A one-year seasonal analysis of martian gravity waves using MCS data

Abstract

Temperature measurements from the Mars Climate Sounder on NASA’s Mars Reconnaissance Orbiter are examined for gravity wave signals using the Stockwell transform, a technique previously applied to terrestrial temperature profiles. An analysis is presented for internal-gravity waves throughout the martian atmosphere for the period July 2007–May 2009, representing a full martian year of data, divided by season. Momentum fluxes observed in the altitude range 200–20Pa are measured as ∼10−5–10−3Pa, significantly higher than at equivalent altitudes on Earth, and are primarily peaked around the tropics. Observed orographic effects are minimal; the primary observed effects are seasonal. Waves are shown to vary significantly in wavelength with latitude, but are generally approximately zonally symmetric. Horizontal wavelengths are consistently much shorter in the northern hemisphere than the southern.