Two different approaches for the inner magnetosphere currents estimation: ion pressure measurements and the curlometer technique, using CLUSTER CIS and FGM data.

Details Two different approaches for the inner magnetosphere currents estimation: ion pressure measurements and the curlometer technique, using CLUSTER CIS and FGM data. Two different approaches for the inner magnetosphere currents estimation: ion pressure measurements and the curlometer technique, using CLUSTER CIS and FGM data.

Dec 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003agufmsm52a0559v&link_type=abstract

American Geophysical Union, Fall Meeting 2003, abstract #SM52A-0559

Physics

7807 Charged Particle Motion And Acceleration

Scientific paper

The inner magnetosphere's electric currents configuration and mapping is one of the keys for understanding current loop closure inside the whole magnetosphere. Development of the ring current as a function of geomagnetic activity is still one of the most interesting aspects about this region. Analyzing thus data from the four CLUSTER spacecraft while passing in the inner magnetosphere (perigee situated at about 4 RE, inclination 90o ), we have been using two different methods to quantify currents in this region. First, based on Maxwell's laws application, the curlometer technique is applied. It is based on four point measurements of the magnetic field, as measured by the four Fluxgate magnetometer instruments onboard Cluster. This allows to determine the current density vector crossing the tetrahedron formed by the spacecraft. Second, based on the general MHD momentum equation, and under simplifying assumptions (static conditions, isotropic distribution,...), we experimentally deduced the perpendicular component of the current density by calculating the pressure gradient between spacecraft. This was done by using the Cluster Ion Spectrometer experiment, which provides full three-dimensional ion distributions (from about 5eV/q to 40 keV/q) with one spacecraft spin time resolution (4 sec) and with mass-per-charge composition determination. Both methods reveal very clear and interesting structures of the current. `Filamentations' of the current are observed in the plasma sheet within the field-aligned currents system, and they appear to be extremely well correlated with low energy protons up-flowing from the ionosphere. Smooth and isotropic structures inside the ring current during low geomagnetic activity are also shown, with a large latitudinal extent. Nevertheless, some unexpected signatures are also observed, such as the inversion of the XGSM current density component during perigee passes, even if not fully understood yet. The comparative study of both methods should allow for the first time to better quantify the offsets induced on the current estimation, and to get a more precise image of the current systems in the inner magnetosphere.

Affiliated with

Also associated with

No associations

Rating

Two different approaches for the inner magnetosphere currents estimation: ion pressure measurements and the curlometer technique, using CLUSTER CIS and FGM data. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Two different approaches for the inner magnetosphere currents estimation: ion pressure measurements and the curlometer technique, using CLUSTER CIS and FGM data., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two different approaches for the inner magnetosphere currents estimation: ion pressure measurements and the curlometer technique, using CLUSTER CIS and FGM data. will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1651063