Stationary planetary waves in the atmosphere of Mars during southern winter

[1] We report new observations of stationary planetary waves in the Southern Hemisphere of Mars by Mars Global Surveyor (MGS). We focus on a period during midwinter (L-s = 134degrees - 160degrees) when independent observations were acquired by two techniques. Radio occultation experiments sounded the atmosphere at essentially fixed latitude (similar to68degreesS) and local time (similar to1030), yielding profiles of geopotential and temperature between the surface and the 9 Pa pressure level. Observations by the Thermal Emission Spectrometer (TES) included systematic limb sounding at nine discrete latitudes and two local times (similar to0200 and similar to1500), yielding temperature profiles at pressures of 1 - 100 Pa. We supplemented these data with a simulation by a Mars general circulation model (MGCM), which provides an accurate synthesis of the observations. These stationary planetary waves have significant amplitudes at zonal wave numbers s = 1 and 2. The s = 1 component propagates vertically, as reflected by a westward tilt with increasing height in the geopotential and temperature fields and a net poleward eddy heat flux. The peak amplitude at s = 1 is similar to1 km in geopotential height and similar to7 K in temperature. The geopotential field of the s = 2 component is "barotropic'' in character, which results through hydrostatic balance in a distinctive temperature field. The peak amplitude at s = 2 is similar to700 m in geopotential height and 4 - 6 K in temperature.