An Overview of Gravity Wave Observations and Modeling during DEEPWAVE

The DEEP propagating gravity WAVE program (DEEPWAVE) is a comprehensive, airborne and ground-based measurement and modeling program centered on New Zealand and focused on providing a new understanding of gravity wave dynamics and impacts from the troposphere through the mesosphere and lower thermosphere. This program employed the NSF/NCAR GV (NGV) research aircraft from a base in New Zealand in a 6-week field measurement campaign in June-July 2014. The region near New Zealand was chosen since all the relevant gravity wave sources (e.g., mountains, cyclones, jet streams) occur strongly here, and upper-level winds in austral winter permit gravity waves to propagate to very high altitudes. During the field phase, the NGV was equipped with new Rayleigh and sodium resonance lidars and a mesospheric temperature mapper, a microwave temperature profiler, as well as dropwindsondes and a full suite of flight level instruments providing measurements spanning altitudes from immediately above the NGV flight altitude (~13 km) to ~100 km. The DLR Falcon, equipped with a down-looking Doppler wind lidar and in situ instrumentation, was also available for coordinated flights. The ground based instrumentation included a wind profiler and radiosonde unit on the west coast of the South Island, as well as ground based lidars and high-altitude radiosonde sites.

Highlights of observations of deep propagating gravity waves during the field phase will be presented. During DEEPWAVE, 16 Intensive Observation Periods (IOPs) occurred, which featured 26 NGV and 13 Falcon research flight missions, as well as a comprehensive suite of ground based observations. These observations include cases of topographically generated gravity waves, as well as waves generated by non-orographic sources such as jet streams and cyclones. Examples of coupling between the lower and upper levels will be shown using the in situ and remote sensing observations, as well as high-resolution models with deep domains. The high-resolution models provide examples of refraction of deep vertically propagating gravity waves associated with the lateral shear of the polar vortex. Predictability links between the tropospheric fronts, cyclones, jet regions, and gravity waves that vertically propagate upward through the stratosphere will be addressed as well.