Deriving new mixing ratios for Venus atmospheric gases using data from the Pioneer Venus Large Probe Neutral Mass Spectrometer.

We present the first published method to convert data obtained by the Pioneer Venus Large Probe Neutral Mass Spectrometer (LNMS) into units of mixing ratio (ppm) and volume percent (v%) against CO and N, the dominant Venus atmospheric gases, including conversion to density (kg m). These unit conversions are key to unlocking the untapped potential of the data, which represents a significant challenge given the scant calibration data in the literature. Herein, we show that our data treatments and conversions yield mixing ratios and volume percent values for HO, N, and SO that are within error to those reported for the gas chromatograph (LGC) on the Pioneer Venus Large Probe (PVLP). For the noble gases, we developed strategies to correct for instrument biases by treating the data as a relative scale and using PVLP and Venera-based measurements as calibration points. Together, these methods, conversions, calibrations, and comparisons afford novel unit conversions for the LNMS data and yield unified measures for Venus' atmosphere from the LNMS and LGC on the PVLP.•Conversion into mixing ratio (ppm), volume percent (v%), and density (kg m).•Mixing ratios are expressed against CO and N.•LNMS and LGC measurements on the PVLP are consistent.