Identification Of Dust Sources Research Articles

Identification of typical dust sources in Tarim Basin based on multi-wavelength Raman polarization lidar

Asian mineral dust is one of the main aerosol sources in the Earth–atmosphere system, which generates significant effect on air quality, human health, and climate change. Meanwhile, knowledge of vertical optical properties of dust aerosol is crucially needed for identification of the dust source and improved understanding of radiative effect in climate model. In the study, triple-wavelength polarization Raman lidar observation combined with photometer, radiosonde and simultaneous model data was performed at Kashi in the northwestern of Tarim Basin. Taklimakan desert, located in the center of Tarim Basin, is the largest desert of Asia. Base on the measurement and model, two typical dust sources in different altitude were identified in the study, namely Taklimakan desert (East Road), Central Asia desert and Middle East desert (West Road). Particle size distribution of photometer shows that these cases were all coarse-mode-dominated with effective radius larger than 1.7 μm. The lidar observations revealed particle linear depolarization ratios (PLDR) of the Taklimakan dust ranged from 0.28 to 0.34 at 355 nm, 0.33 to 0.35 at 532 nm and 0.29–0.35 at 1064 nm, while lidar ratios (LR) ranged from 47 to 54 sr at 355 nm and from 42 to 51 sr at 532 nm wavelength. Spectral variation of LR and PLDR for Asian dust and Saharan dust was analyzed. All observed Asian dust present the consistent spectral variation that lidar ratio at 355 nm is higher than that of 532 nm, which however is not the case for Saharan dust. Both Saharan and Asian dust measurement PLDR at 532 nm is larger than that of 355 nm and 1064 nm. The measured dust properties provide particularly valuable information for dust simulation and dust climate model for different dust source.

Characterization of Particulate Matter Generated at a Nickel Smelter Using Quantitative Mineralogy

Activities performed at mineral processing operations are capable of producing significant quantities of dust. To ensure that regulatory compliance is maintained throughout operation, dust levels are monitored by routine analysis of air filter samples. Determining the quantity and type of particulate matter present in dust allows for the operation to identify the sources of dust and where warranted, implement a dust suppressant strategy. Conventional methods of analysis, such as chemical assay, are unable to rigorously differentiate between phases containing the same elements and may result in ambiguity related to the identification of dust sources. By incorporating Quantitative Evaluation of Materials by Scanning Electron Microscope (QEMSCAN) into their routine monitoring programs, the Sudbury INO smelter has greatly improved characterization of the Ni and Co dust emissions generated at the operation. To determine specific activities responsible for emissions, bulk particulate matter was sampled from several key locations at the smelter that regularly produce dust. QEMSCAN was able to distinguish between critical subspecies of Ni and Co and mineralogical, and chemical signatures in the dust that are representative of locational activity were established. An apportionment of elements contributed by each source was calculated based on this information. The results of the characterization study assisted personnel in developing strategies to mitigate dust emissions that originate from the Smelter operations, and have general implications to occupational hygiene and environmental risk assessment.

Identification of dust sources in a dust hot-spot area in Iran using multi-spectral Sentinel 2 data and deep learning artificial intelligence machine

The drying of wetlands in Iran due to climate change and indiscriminate human activities has increased dust production. Dust storms have become a major problem in arid and semi-arid regions and cause adverse social, economic, and environmental effects. The Jazmurian wetland in Kerman Province is one such area. To identify dust sources in the Jazmurian basin, high resolution Sentinel 2 data were used. From these, sediment supply was mapped. Three artificially intelligent algorithms—artificial neural network (ANN), support vector machine (SVM), and deep-learning neural network (DLNN)—were used to model dust-production potential in the study area. The results show that portions of the Jazmurian basin that have dried up in recent years have a very high potential for dust production. Evaluation of the models’ performances using area-under-curve (AUC) statistics revealed that the DLNN model is more efficient (AUC = 0.97) than either the ANN (AUC = 0.91) or SVM (AUC = 0.92). All three models reveal that NDVI, elevation, annual rainfall, and windspeed are the four most important factors influencing dust-production potential in the study area. This remote sensing-artificial intelligence framework should be tested for mapping dust-production potential in other regions as this study demonstrates highly accurate, high-resolution results. This study yielded fundamental information to identify locations in need of desertification management and mitigation of dust production in the Jazmurian basin.

Anthropogenic Sources Dominate Foliar Chromium Dust Deposition in a Mining-Based Urban Region of South Africa.

Dust pollution can be severe in urban centers near mines and smelters. Identification of dust sources and assessing dust capturing plant morphological traits may help address the problem. A chromium (Cr) mining and ferrochrome smelting region in Sekhukhuneland, South Africa, was investigated to identify the sources of Cr in soil and plant leaf surfaces and to evaluate the association between Cr sources and plant morphology. Combinations of bi- and multivariate statistical analysis techniques were applied. Non-significant relation between Cr quantities in surface soil and on leaf surfaces suggested negligible Cr dust contribution from soil to leaves. Association among Cr, Fe, Mg, Al, and Si levels on leaf surfaces confirmed their shared origin, possibly from chromite containing dust dispersed by mines, smelters, roads, and tailings. Both plant morphology and Cr sources (number and proximity to mines and roads) conjointly determined Cr dust deposition on leaf surfaces. Air mass movement patterns further identified local polluters, i.e., mines, ferrochrome smelters, and roads, as dominant dust sources in the region. Common plant species showed Cr dust adhesion favouring traits (plant tallness, larger leaf area, dense epicuticular wax structures, and larger stomata) and projected dust mitigation prospects for Sekhukhuneland.

Identification of Dust Sources and Storms in the South of Kerman Province Using Remote Sensing Data

Identification of Dust Sources and Storms in the South of Kerman Province Using Remote Sensing Data

Weakened dust activity over China and Mongolia from 2001 to 2020 associated with climate change and land-use management

Dust cycle is actively involved in the Earth’s climate and environmental systems. However, the spatiotemporal pattern and recent trend of dust emission from the drylands in East Asia remain unclear. By calculating dust aerosol optical depth (DOD) from the newly released moderate resolution imaging spectrometer aerosol products, we obtain a relatively long satellite-based time series of dust activity from 2001 to 2020 over China and Mongolia. We identify pronounced interannual variability of dust activity that is consistent with ground-based meteorological observations in the study area. A substantial reduction in spring dust activity in northern China is also found, which seems in accordance with the long-term weakening trend since the 1970s that has been attributed to the wind speed decline by previous studies. However, the spatial pattern of the trends in both annual mean and seasonal dust activity during the last 20 years is divergent, and the most significant dust diminishing is found over north-central China where large-scale vegetation restoration projects have been implemented. It indicates that in addition to the potential contribution of wind speed change, land-use change also plays an important role in the recent inhibition of dust emission. The current results show that dust activity occurs most intensively in spring, followed by summer and relatively weaker in autumn and winter. However, dust activity in autumn and winter has increased significantly in NW China despite the overall decreasing trend in other two seasons, probably associated with different seasonal atmospheric and land surface conditions. Finally, the DOD distribution reveals that the Tarim Basin, Gobi and Qaidam Basin Deserts are three major dust sources in East Asia. Compared to ground observations which are spatially limited and distributed unevenly, remote sensing provides an important complement, and it can serve as reference for identification of dust sources using other methods such as geochemical fingerprint and modeling.

Application of positive matrix factorization and pollutants tracing for identification of dust sources: A case study in Khuzestan, Iran

In this study for identification of internal and external origins of dust events in the southwest of Iran, for the first time, a comprehensive dust sampling was performed in nine regions of Khuzestan over the four seasons. The dust samples were analyzed using INAA nuclear technique. Factors obtained from applying the PMF Modeling indicated five kinds of pollutant sources which include 1) Sedimentary surface soil/dried bed of wetlands, 2) steel and metalworking industries, 3) refineries, 4) waste, and 5) solid fuel as well as oil fuel power plants. These identified sources were used as the tracers to identify the internal dust sources. Investigation of NASA AOT images and the synoptic data at the event dates showed that in the period of mid-autumn up to the early winter, dust events had external origins, that are mainly situated in Iraq and Saudi Arabia, while in the period of mid-summer to early autumn and mid-winter up to the early spring, the internal sources such as mud-salt zones or areas with fine sediments with evaporitic deposits and puffy grounds in the regions between Omidieh - Mahshahr, south, and southeast of Ahvaz, “Dasht-E-Azadegan,” and dried bed of Hoor-Al-Azim are more dominant.

Characteristics of dust aerosols and identification of dust sources in Xinjiang, China

Changes in atmospheric particulate matter content directly affect the Earth-atmosphere system balance and climate change and indirectly affect the environment and ecology. Therefore, this matter is receiving increasing attention. A typical arid area with a fragile ecological environment and frequent dust activities, Xinjiang, China, was investigated using Moderate Resolution Imaging Spectroradiometer (MODIS) daily aerosol optical thickness and Ångström wavelength exponent data to obtain the temporal and spatial distribution characteristics of long-term dust aerosols over 20 years. The frequency of occurrence was calculated to accurately identify anthropogenic and natural sources, and data, such as wind speed, were superimposed to quantitatively estimate dust aerosol emissions. The factors that influenced dust aerosol emissions are discussed. The results show that the distribution of dust aerosols in South and North Xinjiang is obviously different, and the average dust aerosol optical depth (DOD) in spring is higher than that in other seasons. The sources of natural dust have little variation and are primarily located in Lop Nur, on the edges of the Taklamakan and Gurbantunggut deserts, in the central Tuha Basin, and in dried-up lakes. The sources of anthropogenic dust are mainly distributed in the farmland areas of the oasis plain and the impact fan plain. Natural dust aerosols are dominant in Xinjiang, with high natural dust emissions in spring. Changes in anthropogenic dust aerosols are caused by production activities, and the annual average anthropogenic dust emissions account for 8% of the total dust emissions. Precipitation can promote a reduction in natural dust emissions. Topography has an obvious effect on the formation and transportation of dust aerosols, which manifests as the frequent occurrence of dust in the basin. The population density data and Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime light data reveal, that the intensity of human activities has a great impact on anthropogenic dust aerosols. This study provides support for research on how aerosols affect climate and environmental changes in Xinjiang.

The Use of Aerosol Optical Properties in Identification of Dust Sources in Iraq

In recent years, dust events in Iraq become very frequent due to its emission from active local dust sources or transportation from abroad. This study aims to identify dust sources in Iraq for the period (1st January, 2005 to 31 December, 2016) using mean of monthly mean of the aerosol optical properties including Deep Blue Aerosol Optical Depth(DB-AOD), Deep Blue Angstrom Exponent(DB-AE) and UV Positive Absorption Aerosol Index(AAI) acquired from space borne instruments including MODerate resolution Imaging Spectroradiometer (MODIS) for both Aqua and Terra, Multiangle Imaging SpectroRadiometer (MISR) and Ozone Monitoring Instrument (OMI), considering the dust aerosols having values of AOD>0.5, AE<0.5 and AI>0.7 based on the predefined thresholds. The results show that Al-Jazira and the southern region of Iraq considered as significant dust sources most of the year, with the absence of active dust sources in December, January, October and November. While spring and summer months show many active dust sources in the Alluvial plain, western plateau, southern and southeastern parts of Iraq with high AOD, low AE and high AAI especially in April, May, June and July. MISR/AOD shows lower values of MODIS-DB in Iraq along months of the years, which could be due to the insufficient coverage over dust regional sources compared to MODIS.

Geochemical characterization of modern aeolian dust over the Northeastern Arabian Sea: Implication for dust transport in the Arabian Sea

The Arabian Sea, one of the most biologically productive oceanic regions, receive significant amount of nutrients through aeolian dust deposition which have potential to modulate surface water biogeochemical processes. Identification of dust sources is important to assess role of dust deposition to surface water biogeochemistry. Here we report geochemical characteristics (major elements and trace metals composition, clay mineralogy and radiogenic isotopes of Sr and Nd) of aeolian dust, derived from dust storms in Middle East and South West Asia, to decipher its sources and possible transport pathways over the Arabian Sea. Twelve bulk aerosol samples were collected, during dusty period, at a coastal station (Goa; 15.4o N, 73.8o E) located in the Northeastern Arabian Sea, spanning over three years in different seasons. A preliminary estimation of sources for dust storms was done using satellite imagery and air mass back trajectory analyses. Major element and trace metal compositions of storm derived dust samples indicate insignificant contribution from anthropogenic sources. Illite and chlorite are major clay minerals found in all dust samples, however, high palygorskite content were observed for dust sourced from the Arabian Peninsula. A more uniform Sr-Nd signature is found for those derived from Arabia, however, highly variable Sr-Nd isotope signatures were observed for those derived from the South West Asia (Iran and Makran coast). The reported comprehensive data set on geochemical characteristics of mineral dust, is the first attempt that provides important information to understand present and past dust emission and deposition over the Arabian Sea.

Identification of dust sources using long term satellite and climatic data: A case study of Tigris and Euphrates basin

Dust storms are considered as one of the most important environmental challenges in the West Asia region. In addition to the harmful impacts of dust storms on human health, they also have particular effects on socioeconomic and agroecological domains of human communities. Identify the sources of dust storms is the first step to combat against these devastating phenomena. Accordingly, the present study was conducted to determine dust sources of the Tigris and Euphrates basin using satellite and climatic data. Monthly LST and NDVI of MODIS, monthly wind speed, soil moisture, and absolute air humidity data from GLDAS, monthly TRMM precipitation, and soil texture data of FAO were used. The Analytic Hierarchy Process (AHP) model was applied to determine the weights of the collected data (i.e. criteria or drivers for dust storms formation). Susceptible Areas to Dust Storm Formation (SADSF) were determined using the Weighted Linear Combination (WLC) model for months of June, July, and August from 2000 to 2017. After performing SADSF analysis, five main dust sources were identified in the whole basin. To evaluate the accuracy of the results, the number of real Observed Dust Storms (ODS) in each source was compared to the repetition of allocation in SADSF for each pixel over the 18-year period of this study from 2000 to 2017. Results indicated that the area of SADSF has significantly grown for all three months since 2008. The areas of SADSF in June and July were almost the same, while they were significantly bigger than August. Among identified dust sources, the highest SADSF repetition was in the northwest of Iraq followed by eastern Syria, southern Iraq, southeast border of Iraq, and east border of Iraq, respectively. The correlation coefficient between the SADSF repetition with the number of ODS events in those recognized dust sources was equal to 0.88, 0.76, and 0.74 for June, July, and August, respectively, that shows the accuracy of our results in comparison to actual data.

Assessing Landscape Dust Emission Potential Using Combined Ground‐Based Measurements and Remote Sensing Data

AbstractModeled estimates of eolian dust emission can vary by an order of magnitude due to the spatiotemporal heterogeneity of emissions. To better constrain location and magnitude of emissions, a surface erodibility factor is typically employed in models. Several landscape‐scale schemes representing surface dust emission potential for use in models have recently been proposed, but validation of such schemes has only been attempted indirectly with medium‐resolution remote sensing of mineral aerosol loadings and high‐resolution land surface mapping. In this study, we used dust emission source points identified in Namibia with Landsat imagery together with field‐based dust emission measurements using a Portable In‐situ Wind Erosion Laboratory wind tunnel to assess the performance of schemes aiming to represent erodibility in global dust cycle modeling. From analyses of the surface and samples taken at the time of wind tunnel testing, a Boosted Regression Tree analysis identified the significant factors controlling erodibility based on Portable In‐situ Wind Erosion Laboratory dust flux measurements and various surface characteristics, such as soil moisture, particle size, crusting degree, and mineralogy. Despite recent attention to improving the characterization of surface dust emission potential, our assessment indicates a high level of variability in the measured fluxes within similar geomorphologic classes. This variability poses challenges to dust modeling attempts based on geomorphology and/or spectral‐defined classes. Our approach using high‐resolution identification of dust sources to guide ground‐based testing of emissivity offers a valuable means to help constrain and validate dust emission schemes. Detailed determination of the relative strength of factors controlling emission can provide further improvement to regional and global dust cycle modeling.

Identification of Dust Sources in a Saharan Dust Hot-Spot and Their Implementation in a Dust-Emission Model

Although mineral dust plays a key role in the Earth’s climate system and in climate and weather prediction, models still have difficulties in predicting the amount and distribution of mineral dust in the atmosphere. One reason for this is the limited understanding of the distribution of dust sources and their behavior with respect to their spatiotemporal variability in activity. For a better estimation of the atmospheric dust load, this paper presents an approach to localize dust sources and thereby estimate the sediment supply for a study area centered on the Aïr Massif in Niger with a north–south extent of 16 ∘ –22 ∘ N and an east–west extent of 4 ∘ –12 ∘ E. This approach uses optical Sentinel-2 data at visible and near infrared wavelengths together with HydroSHEDS flow accumulation data to localize ephemeral riverbeds. Visible channels from Sentinel-2 data are used to detect sand sheets and dunes. The identified sediment supply map was compared to the dust source activation frequency derived from the analysis of Desert-Dust-RGB imagery from the Meteosat Second Generation series of satellites. This comparison reveals the strong connection between dust activity, prevailing meteorology and sediment supply. In a second step, the sediment supply information was implemented in a dust-emission model. The simulated emission flux shows how much the model results benefit from the updated sediment supply information in localizing the main dust sources and in retrieving the seasonality of dust activity from these sources. The described approach to characterize dust sources can be implemented in other regional model studies, or even globally, and can thereby help to get a more accurate picture of dust source distribution and a more realistic estimation of the atmospheric dust load.

Geomorphic and land cover identification of dust sources in the eastern Great Basin of Utah, U.S.A.

This study identifies anthropogenically disturbed areas and barren playa surfaces as the two primary dust source types that repeatedly contribute to dust storm events in the eastern Great Basin of western Utah, U.S.A. This semi-arid desert region is an important contributor to dust production in North America, with this study being the first to specifically identify and characterize regional dust sources. From 2004 to 2010, a total of 51dust event days (DEDs) affected the air quality in Salt Lake City, UT. MODIS satellite imagery during 16 of these DEDs was analyzed to identify dust plumes, and assess the characteristics of dust source areas. A total of 168 plumes were identified, and showed mobilization of dust from Quaternary deposits located within the Bonneville Basin. This analysis identifies 4 major and 5 secondary source areas for dust in this region, which produce dust primarily during the spring and fall months and during moderate or greater drought conditions, with a Palmer Drought Index (PDI) of −2 or less. The largest number of observed dust plumes (~60% of all plumes) originated from playas (ephemeral lakes) and are classified as barren land cover with a silty clay soil sediment surface. Playa surfaces in this region undergo numerous recurrent anthropogenic disturbances, including military operations and anthropogenic water withdrawal. Anthropogenic disturbance is necessary to produce dust from the vegetated landscape in the eastern Great Basin, as evidenced by the new dust source active from 2008 to 2010 in the area burned by the 2007 Milford Flat Fire; this fire was the largest in Utah's history due to extensive cover of invasive cheatgrass (Bromus tectorum) along with drought conditions. However, dust mobilization from the Milford Flat Burned Area was limited to regions that had been significantly disturbed by post-fire land management techniques that consisted of seeding, followed by chaining or tilling of the soil. Dust storms in the eastern Great Basin negatively impact air quality and transportation in the populated regions of Utah; this study details an improved forecasting protocol for dust storm events that will benefit transportation planning and improve public health.

Characterization of the composition of dust fallout and identification of dust sources in arid and semiarid North China

A source analysis to characterize the composition of dust fallout in arid and semiarid North China, an important source area of dust for East Asia, was performed. Monthly samples were obtained from April 2001 to March 2002 at 29 sites in sandy and gobi deserts, steppes, and loess areas, and the following elements were analyzed: Ce, Co, Cs, Eu, Fe, Hf, Lu, Nd, Rb, Sc, Ta, Tb, Th, As, La, Na, Sb, Sm, U, Yb, Al, Ca, Mg, Mn, Ti, and V. Although the dust compositions differed, it was difficult to determine the potential dust source areas based solely on the elemental fingerprints of the dust. Principal components analysis showed that at most sites Sm, Sc, La, Ce, Eu, and Th were most strongly correlated ( r > 0.7) with other elements, whereas crustal elements such as Al, Fe, and Ti were only strongly correlated with the other elements at a few sites. Of the 26 elements that we analyzed, maybe only Sb was representative of anthropogenic pollution, but pollutant sources were unclear because at most sites, in different months, the crustal-derived elements and those derived from anthropogenic pollutants always appeared synchronously, creating difficulties and high uncertainties in source identification.

Grain size effect on Sr and Nd isotopic compositions in eolian dust: Implications for tracing dust provenance and Nd model age

Strontium (Sr) and neodymium (Nd) isotopic compositions enable identification of dust sources and reconstruction of atmospheric dispersal pathways. The Sr and Nd isotopic compositions in eolian dust change systematically with grain size in ways not yet fully understood. This study demonstrates the grain size effect on the Sr and Nd isotopic compositions in loess and 2006 dust fall, based on analyses of seven separated grain size fractions. The analytical results indicate that Sr isotopic ratios strongly depend on the grain size fractions in samples from all types of eolian dust. In contrast, the Nd isotopic ratios exhibit little variation in loess, although they vary significantly with grain size in samples from a 2006 dust fall. Furthermore, Nd model ages tend to increase with increasing grain size in samples from all types of eolian dust. Comparatively, Sr isotopic compositions exhibit high sensitively to wind sorting, while Nd isotopic compositions show greater sensitively to dust origin. The principal cause for the different patterns of Sr and Nd isotopic composition variability with grain size appears related to the different geochemical behaviors between rubidium (Rb) and Sr, and the similar geochemical behaviors between samarium (Sm) and Nd. The Nd isotope data indicate that the various grain size fractions in loess have similar origins for each sample. In contrast, various provenance components may separate into different grain size fractions for the studied 2006 dust fall. The Sr and Nd isotope compositions further confirm that the 2006 dust fall and Pleistocene loess in Beijing have different sources. The loess deposits found in Beijing and those found on the Chinese Loess Plateau also derive from different sources. Variations between Sr and Nd isotopic compositions and Nd model ages with grain size need to be considered when directly comparing analyses of eolian dust of different grain size.

The transport history of two Saharan dust events archived in an Alpine ice core

Abstract. Mineral dust from the Saharan desert can be transported across the Mediterranean towards the Alpine region several times a year. When coinciding with snowfall, the dust can be deposited on Alpine glaciers and then appears as yellow or red layers in ice cores. Two such significant dust events were identified in an ice core drilled at the high-accumulation site Piz Zupó in the Swiss Alps (46°22' N, 9°55' E, 3850 m a.s.l.). From stable oxygen isotopes and major ion concentrations, the events were approximately dated as October and March 2000. In order to link the dust record in the ice core to the meteorological situation that led to the dust events, a novel methodology based on back-trajectory analysis was developed. It allowed the detailed analysis of the specific meteorologic flow evolution that was associated with Saharan dust transport into the Alps, and the identification of dust sources, atmospheric transport paths, and wet deposition periods for both dust events. Differences in the chemical signature of the two dust events were interpreted with respect to contributions from the dust sources and aerosol scavenging during the transport. For the October event, the trajectory analysis indicated that dust deposition took place during 13–15 October 2000. Mobilisation areas of dust were mainly identified in the Algerian and Libyan deserts. A combination of an upper-level potential vorticity streamer and a midlevel jet across Algeria first brought moist Atlantic air and later mixed air from the tropics and Saharan desert across the Mediterranean towards the Alps. The March event consisted of two different deposition phases which took place during 17–19 and 23–25 March 2000. The first phase was associated with an exceptional transport pathway past Iceland and towards the Alps from northerly directions. The second phase was similar to the October event. A significant peak of methanesulphonic acid associated with the March dust event was most likely caused by incorporation of biogenic aerosol while passing through the marine boundary layer of the western Mediterranean during a local phytoplankton bloom. From this study, we conclude that for a detailed understanding of the chemical signal recorded in dust events at Piz Zupó, it is essential to consider the whole transport sequence of mineral aerosol, consisting of dust mobilisation, transport, and deposition at the glacier.