UMD AOSC Seminar
Traveling Waves and Instabilities in the Martian Atmosphere
Dr. John Wilson
NOAA Geophysical Fluid Dynamics Laboratory
Planetary-scale traveling waves in the martian atmosphere were first anticipated in the 1960s and were subsequently inferred from observations by the Viking Landers in the late 1970s. The recent observations by Mars Global Surveyor (MGS) have provided a much more detailed understanding of planetary-scale wave activity and reveal the important role that these waves play in the dust cycle. Eastward traveling waves with zonal wavenumbers 1-3 and periods of 2-10 days are particularly prominent in both MGS Thermal Emission Spectrometer (TES) temperature retrievals and Mars global circulation model (MGCM) simulations. These waves display a relatively high degree of regularity, in contrast to their terrestrial counterparts. The initiation and evolution of a number of regional scale dust storms has been documented in detail with visual imagery and with temperature and dust opacity observations. These storms are evidently associated with traveling waves embedded in the strong westerly jet that is present in the northern hemisphere in the fall, winter and spring seasons. I will describe the characteristics and climatology of transient waves in the MGS Reanalysis derived from an assimilation of MGS TES data with the UK Mars global circulation model. I will also discuss investigations of traveling baroclinic wave behavior present in annual cycle simulations of the martian atmosphere using the GFDL MGCM.
April 30, 2009, Thursday