Learn More
S U M M A R Y The CHAMP magnetic field mission is providing highly reliable measurements from which the global lithospheric magnetic field can be determined in unprecedented resolution and accuracy. Using almost 5 yr of data, we derive our fourth generation lithospheric field model termed MF4, which is expanded to spherical harmonic degree and order 90.(More)
[1] Six years of low-orbit CHAMP satellite magnetic measurements have provided an exceptionally highquality data resource for lithospheric magnetic field modeling and interpretation. Here we describe the fifth-generation satellite-only magnetic field model MF5. The model extends to spherical harmonic degree 100. As a result of careful data selection,(More)
[1] A global Earth Magnetic Anomaly Grid (EMAG2) has been compiled from satellite, ship, and airborne magnetic measurements. EMAG2 is a significant update of our previous candidate grid for the World Digital Magnetic Anomaly Map. The resolution has been improved from 3 arc min to 2 arc min, and the altitude has been reduced from 5 km to 4 km above the(More)
[1] New observations obtained by the satellite CHAMP reveal a detailed picture of the noon-time equatorial electrojet (EEJ). The low orbit of CHAMP and its high-precision magnetometers reveal the spatial structure of the EEJ with unprecedented accuracy. Data from more than two and a half years have been used to investigate average features and also the(More)
[1] The equatorial electrojet (EEJ) is an eastward electric current on the day-side, flowing in a narrow band along the dip equator in the ionospheric E region. Recent magnetic observations from the CHAMP, Ørsted, and SAC-C satellites, comprising more than 95,000 dip equator crossings from 1999 to 2006, have provided an unprecedented longitudinal coverage(More)
Satellite magnetic anomaly maps derived by different techniques from Magsat/POGO data vary by more than a factor of 2 in the deduced strength of the lithospheric magnetic field. Here, we present a first anomaly map from new CHAMP scalar magnetic field data. After subtracting a recent Ørsted main and external field model, we remove remaining unmodeled(More)
This paper is concerned with the minimal number of profiles at which a unanimous and anonymous social choice function is manipulable. The lower bound is derived when there are three alternatives to choose from. Examples of social choice functions attaining the lower bound are given. We conjecture that these examples are in fact all minimally manipulable(More)
[1] The diamagnetic effect generally reduces the magnetic field inside a plasma. Its importance is appreciated in regions like the magnetosphere and the solar wind. In the ionosphere, depletions of the geomagnetic field have up to now been considered negligible. The CHAMP satellite provides for the first time the combination of highresolution magnetic field(More)