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Related papers: Parabolic dunes in north-eastern Brazil

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Transverse dunes appear in regions of mainly unidirectional wind and high sand availability. A dune model is extended to two dimensional calculation of the shear stress. It is applied to simulate dynamics and morphology of transverse dunes…

Condensed Matter · Physics 2015-06-24 Veit Schwämmle , Hans J. Herrmann

Barchans are dunes commonly found in dune fields on Earth, Mars and other celestial bodies, where they can interact with each other. This article concerns experimental data for the flow over subaqueous barchans that are either isolated or…

Fluid Dynamics · Physics 2024-01-09 Jimmy Gabriel Alvarez , Danilo da Silva Borges , Erick de Moraes Franklin

The dune skeleton model is a reduced model to describe the formation process and dynamics of characteristic types of dunes emerging under unidirectional steady wind. Using this model, we study the dependency of the morphodynamics of…

Pattern Formation and Solitons · Physics 2016-09-09 H. Niiya , A. Awazu , H. Nishimori

We survey recent work on local well-posedness results for parabolic equations and systems with rough initial data.

Analysis of PDEs · Mathematics 2013-10-15 Herbert Koch , Tobias Lamm

Global vegetation structure mapping is critical for understanding the global carbon cycle and maximizing the efficacy of nature-based carbon sequestration initiatives. Moreover, vegetation structure mapping can help reduce the impacts of…

In this paper we build models for short-term, mean-term and long-term dynamics of dune in desert. They are models that are degenerated parabolic equations which are, moreover, singularly perturbed. We, then give existence and uniqueness…

Analysis of PDEs · Mathematics 2016-03-30 Mohamed Ould Badahi , Ibrahima Faye , Diaraf Seck

Barchans are crescent-shape dunes ubiquitous on Earth and other celestial bodies, which are organized in barchan fields where they interact with each other. Over the last decades, satellite images have been largely employed to detect…

We report an experimental investigation of aeolian sand ripples, performed both in a wind tunnel and on stoss slopes of dunes. Starting from a flat bed, we can identify three regimes: appearance of an initial wavelength, coarsening of the…

Soft Condensed Matter · Physics 2007-05-23 Bruno Andreotti , Philippe Claudin , Olivier Pouliquen

Barchan dunes emerge as a collective phenomena involving the generation of thousands of them in so called barchan dune fields. By measuring the size and position of dunes in Moroccan barchan dune fields, we find that these dunes tend to…

Soft Condensed Matter · Physics 2011-03-29 Orencio Durán , Veit Schwämmle , Pedro G. Lind , Hans J. Herrmann

Sand patches are one of the precursors to early-stage protodunes and occur widely in both desert and coastal aeolian environments. Here we show field evidence of a mechanism to explain the initiation of sand patches on non-erodible…

Banded patterns consisting of alternating bare soil and dense vegetation have been observed in water-limited ecosystems across the globe, often appearing along gently sloped terrain with the stripes aligned transverse to the elevation…

Pattern Formation and Solitons · Physics 2023-06-16 Punit Gandhi , Lucien Werner , Sarah Iams , Karna Gowda , Mary Silber

Barchan dunes, or simply barchans, are crescent-shaped dunes found in diverse environments such as the bottom of rivers, Earth's deserts and the surface of Mars. In a recent paper [Phys. Rev. E 101, 012905 (2020)], we investigated the…

Geophysics · Physics 2021-01-26 Carlos Azael Alvarez Zambrano , Erick de Moraes Franklin

In this paper we build models for short-term, mean-term and long-term dynamics of dune and megariple morphodynamics. They are models that are degenerated parabolic equations which are, moreover, singularly perturbed. We, then give an…

Analysis of PDEs · Mathematics 2010-11-24 Ibrahima Faye , Emmanuel Frenod , Diaraf Seck

Decision-support systems benefit from hidden patterns extracted from digital information. In the specific domain of gastropod characterization, morphometrical measurements support biologists in the identification of land snail specimens.…

Quantitative Methods · Quantitative Biology 2021-09-15 Marcelo N. Almeida , Rodolfo Alves de Oliveira , Luiz Olmes , Gustavo S. Semaan , Daniel de Oliveira , Lucio Santos , Marcos Bedo

We aim to identify the spatial distribution of vegetation and its growth dynamics with the purpose of obtaining a qualitative assessment of vegetation characteristics tied to its condition, productivity and health, and to land degradation.…

Statistical Mechanics · Physics 2024-09-16 Hediye Yarahmadi , Yves Desille , John Goold , Francesca Pietracaprina

In nature, barchan dunes typically exist as members of larger fields that display striking, enigmatic structures that cannot be readily explained by examining the dynamics at the scale of single dunes, or by appealing to patterns in…

Soft Condensed Matter · Physics 2013-07-15 S. Worman , A. B. Murray , R. Littlewood , B. Andreotti , P. Claudin

From 1998 to 2003 the CCD Solar Astrolabe of the Observatorio Nacional in Rio de Janeiro made more than 20000 observations of the Solar Semidiameter. In the present work similar corrections for the observational results of 2002 and 2003…

Solar and Stellar Astrophysics · Physics 2013-01-10 Sérgio Calderari Boscardin

Remote sensing satellite data offer the unique possibility to map land use land cover transformations by providing spatially explicit information. However, detection of short-term processes and land use patterns of high spatial-temporal…

Computer Vision and Pattern Recognition · Computer Science 2017-09-25 Ron Hagensieker , Ribana Roscher , Johannes Rosentreter , Benjamin Jakimow , Björn Waske

The simplest type of dune is the transverse one, which propagates with invariant profile orthogonally to a fixed wind direction. Here we show numerically and with a linear stability analysis that transverse dunes are unstable with respect…

Soft Condensed Matter · Physics 2015-05-30 Eric J. R. Parteli , José S. Andrade , Hans J. Herrmann

Spatially explicit quantification of forest biomass is important for forest-health monitoring and carbon accounting. Direct field measurements of biomass are laborious and expensive, typically limiting their spatial and temporal sampling…

Applications · Statistics 2024-07-11 Paul B. May , Andrew O. Finley