High-Resolution Simulations of Internal Gravity-Wave Fine Structure Interactions and Implications for Atmospheric Turbulence Forecasting

2009 ◽  
Author(s):  
Joseph Werne ◽  
David C. Fritts ◽  
Ling Wang
Keyword(s):  
Fine Structure ◽  
High Resolution ◽  
Gravity Wave ◽  
Atmospheric Turbulence ◽  
Internal Gravity Wave

scholarly journals Numerical Evaluation of Energy Transfers in Internal Gravity Wave Spectra of the Ocean

2019 ◽  
Vol 49 (3) ◽  
pp. 737-749 ◽  
Author(s):  
Carsten Eden ◽  
Friederike Pollmann ◽  
Dirk Olbers
Keyword(s):  
Fine Structure ◽  
Gravity Wave ◽  
Numerical Evaluation ◽  
Weak Interactions ◽  
Wave Spectrum ◽  
Internal Gravity Wave ◽  
Spectral Energy ◽  
Spectral Slope ◽  
Energy Transfers ◽  
Mixing Rates

AbstractSpectral energy transfers by internal gravity wave–wave interactions for given empirical energy spectra are evaluated numerically from the kinetic equation that is derived from the assumption of weak interactions. Wave spectrum parameters, such as bandwidth, spectral slope, and Coriolis frequency f, are varied, as is the spectral resolution. In agreement with previous studies, we find in all cases a forward energy cascade toward smaller vertical and horizontal wavelengths. Energy sinks due to the transfers are predominantly at frequencies between 2f and 3f. While the mechanism of the energy transfer differs partly from findings of previous studies, a parameterization for internal wave dissipation—which is used in the fine structure parameterization to estimate dissipation and mixing rates from observations—agrees well with the numerical evaluation of the energy transfers. We also find a dependency of the energy transfers on the spectral slope, offering the possibility to decrease the bias of the fine structure parameterization by improving the knowledge about the spatial variations of this (and other) spectral parameter.

scholarly journals Newly Identified Instabilities Enhance Atmospheric Turbulence

Eos ◽  
2021 ◽  
Vol 102 ◽  
Author(s):  
Morgan Rehnberg
Keyword(s):  
High Resolution ◽  
Gravity Wave ◽  
Atmospheric Turbulence ◽  
High Resolution Imaging ◽  
Wave Modulation ◽  
Resolution Imaging

New high-resolution imaging and modeling reveal the first evidence of enhanced turbulence due to gravity wave modulation of Kelvin-Helmholtz instabilities.

High-resolution scanning electron microscopy of thin-film magnetic media of magnetic recording disk

1992 ◽  
Vol 50 (2) ◽  
pp. 1334-1335
Author(s):  
K. Ogura ◽  
H. Nishioka ◽  
N. Ikeo ◽  
T. Kanazawa ◽  
J. Teshima
Keyword(s):  
Thin Film ◽  
Fine Structure ◽  
High Resolution ◽  
Magnetic Recording ◽  
High Performance ◽  
Magnetic Hysteresis ◽  
Grain Structure ◽  
Magnetic Media ◽  
Cross Sectional ◽  
Resolution Observation

Structural appraisal of thin film magnetic media is very important because their magnetic characters such as magnetic hysteresis and recording behaviors are drastically altered by the grain structure of the film. However, in general, the surface of thin film magnetic media of magnetic recording disk which is process completed is protected by several-nm thick sputtered carbon. Therefore, high-resolution observation of a cross-sectional plane of a disk is strongly required to see the fine structure of the thin film magnetic media. Additionally, observation of the top protection film is also very important in this field.Recently, several different process-completed magnetic disks were examined with a UHR-SEM, the JEOL JSM 890, which consisted of a field emission gun and a high-performance immerse lens. The disks were cut into approximately 10-mm squares, the bottom of these pieces were carved into more than half of the total thickness of the disks, and they were bent. There were many cracks on the bent disks. When these disks were observed with the UHR-SEM, it was very difficult to observe the fine structure of thin film magnetic media which appeared on the cracks, because of a very heavy contamination on the observing area.

On parametric instabilities of finite-amplitude internal gravity waves

1982 ◽  
Vol 119 ◽  
pp. 367-377 ◽  
Author(s):  
J. Klostermeyer
Keyword(s):  
Gravity Wave ◽  
Internal Gravity Wave ◽  
Maximum Growth ◽  
Numerical Approach ◽  
Internal Gravity Waves ◽  
Resonant Interaction ◽  
Finite Amplitude ◽  
Interaction Diagram ◽  
Parametric Instabilities ◽  
Boussinesq Fluid

The equations describing parametric instabilities of a finite-amplitude internal gravity wave in an inviscid Boussinesq fluid are studied numerically. By improving the numerical approach, discarding the concept of spurious roots and considering the whole range of directions of the Floquet vector, Mied's work is generalized to its full complexity. In the limit of large disturbance wavenumbers, the unstable disturbances propagate in the directions of the two infinite curve segments of the related resonant-interaction diagram. They can therefore be classified into two families which are characterized by special propagation directions. At high wavenumbers the maximum growth rates converge to limits which do not depend on the direction of the Floquet vector. The limits are different for both families; the disturbance waves propagating at the smaller angle to the basic gravity wave grow at the larger rate.

scholarly journals Warm molecular gas in the M17 SW nebula

2009 ◽  
Vol 5 (H15) ◽  
pp. 401-401
Author(s):  
J. P. Pérez-Beaupuits ◽  
M. Spaans ◽  
M. Hogerheijde ◽  
R. Güsten
Keyword(s):  
Fine Structure ◽  
High Resolution ◽  
Molecular Gas ◽  
Structure Transition ◽  
Dual Color

AbstractHigh resolution maps of the 12CO J = 6 → 5 line and the [C I]3P2 →3P1 (370 μm) fine-structure transition in the Galactic nebula M17 SW are presented. The maps were obtained using the dual color multiple pixel receiver CHAMP+ on the APEX† telescope.

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