|
|
 |
|
|
Ann. Geophys., 26, 387-394, 2008
www.ann-geophys.net/26/387/2008/
© European Geosciences Union 2008
Solar wind dependence of ion parameters in the Earth's magnetospheric region calculated from CLUSTER observations
M. H. Denton1,2 and M. G. G. T. Taylor2
1Department of Communication Systems, Lancaster University, Lancaster, LA1 4WA, UK
2Science Operations Department, European Space Agency, 2201AZ Noordwijk ZH, The Netherlands
Abstract. Moments calculated from the ion distributions (~0–40 keV) measured by
the Cluster Ion Spectrometry (CIS) instrument are combined with data from
the Cluster Flux Gate Magnetometer (FGM) instrument and used to characterise
the bulk properties of the plasma in the near-Earth magnetosphere over five
years (2001–2005). Results are presented in the form of 2-D xy, xz and yz
GSM cuts through the magnetosphere using data obtained from the Cluster
Science Data System (CSDS) and the Cluster Active Archive (CAA). Analysis
reveals the distribution of ~0–40 keV ions in the inner magnetosphere
is highly ordered and highly responsive to changes in solar wind velocity.
Specifically, elevations in temperature are found to occur across the entire
nightside plasma sheet region during times of fast solar wind. We
demonstrate that the nightside plasma sheet ion temperature at a downtail
distance of ~12 to 19 Earth radii increases by a factor of ~2
during periods of fast solar wind (500–1000 km s−1) compared to periods
of slow solar wind (100–400 km s−1). The spatial extent of these
increases are shown in the xy, xz and yz GSM planes. The results from the
study have implications for modelling studies and simulations of
solar-wind/magnetosphere coupling, which ultimately rely on in situ observations of
the plasma sheet properties for input/boundary conditions.
Full Article in PDF (345 KB) |
|
|
