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NASA MODIS satellite images of long-range dust transportation from Saharan source areas.-a = North Atlantic and southward transport (June 6, 2004); b = Saharan dust over the Mediterranean Sea (July 16, 2003); c = North African dust over the Red Sea from the Tokar Delta (June 20, 2012). Source: NASA Earth Observatory: htt p://earthobservatory.nasa.gov/
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Wind-blown dust and dust storms play important role in several environmental processes of our planet. Geographical distributions and seasonality patterns of major dust source areas were analysed in this paper by using the daily aerosol measurements of NASA’s Total Ozone Mapping Spectrometer between 1979 and 2011.
Spatial investigations of aerosol m...
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... dust is often detectable over the Atlantic Ocean, Mediterranean and Red Sea, and also in the atmosphere of distant areas ( Figure 6). Typically, four main long-range transportation routes can be distinguished: (1) westward trans- port of the Saharan Air Layer over the North Atlantic into the direction of North and South America (Prospero, J.M. et al. 1970;Swap, R. et al. 1992) (Barkan, J. et al. 2005;Engelstaedter, S. et al. 2006; Varga, Gy. 2012); and (4) eastward to the Middle East by Sharav cyclones (Alpert, P. and Ziv, B. 1989) or by gap winds at the Tokar Delta (Goudie, A.S. and Middleton, N.J. 2006). ...
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Citations
... The Sahara desert and the Sahel region in northern Africa are the most active global dust sources, emitting between 790 and 840 million tonnes annually. Other notable source regions include the Gobi and Taklamakan deserts in East Asia, the Sistan Basin and other regions of the Middle East, central Asia (Karakum desert), central Australia (Lake Eyre Basin), South America (Atacama and Patagonian deserts), South Africa, and the southern USA and northern Mexico (Prospero et al., 2002;Washington et al., 2003;Huneeus et al., 2011;Ginoux et al., 2010Ginoux et al., , 2012Varga, 2012;Orlovsky et al., 2005;Alizadeh Choobari et al., 2013). ...
... There are three distinct modes of aeolian sediment influx into the lower Helmand and Arghandab valleys. (i) Fine-grained aeolian sediments derived from dust storms initiated both from the basin (Rashki, 2012) and the regional dust belt (the central Asian deserts in the north, and both Dashte-Lut and Dashte Kevir in Iran in the west (Shao et al., 2011;Vagara, 2012); (ii) aeolian sediment transport during the Bade Sadobist Roza, or "the 120-day wind") (Tate, 1909); and (iii) sand movement by large mobile dunes and sand-sheets (e.g., Heydari Nasab et al., 2018). Tate (1909) described conditions of sand transport during one of 120-day wind south of Sistan, "It was impossible to keep lanterns alight, and after one or two narrow escapes from heavy falls everyone dismounted, for neither our animals nor ourselves were able to see the ground ahead, owing to the darkness and the sand which the head-wind blew into our faces". ...
In the Helmand/Sistan basin in southwest Afghanistan, aeolian sediment movement impacts the environment, irrigation canals, agriculture, and fluvial systems. The migration of large sand dunes into the Helmand and Arghandab rivers has a significant impact on the water resources providing livelihood for over three million people. A first step toward mitigating these impacts is to better understand sand dune migration. In this study, dune celerity and flux into the fluvial system are measured using PlanetScope Visual Ortho Scene satellite imagery. Two different time periods were used to quantify flux in five study sites of dune fields along 100 km of the Helmand River and 150 km of the Arghandab and Dori rivers. Results show diverse sand dune celerities with the fastest barchan dune movement south of Zaranj city. Sand dune celerity on the Helmand River right bank in the direction of flow is estimated to vary between 6.2 m/year to 103.1 m/year. The highest unit flux values of 250 m3/m/year occur in the lower Helmand basin. Much lower dune celerity values between 0.2 m/year to 2.9 m/year are calculated for the dune field on the left bank of the Arghandab and Dori rivers. The study also identifies the sensitive locations on the right bank of Helmand River in lower Helmand that may be used to plan sand dune stabilization measures such as mulching and Haloxylon species plantation that have been extensively practiced in the region.
... Even though the AP contributes substantially to global dust emissions, sources and transport pathways over the whole AP have not been systematically examined so far. While progress has been made to identify global-scale dust source regions (Ginoux et al., 2012;Prospero et al., 2002;Tanaka and Chiba, 2006;Varga, 2012;Washington et al., 2003), to the best of our knowledge, no previous study has identified the emission and transport pathways of dust storms over the whole AP. ...
... The tenth source is Wadi Langeb (18.5 • N, 38.5 • E) in the region of Tokar Delta and extends westward to the Nubian desert between the Nile River and the Red Sea (400,000 km 2 ). The alluvial deposits of the silt-laden Barka River are critical sources of dust storms into the direction of the Red Sea out toward the AP (Varga, 2012) and mainly affects Jeddah and its coastline, Saudi Arabia. The ninth and the tenth sources lie within the fourth (coastal of north of Africa) and the fifth (depression in north of Africa) wind paths that were identified by Cao (Cao et al., 2015). ...
... dried farms, wars) influences that can add to the disturbance of significant parts of desert surfaces, and as a result, new or enlarged 'hot spots' can be identified. Varga, 2012;Washington et al., 2003), to the best of our knowledge, no previous study has identified the emission and transport pathways of dust storms over the whole AP. To clarify, Ginoux et al. (2012) produced a global map of dust sources and identified the dust sources in the Middle East at large-scale; for instance, the Mesopotamia (source number 10 in Ginoux et al., 2012) covers the whole country of Iraq and very large part of Syria; however, in our source identification, we distinguished two separate sources within the Mesopotamia (Mesopotamia Iraq and Syria-Iraq border). ...
The Arabian Peninsula (AP), the largest peninsula in the world, contains ‘hot spot’ areas for intensive dust storms. Dust sources outside the AP can also represent ‘hot spots’ that heavily impact the AP. This study explores the source and transport pathways of severe dust storm events over the AP over nine years (2010–2018) using MODIS Aqua and Terra satellites (0.25–0.5 km/pxl resolution) combined with the HYSPLIT model and synoptic meteorology. The study identified ten dust source ‘hot spots’ that affect the AP; two are local (within the AP) and eight are regional (outside the AP). The identified local dust sources were (1) the Empty Quarter and (2) the Mesopotamian flood plain in southern Iraq, while the regional dust sources were (3) the Syria-Iraq border, (4) Hamun-e Jaz Murian, (5) Coastal desert of Iran, (6) Seistan basin ephemeral lakes, (7) Hamun-e Mashkel, (8) Thar desert of Rajasthan, (9) Nile River basin, and (10) Wadi Langeb Tokar Delta. To the best of our knowledge, this is the first study to investigate the emission and transport of dust storms over the AP at the local and regional/subcontinental levels using medium-high resolution remote sensing. This study has important implications for the international community and the multilateral environmental agreements related to desert dust.
... The heavy contribution of the deserts' dust to the global airborne particulates as well as numerous other effects of dust aerosol are very well documentable [17][18][19]; the effects become very dangerous to human health when the dust is characterized to the PM size [19]. ...
... Due to the dust belt [17] as well as meningitis belt [20] which keep expanding, Africa is one of the best research areas, while targeting the source of different sized particulate matter, PM (PM 1 ,PM 2.5 ,PM 10 ), which are classified under solid aerosols, and breathable air pollutants in particular [21]. ...
... With a reference to the World's Dust Belt [17], the heavily concentrated particulate matter in the west, north and central African sub-regions is attributed to the Sahara Desert, and this has nothing to do with the population. ...
The particulate matter (PM) directly endangers the human health. Remotely sensed tiny atmospheric particles, aerosols, are presented in this research as atmospheric air pollutants. Globally overviewed for the first instances, and then a focus put on Africa and Asia, the selected aerosols are fine particulates (PM2.5), black carbon (BC), and Sulfate (SO4). According to the existing literature, the motivation to research on air pollutants came from the fact that the polluted air globally kills many people, by attacking cardiovascular system. The online accessible remote sensing’s data has been mostly collected from the second version of modern era retrospective analysis for research and applications (MERRA-2), a model selected for its update as well as the fact that its data are directly assimilated from the most renown remote sensors: Moderate resolution Imaging Spectroradiometer (MODIS) and the advanced very high-resolution radiometer (AVHRR). MERRA-2 also compiles data from different aerosol robotic networks (AERONETs). With a vast region of interest, and considering the big temporal resolution, reduced spatio-temporal resolutions facilitated the focused research. Goddard interactive online visualization and analysis infrastructure (GIOVANNI) bridged our research objectives with the data; Geographical Information Systems (Arc GIS) is a main software tool. Map-based as well as time series results for PM2.5 and other atmospheric air pollutants are presented; health dangers associated with the dust from erstwhile research highlighted. Finding that the annually-averaged mass concentration of the dust’s PM2.5 is significantly greater than the mean recommended concentration, 25 μg/m3, in all the seasons of the center of the research region of interest (Africa), this research recommends further research on dust aerosols mitigation strategies, during the seasons of heaviest air pollutants in particular.
... The location of city centers with high population density relative to the source of fine dust and also the direction of the wind carrying large amounts of fine particles, pollutants, and biological materials for long distances are also important factors in the severity of dust effects (Prospero et al. 2002, Varga 2012, Washington et al. 2005. The nature of fine particles and their lightweight allow them to be carried hundreds of kilometers by the wind and affect areas far away from the source (Zhu et al. 2007). ...
In areas with relatively warm and dry climates, dust and sandstorms are important problems influencing the health of people and daily activities. In this study, biological stabilization is investigated as a method to prevent erosion of fine soil particles by the wind as a fine dust that is widely distributed in the atmosphere. For this purpose, 3 volumes of bacterial and cementation solutions, 10, 15, and 20 ml, were sprayed on the surface of soil samples. Treated samples were cured for 1, 4, 7, 14, and 28 days in the laboratory. In this study, Sporosarcina pasteurii bacteria formerly known as Bacillus pasteurii was used as the bio-agent. A wind tunnel was then used as apparatus to measure the resistance of the stabilized samples compared to untreated soil. Results showed an increase from roughly 350% on the first day to 2400% on the 28th day, in resistance against wind erosion for the stabilized samples compared to untreated samples, and therefore, biological stabilization is an appropriate alternative to improve soil resistance against wind erosion and reduce dust. The soil used in this study was sampled from Khuzestan province, which is the most important province involved in the issue of fine dust in Iran.
... TOMS and OMI TOMS-like AI measurement series have been used by several previous studies to identify dust events and source areas (e.g. Prospero et al., 2002;Washington et al., 2003;Gao and Washington, 2009;Gkikas et al., 2009Gkikas et al., , 2013Gkikas et al., , 2016Varga, 2012;Varga et al., 2013Varga et al., , 2014a. ...
Several billion tonnes of mineral dust is emitted, and transported through winds every year from arid-semiarid areas. North African dust hot spots located in the Sahara are responsible for 50–70% of the global mineral dust budget. Dust-loaded air-masses originated from these sources can be transported over long distances and can also affect remote areas, such as North and South Americas, Europe, and the Middle East.
In this study, we analysed 218 identified Saharan dust events (SDEs) in the Carpathian Basin (Central Europe) during 1979 to 2018. Systematic identification of SDEs and analyses of dust emission, dust source area activity, dust transporting wind systems, and transport routes revealed that different synoptic meteorological patterns are responsible for SDEs, and these are occurring mostly in spring and summer. The characteristic synoptic meteorological background of episodes was also identified, and three major types of atmospheric pressure-system patterns were distinguished.
In recent years, several intense wintertime dust deposition events have been recorded in Central Europe. All of the identified unusual episodes were characterised by severe washout of mineral dust material and were related to very similar synoptic meteorological situations. Enhanced southward propagation of a high-latitude upper-level atmospheric trough to north-western Africa and orographic blocking of Atlas Mountains played an essential role in the formation of severe dust storms, whereas the long-range transport was associated with the northward branch of the meandering jet. The occurrence and southerly penetration of high-latitude upper-level atmospheric trough to low-latitudes and the increased meridionality of the dominant flow patterns may be associated with enhanced warming of the Arctic, leading to more meandering jet streams.
Particles size of sampled dust material of some intense deposition episodes were very coarse with a considerable volumetric proportion of > 20 µm particles.
... Meanwhile, the vertical distributions of aerosol subtypes derived from CALIPSO observations in- Figure 1. The global aerosol index distribution and the dust belt location (dashed rectangle) as described in Varga (2012), and the geographical coverage of the NEC domain on the right. Dots in the NEC domain represent monitoring sites (Labels a-g indicate the monitoring sites at Tongliao, Changchun, Harbin, Shenyang, Jiamusi, Jinzhou, and Hulun Buir). ...
Mineral dust particles play an important role in the Earth system,
imposing a variety of effects on air quality, climate, human health, and
economy. Accurate forecasts of dust events are highly desirable to provide
an early warning and inform the decision-making process. East Asia is one of the largest
dust sources in the world. This study applies and evaluates four widely used
regional air quality models to simulate dust storms in northeastern China.
Three dust schemes in the Weather Research and Forecasting model with Chemistry
(WRF-Chem) (version 3.9.1), two schemes in both CHIMERE (version 2017r4) and CMAQ
(version 5.2.1), and one scheme in CAMx (version 6.50) were applied to a
dust event during 4–6 May 2015 in northeastern
China. Most of these models were able to capture this dust event with the exception of
CAMx, which has no dust source map covering the study area; hence, another
dust source mask map was introduced to replace the default one for the
subsequent simulation. Although these models reproduced the spatial pattern
of the dust plume, there were large discrepancies between predicted and
observed PM10 concentrations in each model. In general, CHIMERE had
relatively better performance among all simulations with default
configurations. After parameter tuning, WRF-Chem with the Air Force Weather Agency (AFWA) scheme using
a seasonal dust source map from Ginoux et al. (2012) showed the best
performance, followed by WRF-Chem with the UOC_Shao2004 scheme,
CHIMERE, and CMAQ. The performance of CAMx had significantly improved by
substituting the default dust map and removing the friction velocity
limitation. This study suggested that the dust source maps should be
carefully selected on a regional scale or replaced with a new one constructed
with local data. Moreover, further study and measurement of sandblasting
efficiency of different soil types and locations should be conducted to
improve the accuracy of estimated vertical dust fluxes in air quality models.
... Ginoux et al. (2012) were able to derive the global distribution of dust sources at 10 km resolution by counting the frequency of days marked by high dust optical depth (DOD) (Fig. 1). The Sahara and Sahel regions in Northern Africa are the most active dust sources in terms of emissions (790-840 million t/yr), followed by the Gobi and Taklamakan deserts in East Asia (140-220 million t/yr), the Middle East region (13-20 million t/yr), Central Asia, Eastern Australia, South America (Atacama) and South Africa (10-60 million t/yr each), and Southern US-Northern Mexico (2-60 million t/yr) (Prospero et al., 2002;Washington et al., 2003;Huneeus et al., 2011;Ginoux et al., 2010Ginoux et al., , 2012Varga, 2012). There are also other sparse sources of dust in different climatic regions, such as the active glacial outwash plains of Iceland and specific areas in Alaska, Spain and Turkey Ginoux et al., 2012). ...
We review the major features of desert dust outbreaks that are relevant to the assessment of dust impacts upon human health. Our ultimate goal is to provide scientific guidance for the acquisition of relevant population exposure information for epidemiological studies tackling the short and long term health effects of desert dust. We first describe the source regions and the typical levels of dust particles in regions close and far away from the source areas, along with their size, composition, and bio-aerosol load. We then describe the processes by which dust may become mixed with anthropogenic particulate matter (PM) and/or alter its load in receptor areas. Short term health effects are found during desert dust episodes in different regions of the world, but in a number of cases the results differ when it comes to associate the effects to the bulk PM, the desert dust-PM, or non-desert dust-PM. These differences are likely due to the different monitoring strategies applied in the epidemiological studies, and to the differences on atmospheric and emission (natural and anthropogenic) patterns of desert dust around the world. We finally propose methods to allow the discrimination of health effects by PM fraction during dust outbreaks, and a strategy to implement desert dust alert and monitoring systems for health studies and air quality management. Keywords: Mineral dust, Atmospheric particulate matter, Aerosols, Epidemiology, Natural and anthropogenic contributions
... Arid regions contribute very large loads to the global atmospheric aerosols, with around 1.5·10 9 tons/year of dust being emitted into the troposphere (Textor et al., 2006;Huneeus et al., 2011;Ginoux et al., 2012;Kok et al., 2017). Among these regions, N Africa (Sahara and Sahel) is the largest contributor, with almost 50% of the global dust emissions (around 0.8 10 9 tons/yr; Prospero et al., 2002;Washington et al., 2003;Walker et al., 2009;Ginoux et al., 2010Ginoux et al., , 2012Huneeus et al., 2011;Varga, 2012). ...
... Dust emitted in N Africa is significally transported towards the Caribbean region (Prospero et al., 2002;Prospero and Lamb, 2003;Ginoux et al., 2012; and references therein); however, under specific meteorological scenarios, dust is also transported towards continental Europe and the Mediterranean region (e.g., Moulin et al., 1997Moulin et al., , 1998Rodriguez et al., 2001;Escudero et al., 2005;Querol et al., 2009;Varga, 2012;Pey et al., 2013). Bergametti et al. (1989aBergametti et al. ( , 1989b, Dayan et al. (1991) and Kubilay and Saydam (1995) reported on the influence of African dust outbreaks (ADOs) on ambient levels of total suspended particles (TSP). ...
The 2001–2016 contribution of African dust outbreaks to ambient regional background PM10 and PM2.5 levels over Spain, as well as changes induced in the PMx composition over NE Spain in 2009–2016, were investigated. A clear decrease in PMx dust contributions from the Canary Islands to N Iberia was found. A parallel increase in the PM2.5/PM10 ratio (30% in the Canary Islands to 57% in NW Iberia) was evidenced, probably due to size segregation and the larger relative contribution of the local PMx with increasing distance from Africa.
PM1–10 and PM2.5–10 measured in Barcelona during African dust outbreaks (ADOs) were 43–46% higher compared to non-ADO days. The continental background contribution prevailed in terms of both PM1–10 and PM2.5–10 during ADO days (62 and 69%, respectively, and 31 and 27% for non-ADO days). The relative contributions of Al2O3/Fe2O3/CaO to PMx fraction showed that Al2O3 is a suitable tracer for African dust in our context; while CaO at the urban site is clearly affected by local resuspension, construction and road dust, and Fe2O3 by dust from vehicle brake discs. The results also provide evidence that PM increases during ADOs are caused not only by the mineral dust load, but by an increased accumulation of locally emitted or co-transported anthropogenic pollutants as compared with non-ADO days. Possible causes for this accumulation are discussed. We recommend that further epidemiological studies should explore independently the potential effects of mineral dust and the anthropogenic PM during ADOs, because, at least over SW Europe, not only mineral dust affects the air quality during African dust episodes.
... Northern China is located at the eastern part of the global dust belt [35] and includes various deserts and desertified areas [36,37], such as the Taklimakan desert in the west, Gobi desert in the mid-west between China and Mongolia, Horqin sandy land, and Hulun Buir sandy land in the east ( Figure 1). It has been defined as having a moderate and subtropical monsoon climate with prevailing westerly and northwesterly winds, which means that the dust emitted from these erodible areas often has a significant influence on large areas of China. ...
The accurate forecasting of dust emission and transport is a societal demand worldwide as dust pollution is part of many health, economic, and environment issues, which significantly impact sustainable development. The dust forecasting ability of present air quality forecast systems is mainly focused on spring dust events in East Asia, but further improvement may be needed as there is still difficulty in forecasting autumn dust activities, such as failing to predict the serious dust storm that occurred on 25 to 26 November 2018. In this study, a state-of-the-art air quality model, CHIMERE, with three coupled dust schemes was introduced for the first time to simulate the dust emissions during this event to qualitatively and quantitatively validate its dust simulating performance over Northern China. The model results reported that two of the three dust schemes were able to capture the dust emission source located in Gansu Province and reproduce the easterly dust transport path, showing moderately close agreement in the horizontal and vertical distribution patterns with the ground-based and satellite observations. The simulated PM10 concentration had a better relationship with the observed values with a correlation coefficient up to 0.96, while it was lower in the transported areas. Meanwhile, the simulations also presented incorrect dust emission positions such as in areas between the Hulun Buir sandy land and Horqin sandy land. Our results indicate that CHIMERE exhibits reasonably good performance regarding its dust simulation and forecast ability over this area, and its application would help to improve the dust analysis and forecast abilities in Northern China.
