Solar wind density intercomparisons on the WIND spacecraft using WAVES and SWE experiments

Abstract. We present solar wind density comparisons using three different instruments on the WIND spacecraft: The thermal noise receiver (TNR) on the WAVES experiment which yields the total electron density from the detection and the analysis of the electron plasma peak; the SWE Fara-day cup detectors which measure ion energy per charge spec-tra and yield the proton and alpha particle densities in the solar wind; and finally the SWE electron spectrometer which provides 3D electron velocity distribution functions and thus the total electron density. The density comparison between the TNR and the SWE Faraday cups shows a remarkably good agreement, with a systematic offset which is lower than 1 % and fluctuations of up to, • 5 % around this value. Due to the well known spacecraft electrical potential effects, the SWE electron spectrometer densities, uncorrected from the potential, exhibit larger differences when compared with the TNR or the SWE Faraday cups measurements. Using these latter densities as reference, we compute a rough estimation of the spacecraft potential