Commission H (Waves in Plasmas) Activity Report

 

November 14th, 2003

 

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

 

1. Research Project

 

(R-1) AKEBONO (EXOS-D) [1989-]

The AKEBONO spacecraft has attained the 14 years of successful operation without any major troubles. The regular data acquisition of MGF, EFD, PWS, VLF, LEP, SMS, TED, and RDM is continued at stations in Japan and Sweden. Some data set are opened at DARTS/AKEBONO web site (http://www.darts.isas.jaxa.jp/akbn/). The PWS and VLF database including the VLF waveform and in situ electron densities derived from PWS observations have also been constructed and are available on request. [For further information: http://www.stp.isas.jaxa.jp/akebono]

 

(R-2) GEOTAIL[1992-]

The GEOTAIL spacecraft has been operated without any major troubles. The　spacecraft is expected to be in a good condition at least until the next　long eclipse in 2004. The condition of the Plasma Wave Instrument onboard GEOTAIL is very normal and it is continuously collecting spectrum data and high resolution waveform data. The 24 hour plots of the observed wave spectrum data are opened in the GEOTAIL-PWI web site http://www.kurasc.kyoto-u.ac.jp/gtlpwi. The Geotail web site is http://www.stp.isas.jaxa.jp/geotail.

 

(R-3) NOZOMI [1998-]

Mars orbiter "NOZOMI" have observed magnetic field, particles, and UV flux in the interplanetary cruising orbit. However, these observation　stopped caused by the system problem after the CME event with the X1.5class solar flare starting on April 21, 2002. It has been confirmed that the last Earth swing-by on June 19 (2003) is　successfully done. Nozomi will arrive at Mars middle of December this　year.　Science observation of plasma wave and radio waves will be after the Mars orbit insertion. The NOZOMI web site is http://www.planet-b.isas.ac.jp/.

 

(R-4) Plasma Wave Experiment in Polar Regions

In order to study the generation and propagation mechanisms of the plasma waves in the Magnetosphere, induction magnetometers, imaging riometers, and VLF and LF radio wave receivers are installed at Syowa Station,Antarctica and three stations in Iceland. 45th Japanese Antarctic Research Expedition (JARE45) team departs from Tokyo on November 28 and succeeds its operation from JARE44.

   The PPB (Polar Patrol Balloon experiment in Antarctica) have been successfully carried out in January 2003 coordinated with AKEBONO satellite observation, in which Pc1 pulsations, ELF hiss, polar chorus and auroral hiss were recorded. The wave data by PPB experiment are opened in web site  http://ppb.nipr.ac.jp/.

ELF magnetic field observations in the frequency range of 1-500 Hz have been carried out at Syowa station since February 2000, using two horizontal search coil magnetometers. The same observation system has been installed at Onagawa observatory in Japan and at Esrange in Sweden.  The main purpose of this monitoring is to investigate the origins of global lightning activity change and the sources of discharge phenomena in the middle and the upper atmosphere such as sprites and elves.  As a result, global sprite occurrence rates and locations are estimated for the first time using ELF transient events observed at Syowa and Onagawa.  From the dynamic spectral analysis of these ELF data it is found that the global lightning activity shows clear 27-day periodicity, which may suggest a possible relationship between solar activity and global lightning activity.

 

(R-5) Alaska Student Rocket Experiment (2000-)

In March, 2002, a rocket (named as SRP-4) was successfully launched from Fairbanks Alaska, in order to study the wave propagation characteristic of LF and MF band, and to measure the electron density and collision frequency in the lower ionosphere. This rocket program is provided internationally to students for the education and training of space science and engineering. The next experiment is under studying and a rocket (SRP-5) will be launched in the winter-time, 2005.

 

(R-6) SELENE

The SELENE spacecraft will be launched in 2005. The fundamental functions of the wave instruments are now examined in the system function test from August 2003 followed by the EMC system test.

The Lunar Radar Sounder (LRS) experiment onboard the SELENE will provide subsurface stratification and tectonic features in the shallow part (several km depth) of the lunar crust, by using an FM/CW radar technique in HF frequency range. Knowledge of the subsurface structure is crucial to better understanding not only of the geologic history of the moon, but also of the regional and global thermal history of the Moon, and also of the origin of the Earth-Moon system. In addition to the subsurface radar experiment, LRS will provide the spectrum of plasma waves, and solar and planetary radio waves in wide frequency range covering from 10 Hz to 30 MHz. 

The Wave Form Caputure (WFC)　onboard the SELENE will observe the plasma waves in the magnetosphere and the solar wind at the lunar distance and wave phenomena in the lunar wake. It is composed of two types of digital receivers, a digital sweep frequency analyzer which covers from 1kHz to 1MHz and a wave form receiver which covers from 100 Hz to 100 kHz.

 

(R-7) Space Solar Power System

2003 Japan-US Joint Workshop on Space Solar Power System (JUSPS'03) was held on July 3-4, 2003 in Uji, Kyoto.

Space Solar Power System (SSPS) is promising technology to harness clean CO₂-free

energy on a continuous basis for many years to come. However, there are many challenging technological hurdles as well as associated problems in components, systems and environmental impacts. The objectives of the workshop are to make assessment of the state-of-the-art technologies and to identify important issues so as to pave a way to accelerate realization of the SSPS to benefit the mankind. The program and proceedings are opened at the web site, http://www.kurasc.kyoto-u.ac.jp/jusps.

 

(R-8) Geospace Environment Simulator

In order to make quantitative evaluation of electromagnetic environment around spacecraft, three dimensional electromagnetic particle simulation 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.

 

(R-9) Solar-Terrestrial Observation Database

For integrated studies of STP (Solar Terrestrial Physics), it is needed to analyze a variety of data. A database system that provides with the environment for data access, plot, analysis, and user communication has been developed. The system works on global networks (the Internet) to connect data and data, data and users, and users and users. The network database system can be downloaded on the web http://dl.infonet.cs.ehime-u.ac.jp.

 

 

2. Conferences

 

2.1 Domestic Conferences (June 2003 – October 2003)

 

1) The 27th Symposium on Coordinated Observation of the ionosphere and the Magnetosphere in the Polar Regions, 2003/7/31-8/1, National Institute of Polar Research

 

2) ACT-JST Summer School "Summer school for astrophysics and space plasma simulations" September 9-13, 2003, Chiba University

 

3) Conference of Hokuriku Chapters of Institute of Electrical Engineering, Japan, September 21-22, Toyama

 

4) Workshop on STE simulations 2003, September 10-12, 2003, Enoshima

 

5) SGEPSS Meeting, Toyama University, Oct.31-Nov.3, 2003

　　　143 papers were aurally presented, in which 40 papers are related with the space plasma waves.

 

2.2 International Conferences (June 2003 – October 2003)

 

1) IUGG2003, Sapporo, Japan, June 30-Luly 11, 2003

 

2) 2003 Japan – United State Joint Workshop on Space Solar Power Systsem (JUSPS’03), Kyoto, Japan, July 3-4, 2003

 

3) The Korea-Japan-China Mini-Workshop on Space Weather, August 18-20, 2003, Toyokawa

 

4) EISCAT2003, California, U.S.A., August 25-29, 2003

 

5) The 4th Japan-Europe Joint Meeting on Plasma Wave Investigation for the Mercury mission

It was held on October 22 to 24 in Radio Science Center for Space & Atmosphere, Kyoto University. Scientists and engineers from Japan and Europe got together in Kyoto and discussed the design and specifications of plasma wave receivers, which are dedicated to the future Mercury mission. The requirements for the ElectroMagnetic Compatibility were also discussed in order to realize the clean spacecraft for the electromagnetic environment.

 

2.3 Future Meetings

 

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

 

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

 

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

 

4) The First Asia-Oceania Geophysics Society Meeting , Singapore, July 5-9, 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