IPIM Modeling of the Ionospheric F2 Layer Depletion at High Latitudes During a High‐Speed Stream Event

Our aim is to understand the effect of high‐speed stream events on the high‐latitude ionosphere and more specifically the decrease of the foF2 frequency during the entire day following the impact. First, we have selected one summertime event, for which a large data set was available: Super Dual Auroral Radar Network (SuperDARN) and European Incoherent SCATter (EISCAT) radars, Tromsø and Sodankylä ionosondes, and the CHAllenging Minisatellite Payload (CHAMP) satellite. We modeled with the IPIM model (IRAP Plasmasphere Ionosphere Model) the dynamics of the ionosphere at Tromsø and Sodankylä using inputs derived from the data. The simulations nicely match the measurements made by the EISCAT radar and the ionosondes, and we showed that the decrease of foF2 is associated with a transition from F2 to F1 layer resulting from a decrease of neutral atomic oxygen concentration. Modeling showed that electrodynamics can explain short‐term behavior on the scale of a few hours, but long‐term behavior on the scale of a few days results from the perturbation induced in the atmosphere. Enhancement of convection is responsible for a sharp increase of the ion temperature by Joule heating, leading through chemistry to an immediate reduction of the F2 layer. Then, ion drag on neutrals is responsible for a rapid heating and expansion of the thermosphere. This expansion affects atomic oxygen through nonthermal upward flow, which results in a decrease of its concentration and amplifies the decrease of [O]/[N2] ratio. This thermospheric change explains long‐term extinction of the F2 layer.

[1]  T. Ulich,et al.  Cosmic radio noise absorption in the high‐latitude ionosphere during solar wind high‐speed streams , 2017 .

[2]  T. Ulich,et al.  Effects of solar wind high‐speed streams on the high‐latitude ionosphere: Superposed epoch study , 2015 .

[3]  P.-L. Blelly,et al.  A new interhemispheric 16‐moment model of the plasmasphere‐ionosphere system: IPIM , 2015 .

[4]  Larry J. Paxton,et al.  Remote Sensing of Earth's Limb by TIMED/GUVI: Retrieval of thermospheric composition and temperature , 2015 .

[5]  R. Schunk,et al.  Changes in thermospheric temperature induced by high-speed solar wind streams , 2012 .

[6]  J. Sojka,et al.  Response of the topside ionosphere to high-speed solar wind streams , 2011 .

[7]  M. Kelley,et al.  Estimates of eddy turbulence consistent with seasonal variations of atomic oxygen and its possible role in the seasonal cycle of mesopause temperature , 2010 .

[8]  P. Blelly,et al.  A new analysis method for determining polar ionosphere and upper atmosphere characteristics from ESR data: Illustration with IPY period , 2010 .

[9]  M. Nicolls,et al.  Observations of ionospheric heating during the passage of solar coronal hole fast streams , 2009 .

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

[11]  B. Emery,et al.  Geoefficiency and energy partitioning in CIR-driven and CME-driven storms , 2009 .

[12]  M. Denton,et al.  Modification of midlatitude ionospheric parameters in the F2 layer by persistent high‐speed solar wind streams , 2009 .

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

[14]  Gordon G. Shepherd,et al.  DWM07 global empirical model of upper thermospheric storm-induced disturbance winds , 2008 .

[15]  G. Crowley,et al.  Periodic modulations in thermospheric composition by solar wind high speed streams , 2008 .

[16]  S. Solomon,et al.  An improved parameterization of thermal electron heating by photoelectrons, with application to an X17 flare , 2008 .

[17]  Stein Haaland,et al.  IMF dependence of high-latitude thermospheric wind pattern derived from CHAMP cross-track measurements , 2008 .

[18]  R. Nerem,et al.  Thermospheric density oscillations due to periodic solar wind high- speed streams , 2008 .

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

[20]  Y. Kasahara,et al.  Corotating solar wind streams and recurrent geomagnetic activity: A review , 2006 .

[21]  J. Lilensten,et al.  An extended TRANSCAR model including ionospheric convection: simulation of EISCAT observations using inputs from AMIE , 2005 .

[22]  D. Drob,et al.  Nrlmsise-00 Empirical Model of the Atmosphere: Statistical Comparisons and Scientific Issues , 2002 .

[23]  P. Newell,et al.  Boundary‐oriented electron precipitation model , 2000 .

[24]  M. Conde,et al.  A large vertical wind in the thermosphere at the auroral oval/polar cap boundary seen simultaneously from Mawson and Davis, Antarctica , 1999 .

[25]  M. Förster,et al.  Thermospheric composition changes deduced from geomagnetic storm modeling , 1999 .

[26]  K. Berrington,et al.  Cooling rate of thermal electrons by electron impact excitation of fine structure levels of atomic oxygen , 1999 .

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

[28]  A. Pavlov.  New electron energy transfer and cooling rates by excitation of O2 , 1998 .

[29]  A. Pavlov.  New electron energy transfer rates for vibrational excitation of N2 , 1998 .

[30]  M. Förster,et al.  An estimate of the non-barometric effect in the [O] height distribution at low latitudes during magnetically disturbed periods , 1997 .

[31]  J. Gosling.  COROTATING AND TRANSIENT SOLAR WIND FLOWS IN THREE DIMENSIONS , 1996 .

[32]  Larry J. Paxton,et al.  Satellite remote sensing of thermospheric O/N2 and solar EUV: 1. Theory , 1995 .

[33]  T. B. Jones,et al.  DARN/SuperDARN , 1995 .

[34]  G. Kockarts.  Penetration of solar radiation in the Schumann-Runge bands of molecular oxygen: a robust approximation , 1994 .

[35]  R. W. Schunk,et al.  A comparative study of the time-dependent standard 8-, 13- and 16-moment transport formulations of the polar wind , 1993 .

[36]  T. Killeen,et al.  On the mechanisms responsible for high-latitude thermospheric composition variations during the recovery phase of a geomagnetic storm , 1989 .

[37]  M. S. Gussenhoven,et al.  Statistical and functional representations of the pattern of auroral energy flux, number flux, and conductivity , 1987 .

[38]  G. W. Prölss.  Storm-induced changes in the thermospheric composition at middle latitudes , 1987 .

[39]  S. Akasofu.  Interplanetary energy flux associated with magnetospheric substorms , 1979 .

[40]  Robert W. Schunk,et al.  Electron temperatures in the F region of the ionosphere - Theory and observations , 1978 .

[41]  Masahisa Sugiura,et al.  Hourly values of equatorial dst for the igy , 1963 .