Exploration of Mars in the SPICAM-IR Experiment onboard the Mars-Express Spacecraft: 2. Nadir Observations: Simultaneous Observations of Water Vapor and O_2 Glow in the Martian Atmosphere

摘要

The SPICAM experiment onboard the Mars-Express spacecraft includes sounding the Martian atmosphere in the-ultra-violet (118-320 nm) and near IR (1-1.7 μm) ranges. The infrared spectrometer operates in the range of 1-1.7 μm with a resolution of 3.5 cm~(-1) in the mode of nadir observations and solar and stellar occultations. This paper is devoted to analyzing the basic results of nadir observations of the infra-red SPICAM channel during the first Martian year of the instrument operation: from January 2004 to November 2005. One of the primary goals of SPICAM-IR is water vapor monitoring in the atmosphere of Mars in the band of 1.37 μm and ozone abundance determination from the day-time airglow of molecular oxygen O_2(a~1Δ_g) in the band of 1.27 μm. Simultaneous measurements of these minor constituents of the planet are necessary for understanding photochemical processes in the Martian atmosphere. The degree of their anticorrelation and a comparison with the results of photochemical modeling of the atmosphere will contribute to our knowledge of the Martian atmosphere stability.