Activity Report of the National Committee for
Geomagnetism and Aeronomy
Yohsuke KAMIDE Chair of the National Committee for Geomagnetism and Aeronomy
W e report herewith on IAGA-related research activity in Japan over the period of 2004-2007 in terms of three areas: “Solar-Terrestrial Research,” “Earth and Planetary Interior,” and “Meetings, Reorganizations and Research Programs.” The following is a summary of what has been accomplished over the last four years in each of these three areas:
1. Solar-Terrestrial Research
Sun and interplanetary space
The Japanese solar observation satellite “Hinode” was successfully launched in September 2006, and
a new solar observation system, “SMART,” was installed at the Hida Observatory.
They are expected to
be the new major data sources in the research of solar flares and coronal mass ejections.
Observations of the solar wind has continued using the interplanetary scintillation (IPS) technique, which is capable of observing the structure and dynamics of the solar wind in three dimensions (3D) with a relatively short time cadence. To make the solar wind observations with higher spatial and temporal resolution using the IPS tomographic method, construction of a large IPS antenna began in 2006. A test of solar wind predictions is being carried out under collaboration between CASS/UCSD and STEL. The 3D structure and propagation of coronal mass ejections (CMEs) have also been studied jointly by a cosmic ray group and a solar wind group.
Construction of a global network of muon detectors in four countries has been completed and high-quality observations of high-energy cosmic ray streaming, showing dramatic variations in response
the CME arrival at Earth.
In collaboration with the Tibet air shower experiment, the sidereal anisotropy
provides useful information on the local interstellar magnetic field surrounding the heliosphere.
longitudinal variations of interplanetary neutral hydrogen Lyman alpha emission, as well as their relation to the solar photon flux, have been reported. The first attempt to monitor long-term variations in the solar wind mass flux at all heliographic latitudes has been made by combining IPS observations and the
the real heliospheric interaction is not simple and asymmetric, deflection in the global heliosphere structure are warranted.
1.2. Magnetosphere The major driver of observational space physics over the last four years has been the data from Cluster-II, which the Japanese community has joined to use. With unprecedented multi-point
measurements, the science community is setting the time series data obtained by each spacecraft.
up a scheme to separate spatial and temporal effects in Together with the results from full particle simulations
that have recently become available, the importance of multi-scale interactions plasmas in the solar-terrestrial system is increasingly recognized. The successful
as basic processes launch of THEMIS
February in space.
Considerable advances in the studies of electron acceleration in the radiation belts during storms and substorms have been made by Japanese scientists through computer simulations of wave-particle