Aeolian Research最新文献

{"title":"Characterization of 21 years of dust events across four West Texas regions","authors":"M.C. Robinson,&nbsp;K. Ardon-Dryer","doi":"10.1016/j.aeolia.2024.100930","DOIUrl":"https://doi.org/10.1016/j.aeolia.2024.100930","url":null,"abstract":"<div><p>Dust events are caused by strong winds that lift dust particles into the air. Due to surrounding deserts and agriculture, West Texas experiences many dust events. This study examines dust events that occurred between 2000 and 2020 across four locations: Amarillo, Lubbock, Midland, and El Paso. A total of 1,834 dust events were identified across the four locations with an average of 22 dust events annually. 227 dust events were observed in Amarillo, 609 in Lubbock, 545 in Midland, and 453 dust events were observed in El Paso. A slight increasing trend of dust events over time was observed for Amarillo, Lubbock, and Midland while El Paso showed a decreasing trend. Most dust events occurred during the spring to early summer months and they lasted an hour or less. Many dust events occurred during times of drought and periods of La Niña. Separation of the dust events based on the meteorological disturbance that caused them (convective vs. synoptic) showed that synoptic disturbances contribute to &gt;60 % of the dust events, while convective disturbances were responsible for most of the remaining. Synoptic disturbances were predominately in spring while convective disturbances were common in the early summer months. A comparison of meteorological parameters measured during each disturbance shows that synoptic dust events were associated with lower temperatures, dew point, and relative humidity, but with higher wind speeds and gusts.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"67 ","pages":"Article 100930"},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1875963724000417/pdfft?md5=b56fd224fd238b77ad4aefbe25b1722b&pid=1-s2.0-S1875963724000417-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141067923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphological and sedimentary characteristics of raked linear dunes in the southeastern Taklimakan Desert, China","authors":"Fang Ma,&nbsp;Ping Lü,&nbsp;Min Cao,&nbsp;Junlin Yu,&nbsp;Zishu Xia","doi":"10.1016/j.aeolia.2024.100923","DOIUrl":"https://doi.org/10.1016/j.aeolia.2024.100923","url":null,"abstract":"<div><p>Raked linear dunes were rarely reported, except in the Kumtagh Desert, leaving little known about the dynamic process. However, numerous raked linear dunes have formed in the Kat Kum dunefield of the southeastern Taklimakan Desert, which provides a new case to study the morphodynamics of these dunes. We conducted a comprehensive analysis on the dune morphometry, wind regime, sedimentary characteristics, and sand availability of these dunes. We found that grain size variation is an essential factor affecting the formation of raked linear dunes in addition to wind regime and limited sand availability. These dunes in the Kat Kum present small scale and easily reshaped with fast migration rate compared with these in the Kumtagh Desert, and distributed in areas with low sand cover. The primary ridge extended obliquely to the resultant drift direction, whereas the subsidiary ridge extend is nearly parallel to this direction. The grain size of the primary ridge is noticeably coarser than that of the subsidiary ridge. These dunes seem to have evolved from barchans. Under a north-northeast wind, barchans reshaped to asymmetrical barchans by extending their southeast limbs and eroding their northwest limbs, causing the ridge to be oblique to the resultant drift direction. The strong east-northeast wind erodes and reshapes the primary ridge, transporting fine sand to the northwest and resulting in the formation of proto-subsidiary ridges. With the elongation and lateral movement of primary ridge, a continuous subsidiary ridge with regular dune spacing forms on the northwest flank.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"67 ","pages":"Article 100923"},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140554223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined use of HYSPLIT model and MODIS aerosols optical depth to study the spatiotemporal circulation patterns of Saharan dust events over Central Europe","authors":"Nadia Gammoudi ,&nbsp;János Kovács ,&nbsp;Fruzsina Gresina ,&nbsp;György Varga","doi":"10.1016/j.aeolia.2024.100899","DOIUrl":"https://doi.org/10.1016/j.aeolia.2024.100899","url":null,"abstract":"<div><p>Mineral dust released from the desert region and transported into the atmosphere has a crucial impact on the Earth's climate system's biogeochemical cycle. It has serious adverse effects on human health. The Sahara is one of the world's dustiest areas. This investigation intends to uncover the underlying reasons for atmospheric dust dispersion throughout the year by tracking the dust<!--> <!-->transport and deposition in Central Europe, focusing on arid areas of North Africa. In this paper, we use the GDAS (Global Data Assimilation System) archival meteorological database to compute the analytical forward trajectories and configure the particle concentrations using the HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model. Besides, we investigate the synoptic meteorological conditions of acute Saharan dust episodes to determine the dynamic atmospheric system during their onset. The forward trajectories reveal the seasonality of wind-blown dust throughout the year. Dust storms are typically more prevalent in the spring, with a second peak in the Summer. As a result, particle transport takes various paths as the seasons and climatic conditions change. The most dust-laden masses, which reach high altitudes from the source areas, are often transported to Central Europe, where their seasonal distribution is relatively similar to that of the studied African region. However, the intensity and frequency of Saharan dust events (SDEs) have significantly changed in the previous decades, with an increased number of intense winter storms. According to the synoptic analysis, this variability is strongly linked to two factors. (1) The intensity and lifetime variation of the Mediterranean cyclones and (2) Climate change triggered lee-side (Sharav) cyclogenesis modified by the topographic complexity of Atlas. This study also confirmed the effectiveness of the HYSPLIT model in simulating atmospheric dust after comparing it with annual aerosol optical depth measurements from MODIS (Moderate-Resolution Imaging Spectroradiometer) data.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"67 ","pages":"Article 100899"},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1875963724000107/pdfft?md5=2ea2e44bc4cc2ac67094f7c259372105&pid=1-s2.0-S1875963724000107-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140103387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reconstructing star dune dynamics using ground penetrating radar – How movement shapes complex surface structures","authors":"Manuel Herzog ,&nbsp;Alexander Schmitt ,&nbsp;Olaf Bubenzer","doi":"10.1016/j.aeolia.2024.100920","DOIUrl":"https://doi.org/10.1016/j.aeolia.2024.100920","url":null,"abstract":"<div><p>The evolution of large star dunes, because of their remote location, size and surface complexity, is barely recorded and understood. This lack of understanding applies to surface and subsurface features alike. In order to detect the transformation, the detailed subsurface stratigraphy and the relative chronology of large star dunes, we used ground penetrating radar (GPR) on all major arms of a complex star dune of Erg Chebbi, south-eastern Morocco. We used a 350 MHz digital antenna from Geophysical Survey Systems, Inc (GSSI), reaching a depth of 12.5 m to identify main radar facies associated with former downwind dune flanks describing the depositional history. Our results enable the determination of former dune crest positions, their potential past movement and in consequence the construction of the paleo-dune topography. In accordance with simulated historical wind data, we found a potential sediment deficit on the south-eastern side of the dune. This also correlates with surface data describing an oblique form of the star dune and the spatial distribution frequency of its major arms. Our detailed recordings show, for the first time, the complex internal composition of all arms of one large star dune and surface sensitive form-flow interactions. Our results allow the discrimination of deposition phases and therefore, we have constructed a relative chronology as a basis for future sampling and the reconstruction of star dune evolution in general.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"67 ","pages":"Article 100920"},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1875963724000314/pdfft?md5=9c20c075b4d75bb64e8ddd31f3c4c456&pid=1-s2.0-S1875963724000314-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141067922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulations of dune morphology under tri-directional wind regimes and application to dunes on Mars","authors":"David M. Rubin ,&nbsp;Olivier Rozier ,&nbsp;Clément Narteau ,&nbsp;Sylvain Courrech du Pont","doi":"10.1016/j.aeolia.2024.100922","DOIUrl":"https://doi.org/10.1016/j.aeolia.2024.100922","url":null,"abstract":"<div><p>Dune morphology was simulated using coupled models of wind flow and sand transport for 4728 tri-directional wind regimes and bed conditions. The dominant control of dune morphology is sand coverage on the bed. Dunes on a fully sand-covered bed tend to form a periodic pattern of long crests with a relatively uniform spacing. In contrast, dunes on a starved bed have greater diversity of crest orientations and shapes, including complex shapes that have not been simulated or observed in bidirectional wind regimes. These specific dune shapes resulting from the tri-directional wind regime persist regardless of whether the transport capacity of the weakest wind is comparable to or only 1/10th that of the dominant wind.</p><p>On sand-covered beds, dunes generally have only a single modal orientation (approximately that with maximum gross bedform-normal transport). The exceptions are where two strong winds diverge by 90° (two dune orientations arise), where three winds have triradial symmetry (three dune orientations), or winds have modest deviations from triradial symmetry (two dune orientations).</p><p>On a starved bed, increasing the divergence angle between two strong winds produces a highly generalized sequence of: barchan dunes (divergence angle ∼30° between the two dominant winds), squat barchans or domes (divergence angle of ∼60°), dunes with two or three crest orientations (divergence angles ∼90° or 120°), to slug-shaped or boomerang-shaped dunes (divergence angle 180°, i.e., reversing winds). The simulated morphologies include a wide variety of Martian dune shapes, which allows their formative wind regimes to be inferred.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"67 ","pages":"Article 100922"},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1875963724000338/pdfft?md5=b92477c20eb1555d01d08ef350ca4532&pid=1-s2.0-S1875963724000338-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140290361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of backdune morphology on air flow dynamics through an excavated foredune notch","authors":"Duc Nguyen ,&nbsp;Sarah Wakes ,&nbsp;Mike Hilton","doi":"10.1016/j.aeolia.2024.100929","DOIUrl":"https://doi.org/10.1016/j.aeolia.2024.100929","url":null,"abstract":"<div><p>On many metropolitan and developed coasts foredunes are narrow, vegetated, highly stable and confined by hinterland development. Such foredunes are most likely to erode, rather than landward migration, in response to ongoing eustatic sea-level rise. Foredune notching may be undertaken on such coasts to facilitate sand transport through the foredune zone and accomplish degrees of foredune landward migration; however, the efficacy of this method has not been examined in relation to the backdune topography, which in many instances takes the form of a dyke or similar infrastructure.</p><p>Computational Fluid Dynamics (CFD) is used to investigate how the space behind a notch, and the slope of the seaward face of the backdune topography, modifies near-surface wind through foredune notches. Incident winds are simulated parallel to the notch long axis and the effects of changing backdune morphology on the secondary winds through the notch are examined. Swale widths between 3 and 53 m and hinterland gradients between 0° and 90° are examined.</p><p>Air flow through the notch is strongly influenced by the morphology of backdune infrastructure. Wind speed increases through the notch as the spacing behind the notch increases and the slope of the hinterland topography decreases. An increase in spacing reduces the landward extension of wind recirculation in the lee of the notch. To maximise notch efficiency and sediment accumulation in the lee of the foredune the minimum spacing should be 8 and 30 m when the slope of the backdune infrastructure is 20° and 90°, respectively.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"67 ","pages":"Article 100929"},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1875963724000405/pdfft?md5=f4cc8ded9de28d8a73fcb3196ed9c189&pid=1-s2.0-S1875963724000405-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140950285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vortex core regions of nebkhas and their implications on shadow dune formation","authors":"Yongcheng Zhao,&nbsp;Xin Gao,&nbsp;Jiaqiang Lei","doi":"10.1016/j.aeolia.2024.100926","DOIUrl":"https://doi.org/10.1016/j.aeolia.2024.100926","url":null,"abstract":"<div><p>Shadow dunes develop at the lee side of obstacles and are scale-dependent on the obstacle size. However, our recent field investigations showed that the lengths of shadow dunes are not always proportional to the size of obstacles. In this work, field investigations and computational fluid dynamics (CFD) simulations were conducted to study the effects of the scale and vortex of nebkhas on shadow dune development. Results show that although the shadow dune lengths are proportionate to the width (<em>W</em>) and height (<em>H</em>) of nebkhas, the increment rate decreased massively when the <em>W</em> and <em>H</em> of nebkhas are larger than 6 and 2 m, respectively. The CFD simulations suggest that the vortex core regions of the paired symmetrical reversing flow gradually move to the upwind region as the aspect ratio (<em>H/W</em>) of the nebkhas decreases. The size of the paired symmetrical reversing flows is reduced, and the merging of the reversing flows is prevented, potentially entraining the sediments far from the wake region. The sediments could rotate and deposit on both sides of the leeward face of the nebkhas and therefore contribute to the occurrence of short, tongue-like shadow dunes, which are particularly notable when <em>H/W</em> &lt; 1. The vortex core region always occurs at the foot of the lee side of nebkhas with the same <em>H/W</em> regardless of the scale of the nebkhas or the incident wind speed.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"67 ","pages":"Article 100926"},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140816706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heavy minerals of the aeolian sediments in the East Slovak Basin (Western Carpathians) – Implications for their origin, transport process and sedimentary history","authors":"Katarína Bónová ,&nbsp;Ján Bóna ,&nbsp;Tomáš Mikuš ,&nbsp;Andrea Ferková","doi":"10.1016/j.aeolia.2024.100897","DOIUrl":"https://doi.org/10.1016/j.aeolia.2024.100897","url":null,"abstract":"<div><p>Aeolian sediments usually indicate glacial or periglacial arid-climate conditions, and knowledge of their sedimentary character and mineral composition can reveal the locality’s palaeo-environment and palaeo-geographic history. Reconstruction is provided by heavy-mineral surface micro-textural and geochemical analysis, and this detected the source area, source rocks and transport conditions for the Würmian wind-blown sands which form several dune types in the East Slovak Basin. The heavy-mineral morphology, surface micro-textures and low mineral maturity of the aeolian sediments preserve traces of past sub-aquatic environments and local aeolian transport. The heavy-mineral geochemistry suggests initial detrital derivation from local sources. This was formed by re-worked and re-mobilised Magura Nappe flysch sandstones in the Western Carpathians, with likely contribution of the Pieniny Klippen Belt flysch sediments indicated in sporadic pyrope-rich garnet. The associated detrital pyroxene and amphibole geochemistry denotes primary andesite source rocks which dominate lithology in the surrounding Neogene volcanic mountain chains. These are the Slanské vrchy, Vihorlatské vrchy and Zemplínske vrchy Mountains. The further occurrence of detrital hydrogrossular indicates derivation from contact-metamorphic zones associated with the volcanic rocks. Although different garnet types in the distinct dune profile zones may have resulted from heavy mineral re-sorting during active dune movement, they suggest sources changed by local wind directions. Orientation of basic linear features of the dunes derived from the digital terrain model indicates (paleo)wind generally from the north.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"66 ","pages":"Article 100897"},"PeriodicalIF":3.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139726410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adhesion theory and model for air humidity impact on dust emission","authors":"Yaping Shao","doi":"10.1016/j.aeolia.2024.100898","DOIUrl":"https://doi.org/10.1016/j.aeolia.2024.100898","url":null,"abstract":"<div><p>It has been suggested that air humidity influences dust emission under very dry conditions and adhesion might be the responsible process which changes the binding between soil particles. The process of adhesion is so far poorly understood and difficult to quantify. Here, a critical examination of the relevant studies is provided, and an adhesion model is proposed. Both isothermal-kinematic and diffusion processes can limit the soil liquid–water and water–vapor exchange in soil, but for the particle size range concerned in aeolian studies, diffusion appears to be the limiting process. The model shows that soil moisture in the topsoil layers is positively correlated with air humidity, but with delays of several hours. The model performance is influenced by several parameters but is particularly sensitive to the equilibrium soil water–vapor content. This implies that soil microscopic properties can strongly influence adhesion. A new formulation of soil water retention function covering the entire soil moisture range is also proposed, which links soil water retention function and pore size distribution. Using a relationship between soil particle-size and pore-size distributions, an adhesion-affected grain size can be estimated, which defines the upper size limit of soil particles influenced by soil moisture. This study explains how air humidity influences soil moisture through adhesion and dust emission and why low air humidity promotes the emission of finer dust particles.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"66 ","pages":"Article 100898"},"PeriodicalIF":3.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1875963724000090/pdfft?md5=46f661bb30127f01b08f1632a92e38fe&pid=1-s2.0-S1875963724000090-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139748488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constant stress layer characteristics in simulated stratified air flows: Implications for aeolian transport","authors":"Lukas F. Meldau, Bailiang Li, Cheryl McKenna Neuman, James R. Cooper","doi":"10.1016/j.aeolia.2023.100888","DOIUrl":"https://doi.org/10.1016/j.aeolia.2023.100888","url":null,"abstract":"<p>Varying thermal atmospheric stability conditions and their effects on shearing flows has long been a subject of interest for researchers working in atmospheric science. The development of new instrument technologies now offers an opportunity to study flows with high spatial and temporal resolutions in wind tunnel atmospheric boundary layers. In the presented study, we use a laser Doppler anemometer within the Trent Environmental Wind Tunnel Laboratory to investigate the influence of thermal stratification on the constant stress layer. Analyses of the thermal stratification represented by the gradient Richardson number and the apparent von Kármán parameter, shear velocity, and the slope of the streamwise velocity profiles reveal strong linear relationships. An exponential relationship between thermal stability and the apparent roughness length is also revealed. Profiles of the streamwise and vertical velocity and turbulence intensity, as well as the dimensionless Reynolds stress, are influenced by the gradient Richardson number. These findings have implications for producing accurate models of sediment entrainment and transport by wind in non-neutral conditions.</p>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"29 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139028669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}