True-Color MARCI Mosaics and Southern Polar Seasonal Cap Ellipse Fits for Mars Years 28–37

Description This dataset contains the true-color MARCI mosaics and the SPSC ellipse fit parameters described in Acharya & Calvin (Submitted to JGR), "Growth, Recession, and Interannual Variability of the Martian Southern Polar Seasonal Cap from New True-Color MARCI Mosaics". These mosaics span Mars Years (MYs) 28-37 at 2° Ls intervals and capture both the growth and retreat phase of the SPSC for the first time using MARCI. Content MARCI Mosaics Mosiacs (ZIP archives) Polar stereographic projections of the southern hemisphere from 90° S to 20° S, centered at 90° S, 0° E. Mosaics are generated at 2° Ls averages and organized into two ZIP archives based on the processing applied: MOS_0_290_PNGS.zip - mosaics convering Ls 0°-290°, processed with cross-track gradient correction only MOS_290_360_PNGS.zip - mosiacs overing Ls 290°-360°, processed with both cross-track and along-tracking gradient corrections to compensate for strong gradient between the unfrosted and frosted region during late summer. Mosaic filenames are encoded by Earth date rather than MY. Use the included conversion CSV (see below) to map Earth Months to the corresponding MY and Ls range. Ellipse Fit Paramters (CSV) Two csv files contain the ellipse fit paramters derived from HSV-based cap detection algorithm: SPSC_Latitude_Ls0_Ls290.csv - refined ellipse fit used for latitudinal extent analysis presented in the manuscript for Ls 64°-290°. SPSC_Latitude_Ls290_Ls360.csv - refined ellipse fit used for latitudinal extent analysis presented in the manuscript for Ls 290°-360°. Ellipse fits are indexed by Earth date. Use the conversion csv (MARCI_DATE_CONVERSION.csv) to translate Earth date to MY and Ls. Processing Code All the ISIS shell scripts and custom Python scripts used to generate mosiacs are publicily available on Github at: acharyapruthvi/TRUE_COLOUR_MARCI_MOSAIC_WORKFLOW The repository includes the image correction and mosaic generation pipelines along with a step-by-step instructions on how to run the workflow. A complete list of the ISIS command and custom script is provided in Appendix A of the associated manuscript. Data Source RAW MARCI observations were obtained from the NASA Planetary Data System (PDS) Imaging Node. MARCI is operated by Malin Space Science System and is aboard MRO. Intended Use These mosaics are optimizzed for tracking the SPSC edge and surface frost features. They are not indended for absolute radiometric or albedo measurement due to cross-track and along-track normalization steps applied during processing.