scholarly journals Sudden narrow temperature-inversion-layer formation in ALOHA-93 as a critical-layer-interaction phenomenon

1998 ◽  
Vol 103 (D6) ◽  
pp. 6323-6332 ◽  
Author(s):  
T. Y. Huang ◽  
H. Hur ◽  
T. F. Tuan ◽  
X. Li ◽  
E. M. Dewan ◽  
...  
Keyword(s):  
Inversion Layer ◽  
Temperature Inversion ◽  
Critical Layer ◽  
Layer Formation ◽  
Layer Interaction ◽  
Interaction Phenomenon

A theoretical model analysis of the sudden narrow temperature-layer formation observed in the ALOHA-93 Campaign

2002 ◽  
Vol 80 (12) ◽  
pp. 1543-1558 ◽  
Author(s):  
H Hur ◽  
T Y Huang ◽  
Z Zhao ◽  
P Karunanayaka ◽  
T F Tuan
Keyword(s):  
Energy Dissipation ◽  
Gravity Wave ◽  
Temperature Rise ◽  
Critical Level ◽  
Inversion Layer ◽  
Phase Speed ◽  
Temperature Inversion ◽  
Critical Layer ◽  
Mean Flow ◽  
Wind Profiles

The behavior of temperature and wind profiles observed on 21 October 1993 in the ALOHA-93 Campaign is theoretically and numerically analyzed. A sudden temperature rise took place in a very narrow vertical region (3–4 km) at about 87 km. Simultaneously observed radar wind profiles and mesospheric airglow wave structures that show a horizontal phase speed of 35 m/s and a period of about half an hour strongly suggest that a critical level may occur in the proximity of that altitude and that the energy dissipation due to the interaction of the gravity wave with the critical level causes the temperature rise. The numerical model used is a solution to the gravity wave – mean-flow interaction in the critical layer, including a simple cooling mechanism and a wave-energy dissipation simulated by the "optical model" technique. The solutions for the temperature variations so obtained show good agreement with the observed temperature profiles at different times, providing a quantitative explanation for the temperature inversion layer as a phenomenon of gravity wave – critical layer interaction. PACS Nos.: 91.10V, 94.10D

The Tropopause Inversion Layer Interaction With the Inertial Gravity Wave Activities and Its Latitudinal Variability

2019 ◽  
Vol 124 (14) ◽  
pp. 7512-7522
Author(s):  
Yehui Zhang ◽  
Shaodong Zhang ◽  
Chunming Huang ◽  
Kaiming Huang ◽  
Yun Gong
Keyword(s):  
Gravity Wave ◽  
Inversion Layer ◽  
Layer Interaction

scholarly journals Long-term Lidar Observations of the Gravity Wave Activity near the Mesopause at Arecibo

2018 ◽  
Author(s):  
Xianchang Yue ◽  
Jonathan S. Friedman ◽  
Qihou Zhou ◽  
Xiongbin Wu ◽  
Jens Lautenbach
Keyword(s):  
Potential Energy ◽  
Gravity Wave ◽  
Inversion Layer ◽  
Lower Thermosphere ◽  
Temperature Inversion ◽  
Temperature Structure ◽  
Mean Temperature ◽  
The Mean ◽  
Highly Correlated ◽  
Lidar Observations

Abstract. 11-years 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), are used to estimate seasonal variations of the mean temperature, the squared Brunt-Väisälä frequency, and the gravity wave potential energy in a composite year. The following unique features are obtained: (1) The mean temperature structure shows similar characteristics as a prior report based on a smaller dataset: (2) The profiles of the squared Brunt-Väisälä frequency usually reach the maxima at or just below the temperature inversion layer when that layer is present. The first complete range-resolved climatology of potential energy of temperature fluctuations in the tropical MLT exhibits an altitude dependent combination of annual oscillation (AO) and semiannual oscillation (SAO). Between 88 to 96 km altitude, the amplitudes of AO and SAO are comparable, and their phases are almost the same and quite close to day of year (DOY) 100. Below 88 km, the SAO amplitude is significantly larger than AO and the AO phase shifts to DOY 200 and after. At 97 to 98 km altitude, the amplitudes of AO and SAO reach their minima, and both phases shift significantly. Above that, the AO amplitude becomes greater. The annual mean potential energy profile reaches the minimum at 91 to 92 km altitude. The altitude-dependent SAO of the potential energy is found to be highly correlated with the satellite observed mean zonal winds reported in the literature.

Observation and analysis of the temperature inversion layer by Raman lidar up to the lower stratosphere

2015 ◽  
Vol 54 (34) ◽  
pp. 10079 ◽  
Author(s):  
Yufeng Wang ◽  
Xiaoming Cao ◽  
Tingyao He ◽  
Fei Gao ◽  
Dengxin Hua ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
Inversion Layer ◽  
Temperature Inversion ◽  
Raman Lidar

scholarly journals Does a ‘turbophoretic’ effect account for layer concentrations of insects migrating in the stable night-time atmosphere?

2008 ◽  
Vol 6 (30) ◽  
pp. 87-95 ◽  
Author(s):  
A.M Reynolds ◽  
D.R Reynolds ◽  
J.R Riley
Keyword(s):  
Vertical Profile ◽  
Temperature Inversion ◽  
Nocturnal Boundary Layer ◽  
Local Minima ◽  
Layer Formation ◽  
Night Time ◽  
Local Maxima ◽  
Neutrally Buoyant ◽  
Obvious Feature ◽  
Horizontal Layers

Large migrating insects, such as noctuid moths and acridoid grasshoppers, flying within the stable nocturnal boundary layer commonly become concentrated into horizontal layers. These layers frequently occur near the top of the surface temperature inversion where warm fast-moving airflows provide good conditions for downwind migration. On some occasions, a layer may coincide with a higher altitude temperature maximum such as a subsidence inversion, while on others, it may seem unrelated to any obvious feature in the vertical profile of meteorological variables. Insects within the layers are frequently orientated, either downwind or at an angle to the wind, but the mechanisms involved in both layer formation and common orientation have remained elusive. Here, we show through the results of numerical simulations that if insects are treated as neutrally buoyant particles, they tend to be advected by vertical gusts (through the ‘turbophoretic’ mechanism) into layers in the atmosphere where the turbulent kinetic energy has local minima. These locations typically coincide with local maxima in the wind speed and/or air temperature, and they may also provide cues for orientation. However, the degree of layering predicted by this model is very much weaker than that observed in the field. We have therefore hypothesized that insects behave in a way that amplifies the turbophoretic effect by initiating climbs or descents in response to vertical gusts. New simulations incorporating this behaviour demonstrated the formation of layers that closely mimic field observations, both in the degree of concentration in layers and the rate at which they form.

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