Wind/SWE observations of firehose constraint on solar wind proton temperature anisotropy

�2 , and the fitting parameters Sp � 1a ndap ’ 0.7. Observations from the Wind spacecraft are reported here. These measurements show for the first time with a comprehensive plasma and magnetic field data set that this constraint is statistically satisfied in the solar wind near 1 AU, with best-fit values of Sp = 1.21 ± 0.26 and ap = 0.76 ± 0.14. INDEX TERMS: 7871 Space Plasma Physics: Waves and instabilities; 7867 Space Plasma Physics: Wave/particle interactions; 2164 Interplanetary Physics: Solar wind plasma. Citation: Kasper, J. C., A. J. Lazarus, and S. P. Gary, Wind/SWE observations of firehose constraint on solar wind proton temperature anisotropy, Geophys. Res. Lett., 29(17), 1839, doi:10.1029/ 2002GL015128, 2002.

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