Regional Distribution of Mesospheric Small‐Scale Gravity Waves During DEEPWAVE. Issue 13 (12th July 2019)

• Record Type: Journal Article
• Authors: Pautet, P.‐D.; Taylor, M. J.; Eckermann, S. D.; Criddle, N.
• Is Part Of: Journal of geophysical research. Volume 124:Issue 13(2019)
• Page Start: 7069
• Page End: 7081
• Publication Date: 2019-07-12
• Subjects: gravity waves -- MLT -- DEEPWAVE -- airglow; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1029/2019JD030271
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: The Deep Propagating Gravity Wave Experiment project took place in June and July 2014 in New Zealand. Its overarching goal was to study gravity waves (GWs) as they propagate from the ground up to ~100 km, with a large number of ground‐based, airborne, and satellite instruments, combined with numerical forecast models. A suite of three mesospheric airglow imagers operated onboard the NSF Gulfstream V (GV) aircraft during 25 nighttime flights, recording the GW activity at OH altitude over a large region (>7, 000, 000 km 2 ). Analysis of this data set reveals the distribution of the small‐scale GW mean power and direction of propagation. GW activity occurred everywhere and during every flight, even over open oceans with no neighboring tropospheric sources. Over the mountainous regions (New Zealand, Tasmania, isolated islands), mean power reached high values (more than 100 times larger than over the waters), but with a considerable variability. This variability existed from day to day over the same region, but even during the same flight, depending on forcing strength and on the middle atmosphere conditions. Results reveal a strong correlation between tropospheric sources, satellite stratospheric measurements, and mesosphere lower thermosphere airglow observations. The large‐amplitude GWs only account for a small amount of the total (~6%), even though they carry the most momentum and energy. The weaker wave activity measured over the oceans might originate from distance sources (polar vortex, weather fronts), implying that a ducted mechanism helped for their long range propagation. Key Points: Observation of small‐scale mesospheric gravity waves onboard an NSF aircraft during a two‐month period over a large region surrounding New Zealand The average power and direction associated with these waves have been measured They exhibit two different regimes, depending on the forcing, and the middle atmosphere conditions