The Advanced Mesospheric Temperature Mapper: Remote Sensing of the Nighttime OH Layer During the DEEPWAVE Campaign

The Advanced Mesospheric Temperature Mapper [AMTM] is a remote sensing instrument developed at Utah State University to map temperature structures in the hydroxyl airglow emission at ~87 km. These maps can then be used to quantify wave field characteristics and to observe general climatology trends. Two recent campaigns that it has been involved with are the DEEPWAVE campaign in Lauder, New Zealand and the Super Soaker campaign in Fairbanks, Alaska. The Deep Propagating Gravity Wave Experiment, “DEEPWAVE” was an international measurement and modeling program intended to characterize the generation and propagation of a broad range of atmospheric gravity waves with measurements extending from the ground to ~100 km altitude. A suite of aircraft-borne and ground-based aeronomic and weather measurements was deployed from New Zealand during a two-month period in June-July of 2014 to investigate wintertime gravity wave [GW] events as well as to study their climatology. Data used in this study were obtained by a collection of ground-based instrumentation operated at the Lauder Station of the National Institute of Water and Atmospheric Research [NIWA] in New Zealand (45.0°S). Instruments included an AMTM, a Rayleigh lidar and an all-sky imager. Analysis of image data obtained by the AMTM revealed a rich spectrum of GWs with 19 unprecedented quasi-stationary mountain wave [MW] events generated by orographic forcing. This is the largest occurrence of MW activity recorded at heights of 80-100 km. This study will focus on four such events, illustrating their varying MW properties and in three cases determining their corresponding momentum flux. The Super Soaker Sounding Rocket Mission was designed to study the transport, chemistry, and energetics of water in the mesosphere-lower thermosphere [MLT] region with the intent to create a Polar Mesospheric Cloud [PMC] through water deposition. Three sounding rockets were launched on January 26, 2018 into clear night-time skies over central Alaska with coincident ground-based AMTM, Rayleigh and Resonance lidar observations. In addition, the AMTM collected data for two months preceding and following the launch to establish typical GW characteristics and temperature variability during this period. This study will include an overview of PMC, a summary of the scientific goals and questions of the mission, results collected from the AMTM with an emphasis on the GWs, and an analysis of the wintertime climatology of the Fairbanks area at this time

Large‐Amplitude Mountain Waves in the Mesosphere Observed on 21 June 2014 During DEEPWAVE: 1.Wave Development, Scales, Momentum Fluxes, and Environmental Sensitivity

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 (km) can play large roles in the momentum budget of the mesopause region when forcing and propagation conditions allow them to reach mesospheric altitudes with large amplitudes. A detailed analysis of the instability dynamics accompanying this breaking MW event is presented in a companion paper, Fritts et al. (2019, https://doi.org/10.1029/2019jd030899)

DEEPWAVE: Ground-Based Investigation of Mesospheric Gravity Wave Signatures

This poster presents an overview of the first night of observations at Lauder which includes an amazing variety of wave activity. The Deep Propagating Gravity Wave Experiment [DEEPWAVE] is a comprehensive international measurement and modelling program designed to characterize and predict the generation and propagation of deeply propagating atmospheric waves with measurements extending from the ground to ~100 km altitude. These waves typically arise from sources located at lower altitudes such as storms, frontal weather systems and mountain ranges, and then dissipate at high altitudes in the mesosphere and lower thermosphere (\u3e80 km altitude) depositing large amounts of momentum

Investigating Mesospheric Mountain Wave Characteristics Over New Zealand During DEEPWAVE

The Deep Propagating Gravity Wave Experiment, DEEPWAVE was an international measurement and modelling program designed to characterize the generation and propagation of a broad range of atmospheric gravity waves [GWs] with measurements extending from the ground to ~100 km altitude. A suite of aircraft-borne and ground-based aeronomic and weather measurements was deployed from New Zealand during a two-month period [June-July] in 2014 to investigate the wintertime gravity wave climatology. Data used in this study were obtained by a collection of ground-based instrumentation operated at NIWA Lauder Station, NZ [45.0°S]. Instruments included an Advanced Mesospheric Temperature Mapper [AMTM], a Rayleigh Lidar and an All-Sky Imager. Analysis of image data obtained by the AMTM revealed a rich spectrum of GWs with 19 amazing mountain wave [MW] events generated by orographic forcing. This is the largest occurrence of MW activity recorded at MLT heights [80-100 km]. Here we show examples of three such events, illustrating their varying properties and their associated Momentum Flux [MF]