Growth Rate of Gravity Wave Amplitudes Observed in Sodium Lidar Density Profiles and Nightglow Image Data
1
Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA
2
State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing 100036, China
3
National Institute for Space Research, São José dos Campos 01000-000, Brazil
*
Author to whom correspondence should be addressed.
†
Current address: 306 N. Wright St., 5066 ECEB, MC-702, Urbana, IL 61801, USA.
Atmosphere 2019, 10(12), 750; https://doi.org/10.3390/atmos10120750
Received: 22 October 2019 / Revised: 18 November 2019 / Accepted: 26 November 2019 / Published: 28 November 2019
(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)
Amplitude growth rates of quasi-monochromatic gravity waves were estimated and compared from multiple instrument measurements carried out in Brazil. Gravity wave parameters, such as the wave amplitude and growth rate in distinct altitudes, were derived from sodium lidar density and nightglow all-sky images. Lidar observations were carried out in São Jose dos Campos (23 S, 46 W) from 1994 to 2004, while all-sky imagery of multiple airglow layers was conducted in Cachoeira Paulista (23 S, 45 W) from 1999–2000 and 2004–2005. We have found that most of the measured amplitude growth rates indicate dissipative behavior for gravity waves identified in both lidar profiles and airglow image datasets. Only a small fraction of the observed wave events (4% imager; 9% lidar) are nondissipative (freely propagating waves). Our findings also show that imager waves are strongly dissipated within the mesosphere and lower thermosphere region (MLT), decaying in amplitude in short distances (<12 km), while lidar waves tend to maintain a constant amplitude within that region. Part of the observed waves (16% imager; 36% lidar) showed unchanging amplitude with altitude (saturated waves). About 51.6% of the imager waves present strong attenuation (overdamped waves) in contrast with 9% of lidar waves. The general saturated or damped behavior is consistent with diffusive filtering processes imposing limits to amplitude growth rates of the observed gravity waves.
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Keywords:
all-sky imager; sodium lidar; gravity waves; mesospheric nightglow; amplitude growth rate; wave dissipation
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MDPI and ACS Style
Vargas, F.; Yang, G.; Batista, P.; Gobbi, D. Growth Rate of Gravity Wave Amplitudes Observed in Sodium Lidar Density Profiles and Nightglow Image Data. Atmosphere 2019, 10, 750.
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