Nonlinear interaction of small‐scale Rossby waves with an intense large‐scale zonal flow

1994 ◽  
Vol 6 (3) ◽  
pp. 1158-1167 ◽  
Author(s):  
Dmitrii Yu. Manin ◽  
Sergey V. Nazarenko
Keyword(s):  
Nonlinear Interaction ◽  
Large Scale ◽  
Rossby Waves ◽  
Zonal Flow ◽  
Small Scale

scholarly journals Excitation of zonal flow by the modulational instability in electron temperature gradient driven turbulence

2008 ◽  
Vol 74 (3) ◽  
pp. 381-389 ◽  
Author(s):  
Yu. A. ZALIZNYAK ◽  
A. I. YAKIMENKO ◽  
V. M. LASHKIN
Keyword(s):  
Temperature Gradient ◽  
Electron Temperature ◽  
Large Scale ◽  
Modulational Instability ◽  
Zonal Flow ◽  
Finite Amplitude ◽  
Small Scale ◽  
Drift Waves ◽  
Zonal Flows ◽  
Electron Temperature Gradient

AbstractThe generation of large-scale zonal flows by small-scale electrostatic drift waves in electron temperature gradient driven turbulence model is considered. The generation mechanism is based on the modulational instability of a finite amplitude monochromatic drift wave. The threshold and growth rate of the instability as well as the optimal spatial scale of zonal flow are obtained.

scholarly journals Spectral evolution of two-layer weak geostrophic turbulence. Part I: Typical scenarios

1996 ◽  
Vol 3 (3) ◽  
pp. 166-195 ◽  
Author(s):  
T. Soomere
Keyword(s):  
Large Scale ◽  
Rossby Waves ◽  
Initial Conditions ◽  
Local Equilibrium ◽  
Zonal Flow ◽  
Underlying Mechanism ◽  
Wave System ◽  
Spectral Evolution ◽  
Initial State ◽  
Geostrophic Turbulence

Abstract. Long-time evolution of large-scale geophysical flows is considered in a β-plane approximation. Motions in an infinite 2-layer model ocean are treated as a system of weakly nonlinear Rossby waves (weak geostrophic turbulence). The evolution of the energy spectrum of the barotropic and the baroclinic modes is investigated on the basis of numerical experiments with the kinetic equation for baroclinic Rossby waves. The basic features of free (nonforced inviscid) spectral evolution of baroclinic flows are similar to those of the barotropic motions. A portion of the energy is transferred to a sharp spectral peak while the rest of it is isotropically distributed. The peak corresponds to an intensive nearly zonal barotropic flow. Typically, this well-defined barotropic zonal anisotropy inhibits the reinforcement of its baroclinic analogy. For a certain set of initial conditions (in particular, if the barotropic zonal flow is not present initially), a zonal anisotropy of both modes is generated. The interplay between the multimodal nearly zonal flow components leads to the excitation of large-scale (several times exceeding the scale of the initial state), mostly meridional, baroclinic motions at the expense of the barotropic nearly zonal flow. The underlying mechanism is explained on the level of elementary mixed-triad interaction. The whole wave field retains its essentially baroclinic as well as spectrally broad nature. It evidently tends towards a thermodynamically equilibrated final state, consisting of the superposition of a (usually barotropic, but occasionally multimodal) zonal flow and a wave system with a Raleigh-Jeans spectrum. This evolution takes place as a multi-staged process, with fast convergence of the modal spectra to a local equilibrium followed by a more gradual adjustment of the energy balance between the modes.

Inertia–gravity waves in a liquid-filled, differentially heated, rotating annulus

2015 ◽  
Vol 782 ◽  
pp. 144-177 ◽  
Author(s):  
Anthony Randriamampianina ◽  
Emilia Crespo del Arco
Keyword(s):  
Prandtl Number ◽  
Gravity Waves ◽  
Large Scale ◽  
Baroclinic Instability ◽  
Zonal Flow ◽  
Small Scale ◽  
Mean Flow ◽  
Baroclinic Waves ◽  
Fluid Properties ◽  
Spatio Temporal

Direct numerical simulations based on high-resolution pseudospectral methods are carried out for detailed investigation into the instabilities arising in a differentially heated, rotating annulus, the baroclinic cavity. Following previous works using air (Randriamampianina et al., J. Fluid Mech., vol. 561, 2006, pp. 359–389), a liquid defined by Prandtl number $Pr=16$ is considered in order to better understand, via the Prandtl number, the effects of fluid properties on the onset of gravity waves. The computations are particularly aimed at identifying and characterizing the spontaneously emitted small-scale fluctuations occurring simultaneously with the baroclinic waves. These features have been observed as soon as the baroclinic instability sets in. A three-term decomposition is introduced to isolate the fluctuation field from the large-scale baroclinic waves and the time-averaged mean flow. Even though these fluctuations are found to propagate as packets, they remain attached to the background baroclinic waves, locally triggering spatio-temporal chaos, a behaviour not observed with the air-filled cavity. The properties of these features are analysed and discussed in the context of linear theory. Based on the Richardson number criterion, the characteristics of the generation mechanism are consistent with a localized instability of the shear zonal flow, invoking resonant over-reflection.

scholarly journals The Dynamics of Vortex Rossby Waves and Secondary Eyewall Development in Hurricane Matthew (2016): New Insights from Radar Measurements

2020 ◽  
Vol 77 (7) ◽  
pp. 2349-2374 ◽  
Author(s):  
Stephen R. Guimond ◽  
Paul D. Reasor ◽  
Gerald M. Heymsfield ◽  
Matthew M. McLinden
Keyword(s):  
Angular Momentum ◽  
Large Scale ◽  
Rossby Waves ◽  
Inner Core ◽  
Small Scale ◽  
Wave Kinematics ◽  
Secondary Eyewall Formation ◽  
Radial Flux ◽  
Momentum Budget ◽  
Radar Measurements

AbstractThe structure of vortex Rossby waves (VRWs) and their role in the development of a secondary eyewall in Hurricane Matthew (2016) is examined from observations taken during the NOAA Sensing Hazards with Operational Unmanned Technology (SHOUT) field experiment. Radar measurements from ground-based and airborne systems, with a focus on the NASA High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) instrument on the Global Hawk aircraft, revealed the presence of ~12–15-km-wavelength spiral bands breaking from the inner-core eyewall in the downshear-right quadrant. The vorticity characteristics and calculations of the intrinsic phase speeds of the bands are shown to be consistent with sheared VRWs. A new angular momentum budget methodology is presented that allows an understanding of the secondary eyewall development process with narrow-swath radar measurements. Filtering of the governing equations enables explicit insight into the nonlinear dynamics of scale interactions and the role of the VRWs in the storm structure change. The results indicate that the large-scale (scales > 15 km) vertical flux convergence of angular momentum associated with the VRWs dominates the time tendency with smaller effects from the radial flux term. The small-scale (scales ≤ 15 km) vertical term produces weak, but nonnegligible nonlinear forcing of the large scales primarily through the Reynolds and cross-stress components. The projection of the wave kinematics onto the low-wavenumber (0 and 1) fields appears to be the more significant dynamic process. Flight-level observations show secondary peaks in tangential winds in the radial region where the VRW forcing signatures are active, connecting them with the secondary eyewall formation process.

Rossby-wave driven zonal flows in the ionospheric E-layer

2007 ◽  
Vol 73 (1) ◽  
pp. 131-140 ◽  
Author(s):  
T. D. KALADZE ◽  
D. J. WU ◽  
O. A. POKHOTELOV ◽  
R. Z. SAGDEEV ◽  
L. STENFLO ◽  
...  
Keyword(s):  
Large Scale ◽  
Rossby Waves ◽  
Maximum Growth ◽  
Present Theory ◽  
Finite Amplitude ◽  
Maximum Growth Rate ◽  
Small Scale ◽  
Reynolds Stresses ◽  
Zonal Flows ◽  
Coupled Equations

Abstract.A novel mechanism for the generation of large-scale zonal flows by small-scale Rossby waves in the Earth's ionospheric E-layer is considered. The generation mechanism is based on the parametric excitation of convective cells by finite amplitude magnetized Rossby waves. To describe this process a generalized Charney equation containing both vector and scalar (Korteweg–de Vries type) nonlinearities is used. The magnetized Rossby waves are supposed to have arbitrary wavelengths (as compared with the Rossby radius). A set of coupled equations describing the nonlinear interaction of magnetized Rossby waves and zonal flows is obtained. The generation of zonal flows is due to the Reynolds stresses produced by finite amplitude magnetized Rossby waves. It is found that the wave vector of the fastest growing mode is perpendicular to that of the magnetized Rossby pump wave. Explicit expression for the maximum growth rate as well as for the optimal spatial dimensions of the zonal flows are obtained. A comparison with existing results is carried out. The present theory can be used for the interpretation of the observations of Rossby-type waves in the Earth's ionosphere.

Influence of non-monochromaticity on zonal-flow generation by magnetized Rossby waves in the ionospheric E-layer

2009 ◽  
Vol 75 (3) ◽  
pp. 345-357 ◽  
Author(s):  
T. D. KALADZE ◽  
H. A. SHAH ◽  
G. MURTAZA ◽  
L. V. TSAMALASHVILI ◽  
M. SHAD ◽  
...  
Keyword(s):  
Large Scale ◽  
Laboratory Experiments ◽  
Low Frequency ◽  
Zonal Flow ◽  
Present Theory ◽  
Resonant Interaction ◽  
Finite Amplitude ◽  
Small Scale ◽  
Zonal Flows ◽  
Flow Generation

AbstractThe influence of non-monochromaticity on low-frequency, large-scale zonal-flow nonlinear generation by small-scale magnetized Rossby (MR) waves in the Earth's ionospheric E-layer is considered. The modified parametric approach is used with an arbitrary spectrum of primary modes. It is shown that the broadening of the wave packet spectrum of pump MR waves leads to a resonant interaction with a growth rate of the order of the monochromatic case. In the case when zonal-flow generation by MR modes is prohibited by the Lighthill stability criterion, the so-called two-stream-like mechanism for the generation of sheared zonal flows by finite-amplitude MR waves in the ionospheric E-layer is possible. The growth rates of zonal-flow instabilities and the conditions for driving them are determined. The present theory can be used for the interpretation of the observations of Rossby-type waves in the Earth's ionosphere and in laboratory experiments.

The Central Barrier, Asymmetry and Random Phase in Chaotic Transport and Mixing by Rossby Waves in a Jet

1998 ◽  
Vol 08 (06) ◽  
pp. 1131-1152 ◽  
Author(s):  
Huijun Yang
Keyword(s):  
Large Scale ◽  
Rossby Waves ◽  
Random Phase ◽  
Kinematic Model ◽  
Global Bifurcation ◽  
Heteroclinic Orbit ◽  
Phase Speed ◽  
Small Scale ◽  
Transport And Mixing ◽  
Geophysical Flow

The central barrier, asymmetry and random perturbation in transport and mixing by Rossby waves in a jet were investigated by simple kinematic model. Two complementary methods were used: A high-resolution Lagrangian Field Advection Model (FAM) and a finite-time Lyapunov exponent analysis. The present study revealed the following: (1) A central barrier can be formed in two Rossby waves without shear flow as well as in a jet, (2) the central barrier may occur in the region with maximum jet speed relative to the phase speed of the traveling wave, whereas the chaotic mixing most likely occurs near the critical lines; the central barrier widens as the phase speed of traveling waves relative to the jet speed increases, (3) asymmetry of wave-breaking is directly related to asymmetry of the critical line location in a jet, (4) the central barrier survives small random perturbations, (5) global bifurcation from a homoclinic orbit to a heteroclinic orbit and global chaos are two main mechanisms for the central barrier destruction. The results suggest that the small scale motions and random processes may not significantly affect the major character of Lagrangian transport and mixing by large-scale geophysical flow. Also potential vorticity mixing provides a unique kinematic and dynamic view of many features of the geophysical flow.

scholarly journals Revisiting the Quasi Biennial Oscillation as Seen in ERA5. Part II: Evaluation of Waves and Wave Forcing

2020 ◽  
Author(s):  
Hamid A. Pahlavan ◽  
John M. Wallace ◽  
Qiang Fu ◽  
George N. Kiladis
Keyword(s):  
Gravity Waves ◽  
Rossby Waves ◽  
Zonal Flow ◽  
Small Scale ◽  
Tropical Region ◽  
Quasi Biennial Oscillation ◽  
Wave Forcing ◽  
Different Types ◽  
Zonal Momentum ◽  
Biennial Oscillation

AbstractThis paper describes stratospheric waves in ERA5 reanalysis and evaluates the contributions of different types of waves to the driving of the quasi-biennial oscillation (QBO). Because of its higher spatial resolution compared to its predecessors, ERA5 is capable of resolving a broader spectrum of waves. It is shown that the resolved waves contribute to both eastward and westward accelerations near the equator, mainly by the way of the vertical flux of zonal momentum. The eastward accelerations by the resolved waves are mainly due to Kelvin waves and small-scale gravity (SSG) waves with zonal wavelengths smaller than 2000 km, whereas the westward accelerations are forced mainly by SSG waves, with smaller contributions from inertio-gravity and mixed-Rossby-gravity waves. Extratropical Rossby waves disperse upward and equatorward into the tropical region and impart a westward acceleration to the zonal flow. They appear to be responsible for at least some of the irregularities in the QBO cycle.

Small-Scale Science to Large-Scale Profession

2000 ◽  
Vol 45 (4) ◽  
pp. 396-398
Author(s):  
Roger Smith
Keyword(s):  
Large Scale ◽  
Small Scale

Development of Physics Learning Module Based on Guided Inquiry with Light Wave Material in Class XI of Senior High School

2020 ◽  
Vol 1 (1) ◽  
pp. 1-10
Author(s):  
Evi Rahmawati ◽  
Irnin Agustina Dwi Astuti ◽  
N Nurhayati
Keyword(s):  
Large Scale ◽  
Learning Strategy ◽  
Student Response ◽  
Average Score ◽  
Small Scale ◽  
Design Development ◽  
Teacher Response ◽  
Student Responses ◽  
Analysis Design ◽  
Scientific Skills

IPA Integrated is a place for students to study themselves and the surrounding environment applied in daily life. Integrated IPA Learning provides a direct experience to students through the use and development of scientific skills and attitudes. The importance of integrated IPA requires to pack learning well, integrated IPA integration with the preparation of modules combined with learning strategy can maximize the learning process in school. In SMP 209 Jakarta, the value of the integrated IPA is obtained from 34 students there are 10 students completed and 24 students are not complete because they get the value below the KKM of 68. This research is a development study with the development model of ADDIE (Analysis, Design, Development, Implementation, and Evaluation). The use of KPS-based integrated IPA modules (Science Process sSkills) on the theme of rainbow phenomenon obtained by media expert validation results with an average score of 84.38%, average material expert 82.18%, average linguist 75.37%. So the average of all aspects obtained by 80.55% is worth using and tested to students. The results of the teacher response obtained 88.69% value with excellent criteria. Student responses on a small scale acquired an average score of 85.19% with highly agreed criteria and on the large-scale student response gained a yield of 86.44% with very agreed criteria. So the module can be concluded receiving a good response by the teacher and students.

Sign in / Sign up

Export Citation Format

Share Document