CRRES Electric Field Power Spectral Distributions

The ULF wave power during the CRRES mission is investigated using the CRRES electric field instrument. The wave power spectral characteristics are examined as a function of L in terms of long-term averages, and in terms of magnetic activity (Kp). Previous work has fit the power spectral density to activity-dependent power law spectra [Holzworth and Mozer, 1979]. Results from the current study are compared with these earlier results. There are a significant number of cases where the observed spectra deviate from a power law, exhibiting a secondary peak around 8 mHz . The regularity and nature of these spectra are examined as well.