Ion temperature anisotropies in the Earth's high-latitude magnetosheath: Hawkeye observations
| dc.contributor.author | Tan, Lun C. | |
| dc.contributor.author | Fung, S. F. | |
| dc.contributor.author | Kessel, R. L. | |
| dc.contributor.author | Chen, S.-H. | |
| dc.contributor.author | Green, J. L. | |
| dc.contributor.author | Eastman, T. E. | |
| dc.date.accessioned | 2021-07-30T16:55:45Z | |
| dc.date.available | 2021-07-30T16:55:45Z | |
| dc.date.issued | 1998-03-01 | |
| dc.description.abstract | We present here for the first time observations of the inverse correlation between the ion temperature anisotropy and plasma beta in the Earth's high-latitude magnetosheath. Hot proton data with energies of 0.3–8 keV were obtained from magnetosheath passages by the Hawkeye spacecraft which had a polar orbit with an apogee of 20–21 RE. A newly developed technique has been used to calculate the distribution functions of protons in their non-streaming frame in which their first-order anisotropy is absent. The ion-energy dependence of distribution functions indicates the existence of two hot ion components. Thus the correlation has been examined for each hot ion component separately. We have analyzed three Hawkeye magnetosheath passes during which the magnetosheath's magnetic field was close to the spacecraft spin plane, so that the two-dimensional Hawkeye sensor can adequately sample temperature anisotropies. Results of our analyses are consistent with the theoretical prediction given by Gary et al. [1994; 1995] that a universal inverse-correlation relationship exists between the temperature anisotropy and plasma beta of hot ions. | en_US |
| dc.description.sponsorship | We thank J. Van Allen for archiving the Hawkeye data at the National Space Science Data Center (NSSDC). The Hawkeye and IMP-8 data used in this work were obtained from the NSSDC. We also thank T. P. Li for his help in the use of the bootstrap method and the insightful comments from the referees. This work was partially supported by NASA contract NAS 5-97059. | en_US |
| dc.description.uri | https://agupubs.onlinelibrary.wiley.com/doi/10.1029/98GL00306 | en_US |
| dc.format.extent | 4 pages | en_US |
| dc.genre | journal articles | en_US |
| dc.identifier | doi:10.13016/m2rqta-rl1o | |
| dc.identifier.citation | Tan, Lun C. et al.; Ion temperature anisotropies in the Earth's high-latitude magnetosheath: Hawkeye observations; Geophysical Research Letters, 25, 5, p 587-590, 1 March, 1998; https://doi.org/10.1029/98GL00306 | en_US |
| dc.identifier.uri | https://doi.org/10.1029/98GL00306 | |
| dc.identifier.uri | http://hdl.handle.net/11603/22225 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | American Geophysical Union | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Goddard Planetary Heliophysics Institute (GPHI) | |
| dc.rights | This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author. | |
| dc.rights | Public Domain Mark 1.0 | * |
| dc.rights | This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law. | |
| dc.rights.uri | http://creativecommons.org/publicdomain/mark/1.0/ | * |
| dc.title | Ion temperature anisotropies in the Earth's high-latitude magnetosheath: Hawkeye observations | en_US |
| dc.type | Text | en_US |