資料7-HCommission H (Waves in Plasmas) Activity Report(ed.) Okada T. and Y. Omura

Topics<Cluster and Themis>
Bow Shock: Hobara et al. (2010) reported the width of the terrestrial collisionless shock front, which isone of the key shock parameters. The width of the main shock transition layer is related to the nature of thecollisionless process that balances nonlinearity and therefore leads to the formation of the shock itself. Theshock width determines how the incoming plasma particles interact with the macroscopic fields within thefront and, therefore, the processes that result in the energy redistribution at the front.
Cluster and Themis measurements at the quasi perpendicular part of the terrestrial bow shock are used
to study the spatial scale of the magnetic ramp. It is shown that statistically the ramp spatial scale decreases
with the increase of the shock Mach number (Fig. 1). This decrease of the shock scale together withpreviously observed whistler packets in the foot of supercritical quasi perpendicular shock indicates that itis the dispersion that determines the size of magnetic ramp even for supercritical shocks

Fig. 1. Scatterplot of experimentally derived
shock spatial scale normalized on the ion
inertial length Li (left axis) and electron
inertial length Le (right axis) inertial lengths
as a function of Alfven Mach number. The
dashed line represents the values of theshock spatial scale averaged over shocks
with Alfven Mach number in the ranges from
2 to 12 by a step of 2. The vertical lines
represent the corresponding statistical error
bars.
Reference:
Hobara, Y., M. Balikhin, V. Krasnoselskikh, M. Gedalin, and H. Yamagishi (2010), Statistical study of thequasi perpendicular shock ramp widths, J. Geophys. Res., 115, A11106, doi:10.1029/2010JA015659.

Conferences and Meetings
1) 2010 Asia-Pacific radio Science Conference (AP-RASC’10), Toyama, September 22-26
2) The 128th Meeting of Society of Geomagnetism and Earth, Planetary and Space Science,Okinawa, November, 2010
3)
Second Remote Sensing of the Inner Heliosphere Workshop - Aberystwyth
University, Wales, UK - 06-10 June 2011
4) XXV IUGG General Assembly 28 June - 7 July 2011, Melbourne, Australia
http://www.iugg2011.com/The IUGG GA brings the 8 member Associations, including IAGA, together every fouryears. Much of the IAGA program is relevant to URSI scientists. The IAGA program at15)

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IUGG consists of 16 IAGA Symposia, 5 Joint Symposia with other Associations led byIAGA, plus other Symposia co-sponsored by IAGA.
AGU Chapman Conference on Dynamics of the Earth's Radiation Belts and Inner
Magnetosphere 17 - 22 July 2011, St. John's, Newfoundland and Labrador, Canada
http://www.agu.org/meetings/chapman/2011/ecall/index.php
ISSS-10 The 10th International School / Symposium for Space Simulations 24 - 31 July2011, Banff, Alberta, Canada http://www.ualberta.ca/~isss10/
AOGS 2011 Asia Oceania Geosciences Society Meeting 8 - 12 August 2011, Taipei, Taiwan
http://www.asiaoceania.org/aogs2011/
XXX URSI General Assembly and Scientific Symposium of International Union of Radio
Science, 13 - 20 August 2011, Istanbul, Turkey
http://www.ursigass2011.org/
Commission H Sessions:
H1: Nonlinear Waves and Turbulence in Plasmas
H2: Micro/macro-scale Kinetic Processes at Boundary Layers in
Terrestrial and Planetary Environments
H3&4: Wave-particle Interactions and Their Effects on Planetary
Radiation Belts
HG1&2: Radio Sounding in Ionospheres and Magnetospheres and AssociatedPlasma Phenomena
HG3&4: Active Experiments in the Ionosphere and Magnetosphere
H9: Laboratory Simulation of Space and Dust-related Phenomena
H10: Waves as Signatures of Inflowing Plasma Interaction with SolarSystem Bodies
H11: Open session on all aspects of waves in space and laboratory
plasmas on all aspects of waves in space and laboratory plasmas
AGU Fall Meeting, 5-9 December 20112