Aeolian ResearchPub Date : 2022-03-01DOI: 10.1016/j.aeolia.2022.100786
Diana Francis , Ricardo Fonseca , Narendra Nelli , Oriol Teixido , Ruqaya Mohamed , Richard Perry
{"title":"Increased Shamal winds and dust activity over the Arabian Peninsula during the COVID-19 lockdown period in 2020","authors":"Diana Francis , Ricardo Fonseca , Narendra Nelli , Oriol Teixido , Ruqaya Mohamed , Richard Perry","doi":"10.1016/j.aeolia.2022.100786","DOIUrl":"10.1016/j.aeolia.2022.100786","url":null,"abstract":"<div><p>While anthropogenic pollutants have decreased during the lockdown imposed as an effort to contain the spread of the Coronavirus disease 2019 (COVID-19), changes in particulate matter (PM) do not necessarily exhibit the same tendency. This is the case for the eastern Arabian Peninsula, where in March–June 2020, and with respect to the same period in 2016–2019, a 30 % increase in PM concentration is observed. A stronger than normal nocturnal low-level jet and subtropical jet over parts of Saudi Arabia, in response to anomalous convection over the tropical Indian Ocean, promoted enhanced and more frequent episodes of Shamal winds over the Arabian Peninsula. Increased surface winds associated with the downward mixing of momentum to the surface fostered, in turn, dust lifting and increased PM concentrations. The stronger low-level winds also favoured long-range transport of aerosols, changing the PM values downstream. The competing effects of reduced anthropogenic and increased dust concentrations leave a small positive signal (<5 W m<sup>−2</sup>) in the net surface radiation flux (R<sub>net</sub>), with the former dominating during daytime and the latter at night. However, in parts of the Arabian Gulf, Sea of Oman and Iran R<sub>net</sub> increased by >20 W m<sup>−2</sup> with respect to the baseline period, owing to a clearer environment and weaker winds. It is concluded that a reduction in anthropogenic emissions due to the lockdown does not necessarily go hand in hand with lower particulate matter concentrations. Therefore, emissions reduction strategies need to account for feedback effects in order to reach the planned long-term outcomes.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"55 ","pages":"Article 100786"},"PeriodicalIF":3.3,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8883805/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10742108","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}
Aeolian ResearchPub Date : 2022-03-01DOI: 10.1016/j.aeolia.2022.100787
Lihai Tan , Jianjun Qu , Tao Wang , Weimin Zhang , Suping Zhao , Hongtao Wang
{"title":"Vertical flux density and frequency profiles of wind-blown sand as a function of the grain size over gobi and implications for aeolian transport processes","authors":"Lihai Tan , Jianjun Qu , Tao Wang , Weimin Zhang , Suping Zhao , Hongtao Wang","doi":"10.1016/j.aeolia.2022.100787","DOIUrl":"10.1016/j.aeolia.2022.100787","url":null,"abstract":"<div><p><span>Vertical profiles of wind-blown sand as a function of the grain size are significant to better understand the microscopic process of heterogeneous saltation. Here, vertical flux density and frequency profiles of wind-blown sand as a function of the grain size over three typical gobi surfaces during three transport events were revealed. The results indicate that given the three gobi surfaces examined, the sand flux density of smaller sand particles (69–316 μm) exponentially decayed with the height, while the sand flux density of larger grains (363–976 μm) gradually deviated from the above exponential decay with the height and exhibited nonmonotonic variation with the height. The frequency of coarse grains (209–976 μm) continuously increased with the elevation until an inflection occurred at a certain height above the ground (0.17–1.3 m), and above the </span>inflection point, the frequency of coarse grains exponentially decreased with the height. However, the frequency of fine grains (67–163 μm) initially decreased with the elevation. This trend was reversed at heights ranging from 0.17 to 0.73 m above the ground, after which the frequency exponentially increased. In contrast, the frequency profile of ∼180-μm diameter sand grains revealed an exponential decay curve throughout the entire elevation range examined. These results indicate that grains larger than 180 μm participated in the grain-bed collision process over gobi, and the rebound height was positively related to the grain size, while grains smaller than 180 μm were more notably affected by turbulence.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"55 ","pages":"Article 100787"},"PeriodicalIF":3.3,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44699765","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}
Aeolian ResearchPub Date : 2022-03-01DOI: 10.1016/j.aeolia.2022.100785
Ahmed Dawelbeit , Etienne Jaillard , Ali Eisawi
{"title":"Grain size analysis of the latest Quaternary Kordofan Sand of Central Sudan: Depositional environment and mode of transportation","authors":"Ahmed Dawelbeit , Etienne Jaillard , Ali Eisawi","doi":"10.1016/j.aeolia.2022.100785","DOIUrl":"10.1016/j.aeolia.2022.100785","url":null,"abstract":"<div><p><span>Grain size analysis is a powerful tool for determining the depositional environment. Grain size analysis for 48 samples from four sections along a 280 km long, nearly north–south-trending transect, has been conducted in the mainly </span>Holocene<span><span> Kordofan Sand in the Kordofan Region of Central Sudan. In these sections, this part of the Kordofan Sand comprises three pedosedimentary sequences. The lower sequence (∼13–10 kyr) has been pedogenized during the African Humid Period and ends up farther West with lacustrine or palustrine carbonates. The middle sequence (∼6–3 kyr) is represented by sand with low degree of pedogenesis and corresponds to the African Humid Period. The upper sequence was deposited after a hiatus lasting from ∼3.3 to 1.1 ka BP, and constitutes the present-day surficial deposits, showing little or no pedogenesis. Spatial grain size distribution and mode of transport show a southward fining trend, indicating that the sandy sediments were transported from north to south. This interpretation is supported by the results of mean grain size – sorting, and sorting – skewness interrelations, which provided a linear relationship. Vertical variation in grain size distribution in the studied sections shows variable energy over time in the north and constant, low energy in the south. The dominance of saltation as a transport mode confirms that the studied sediments were deposited in aeolian environment. The low sorting degree, the presence of coarse grains, and the still active transverse dunes and </span>barchans<span><span> in the North, indicate that the Late Pleistocene part of the Kordofan Sandstone is submitted to reworking until now. Consequently, the mainly Holocene sand sequences were fed both by distal, fine-grained Saharan material and by proximal, coarser-grained sand </span>proceeding from the Late Pleistocene aeolian dunes.</span></span></p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"55 ","pages":"Article 100785"},"PeriodicalIF":3.3,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46881081","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":"Dynamic processes of dust emission from gobi: A portable wind tunnel study atop the Mogao Grottoes, Dunhuang, China","authors":"Weimin Zhang , Lihai Tan , Linhao Liang , Shuyi Chen , Guobin Zhang , Hongtao Zhan , Fei Qiu , Shaoxiu Ma","doi":"10.1016/j.aeolia.2022.100784","DOIUrl":"10.1016/j.aeolia.2022.100784","url":null,"abstract":"<div><p><span>The dynamic process of dust emission from gobi is a largely un-solved scientific question while it is essential for minimizing the dust hazards. In this study, field wind tunnel experiments have been performed to reveal the processes of dust emission from gobi on the top of the Mogao Grottoes. We found that the dust content of gobi is the dominant factor that determines the intensity of dust emission. The vertical PM10 flux increased exponentially with the increase of dust content on the gobi surface at a given </span>wind speed. The impact energy of saltating particles is another control factor of the dust emission flux. The vertical PM10 flux due to saltation bombardment of the external sand supply was 5–13 times larger than that without the bombardment of sand supply. This study indicates that gobi on the top of the Mogao Grottoes is one of the main dust sources as it has an abundance of sand supply from Mingsha Mountain as well as its richness in dust content. Hence, it is imperative to expand the existing sand control system on the top of the Mogao Grottoes in order to minimize the impact of dust hazards on the Mogao Grottoes.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"55 ","pages":"Article 100784"},"PeriodicalIF":3.3,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46862617","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}
Aeolian ResearchPub Date : 2022-03-01DOI: 10.1016/j.aeolia.2022.100776
Laura Antonela Iturri , Roger Funk , Michael Sommer , Daniel Eduardo Buschiazzo
{"title":"Transport preferences of P forms in wind-blown sediments of two susceptible soils","authors":"Laura Antonela Iturri , Roger Funk , Michael Sommer , Daniel Eduardo Buschiazzo","doi":"10.1016/j.aeolia.2022.100776","DOIUrl":"10.1016/j.aeolia.2022.100776","url":null,"abstract":"<div><p>Wind erosion of agricultural soils affects their stock of essential elements for plants, like phosphorus (P). It is known that the composition of the eroded sediments varies with height, according to the size and density of the transported substances. Aim of this study was to analyze the concentration and enrichment ratios of P forms in sediments transported by the wind. A wind-tunnel study was performed on a sandy- and a sandy loam soil in order to measure P forms concentrations in the saltating sediments. P concentrations were also measured in the particulate matter (PM) of each soil, gained with the Easy Dust Generator. In both soils, inorganic- (P<sub>i</sub>) and organic P (P<sub>o</sub>) were preferentially transported in PM, with enrichment ratios of 1.8 and 5.5, respectively. Nevertheless, a P<sub>i</sub>/P<sub>o</sub> of 0.9 indicated that the accumulation of the minor P<sub>o</sub> in PM was more pronounced than P<sub>i</sub>. This agrees with P-rich light and easily erodible organic compounds, almost exclusively accumulated in PM, and in relatively heavy and less erodible minerals, like apatites, in lower height sediments. Labile P (P<sub>l</sub>) was preferentially transported in saltating sediments of both soils. This was attributed to the selective Bray & Kurtz I’s extraction of the abundant inorganic P forms of these sediments. Total P (P<sub>t</sub>) copied the transport trends of P<sub>i</sub>, the major form. According to the transporting trends, P<sub>i</sub> and P<sub>o</sub> would be re-sedimented at longer distances from the source than P<sub>l</sub>. Outcomes become useful for modeling the influence of wind erosion on P cycling.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"55 ","pages":"Article 100776"},"PeriodicalIF":3.3,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44472725","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}
Aeolian ResearchPub Date : 2022-02-01DOI: 10.1016/j.aeolia.2022.100774
Cesar E. Ramirez , Natalia Quinete , Luisa Rojas de Astudillo , Luis E. Arroyo-Mora , Douglas Seba , Piero Gardinali
{"title":"Elemental composition of airborne particulate matter from coastal South Florida area influenced by African dust events","authors":"Cesar E. Ramirez , Natalia Quinete , Luisa Rojas de Astudillo , Luis E. Arroyo-Mora , Douglas Seba , Piero Gardinali","doi":"10.1016/j.aeolia.2022.100774","DOIUrl":"10.1016/j.aeolia.2022.100774","url":null,"abstract":"<div><p>Airborne particulate matter (APM) is a complex mixture of dust, dirt, soot and smoke containing both organic and inorganic components as well as biological particles. APM below 10 µm can enter the respiratory track and are known to cause adverse health effects. African dust storms are responsible for the transport of large amount of APM across the Atlantic Ocean during summer months. Anthropogenic activities are also responsible for APM pollution contribution in coastal areas and could have potential effects on sensitive ecosystems. The present study evaluates the elemental composition of APM collected from a coastal area in South Florida. In this study, a high-volume air sampler equipped with Versapor filters and located near the Port of Fort Lauderdale was employed for APM collection from 2005 to 2010. APM chemical composition was analyzed for multiple elements by ICP-MS. Seven of the eleven metals listed by the EPA as hazardous air pollutants (Mn, Cd, Cr, Ni, Pb, As, Co and Se) were detected in the samples. Iron and aluminum were the most abundant elements found in all samples, followed by V and Ni, which are usually associated with anthropogenic pollution coming from fossil fuel combustion. Specific sources of APM pollution were identified by principal component analysis and using the U.S. EPA UNMIX model for environmental data analyses. Rare earth elements were used to identify contributions of geological material to the APM and African dust influence during the summer months.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"54 ","pages":"Article 100774"},"PeriodicalIF":3.3,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41995694","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":"Classification of synoptic weather clusters associated with dust accumulation over southeastern areas of the Caspian Sea (Northeast Iran and Karakum desert)","authors":"Kaveh Mohammadpour , Maurizio Sciortino , Dimitris G. Kaskaoutis , Alireza Rashki","doi":"10.1016/j.aeolia.2022.100771","DOIUrl":"10.1016/j.aeolia.2022.100771","url":null,"abstract":"<div><p><span>In this study, daily-mean total and dust aerosol optical depth (TAOD, DAOD, respectively) obtained from the Monitoring Atmospheric Composition and Climate (MACC) and meteorological fields from ERA-Interim reanalysis are used to identify spatial patterns of dust accumulation over northeast Iran and Karakum Desert during 2003–2012. The most dust-affected area is defined using highest variances of DAOD by </span><em>S-mode</em> and weather clusters by <em>T-mode</em><span> principal component analysis (PCA). Six weather clusters are classified via the statistical analysis, associated with high DAOD values, with larger frequency in spring, while PC1 (41 cases) dominates in summer. The results show that changes in the intensity and expansion of the Siberian/European high-pressures in spring modulate strong northeasterlies or northwesterlies over Central Asia, which are associated with frontal dust storms over the desert areas (Aralkum, Karakum). In addition, dynamic conditions associated with the sub-tropical jet stream and the Iranian trough, and combined with convective conditions at areas of thermal lows in east Iran, create a strong southwesterly wind – called Qibla – over the Iranian Plateau. These two contrasting wind regimes converge over northeast Iran/Karakum Desert, facilitating dust accumulation over the area. In summer, northerly winds dominate over Central Asia, but the absence of Qibla flow allows them to traverse till the north coast of the Arabian Sea, where they converge with the southwest monsoon flow. The accumulation of dust over northeast Iran/Karakum is lesser than that over Pakistan and Thar desert. Furthermore, the upper-level sub-tropical jet stream moves northward in summer, with core over Turkmenistan/Uzbekistan.</span></p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"54 ","pages":"Article 100771"},"PeriodicalIF":3.3,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47455308","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}
Aeolian ResearchPub Date : 2022-02-01DOI: 10.1016/j.aeolia.2022.100772
Andrew S. Goudie
{"title":"Nebkhas: An essay in aeolian biogeomorphology","authors":"Andrew S. Goudie","doi":"10.1016/j.aeolia.2022.100772","DOIUrl":"10.1016/j.aeolia.2022.100772","url":null,"abstract":"<div><p><span>Nebkhas are a type of anchored dune that forms by sediment accumulation around grasses, shrubs or trees. This paper outlines their importance, their distribution at global and local scales, summarises what is known about their morphology, discusses those plants with which they are associated, draws attention to the materials of which they are composed, and then concludes with a discussion of their ages. Nebkhas are very widespread in dry and coastal environments. They have considerable importance because they can be ‘islands of fertility’ and have major hydrological and biological effects. They can, if eroded, be major sources of dust emission. Examples of coastal nebkhas are known from both temperate areas and from lower latitude drylands, as along the Caspian shoreline in Iran, Kuwait, northern Peru, Namibia, Western Sahara, the Makran, southwest Madagascar, and Mauritania. Dryland nebkhas have been described from numerous areas, with concentrations of studies in Kuwait, the southwest USA, northwest China, and Iran. Within an area with suitable climatic conditions, nebkhas do not occur everywhere. Certain conditions need to be met for their development and these are illustrated with examples from the Tarim and Qaidam basins of China, the Lut of Iran, northwest Argentina, and the Namib. For this, Google Earth was employed. The heights of these features range from a matter of centimeters to as much as 20 m. There is a considerable quantity of data on the plants that are associated with the development of nebkhas. They have to have certain qualities for this role: ability to withstand drought, tolerate salt, thrive on sand burial, have wide shallow rooting systems to obtain water from fog and occasional rain events, extract moisture from groundwater, withstand sand abrasion, and develop </span>adventitious roots<span>. Although nebkhas are normally thought of as a type of sand dune, and most nebkhas are indeed composed of sand-sized material, largely consisting of quartz, there are many nebkhas which contain appreciable amounts of silt and clay, as well as salts such as gypsum. Although some nebkhas are ephemeral features, various dating techniques have shown that they can be decades, centuries and even millennia old.</span></p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"54 ","pages":"Article 100772"},"PeriodicalIF":3.3,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46768480","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}
Aeolian ResearchPub Date : 2022-02-01DOI: 10.1016/j.aeolia.2021.100769
Brandon L. Edwards , Nicholas P. Webb , Magda S. Galloza , Justin W. Van Zee , Ericha M. Courtright , Brad F. Cooper , Loretta J. Metz , Jeffrey E. Herrick , Gregory S. Okin , Michael C. Duniway , John Tatarko , Negussie H. Tedala , Daniel N. Moriasi , Beth A. Newingham , Frederick B. Pierson , David Toledo , R. Scott Van Pelt
{"title":"Parameterizing an aeolian erosion model for rangelands","authors":"Brandon L. Edwards , Nicholas P. Webb , Magda S. Galloza , Justin W. Van Zee , Ericha M. Courtright , Brad F. Cooper , Loretta J. Metz , Jeffrey E. Herrick , Gregory S. Okin , Michael C. Duniway , John Tatarko , Negussie H. Tedala , Daniel N. Moriasi , Beth A. Newingham , Frederick B. Pierson , David Toledo , R. Scott Van Pelt","doi":"10.1016/j.aeolia.2021.100769","DOIUrl":"10.1016/j.aeolia.2021.100769","url":null,"abstract":"<div><p>Aeolian processes are fundamental to arid and semi-arid ecosystems, but modeling approaches are poorly developed for assessing impacts of management and environmental change on sediment transport rates over meaningful spatial and temporal scales. For model estimates to provide value, estimates of sediment flux that encapsulate intra- and inter-annual and spatial variability are needed. Further, it is important to quantify and communicate transparent estimates of model uncertainty to users. Here, we present a wind erosion and dust emission model parameterized for rangelands using a Generalized Likelihood Uncertainty Estimation framework. Modeled horizontal sediment flux was calibrated using data from five diverse grassland and shrubland sites from the USDA National Wind Erosion Research Network. Observations of wind speed, vegetation height, length of gaps between vegetation, and percent bare ground were used as model inputs. Horizontal sediment flux estimates from 10,000 independently selected parameter sets were compared to flux observations from 44 ∼ month-long collection periods to calculate a likelihood measure for each model. Results show good agreement for individual sampling periods across sites with few observations falling outside prediction bounds and a one-to-one relationship between median predictions and observations. Additionally, combined distributions of sediment flux estimates from all sample periods for a given site closely approximated the probability of observing a given flux at that site. These results suggest AERO effectively represents temporal variability in aeolian transport rates at rangeland sites and provides robust assessments suitable for assessing land health and better predicting changes in air quality and the impacts of land management activities.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"54 ","pages":"Article 100769"},"PeriodicalIF":3.3,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1875963721001063/pdfft?md5=973d98e964768d330fe2d1d17b9d4953&pid=1-s2.0-S1875963721001063-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42864257","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}
Aeolian ResearchPub Date : 2022-02-01DOI: 10.1016/j.aeolia.2021.100766
Mark Hennen , Adrian Chappell , Brandon L. Edwards , Akasha M. Faist , Tarek Kandakji , Matthew C. Baddock , Brandi Wheeler , Gayle Tyree , Ronald Treminio , Nicholas P. Webb
{"title":"A North American dust emission climatology (2001–2020) calibrated to dust point sources from satellite observations","authors":"Mark Hennen , Adrian Chappell , Brandon L. Edwards , Akasha M. Faist , Tarek Kandakji , Matthew C. Baddock , Brandi Wheeler , Gayle Tyree , Ronald Treminio , Nicholas P. Webb","doi":"10.1016/j.aeolia.2021.100766","DOIUrl":"10.1016/j.aeolia.2021.100766","url":null,"abstract":"<div><p>Measurements of atmospheric dust have long influenced our understanding of dust sources and dust model calibration. However, assessing dust emission magnitude and frequency may reveal different dust source dynamics and is critical for informing land management. Here we use MODIS (500 m) albedo-based daily wind friction estimates to produce a new dust emission climatology of North America (2001–2020), calibrated by the novel use of dust point sources from optical satellite observations (rather than being tuned to dust in the atmosphere). Calibrated dust emission occurred predominantly in the biomes of the Great Plains (GP) and North American Deserts (NAD), in broad agreement with maps of aerosol optical depth and dust deposition but with considerably smaller frequency and magnitude. Combined, these biomes produced 7.2 Tg y<sup>-1</sup> with contributions split between biomes (59.8% NAD, 40.2% GP) due to the contrasting conditions. Dust emission is dependent on different wind friction conditions on either side of the Rocky Mountains. In general, across the deserts, aerodynamic roughness was persistently small and dust sources were activated in areas prone to large wind speeds; desert dust emissions were wind speed limited. Across the Great Plains, large winds persist, and dust emission occurred when vegetation cover was reduced; vegetated dust emissions were roughness limited. We found comparable aerodynamic roughness exists across biomes/vegetation classes demonstrating that dust emission areas are not restricted to a single biome, instead they are spread across an ‘envelope’ of conducive wind friction conditions. Wind friction dynamics, describing the interplay between changing vegetation roughness (e.g., due to climate and land management) and changing winds (stilling and its reversal), influence modelled dust emission magnitude and frequency and its current and future climatology. We confirm previous results that in the second half of the 21st century the southern Great Plains is the most vulnerable to increased dust emission and show for the first time that risk is due to increased wind friction (by decreased vegetation roughness and / or increased wind speed). Regardless of how well calibrated models are to atmospheric dust, assuming roughness is static in time and / or homogeneous over space, will not adequately represent current and future dust source dynamics.</p></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"54 ","pages":"Article 100766"},"PeriodicalIF":3.3,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1875963721001038/pdfft?md5=95232556baef70495b63a4d27383325d&pid=1-s2.0-S1875963721001038-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44501344","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}