Pergamon Press plc [w THE DETERMINATION OF ION TEWERATURE IN ME AURORAL F-REGION IONOSfflERE

• Main Author: K. J. Winser
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Maurice; EISCAT
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.694.6226; http://www.eiscat.rl.ac.uk/Members/mike/publications/pdfs/1988/42_LockwoodandWinser_1988.pdf

Absrracr. Assessment Is made of the effect of the assumed form for the ion velocity distribution function on estimates of three-dimensional ion temperatUr @ from one-dimensional observations. Incoherent scatter observations by the EISCAT radar at a variety of aspect angles are used to demonstrate features of ion temperature determination and to study the ion velocity distribution function. One form of the distribution function which has recently been widely used in the interpretation of EISCAT measurements, is found to be consistent with the data presented here, in that no deviation from a Naxwellian can be detected for observations along the magnetic field line and that the ion temperature and its anisotropy are accurately predicted. It is shown that theoretical predictions of the anisotropy by Elonte Carlo c~u~t~n $ are very accurate, the observed value being greater by only a few pecent. It is also demonstrated for the case studied that errors of up to 93 % are introduced into the ion temperature estimate if the anisotropy is neglected. Observations at an aspect angle of 54.70, which are not subject to this error, have a much smaller ~c~rt~nty (less than 1%) due to the adopted form of the distribution of line-of-sight velocity. In a remarkable series of papers, culminating in their review published in 1979, St-Maurice