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CLUSTER observation of collisionless transport at the magnetopause
Author(s) -
Panov E. V.,
Büchner J.,
Fränz M.,
Korth A.,
Savin S. P.,
Fornaçon K.H.,
Dandouras I.,
Rème H.
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl026556
Subject(s) - magnetosheath , physics , magnetopause , proton , gyroradius , pitch angle , population , magnetic field , radius , cyclotron , computational physics , flux (metallurgy) , current sheet , magnetosphere , earth radius , atomic physics , geophysics , magnetohydrodynamics , nuclear physics , materials science , computer science , demography , computer security , quantum mechanics , sociology , metallurgy
On May 10, 2002 the CLUSTER spacecraft (SC) encountered a ∼450 km (five magnetosheath thermal proton gyro‐radii) wide high‐latitude magnetopause (MP). Magnetic field observations indicate the crossing of a ∼130 km thick MP current sheet (CS) located inside a magnetic hole. Proton flux measurements diagnose a dense boundary layer (BL) directly attached to the MP and an additional rare BL located earthwards from the MP. Enhanced magnetic fluctuations are found near the local proton‐cyclotron frequency Ω cp (0.4–2 Hz). Applying the phase‐differencing technique we obtained a wavelength of 150–250 km and the propagating direction earthward perpendicular to the MP. Inside the MP the pitch‐angle proton distribution demonstrates the presence of a transverse population. The formation of the two BLs can be understood by enhanced collisionless diffusion of magnetosheath protons due to wave‐particle interaction, while higher‐energy protons ( W p > 300 eV) penetrate into the BLs also via finite gyro‐radius effect.