Stratospheric Gravity Wave Activity during the 2014 DEEPWAVE Field Campaign: An Observational Perspective Using Satellite Nadir Radiances

The field deployment of the Deep Propagating Gravity Wave Experiment (DEEPWAVE) took place from 6 June to 21 July 2014 from an operating base in Christchurch, New Zealand (see the overview presentation of Doyle et al., this session). The choice of the greater New Zealand region as a localized “hot spot” for the generation and deep vertical propagation of both orographic and nonorographic gravity waves was based to some extent on long-term climatologies of stratospheric gravity waves resolved in nadir radiance imagery from the Atmospheric Infrared Sounder (AIRS) on the polar orbiting Aqua satellite. Accordingly, near-realtime (NRT) AIRS radiances were used for the first time during DEEPWAVE to provide "nowcasts" of gravity-wave activity for flight planning and model/data validation, as well as the conventional research-quality radiances that became available some days later for later validation and research studies. Here we review this effort and present examples of how AIRS data were used to validate specific model forecasts and flight plans. We also use these AIRS gravity-wave products to provide a broader global and climatological perspective on stratospheric gravity-wave activity during the 2014 DEEPWAVE deployment. Initial comparisons with aircraft observations reveal gravity waves observed that were both visible and invisible to AIRS, highlighting again the importance of a detailed understanding of the sensitivity of nadir sensors to gravity waves with different horizontal and vertical wavelengths.