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Related papers: Direct validation of dune instability theory

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Millimeter astronomy provides valuable information on the birthplaces of planetary systems. In order to compare theoretical models with observations, the dust component has to be carefully calculated. Here, we aim to study the effects of…

Earth and Planetary Astrophysics · Physics 2022-10-12 Remo Burn , Alexandre Emsenhuber , Jesse Weder , Oliver Völkel , Hubert Klahr , Til Birnstiel , Barbara Ercolano , Christoph Mordasini

We calculate the formation of dust clouds in atmospheres of giant gas-planets. The chemical structure and the evolution of the grain size distribution in the dust cloud layer is discussed based on a consistent treatment of seed formation,…

Astrophysics · Physics 2007-11-26 Christiane Helling

The structure and intensity of turbulence in the atmospheric boundary layer (ABL) drives fluxes of sediment, contaminants, heat, moisture and CO$_2$ at the Earth's surface. Where ABL flows encounter changes in roughness -- such as cities,…

Atmospheric and Oceanic Physics · Physics 2024-05-29 Justin P. Cooke , Douglas J. Jerolmack , George I. Park

Radiation-dust driven outflows, where radiation pressure on dust grains accelerates gas, occur in many astrophysical environments. Almost all previous numerical studies of these systems have assumed that the dust was perfectly-coupled to…

This paper reports a downscaled water tunnel experiment to study the temporal characteristics of a double dune interaction system and the new pattern of dune interaction when the initial mass ratio of the two dunes is large. These topics…

Geophysics · Physics 2022-04-04 Nan He , Yang Zhang , Yuanwei Lin , Bin Yang , Xin Gao , Pan Jia

A key element when modeling dust in any astrophysical environment is a self-consistent treatment of the evolution of the dust material properties (size distribution, chemical composition and structure) as they react to and adjust to the…

Astrophysics of Galaxies · Physics 2020-11-30 Nathalie Ysard

We study the morphological evolution of surfaces during ion sputtering and we compare their dynamical roughening with aeolian ripple formation in sandy deserts. We show that, although the two phenomena are physically different, they must…

Soft Condensed Matter · Physics 2007-09-19 T. Aste , U. Valbusa

The aim of our study is to use dynamical simulations to explore the influence of two important dynamical bar parameters, bar strength and bar pattern speed, on the shape of the bar dust lanes. To quantify the shape of the dust lanes we have…

Spatial patterns arising spontaneously due to internal processes are ubiquitous in nature, varying from regular patterns of dryland vegetation to complex structures of bacterial colonies. Many of these patterns can be explained in the…

Pattern Formation and Solitons · Physics 2017-08-02 Yuval R. Zelnik , Omer Tzuk

We develop a model of dust evolution in a multiphase, inhomogeneous ISM including dust growth and destruction processes. The physical conditions for grain evolution are taken from hydrodynamical simulations of giant molecular clouds in a…

Astrophysics of Galaxies · Physics 2016-11-09 Svitlana Zhukovska , Clare Dobbs , Edward B. Jenkins , Ralf Klessen

We apply two independent data analysis methodologies to locate stable climate states in an intermediate complexity climate model and analyze their interplay. First, drawing from the theory of quasipotentials, and viewing the state space as…

Atmospheric and Oceanic Physics · Physics 2021-07-07 Georgios Margazoglou , Tobias Grafke , Alessandro Laio , Valerio Lucarini

Our aim in this note is to introduce and study a mathematical model for the description of traveling sand dunes. We use surface flow process of sand under the effect of wind and gravity. We model this phenomena by a non linear…

Analysis of PDEs · Mathematics 2021-03-23 Noureddine Igbida , Fahd Karami , Driss Meskine

Interstellar dust forms during stellar mass-loss events, occurring either during a star's giant phase or during supernova explosions. This PhD thesis provides an in-depth investigation into the theory of dust condensation and growth,…

Solar and Stellar Astrophysics · Physics 2026-04-02 C. Dominik

Recent research on the buildup of rocks from small dust grains has reaffirmed that grain growth in protoplanetary disks should occur quickly. Calculation of growth rates have been made for a variety of growth processes and generally predict…

Astrophysics · Physics 2007-05-23 Steven V. W. Beckwith , Thomas Henning , Yoshitsugu Nakagawa

On Mars, fields of sand dunes contrast with the general cratered, rocky terrain commonly seen from orbit. Near the equator, in Gale Crater, images from the rover, Curiosity, also reveal order on smaller scales: ripples on dunes, and ground…

In a recent article (Forterre, PRL, 2001), we have reported a new instability observed in rapid granular flows down inclined planes that leads to the spontaneous formation of longitudinal vortices. From the experimental observations, we…

Soft Condensed Matter · Physics 2009-11-07 Yoel Forterre , Olivier Pouliquen

The hot and diffuse nature of the Sun's extended atmosphere allows it to persist in non-equilibrium states for long enough that wave-particle instabilities can arise and modify the evolution of the expanding solar wind. Determining which…

We study the non-linear evolution of the acoustic 'Resonant Drag Instability' (RDI) using numerical simulations. The acoustic RDI is excited in a dust-gas mixture when dust grains stream through gas, interacting with sound waves to cause a…

Astrophysics of Galaxies · Physics 2019-08-21 Eric R. Moseley , Jonathan Squire , Philip F. Hopkins

Size segregation in bedload transport is studied numerically with a coupled fluid-discrete element model. Starting from an initial deposit of small spherical particles on top of a large particle bed, the segregation dynamics of the bed is…

Long-term stability and physical consistency are critical properties for AI-based weather models if they are going to be used for subseasonal-to-seasonal forecasts or beyond, e.g., climate change projection. However, current AI-based…

Fluid Dynamics · Physics 2024-12-10 Ashesh Chattopadhyay , Y. Qiang Sun , Pedram Hassanzadeh
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