashi,et al.  Global characteristics of electromagnetic ion cyclotron waves: Occurrence rate and its storm dependence , 2013 .

[34]  R. Nakamura,et al.  Profiles of electron temperature and B z along Earth's magnetotail , 2013 .

[35]  M. Fujimoto,et al.  Three‐dimensional structure of magnetic reconnection in the magnetotail from Geotail observations , 2013 .

[36]  L. Kistler,et al.  Oxygen and hydrogen ion abundance in the near-Earth magnetosphere: Statistical results on the response to the geomagnetic and solar wind activity conditions: OXYGEN ABUNDANCE IN THE MAGNETOSPHERE , 2012, 1210.4365.

[37]  Vassilis Angelopoulos,et al.  The ARTEMIS Mission , 2011 .

[38]  H. Karimabadi,et al.  Flushing effect in reconnection: Effects of minority species of oxygen ions , 2011 .

[39]  C. Owen,et al.  Average magnetotail electron and proton pitch angle distributions from Cluster PEACE and CIS observations , 2011 .

[40]  B. Klecker,et al.  H+ and O+ content of the plasma sheet at 15–19 Re as a function of geomagnetic and solar activity , 2010 .

[41]  B. Klecker,et al.  Statistical study of O+ transport from the cusp to the lobes with Cluster CODIF data , 2010 .

[42]  C. Russell,et al.  Escape of O+ through the distant tail plasma sheet , 2010 .

[43]  B. Klecker,et al.  Cusp as a source for oxygen in the plasma sheet during geomagnetic storms , 2010 .

[44]  R. Nakamura,et al.  Thin embedded current sheets: Cluster observations of ion kinetic structure and analytical models , 2009 .

[45]  K. Svenes,et al.  Plasma transport in the magnetotail lobes , 2009 .

[46]  R. Wolf,et al.  Plasma sheet P5/3 and n and associated plasma and energy transport for different convection strengths and AE levels , 2009 .

[47]  Patrick T. Newell,et al.  Diffuse, monoenergetic, and broadband aurora: The global precipitation budget , 2009 .

[48]  M. Ashour‐Abdalla,et al.  Cluster observations and numerical modeling of energy‐dispersed ionospheric H+ ions bouncing at the plasma sheet boundary layer , 2009 .

[49]  Vassilis Angelopoulos,et al.  The Electric Field Instrument (EFI) for THEMIS , 2008 .

[50]  R. Abiad,et al.  The THEMIS ESA Plasma Instrument and In-flight Calibration , 2008 .

[51]  J. Sauvaud,et al.  Transients in oxygen outflow above the polar cap as observed by the Cluster spacecraft , 2008 .

[52]  J. Quinn,et al.  Plasma convection in the magnetotail lobes: statistical results from Cluster EDI measurements , 2008 .

[53]  U. Auster,et al.  First Results from the THEMIS Mission , 2008 .

[54]  Werner Magnes,et al.  The THEMIS Fluxgate Magnetometer , 2008 .

[55]  Vassilis Angelopoulos,et al.  The THEMIS Mission , 2008 .

[56]  J. Sauvaud,et al.  A multi-satellite study of accelerated ionospheric ion beams above the polar cap , 2006 .

[57]  A. Sharma,et al.  “Matreshka” model of multilayered current sheet , 2006 .

[58]  M. Ashour‐Abdalla,et al.  Understanding magnetotail current sheet meso-scale structures using MHD simulations , 2006 .

[59]  S. Schwartz,et al.  Electron anisotropy constraint in the magnetosheath: Cluster observations , 2005 .

[60]  J. Sauvaud,et al.  Contribution of nonadiabatic ions to the cross-tail current in an O+ dominated thin current sheet , 2005 .

[61]  P. Pritchett.  Externally driven magnetic reconnection in the presence of a normal magnetic field , 2005 .

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

[63]  A. Lui.  Potential Plasma Instabilities For Substorm Expansion Onsets , 2004 .

[64]  Robert L. Lysak,et al.  Magnetosphere-ionosphere coupling by Alfvén waves at midlatitudes , 2004 .

[65]  V. A. Sergeev,et al.  Quantitative magnetotail characteristics of different magnetospheric states , 2004 .

[66]  J. Birn,et al.  Thin current sheets and loss of equilibrium: Three‐dimensional theory and simulations , 2004 .

[67]  M. W. Dunlop,et al.  Case studies of the dynamics of ionospheric ions in the Earth's magnetotail , 2004 .

[68]  A. Vaivads,et al.  Heating of beam ions by ion acoustic waves , 1998 .

[69]  Daniel N. Baker,et al.  Neutral line model of substorms: Past results and present view , 1996 .

[70]  V. A. Sergeev,et al.  Steady magnetospheric convection: A review of recent results , 1996 .

[71]  G. Paschmann,et al.  Bursty bulk flows in the inner central plasma sheet , 1992 .

[72]  C. Russell,et al.  Influences of solar wind parameters and geomagnetic activity on the tail lobe magnetic field: A statistical study , 1991 .

[73]  M. Ashour‐Abdalla,et al.  Ion beam heating in the auroral zone , 1990 .

[74]  R. Winglee,et al.  Simulations and observations of heating of auroral ion beams , 1989 .

[75]  G. Paschmann,et al.  Average plasma properties in the central plasma sheet , 1989 .

[76]  M. Hudson,et al.  Oxygen acoustic solitary waves in a magnetized plasma , 1989 .

[77]  M. Hudson,et al.  Linear stability of the H+ ‐ O+ two‐stream interaction in a magnetized plasma , 1988 .

[78]  Wolfgang Baumjohann,et al.  The magnetopause for large magnetic shear: AMPTE/IRM observations , 1986 .

[79]  J. Cladis.  Parallel acceleration and transport of ions from polar ionosphere to plasma sheet , 1986 .

[80]  M. André.  Ion waves generated by streaming particles , 1985 .

[81]  A. Vedenov,et al.  Quasilinear Effects in Two-Stream Instabilities , 1975 .

[82]  R. Sagdeev,et al.  Quasi-linear theory of plasma oscillations , 1962 .

[83]  R. Sagdeev,et al.  STABILITY OF PLASMA , 1961 .