We present the analysis of plasma and field data acquired from the AMPTE/IRM satellite for ULF wave fluctuations in the subsolar magnetosheath under a "quiet" condition. A total of seven magnetosheath crossings, representing twelve hours of observations, were selected for statistical analysis. The statistical analysis results indicated that mirror-like compressional fluctuations are typical of the quiet-state subsolar magnetosheath. It is also found that mirror-like fluctuations with typical frequencies between 10 mHz and 80 mHz (or 0.02 f(H) + less than or equal to f less than or equal to 0.2 f(H) +, where f is the wave frequency and f(H) the local proton gyro frequency) are associated with 0.1 less than or equal to (T-perpendicular to/T-II - 1) less than or equal to 0.6 and 1 less than or equal to beta(p) less than or equal to 10 magnetopause plasma, where beta(p) is the proton beta and T-perpendicular to and T-II are the perpendicular and parallel proton temperature, respectively. We also found that the condition for mirror instability, T-perpendicular to/T-II > 1 + beta(perpendicular to)(-1), is generally not satisfied in the entire region of the magnetosheath, especially near the magnetopause. This may indicate that temperature anisotropy is reduced due to the development of mirror waves as suggested by Price et al. [1986] and Lee et al. [1988].
