Mars Global Surveyor's Mars Orbiter Camera (MOC) Wide‐Angle Images (1999–2006): 2. Data Investigation Into North Polar Hood Formation, Broad Brightness Changes in Acidalia, and Seasonal Frost in Hellas

Abstract

AbstractMars Orbiter Camera Wide Angle images were taken from late 1999 through most of 2006, in both red and blue, providing nearly daily, nearly global coverage of Mars for approximately four Mars Years. Significant work has been published from those data, but there did not exist in a public archive a uniform, full time series of the processed data for easier analysis. The companion work to this (Robbins, 2023a, https://doi.org/10.1029/2022EA002673) presents that processing and quality control of the data, producing the full time series in both colors, in equirectangular and polar stereographic projections, in mosaics that have been binned into four different time intervals (daily, ΔLs = 2°, 5°, and 10° [≈4 through 19 days]) and as approximately true‐color composites. The multidimensional data set can be mined for surface and atmospheric variations on Mars. To demonstrate agreement with past work, several well‐known trends are demonstrated in a review‐style narrative format in Supporting Information S1, including changes after a global dust storm, seasonal frost variations at the poles, and surface variations. The data are analyzed further in the main text to demonstrate new qualitative and quantitative analyses of atmospheric and surface features: the North Polar Hood can form earlier than previously demonstrated, Acidalia has significant seasonal brightness variations that can be quantified, and the seasonal frost deposition and sublimation of Hellas can be quantified and shown to vary from year‐to‐year. These different investigations represent a small slice of what can be done now that these data are made available and easily accessible.