Large‐Amplitude Mountain Waves in the Mesosphere Observed on 21 June 2014 During DEEPWAVE: 1. Wave Development, Scales, Momentum Fluxes, and Environmental Sensitivity
Abstract
A remarkable, large‐amplitude, mountain wave (MW) breaking event was observed on the night of 21 June 2014 by ground‐based optical instruments operated on the New Zealand South Island during the Deep Propagating Gravity Wave Experiment (DEEPWAVE). Concurrent measurements of the MW structures, amplitudes, and background environment were made using an Advanced Mesospheric Temperature Mapper, a Rayleigh Lidar, an All‐Sky Imager, and a Fabry‐Perot Interferometer. The MW event was observed primarily in the OH airglow emission layer at an altitude of ~82 km, over an ~2‐hr interval (~10:30–12:30 UT), during strong eastward winds at the OH altitude and above, which weakened with time. The MWs displayed dominant horizontal wavelengths ranging from ~40 to 70 km and temperature perturbation amplitudes as large as ~35 K. The waves were characterized by an unusual, “saw‐tooth” pattern in the larger‐scale temperature field exhibiting narrow cold phases separating much broader warm phases with increasing temperatures toward the east, indicative of strong overturning and instability development. Estimates of the momentum fluxes during this event revealed a distinct periodicity (~25 min) with three well‐defined peaks ranging from ~600 to 800 m2/s2, among the largest ever inferred at these altitudes. These results suggest that MW forcing at small horizontal scales (https://doi.org/10.1029/2019jd030899).
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 15, 2019
- Source ID
- 10.1029/2019jd030932
Entities
People
- Ben Liley
- Bernd Kaifler
- David C Fritts
- Gonzalo Hernandez
- James D. Doyle
- James Russell III
- M. McCarthy
- Markus Rapp
- Michael J. Taylor
- Neal R. Criddle
- Pattilyn Mclaughlin
- Pierre‐Dominique Pautet
- S. M. Smith
- Stephen D. Eckermann
- William R. Pendleton Jr.
- Yucheng Zhao
Organizations
- Boston University
- G & A Technical Software
- German Aerospace Center
- German Research Foundation
- Hampton University
- National Institute of Water and Atmospheric Research
- National Science Foundation
- United States Naval Research Laboratory
- University of Washington
- Utah State University