High‐latitude ionospheric drivers and their effects on wind patterns in the thermosphere

Winds in the thermosphere are highly important for transporting mass, momentum, and energy over the globe. In the high-latitude region, observations show that ion and neutral motions are strongly coupled when the aurora is present but the coupling is less evident when there is no aurora. In this study, we investigate the ability of the Global Ionosphere-Thermosphere Model (GITM) to simulate the mesoscale wind structure over Alaska during a substorm. Thirteen distinct numerical simulations of a substorm event that occurred between 02:00 and 17:00 Universal Time on 24 November 2012 have been performed. Distinct drivers considered include the Weimer and SuperDARN potential patterns and the OVATION Prime and OVATION-SME auroral models. The effects of the boundary between the neutral wind dynamo calculation and the high-latitude imposed electric potential were also considered. Neutral wind velocities and thermospheric temperatures measured by the Scanning Doppler Imager instruments located at three locations in Alaska were compared to GITM simulation results, and electron densities within GITM were compared to data from the Poker Flat Incoherent Scatter Radar. It was found that the different drivers used between multiple simulations lead to various amounts of momentum coupling within the simulation, affecting the accuracy of the modeled neutral and ion flow patterns and the strength of electron precipitation at high latitudes. This affirms that better observations of auroral precipitation and electric fields are required to accurately understand and consistently reproduce the mesoscale neutral wind flow patterns and temperature structure in the high-latitude thermosphere.

[1]  A. Hedin.  Extension of the MSIS Thermosphere Model into the middle and lower atmosphere , 1991 .

[2]  M. Miller,et al.  Thermospheric winds at high latitudes from chemical release observations , 1982 .

[3]  T. Killeen,et al.  A COMPUTER MODEL OF GLOBAL THERMOSPHERIC WINDS AND TEMPERATURES , 1987 .

[4]  Timothy L Killeen,et al.  Upper thermosphere winds and temperatures in the geomagnetic polar cap: Solar cycle, geomagnetic activity, and interplanetary magnetic field dependencies , 1995 .

[5]  Yue Deng,et al.  Possible reasons for underestimating Joule heating in global models: E field variability, spatial resolution, and vertical velocity , 2007 .

[6]  P. Richards,et al.  EUVAC: A solar EUV Flux Model for aeronomic calculations , 1994 .

[7]  A. Hedin.  Horizontal wind model (HWM) (1990) , 1992 .

[8]  A. Ridley,et al.  Quiet-time low latitude ionospheric electrodynamics in the non-hydrostatic Global Ionosphere–Thermosphere Model , 2012 .

[9]  Timothy Fuller-Rowell,et al.  Height-integrated Pedersen and Hall conductivity patterns inferred from the TIROS-NOAA satellite data , 1987 .

[10]  Gábor Tóth,et al.  The Global Ionosphere-Thermosphere Model , 2006 .

[11]  Jesper Gjerloev,et al.  Evaluation of SuperMAG auroral electrojet indices as indicators of substorms and auroral power , 2011 .

[12]  C. Lathuillère,et al.  Winds in the high‐latitude lower thermosphere: Dependence on the interplanetary magnetic field , 2003 .

[13]  C. Anderson,et al.  Neutral thermospheric dynamics observed with two scanning Doppler imagers: 2. Vertical winds , 2012 .

[14]  Timothy Fuller-Rowell,et al.  An investigation into the influence of tidal forcing on F region equatorial vertical ion drift using a global ionosphere‐thermosphere model with coupled electrodynamics , 2001 .

[15]  C. Anderson,et al.  Neutral thermospheric dynamics observed with two scanning Doppler imagers: 1. Monostatic and bistatic winds , 2012 .

[16]  W. Gault,et al.  Meridional wind in the auroral thermosphere: Results from EISCAT and WINDII‐O(1 D) coordinated measurements , 1997 .

[17]  Dieter Bilitza,et al.  Goals and status of the International Reference Ionosphere , 1978 .

[18]  T. Killeen,et al.  An analysis of the high‐latitude thermospheric wind pattern calculated by a thermospheric general circulation model: 2. Neutral parcel transport , 1986 .

[19]  Raymond G. Roble,et al.  A thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (time-GCM): Equinox solar cycle minimum simulations (30–500 km) , 1994 .

[20]  Timothy L. Killeen,et al.  Empirical global model of upper thermosphere winds based on atmosphere and dynamics explorer satellite data , 1988 .

[21]  Paul B. Hays,et al.  An empirical model of the Earth's horizontal wind fields: HWM07 , 2008 .

[22]  J. St.‐Maurice,et al.  Joule heating at high latitudes , 1983 .

[23]  Jeffrey M. Forbes,et al.  On modeling migrating solar tides , 1995 .

[24]  M. Conde,et al.  Mapping thermospheric winds in the auroral zone , 1995 .

[25]  Shengpan P. Zhang,et al.  Neutral winds in the lower thermosphere observed by WINDII during the April 4–5th, 1993 storm , 2000 .

[26]  T. Fuller‐Rowell,et al.  A Three-Dimensional Time-Dependent Global Model of the Thermosphere , 1980 .

[27]  Thomas N. Woods,et al.  Flare Irradiance Spectral Model (FISM): Daily component algorithms and results , 2007 .

[28]  M. Jarvis,et al.  Climatologies of nighttime upper thermospheric winds measured by ground-based Fabry-Perot interferometers during geomagnetically quiet conditions: 2. High-latitude circulation and interplanetary magnetic field dependence , 2006 .

[29]  T. Killeen,et al.  An analysis of the high‐latitude thermospheric wind pattern calculated by a thermospheric general circulation model: 1. Momentum forcing , 1984 .

[30]  A. Ridley,et al.  Dependence of neutral winds on convection E‐field, solar EUV, and auroral particle precipitation at high latitudes , 2006 .

[31]  S. Solomon,et al.  Solar extreme‐ultraviolet irradiance for general circulation models , 2005 .

[32]  T. Killeen,et al.  Observations of thermospheric horizontal neutral winds at Watson Lake, Yukon Territory (Λ = 65°N) , 1996 .

[33]  M. Jarvis,et al.  Climatologies of nighttime upper thermospheric winds measured by ground‐based Fabry‐Perot interferometers during geomagnetically quiet conditions: 1. Local time, latitudinal, seasonal, and solar cycle dependence , 2006 .

[34]  D. Weimer,et al.  Improved Ionospheric Electrodynamic Models and Application to Calculating Joule Heating Rates , 2005 .

[35]  R. Dickinson,et al.  Thermospheric general circulation with coupled dynamics and composition , 1984 .

[36]  A. Hedin.  MSIS‐86 Thermospheric Model , 1987 .

[37]  M. Conde,et al.  Phase compensation of a separation scanned, all-sky imaging Fabry-Perot spectrometer for auroral studies. , 1997, Applied optics.

[38]  Susan K. Avery,et al.  Empirical wind model for the upper, middle and lower atmosphere , 1996 .

[39]  T. Fuller‐Rowell,et al.  The combined effect of solar and geomagnetic activity on high latitude thermospheric neutral winds. Part I. Observations , 1991 .

[40]  Raymond G. Roble,et al.  A thermosphere/ionosphere general circulation model with coupled electrodynamics , 1992 .

[41]  Bodo W. Reinisch,et al.  International Reference Ionosphere 2000 , 2001 .

[42]  T. Killeen,et al.  Observations of neutral winds in the polar cap during northward IMF , 1994 .

[43]  Patrick T. Newell,et al.  Seasonal variations in diffuse, monoenergetic, and broadband aurora , 2009 .

[44]  Raymond G. Roble,et al.  A coupled thermosphere/ionosphere general circulation model , 1988 .

[45]  A. Hedin,et al.  A revised thermospheric model based on mass spectrometer and incoherent scatter data - MSIS-83 , 1983 .

[46]  Mark Conde,et al.  Spatial structure in the thermospheric horizontal wind above Poker Flat, Alaska, during solar minimum , 1998 .

[47]  A. E. Hedin.  MSISE model (1990) , 1992 .

[48]  P. Newell,et al.  OVATION‐SM: A model of auroral precipitation based on SuperMAG generalized auroral electrojet and substorm onset times , 2013 .

[49]  F. McCormac,et al.  Circulation of the polar thermosphere during geomagnetically quiet and active times as observed by Dynamics Explorer 2 , 1987 .

[50]  E. Pereira,et al.  Neutral winds and electric fields in the dusk auroral oval 1. Measurements , 1981 .

[51]  Timothy Fuller-Rowell,et al.  Global Assimilation of Ionospheric Measurements (GAIM) , 2001 .

[52]  P. Rothwell,et al.  Neutral wind modifications above 150 km altitude associated with the polar substorm , 1974 .

[53]  J. D. Stolarik,et al.  Neutral winds above 200 km at high latitudes , 1972 .