HR: 16:00h
AN: SA24A-01    [Abstracts]
TI: Comparison of Global Electromagnetic and Particle Energy Flux Distributions in the High-Latitude Ionosphere
AU: Korth, H
EM: haje.korth@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Lab, 11100 Johns Hopkins Rd., Laurel, MD 20723 United States
AU: * Anderson, B
EM: brian.anderson@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Lab, 11100 Johns Hopkins Rd., Laurel, MD 20723 United States
AU: Waters, C
EM: colin.waters@newcastle.edu.au
AF: Univ of Newcastle, Physics Dept., Callaghan, NSW 2308 Australia
AU: Ruohoniemi, M
EM: michael.ruohoniemi@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Lab, 11100 Johns Hopkins Rd., Laurel, MD 20723 United States
AU: Frey, H
EM: hfrey@ssl.berkeley.edu
AF: Univ California Berkeley, 7 Gauss Way, Berkeley, CA 94720 United States
AU: Immel, T
EM: immel@ssl.berkeley.edu
AF: Univ California Berkeley, 7 Gauss Way, Berkeley, CA 94720 United States
AU: Takahashi, K
EM: kazue.takahashi@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Lab, 11100 Johns Hopkins Rd., Laurel, MD 20723 United States
AU: Rich, F
EM: frederick.rich@hanscom.af.mil
AF: Air Force Research Lab, 29 Randolph Rd, Hanscom AFB, MA 01731 United States
AU: Hairston, M
EM: hairston@utdallas.edu
AF: Univ Texas Dallas, Ctr Space Science POB 830688 F022, Richardson, TX 75083
AB: The interaction of the solar wind with the Earth's magnetic environment in space gives rise to an electromagnetic dynamo which is coupled to the ionosphere-thermosphere (I-T) system via electromagnetic fields and currents. This coupling results in 10s to 100s of GW of power input to the high latitude I-T and quantifying this energy transfer is fundamental to understanding the dynamics of the I-T system. The two major mechanisms of energy transfer at the ionosphere are particle precipitation and electromagnetic (EM) power or Poynting flux. We present a case study comparing global distributions of the large-scale particle and EM energy input into the northern hemisphere ionosphere for the interval 10 January 2002, 1000-1200 UT, using the most direct observations available. The particle energy flux is evaluated for the entire region poleward of 60 deg. MLAT from IMAGE FUV auroral emissions by averaging multiple two-minute snapshots of the energy flux distributions recorded during the two-hour interval. The EM energy input is obtained from average electric fields derived from SuperDARN observations and global maps of the magnetic perturbations observed by the network of Iridium satellites to estimate the distribution of the vertical Poynting vector. The local-time coverage of the combined Iridium/SuperDARN data set is ~18 hours. We find that the that EM and particle energy flux have different spatial distributions and that the EM power of approximately 45 GW is a factor of 3 larger than that due to particle precipitation (17 GW total). In-situ observations of particle precipitation, magnetic field, and plasma drifts by DMSP satellites are used to validate our results.
DE: 2409 Current systems (2721)
DE: 2411 Electric fields (2712)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2455 Particle precipitation
DE: 2704 Auroral phenomena (2407)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005