scholarly journals Inertia-gravity wave in the polar mesopause region inferred from successive images of a meteor train

2013 ◽  
Vol 118 (8) ◽  
pp. 3047-3052 ◽  
Author(s):  
Hidehiko Suzuki ◽  
Takuji Nakamura ◽  
Sharon L. Vadas ◽  
Masaki Tsutsumi ◽  
Makoto Taguchi ◽  
...  
Keyword(s):  
Gravity Wave ◽  
Mesopause Region ◽  
Meteor Train

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.

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 Sensitivity of the Upper Mesosphere to the Lorenz Energy Cycle of the Troposphere

2009 ◽  
Vol 66 (3) ◽  
pp. 647-666 ◽  
Author(s):  
Erich Becker
Keyword(s):  
Kinetic Energy ◽  
Gravity Wave ◽  
General Circulation ◽  
Frictional Heating ◽  
Lower Thermosphere ◽  
Wave Drag ◽  
Wind Component ◽  
Mesopause Region ◽  
Energy Cycle ◽  
Lorenz Energy Cycle

Abstract The concept of a mechanistic general circulation model that explicitly simulates the gravity wave drag in the extratropical upper mesosphere in a self-consistent fashion is proposed. The methodology consists of 1) a standard spectral dynamical core with high resolution, 2) idealized formulations of radiative and latent heating, and 3) a hydrodynamically consistent turbulent diffusion scheme with the diffusion coefficients based on Smagorinsky’s generalized mixing-length formulation and scaled by the Richardson criterion. The model reproduces various mean and variable features of the wave-driven general circulation from the boundary layer to the mesopause region during January. The dissipation of mesoscale kinetic energy (defined as the frictional heating due to the mesoscale flow) in the extratropical troposphere is found to indicate the tropospheric gravity wave sources relevant for the mesosphere/lower thermosphere. This motivates a sensitivity experiment in which the large-scale differential heating is perturbed such that the Lorenz energy cycle as measured by the globally integrated frictional heating becomes stronger. As a result, both the resolved gravity wave activity and the dissipation of mesoscale kinetic energy in the extratropical troposphere are amplified. These changes have strong remote effects in the summer mesopause region, where the gravity wave drag, the residual meridional wind, and the frictional heating shift to lower altitudes. Furthermore, temperatures decrease below the summer mesopause and increase farther up, which is accompanied by an anomalous eastward wind component around the mesopause.

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