| Abstrakt: |
The upstream and downstream plasmas of 109 strong‐compression forward interplanetary shocks are statistically analyzed using 3‐s measurements from the WIND spacecraft. The goal is a comparison of the fluctuation properties of downstream plasmas in comparison with the fluctuation properties of upstream plasmas in the inertial range of frequencies and the magnetic‐structure range of spatial scales. The shocks all have density compression rations of ~2 or more. When possible, each shock is categorized according to the type of solar wind plasma it propagates through: 15 shocks are in coronal‐hole‐origin plasma, 42 shocks are in streamer‐belt‐origin plasma, 36 shocks are in sector‐reversal‐region plasmas, and 11 shocks are in ejecta plasma. The statistical study examines magnetic field and velocity spectral indices, the Alfvénicity, the fluctuation amplitudes, Alfvén ratios, the degree of plasma inhomogeneity, and Taylor microscales, looking in particular at (1) fluctuation values downstream that are related to fluctuation values upstream and (2) systematic differences in fluctuation values associated with the type of plasma. It is argued that inhomogeneity of the downstream plasma can be caused by spatial variations in the shock normal angle θBn caused by field direction variations in the upstream magnetic structure. The importance of determining the type of plasma that the shock propagates through is established. Key Points: Spectral indices, amplitudes, Alfvénicity, Alfvén ratios, the degree of plasma inhomogeneity, and Taylor microscales are examinedStatistically, the properties of downstream fluctuations are correlated with the properties of upstream fluctuationsBecause of variations in the shock normal angle, upstream magnetic structure can lead to downstream plasma structure [ABSTRACT FROM AUTHOR] |
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