High resolution satellite observations of mountain waves

We will present recent high resolution two- and three-dimensional views of mountain waves in the middle atmosphere observed by satellite. We will show examples from both the Atmospheric Infrared Sounder (AIRS) and the High Resolution Dynamics Limb Sounder (HIRDLS). With AIRS CO2 temperature channels we can image gravity wave temperature fluctuations in the stratosphere at high horizontal resolution, with a pixel size of 13.5 km at the nadir. These often show substantial horizontal extension of the wave field beyond the region of elevated terrain where the waves are forced. We will show case study comparisons of observed wave events to models including high-resolution global model and assimilation fields of the European Medium-Range Weather Forecasting (ECMWF) center, and to linear ray-tracing models. The models are capable of capturing the observed morphology of the wave events indicating a good theoretical understanding of wave generation and propagation processes. HIRDLS is an infrared profiler with high vertical resolution (1.2 km) and close horizontal spacing (~100 km) between individual profiles. HIRDLS temperature profiles extend to 60-km altitude and the observations provide the first unambiguous evidence for mountain wave propagation to the mesosphere.