scholarly journals Evidence of gravity wave breaking in lidar data from the mesopause region

2003 ◽  
Vol 30 (4) ◽  
Author(s):  
Patricia Minthorn Franke ◽  
Richard L. Collins
Keyword(s):  
Gravity Wave ◽  
Wave Breaking ◽  
Lidar Data ◽  
Mesopause Region

scholarly journals Tomographic reconstruction of atmospheric gravity wave parameters from airglow observations

2017 ◽  
Author(s):  
Rui Song ◽  
Martin Kaufmann ◽  
Jörn Ungermann ◽  
Manfred Ern ◽  
Guang Liu ◽  
...  
Keyword(s):  
Gravity Wave ◽  
Tomographic Reconstruction ◽  
Lower Thermosphere ◽  
Real Data ◽  
Atmospheric Gravity Wave ◽  
Mesopause Region ◽  
Angle Measurements ◽  
Target Mode ◽  
Observation Strategy ◽  
Atmospheric Gravity

Abstract. Gravity waves (GWs) play an important role in atmospheric dynamics. Especially in the mesosphere and lower thermosphere (MLT) dissipating GWs provide a major contribution to the driving of the global wind system. Therefore global observations of GWs in the MLT region are of particular interest. The small scales of GWs, however, pose a major problem for the observation of GWs from space. We propose a new observation strategy for GWs in the mesopause region by combining limb and sub-limb satellite-borne remote sensing measurements for improving the spatial resolution of temperatures that are retrieved from atmospheric soundings. In our study, we simulate satellite observations of the rotational structure of the O2 A-band nightglow. A key element of the new method is the ability of the instrument or the satellite to operate in so called target mode, i.e. to stare at a particular point in the atmosphere and collect radiances at different viewing angles. These multi-angle measurements of a selected region allow for tomographic reconstruction of a 2-dimensional atmospheric state, in particular of gravity wave structures. As no real data is available, the feasibility of this tomographic retrieval is carried out with simulation data in this work. It shows that one major advantage of this observation strategy is that much smaller scale GWs can be observed. We derive a GW sensitivity function, and it is shown that target mode observations are able to capture GWs with horizontal wavelengths as short as ~ 50 km for a large range of vertical wavelengths. This is far better than the horizontal wavelength limit of 100–200 km obtained for conventional limb sounding.

The Interaction of Katabatic Flow and Mountain Waves. Part II: Case Study Analysis and Conceptual Model

2007 ◽  
Vol 64 (6) ◽  
pp. 1857-1879 ◽  
Author(s):  
Gregory S. Poulos ◽  
James E. Bossert ◽  
Thomas B. McKee ◽  
Roger A. Pielke
Keyword(s):  
Conceptual Model ◽  
Gravity Wave ◽  
Wave Breaking ◽  
Gradient Force ◽  
Pressure Gradient Force ◽  
Wave System ◽  
Katabatic Flow ◽  
Mountain Wave ◽  
Mountain Waves ◽  
Wave Evolution

Via numerical analysis of detailed simulations of an early September 1993 case night, the authors develop a conceptual model of the interaction of katabatic flow in the nocturnal boundary layer with mountain waves (MKI). A companion paper (Part I) describes the synoptic and mesoscale observations of the case night from the Atmospheric Studies in Complex Terrain (ASCOT) experiment and idealized numerical simulations that manifest components of the conceptual model of MKI presented herein. The reader is also referred to Part I for detailed scientific background and motivation. The interaction of these phenomena is complicated and nonlinear since the amplitude, wavelength, and vertical structure of the mountain-wave system developed by flow over the barrier owes some portion of its morphology to the evolving atmospheric stability in which the drainage flows develop. Simultaneously, katabatic flows are impacted by the topographically induced gravity wave evolution, which may include significantly changing wavelength, amplitude, flow magnitude, and wave breaking behavior. In addition to effects caused by turbulence (including scouring), perturbations to the leeside gravity wave structure at altitudes physically distant from the surface-based katabatic flow layer can be reflected in the katabatic flow by transmission through the atmospheric column. The simulations show that the evolution of atmospheric structure aloft can create local variability in the surface pressure gradient force governing katabatic flow. Variability is found to occur on two scales, on the meso-β due to evolution of the mountain-wave system on the order of one hour, and on the microscale due to rapid wave evolution (short wavelength) and wave breaking–induced fluctuations. It is proposed that the MKI mechanism explains a portion of the variability in observational records of katabatic flow.

scholarly journals Long-term lidar observations of the gravity wave activity near the mesopause at Arecibo

2019 ◽  
Vol 19 (5) ◽  
pp. 3207-3221
Author(s):  
Xianchang Yue ◽  
Jonathan S. Friedman ◽  
Qihou Zhou ◽  
Xiongbin Wu ◽  
Jens Lautenbach
Keyword(s):  
Gravity Wave ◽  
Lower Thermosphere ◽  
Strong Support ◽  
Temporal Correlation ◽  
Temperature Inversion ◽  
Dynamical Instability ◽  
Temperature Structure ◽  
Mesopause Region ◽  
Mean Temperature ◽  
Lidar Observations

Abstract. Using 11-year-long K Doppler lidar observations of temperature profiles in the mesosphere and lower thermosphere (MLT) between 85 and 100 km, conducted at the Arecibo Observatory, Puerto Rico (18.35∘ N, 66.75∘ W), seasonal variations of mean temperature, the squared Brunt–Väisälä frequency, N2, and the gravity wave potential energy (GWPE) are estimated in a composite year. The following unique features are obtained. (1) The mean temperature structure shows similar characteristics to an earlier report based on a smaller dataset. (2) Temperature inversion layers (TILs) occur at 94–96 km in spring, at ∼92 km in summer, and at ∼91 km in early autumn. (3) The first complete range-resolved climatology of GWPE derived from temperature data in the tropical MLT exhibits an altitude-dependent combination of annual oscillation (AO) and semiannual oscillation (SAO). The maximum occurs in spring and the minimum in summer, and a second maximum is in autumn and a second minimum in winter. (4) The GWPE per unit volume reduces below ∼97 km altitude in all seasons. The reduction of GWPE is significant at and below the TILs but becomes faint above; this provides strong support for the mechanism that the formation of upper mesospheric TILs is mainly due to the reduction of GWPE. The climatology of GWPE shows an indeed pronounced altitudinal and temporal correlation with the wind field in the tropical mesopause region published in the literature. This suggests the GW activity in the tropical mesopause region should be manifested mainly by the filtering effect of the critical level of the local background wind and the energy conversion due to local dynamical instability.

Gravity Wave Fluxes in the Mesopause Region

2007 ◽  
Author(s):  
Alan Z. Liu* ◽  
Chester S. Gardner
Keyword(s):  
Gravity Wave ◽  
Mesopause Region

scholarly journals Improvement in the technique to extract gravity wave parameters from lidar data

2008 ◽  
Vol 113 (D19) ◽  
Author(s):  
Guotao Yang ◽  
Barclay Clemesha ◽  
Paulo Batista ◽  
Dale Simonich
Keyword(s):  
Gravity Wave ◽  
Lidar Data ◽  
Wave Parameters
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