scholarly journals Front-orography interactions during landfall of the New Year's Day Storm 1992

2019 ◽  
Author(s):  
Clemens Spensberger ◽  
Sebastian Schemm
Keyword(s):  
Gravity Waves ◽  
Wind Band ◽  
Spatial Scales ◽  
Internal Gravity Waves ◽  
Sensitivity Analyses ◽  
Cold Fronts ◽  
Warm Sector ◽  
The Cross ◽  
Flow Deflection ◽  
Crest Height

Abstract. Although following a common synoptic evolution for this region, the New Year's Day Storm 1992 was associated with some of the strongest winds observed along the Norwegian West Cost. The narrow wind band along its bent-back front became famous as the poisonous tail, and paved the way towards today's sting jet terminology. This article re-examines the storm's landfall with a particular focus on the interaction with the orography. Sensitivity analyses based on WRF simulations demonstrate that the formation and the evolution of the warm-air seclusion and its poisonous tail are largely independent from orography. In contrast, the warm sector of the storm is undergoing considerable orographically induced modifications. Both warm and cold fronts are eroded rapidly, and the warm sector is lifted over the orography, thereby accelerating the occlusion process. The insensitivity of the warm-air seclusion to the orographic modifications of the warm sector raises the question to which extent these entities are still interacting after the onset of the occlusion process. Further, we observe ubiquitous and large-amplitude internal gravity waves (IGWs) during the landfall of the warm and cold fronts, exceeding in amplitude the cross-frontal circulation. As the spatial scales of the IGW pattern and of the fronts are comparable, we speculate that wave-front interactions might have contributed to the rapid erosion of the cross-frontal temperature gradient over the orography. Further, IGWs might also provide a plausible cause for the observed near-instantaneous flow deflection around orography at 500 hPa, well above crest height.

scholarly journals Front–orography interactions during landfall of the 1992 New Year's Day Storm

2020 ◽  
Vol 1 (1) ◽  
pp. 175-189 ◽  
Author(s):  
Clemens Spensberger ◽  
Sebastian Schemm
Keyword(s):  
West Coast ◽  
Wind Band ◽  
Sensitivity Analyses ◽  
Cold Air ◽  
Passive Advection ◽  
Cold Fronts ◽  
Warm Sector ◽  
The Way

Abstract. Although following a common synoptic evolution for this region, the 1992 New Year's Day Storm was associated with some of the strongest winds observed along the Norwegian west coast. The narrow wind band along its bent-back front became famous as the “poisonous tail” and paved the way towards today's sting jet terminology. This article re-examines the storm's landfall with a particular focus on the interaction with the orography. Sensitivity analyses based on WRF simulations demonstrate that the formation and the evolution of the warm-air seclusion and its poisonous tail are largely independent of orography. In contrast, the warm sector of the storm undergoes considerable orographically induced modifications. While moving over the orography, both warm and cold fronts are eroded rapidly. This development fits neither the cold-air-damming paradigm nor the passive-advection paradigm describing front–orography interactions. The warm sector is lifted over the orography, thereby accelerating the occlusion process. The insensitivity of the warm-air seclusion to the orographic modifications of the warm sector raises the question of to which extent these entities are still interacting after the onset of the occlusion process.

Can laboratory experiments reach regimes relevant for the oceanic dynamics?

2021 ◽  
Author(s):  
Costanza Rodda ◽  
Clement Savaro ◽  
Antoine Campagne ◽  
Miguel Calpe Linares ◽  
Pierre Augier ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Scaling Laws ◽  
Spatial Scales ◽  
Scaling Law ◽  
Internal Gravity Waves ◽  
Energy Spectra ◽  
Finite Size Effect ◽  
Wave Turbulence ◽  
Common Mechanism ◽  
Buoyancy Frequency

<p>Atmospheric and oceanic energy spectra are characterized by global scaling laws, suggesting a common mechanism driving the energy route to dissipation. Although several possible theories have been proposed, it is not clear yet what the phenomena contributing the most to the energy at the different spatial scales are. One possible scenario is that internal gravity waves, which can be ubiquitously found in the atmosphere and the ocean and play a fundamental role in the energy transfer, cause the observed spectral slopes at the mesoscales in the atmosphere and submesoscales in the oceans. In the context of this open field of investigation, we present an experimental study where internal gravity waves are forced at a given frequency by the oscillating walls of a large pentagonal-shaped domain filled with a stably stratified fluid. The setup is built inside the 13-meters-diameter tank at the Coriolis facility in Grenoble, where geophysical regimes (with high Reynolds number and low Froude) can be achieved and rotation can also be added. The purpose of our investigation is to determine whether it is possible to induce a wave turbulence cascade by forcing internal waves at the large scales. Following a previous study<sup>1</sup>, where instead of the pentagonal a square domain was utilized, we obtained the velocity field employing time-resolved particle image velocimetry and then calculated the energy spectra. The previous study inside a square domain showed some evidence of a cascade, but it was strongly affected by 2D modes that sharpened the spectrum. Therefore, we changed the domain shape to a pentagon to reduce this finite-size effect. When the waves are forced at frequency <em>ω<sub>F</sub>=0.4 N</em>, our data shows that the spectra follow the scaling law <em>ω<sup>-2</sup></em> at frequencies larger than the forcing frequency and extending beyond <em>N</em>. The experimental spectra strikingly resemble the characteristic Garret-Munk spectrum measured in the ocean. As the interaction of weakly non-linear waves dominates the dynamics at frequencies smaller than the buoyancy frequency <em>N</em>, we can conclude that the experimental spectra are generated by weak internal wave turbulence driving the turbulent cascade at the high-frequency end of the spectrum. </p><p> </p><p>1 "<em>Generation of weakly nonlinear turbulence of internal gravity waves in the Coriolis facility", C. Savaro, A. Campagne, M. Calpe Linares, P. Augier, J. Sommeria, T. Valran, S. Viboud, and N. Mordant, PRF 2020</em></p>

scholarly journals The Influence of Tropospheric Processes on Disturbances in the D and E Ionospheric Layers

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1116
Author(s):  
Olga P. Borchevkina ◽  
Sergey O. Adamson ◽  
Yurii A. Dyakov ◽  
Ivan V. Karpov ◽  
Gennady V. Golubkov ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Spatial Scales ◽  
Internal Gravity Waves ◽  
Ionospheric Disturbances ◽  
Satellite Measurements ◽  
Atmospheric Physics ◽  
Temperature Variations ◽  
Physical Mechanisms ◽  
Lidar Observations

Determination of the physical mechanisms of the energy transfer of tropospheric disturbances to the ionosphere is one of the fundamental problems of atmospheric physics. This article presents the observational results of tropospheric and ionospheric disturbances during the passages of the solar terminator and solar eclipse. Lidar observations showed the occurrence of tropospheric regions with noticeably increased amplitudes of density, pressure, and temperature variations with periods corresponding to acoustic and internal gravity waves, which were generated in the troposphere during the development of these events. Simultaneous satellite measurements demonstrate the response of the ionosphere to these tropospheric disturbances. Based on the experimental data, we determine the typical periods and spatial scales of variations. It is shown that the response time of the ionosphere to tropospheric disturbances is 30–40 min.

scholarly journals Internal gravity and infrasound waves during a hurricane in Moscow On May 29, 2017

2019 ◽  
Vol 55 (2) ◽  
pp. 32-40
Author(s):  
S. N. Kulichkov ◽  
I. P. Chunchuzov ◽  
O. E. Popov ◽  
V. G. Perepelkin ◽  
E. V. Golikova ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Atmospheric Pressure ◽  
Measurement Data ◽  
Internal Gravity Waves ◽  
Temporal Modulation ◽  
Frequency Spectra ◽  
Acoustic Gravity Waves ◽  
Cold Fronts ◽  
Phase Velocities ◽  
The Waves

The results of recording of internal gravity waves (IGWs) and infrasound waves from the warm and cold fronts associated with the atmospheric storm passing through Moscow on May 29, 2017 are presented. The waves were recorded by a network of 4 microbarographs IFA–MGU–MSR–ZNS located in Moscow and Moscow region, and compared with the data of measurements of the parameters of infrasound waves at infrasound station IS43 in Dubna. We study the temporal changes in the characteristics of IGWs and infrasound waves (coherence, direction of propagation,phase velocities, characteristic periods and frequency spectra) with the passage of warm and cold fronts through the network. The transition from the gravity to the acoustic dispersive branch of acoustic-gravity waves due to an increase in frequency and the temporal modulation of the phase velocity of infrasound waves caused by IGWs are also studied. The measurement data for PM10 aerosol concentrations and NO2 gas concentrations at various locations in Moscow during a passage of atmospheric storm are presented. The possibility of detecting wave precursors of atmospheric storms simultaneously in variations of atmospheric pressure, wind velocity and aerosol concentrations is studied.

Infrasound generation by meteorological fronts and its propagation in the atmosphere

2021 ◽  
Author(s):  
I.P. Chunchuzov ◽  
S.N. Kulichkov ◽  
O.E. Popov ◽  
V.G. Perepelkin
Keyword(s):  
Frequency Spectrum ◽  
Gravity Waves ◽  
Internal Gravity Waves ◽  
Temporal Variations ◽  
Cold Fronts ◽  
Air Stream ◽  
Grazing Angles

AbstractInfrasound parameters (amplitudes, coherences, grazing angles, azimuths and horizontal phase speeds) derived during the passage of warm and cold fronts through the networks of microbarometers in the cities of Dubna and Moscow are presented. The significant differences observed in the temporal variations of the parameters of infrasound from warm and cold fronts are discussed. Such differences must be taken into account when detecting infrasound precursors of atmospheric storms.A possible mechanism for the generation of infrasound by the turbulent air stream flowing around the geometric irregularities of the meteorological front is proposed.. The observed effect of internal gravity waves on the parameters of infrasound and its frequency spectrum is explained.

Model of the internal gravity waves excited by lithospheric greenhouse effect gases

2001 ◽  
Vol 7 (2s) ◽  
pp. 26-33 ◽  
Author(s):  
O.E. Gotynyan ◽  
◽  
V.N. Ivchenko ◽  
Yu.G. Rapoport ◽  
◽  
...  
Keyword(s):  
Gravity Waves ◽  
Greenhouse Effect ◽  
Internal Gravity Waves

scholarly journals Shear-induced breaking of internal gravity waves

2021 ◽  
Vol 921 ◽  
Author(s):  
Christopher J. Howland ◽  
John R. Taylor ◽  
C.P. Caulfield
Keyword(s):  
Gravity Waves ◽  
Internal Gravity Waves

Abstract

scholarly journals Rolls of the internal gravity waves in the Earth's atmosphere

2014 ◽  
Vol 32 (2) ◽  
pp. 181-186 ◽  
Author(s):  
O. Onishchenko ◽  
O. Pokhotelov ◽  
W. Horton ◽  
A. Smolyakov ◽  
T. Kaladze ◽  
...  
Keyword(s):  
Nonlinear Dynamics ◽  
Gravity Waves ◽  
Closed System ◽  
Wind Shear ◽  
Internal Gravity Waves ◽  
Temperature Gradients ◽  
System Of Equations ◽  
Vertical Temperature ◽  
Earth’S Atmosphere ◽  
Earth's Atmosphere

Abstract. The effect of the wind shear on the roll structures of nonlinear internal gravity waves (IGWs) in the Earth's atmosphere with the finite vertical temperature gradients is investigated. A closed system of equations is derived for the nonlinear dynamics of the IGWs in the presence of temperature gradients and sheared wind. The solution in the form of rolls has been obtained. The new condition for the existence of such structures was found by taking into account the roll spatial scale, the horizontal speed and wind shear parameters. We have shown that the roll structures can exist in a dynamically unstable atmosphere.

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