Geoscience Reference
In-Depth Information
driven instabilities. Pick-up ions conveyed by the solar wind into the night
side magnetosphere can interact with the magnetospheric plasma, which
leads to ion-ion beam instabilities. And, high-energy electron beams in the
magnetotail generate Langmuir waves and electron phase space holes which
travel in the electron beam direction. The spatial distribution of electron
hole propagation allows us to estimate the location of reconnection.
2.4.2.
Non-gyrotropic effects
The sputtered ions from the surface that are picked up are associated with
Alfven or ion cyclotron waves. Those waves may evolve to large ampli-
tude non-linear waves, as at comets. Some complexities arise from the exis-
tence of an intrinsic magnetic field at Mercury. Propagation analysis of
Alfven waves allows us to study the connection of the solar wind with the
magnetosphere.
2.4.3.
Physics of foreshock
Langmuir waves are generated by backstreaming electrons reflected at the
bow shock. Electromagnetic 2
f
pe
radiation is produced from those, by non-
linear coupling or mode conversion, which is the common process with
solar radiations.
In situ
measurements will help discriminate the proposed
mechanisms.
2.5.
Solar radio emissions and diagnostics
2.5.1.
Space weather observation
Monitoring of solar radiation up to 10 MHz (types II and III radio bursts)
allows us to correlate them with the Mercury magnetospheric response in
order to create a solar activity index from the view point of Mercury, pro-
viding context information for the
in situ
measurements.
2.5.2.
Stereoscopic observation
Combined with other spacecraft, the MMO can perform stereoscopic obser-
vations of solar radiation from large-scale plasma structures such as CMEs.
Such studies enable us to estimate the global properties of the solar wind
in the inner heliosphere.