Stratospheric mountain wave propagation and dissipation over New Zealand

In this study, stratospheric propagation and dissipation of orographic gravity waves generated by New Zealand topography are investigated for two cases. In both cases, moderate westerly winds were present throughout the troposphere, providing an environment favorable for wave generation and vertical propagation. Wind shear above the tropopause differs between the two cases, with one one case having negative westerly wind shear unfavorable for vertical propagation and the other having zero to weak positive westerly wind shear more favorable for deep propagation. In situ and microwave temperature profiler observations collected on the NCAR Gulfstream V aircraft as part of the DEEP propagating gravity WAVE (DEEPWAVE) field campaign are used to characterize wave fields in the lower stratosphere in both cases. Atmospheric Infrared Sounder (AIRS) measurements are used to characterize existing waves in the upper stratosphere. High-resolution Weather Research and Forecasting model simulations are compared with aircraft observations and used to study the propagation and dissipation between 10 and 50 km altitude with newly developed gravity wave diagnostics.