MARSIS Transient Layer Detections during Comet Siding Spring Event 2014

<strong>This data is used in the publication, "Prolonged Lifetime of the Transient Ionized Layer in the Martian Atmosphere Caused by Comet Siding Spring" by Luppen et al. 2020.</strong> MARSIS_transient_layer_detections.csv: The data contained in this file are measurements from the Mars Express spacecraft's MARSIS instrument, collected during the Comet Siding Spring flyby event in 2014. The comet is known to have deposited a large amount of material into Mars' ionosphere, producing a transient layer of plasma that was noticed by multiple spacecraft instruments immediately following the comet's closest approach to the planet. The layer was originally thought to have had a lifetime of 1-2 days. Follow-up analysis, represented in this data file, indicate that this layer could have lasted at least 7 days and as many as 32 days after closest approach, much longer than previously reported. Our results help to constrain models of metal ion chemistry in the Martian upper atmosphere. MARSIS_regular_ionospheric_measurements.csv: The data contained in this file are measurements of the regular ionosphere during the comet Siding Spring event. These data are plotted in Figures 3 and 4 of the manuscript. MAVEN_normalized_euv_irradiance.csv: The data contained in this file are measurements collected from the Extreme UltraViolet (EUV) monitor that is part of the Langmuir Probe and Waves (LPW) instrument on the MAVEN spacecraft collected during the comet Siding Spring event. These data are plotted in Figure 5 of the manuscript. FISM_normalized_euv_irradiance.csv: The data contained in this file are measurements collected from the Flare Irradiance Spectral Model (FISM) collected during the comet Siding Spring event. These data are plotted in Figure 5 of the manuscript. MARSIS_averaged_data_figure4.csv: The data contained in this file are derived products from the MARSIS_regular_ionospheric_measurements.csv data. A running mean was calculated with 2 degree SZA bins, the SZA centers of those bins were identified, and a standard deviation was calculated for each bin. These data are plotted in Figure 4 of the manuscript. Note that we make use of a shaded region signifying a 3 sigma standard deviation.