Commission H (Waves in Plasmas) Activity Report

 

March 10th, 2004

 

T. Okada, Y. Omura, and H. Matsumoto

 

1. Research Project

 

(R-1) Geospace Plasma Waves

AKEBONO (EXOS-D) satellite has been making observations since1989. The plasma wave data obtained by the instruments PWS and VLF are available on request [for further information: http://www.stp.isas.jaxa.jp/akebono].

GEOTAIL spacecraft has been operated since 1992. Recently, it experienced the big solar flares in October-November, 2003 and provided　the data on the wave phenomena and solar-terrestrial environment. The Plasma Wave Instrument (PWI) is continuously collecting spectrum data and high time-resolution waveform data. It is expected to be in a good condition at least until the next　long eclipse in 2004.The 24 hour plots of the observed wave spectrum data are opened in the PWI web site http://www.kurasc.kyoto-u.ac.jp/gtlpwi, http://www.stp.isas.jaxa.jp/geotail.

Ground observations at Syowa Station, Antarctica have been carried out in the ELF/VLF/LF bands in order to study the generation and propagation mechanisms of the plasma waves in the ionosphere and magnetosphere. Collaborative experiments with AKEBONO satellite and the magnetically conjugate point in Iceland have also been conducted. The observation data from the PPB (Polar Patrol Balloon experiment in Antarctica) which was carried out in January are opened in web site http://ppb.nipr.ac.jp/.

 

(R-2) Planetary Plasma Wave Experiments

NOZOMI made the final Mars swing-by on December 14, 2003 and became an artificial planet. No plasma wave observation was carried out in the NOZOMI mission. The NOZOMI web site is http://www.planet-b.isas.ac.jp/index-e.html. The information of the failure is http://www.isas.ac.jp/e/snews/2003/1209.shtml.

SELENE spacecraft will be launched in 2006. The functions of the wave instruments have been examined including the EMC system test. The Lunar Radar Sounder (LRS) experiment will provide subsurface stratification and tectonic features of the lunar crust by using an FM/CW radar technique in HF frequency range. LRS will measure the spectrum of the solar and planetary radio waves in the range from 10 Hz to 30 MHz. The Wave Form Capture (WFC) will observe the solar and lunar plasma waves in the frequencies from 100 Hz to 1MHz by using a digital sweep frequency and a waveform receiver.

 

(R-3) Ionospheric Radio Waves

S-310-33 rocket experiment was conducted at Kagoshima Space center, JAXA on January 18th, 2004 in order to measure the profiles of electron density and collision frequency in the lower ionosphere. The propagation characteristics in the ionosphere of the MF wave (NHK Kumamoto Broadcasting Station; 873 kHz) and the DC probe data are used for analysis. This experiment is important to improve the International Reference Ionosphere (IRI) model at altitudes below 75 km. For the same aim, a rocket experiment at high latitudes is now under design by the Alaska Student Rocket Project (ASRP) team. The rocket named as SRP-5 will be launched in Fairbanks, Alaska in the winter time, 2005.

 

(R-4) Space Solar Power System

Space Solar Power System (SSPS) will provide a clean and limitless energy resource from space by microwave power transmission (MPT). The SSPS studies, carried out in the latter half of 1970's under the sponsorship of the US NASA/DOE, contained research on the effects associated with the propagation of intense microwave beams through the ionosphere. Two rocket experiments of MPT in space and some computer experiments are carried out in Japan in 1980's and in 1990's. Japanese SSPS committees in JAXA and USEF now focus on design of MPT experimental satellite and its purpose contains experiments of measurement of interaction between microwaves and ionospheric plasmas.

 

(R-5) Solar-Terrestrial Environment Simulator and Data Base

For integrated studies of STP (Solar Terrestrial Physics), a database system that provides with the environment for data access, plot, analysis, and user communication has been developed. It has been extended and applied on 4-D (3-D in space and 1-D in time) virtual reality system. The network database system can be downloaded on the web https://dl.infonet.cs.ehime-u.ac.jp/download/space_index_e.aspx.

　   In order to make quantitative evaluation of electromagnetic environment around spacecraft, three dimensional electromagnetic particle simulations are being performed using 125 nodes (2 TB Memory) of the Earth Simulator System, reproducing various physical processes induced by emission of heavy ions in electric propulsion.

 

2. Conferences

 

2.1 Conferences and Meetings (November 2003 – March 2004)

 

1)      Symposium on Super DARN network, NIPR, Tokyo, December 19, 2003

2)      AGU 2003 Fall Meeting, San Francisco U.S.A., December 8-12, 2003

3)      3/17-3/19 Kyoto Japan International Workshop "Explosive Phenomena in

Magnetized Plasmas -New Development in Reconnection Research-"

 

2.2 Future Conferences and Meetings

 

1)      First EGU General Assembly, Nice, France April 25-30,2004

2)      Joint AGU-Canadian Geophysical Union (CGU) Meeting, Montrial Canada, May 17-21, 2004.

3)      The First Asia-Oceania Geophysics Society Meeting , Singapore, July 5-9, 2004.

4)      35th COSPAR Scientific Assembly, Paris, France, July 8-25, 2004.

5)      NATO Advanced Study Institute on Sprites, Elves and Intense Lightning Discharges Corte in Corsica, July 21-30, 2004.

6)      Western Pacific Geophysics Meeting : Honolulu Hawaii, August 16-20, 2004

7)      AP-RASC'04, Qingdao, China, August 24-27, 2004.