The Deep-Propagating Gravity Wave Experiment (DEEPWAVE): A Comprehensive Airborne and Ground-Based Measurement Program Based in New Zealand in 2014

Dave Fritts* and Ron Smith, Mike Taylor, Jim Doyle, Steve Eckermann, Biff Williams, Katrina Bossert, Dominique Pautet, Andreas Dörnbrack, Markus Rapp, Dave Broutman, Jun Ma, Chris Kruse, Alison Nugent, Damian Murphy, Iain Reid, Andrew Spargo, and Andrew MacKinnon

GATS Ic.

DEEPWAVE was performed over and around New Zealand, with airborne measurements extending from 6 June to 21 July 2014 and supporting ground-based measurements. DEEPWAVE employed the NSF/NCAR GV and the German DLR Falcon. The GV carried the standard flight-level instruments, dropsondes, and MTP. It also hosted two new airborne lidars and imaging instruments built specifically for DEEPWAVE. The lidars measured densities and temperatures from ~20-60 km in the stratosphere and from ~75-105 km in the mesosphere and lower thermosphere (MLT). An Advanced Mesosphere Temperature Mapper (AMTM) was also developed for the GV, and with additional IR “wing” cameras, imaged the OH airglow extending ~900 km across the GV flight track. The DLR Falcon employed standard flight-level instruments and an aerosol Doppler lidar that measured radial winds below. Ground-based instruments included a boundary layer radar, balloons at multiple sites, two Rayleigh lidars, a second AMTM, and an FPI and meteor radar measuring MLT winds.

DEEPWAVE performed 26 GV flights, 13 Falcon flights, and extensive ground-based measurements. Together, these observed many diverse cases of GW forcing, propagation, and dissipation spanning from 0-100 km. Examples include strong mountain wave (MW) forcing and breaking from the lower stratosphere into the MLT, weak forcing yielding MW penetration into the MLT with large amplitudes and momentum fluxes at scales from ~12-250 km, and trailing waves from orography refracting into the polar vortex at higher altitudes, convective GW generation, large-scale GWs arising from jet stream sources, and strong MWs in the MLT arising from strong flow over a small island. DEEPWAVE yielded a number of surprises, among them the strongest MLT responses often under weak forcing conditions, frequent GW penetration into the MLT, and surprising abilities of forecast models to provide reasonable agreement with observed fields for sources that were well resolved, especially orography and jet streams.


*email: dave@gats-inc.com
*Preference: Invited