High Dust Emission Research Articles

Assessment of dust emissions and their controlling factors on the Hoh Xil, north-central part of the Qinghai-Tibetan plateau

Dust emissions can lead to a series of environmental hazards and are thus a global concern. However, due to the difficulties of dust source identification, there are still great uncertainties in the calculation of dust yield on a global scale. The Qinghai-Tibetan Plateau presents some challenges for understanding the region's calculation of the global dust budget. To address these issues, the Hoh Xil Plateau, a typical dust source on the Qinghai-Tibetan Plateau, was selected as the study area for analyzing dust emission processes and associated influencing factors via a robust model. The results showed that dust emissions on the Hoh Xil Plateau occurred mainly in spring and winter. The wide distribution of bare land and sandy land on the Hoh Xil Plateau is the main reason for the high dust emissions. Wind speed is the dominant factor influencing annual dust emission, while precipitation and temperature were negatively correlated with the dust emission. The recession of expansive lakes in the region resulted in an increase in sandy lake-shores, which induced a potential increase in dust emissions. In addition, the effects of human activities on dust emissions were evident. Positive and negative effects on dust emission changes coexisted on the Hoh Xil Plateau and depended on the development of the county-level economy and the implementation of ecological engineering measures. We believe that this study will clarify the dust yield of the Qinghai-Tibetan Plateau and provide valuable information for understanding the driving factors that cause variations in aeolian processes on the Qinghai-Tibetan Plateau.

An Investigation on the Relationship between Dust Emission and Air Flow as Well as Particle Size with a Novel Containment Two-Chamber Setup.

In the present study with a novel two-chamber setup (TCS) for dustiness investigations, the relationship between pressure differences as well as air velocities and the resulting dust emissions is investigated. The dust emissions of six particle size fractions of acetaminophen at pressure differences between 0 and 12 Pa are examined. The results show that both simulated and measured air velocities increase with increasing pressure difference. Dust emissions decrease significantly with increasing pressure difference and air velocity. Fine particles cause higher dust emissions than coarse particles. A high goodness of fit is obtained with exponential and quadratic functions to describe the relationship between pressure difference and dust emission, indicating that even moderate increases in pressure may lead to a reduction in the emission. Average air velocities within the TCS simulated with Computational Fluid Dynamics are between 0.09 and 0.37 m/s, whereas those measured experimentally are between 0.09 and 0.41 m/s, both ranges corresponding to the recommended values for effective particle separation in containment systems. These results underline the ability of the novel TCS to control pressure and airflow, which is essential for reliable dust emission measurements and thus provide support for further scientific and industrial applications.

The emission, transport, and impacts of the extreme Saharan dust storm of 2015

Abstract. ​​​​​​​Each summer, the Saharan Air Layer (SAL) transports massive amounts of mineral dust across the Atlantic Ocean, affecting weather, climate, and public health over large areas. Despite the considerable impacts of African dust, the causes and impacts of extreme trans-Atlantic African dust events are not fully understood. The “Godzilla” trans-Atlantic dust event of 2020 has been extensively studied, but little is known about other similar events. Here, we examine the June 2015 event, the second strongest trans-Atlantic African dust event that occurred during the summers from 2003–2022. This event was characterized by moderately high dust emissions over western North Africa and an extremely high aerosol optical depth (AOD) over the tropical North Atlantic. The high dust loading over the Atlantic is associated with atmospheric circulation extremes similar to the Godzilla event. Both the African easterly jet (AEJ) and Caribbean low-level jet (CLLJ) have greatly intensified, along with a westward extension of the North Atlantic subtropical high (NASH), all of which favor the westward transport of African dust. The enhanced dust emissions are related to anomalously strong surface winds in dust source regions and reduced vegetation density and soil moisture across the northern Sahel. The dust plume reduced net surface shortwave radiation over the eastern tropical North Atlantic by about 25 W m−2 but increased net longwave flux by about 3 W m−2. In contrast to the Godzilla event, the 2015 event had minor air quality impacts on the US, partially due to the extremely intensified CLLJ that dispersed the dust plume towards the Pacific.

Predicting the Radiation Field of Molecular Clouds Using Denoising Diffusion Probabilistic Models

Accurately quantifying the impact of radiation feedback in star formation is challenging. To address this complex problem, we employ deep-learning techniques known as denoising diffusion probabilistic models (DDPMs) to predict the interstellar radiation field (ISRF) strength based on three-band dust emission at 4.5, 24, and 250 μm. We adopt magnetohydrodynamic simulations from the STARFORGE project that model star formation and giant molecular cloud (GMC) evolution. We generate synthetic dust emission maps matching observed spectral energy distributions in the Monoceros R2 (MonR2) GMC. We train DDPMs to estimate the ISRF using synthetic three-band dust emission. The dispersion between the predictions and true values is within a factor of 0.1 for the test set. We extended our assessment of the diffusion model to include new simulations with varying physical parameters. While there is a consistent offset observed in these out-of-distribution simulations, the model effectively constrains the relative intensity to within a factor of 2. Meanwhile, our analysis reveals a weak correlation between the ISRF solely derived from dust temperature and the actual ISRF. We apply our trained model to predict the ISRF in MonR2, revealing a correspondence between intense ISRF, bright sources, and high dust emission, confirming the model’s ability to capture ISRF variations. Our model robustly predicts radiation feedback distribution, even in complex, poorly constrained ISRF environments like those influenced by nearby star clusters. However, precise ISRF predictions require an accurate training data set mirroring the target molecular cloud’s unique physical conditions.

A review on sustainable utilization of red mud based photocatalytic material for environmental pollution abetment

The inventory of the solid waste produced from Aluminium industries (Bauxite Residue) otherwise called red mud stands at an estimated amount of 4 billion tons globally owing to its current generation. So, to reduce the impact on environment, its safe disposal is posing a great threat to eco-friendly atmosphere and its utilization is must for environmental sustainability. High alkalinity nature and airborne dust emissions may posse threat to flora and fauna, but the mineral composition of red mud and red mud derived products found to be a promising material for the utilization in the field of environmental pollution remediation. The high content of largely inert components such as hematite that can be extracted and gives credibility to the idea that red mud can be used as a potential candidate in the field of photo catalysis. This review explores novel methods for treating red mud and extracting minerals, not only provide value to waste but also demonstrated reduced red mud can be used as effective catalyst in environmental abatement. Modification of red mud, extraction of valuable iron oxides creates a novel opportunity for efficient removal of toxic metals, dyes, inorganic and organic pollutants in the cost-effective method and maintains sustainability.

Risk Assessment of Respirable Dust Exposure to Workers in the Mineral Ore Processing Industry

Introduction: The mineral ore processing industry is a sector that can generate pollutants in the form of dust during the production, commonly known as respirable dust. This dust can enter the upper respiratory tract and lungs, thereby causing health problems to employees working in the mineral ore processing industry. This study aims to investigate health risks associated with exposure to dust in the mineral ore processing industry. Methods: Environmental Health Risk Analysis (EHRA) was used to assess dust exposure over the previous three years, following the NIOSH Manual of Analytical Methods (NMAM) 0600 for dust sampling measurement. Results: Seven locations with high dust emissions were considered for this study. The results of the respirable dust sampling showed that the concentrations in the previous three years ranged from 1,823 to 6,109 mg/m3, followed by a decrease in the following year to 0.049 to 2,715 mg/m3. Meanwhile, in the final year, the concentration of respirable dust ranged from 0.094 to 1.341 mg/m3. The calculated risk quotient (RQ) value for the previous three years remained below 1, indicating safety. Conclusion: Athough respirable dust was considered safe in the previous year, it is important to constantly control exposure due to continued high levels and the possibility of future increases

Estimates of Dust Emissions and Organic Carbon Losses Induced by Wind Erosion in Farmland Worldwide from 2017 to 2021

Wind erosion can cause high dust emissions from agricultural land and can lead to a significant loss of carbon and nutrients from the soil. The carbon balance of farmland soil is an integral part of the carbon cycle, especially under the current drive to develop carbon-neutral practices. However, the amount of global carbon lost due to the wind erosion of farmland is unknown. In this study, global farmland dust emissions were estimated from a dust emission inventory (0.1° × 0.1°, daily) built using the improved Community Multiscale Air Quality Modeling System–FENGSHA (CMAQ-FENGSHA), and global farmland organic carbon losses were estimated by combining this with global soil organic carbon concentration data. The average global annual dust emissions from agricultural land from 2017 to 2021 were 1.75 × 109 g/s. Global dust emissions from agricultural land are concentrated in the UK, Ukraine, and Russia in Europe; in southern Canada and the central US in North America; in the area around Buenos Aires, the capital of Argentina, in South America; and in northeast China in Asia. The global average annual organic carbon loss from agricultural land was 2970 Gg for 2017–2021. The spatial distribution of emissions is roughly consistent with that of dust emissions, which are mainly concentrated in the world’s four major black soil regions. These estimates of dust and organic carbon losses from agricultural land are essential references that can inform the global responses to the carbon cycle, dust emissions, and black soil conservation.

Gaseous and particulate matter emissions from the combustion of biomass-based insulation materials at end-of-life in a small-scale biomass heating boiler

To alleviate the unbearable pressure on forests in Europe, the use of lower quality woody materials or wastes and agricultural fuels is emerging for the production of heat. The two major challenges of using these types of fuels are associated with the chemical composition variability and some fuel characteristics that could trigger potential issues throughout the burning process. This study aimed to investigate the environmental and technical performance of a small-scale multi-fuel biomass heating boiler (20 kW) fired with DINplus certified wood pellets and two granulated biomass-based insulation materials, namely hemp fibers and wood fibers under standard laboratory conditions. The boiler efficiency, particulate matter, and gaseous emissions were evaluated and compared to the legally permissible values specified in EN 303–5:2021. Hemp fiber pellets fulfilled the requirements for residential pellets, while wood fiber pellets showed lower durability and higher nitrogen and sulfur contents than the European standard limits. To respect the emissions regulation, blending wood fibers with certified wood is therefore necessary. Pellets type was noticed to significantly affect the gaseous and dust emissions but marginally the boiler efficiency. This latter was near 80 % for all fuels owing to high sensible and latent heat losses. Hemp fiber pellets showed high CO and dust emissions attributed to their high bulk density and high ash content, respectively, while the wood fiber pellets showed high NOx and SOx emissions accredited to their elemental composition. Gaseous and dust emissions were reduced through the blending of hemp and wood fibers with certified wood pellets. The particulate mass concentrations of the tested pellets fluctuated between 38 and 360 mg.Nm−3. Particulates were mainly composed of potassium, chlorine, sulfur, silicate, calcium, and zinc. From a number perspective, particles with diameters below 1 µm were dominant and their concentration varied between 104 and 106 particles.cm−3. Pelletized biomass-based insulation materials mixed with certified wood could be considered an attractive alternative fuel for residential biomass boilers.

Eurasian Ice Sheet derived meltwater pulses and their role in driving atmospheric dust activity: Late Quaternary loess sources in SE England

The role of Quaternary ice sheet fluctuations in driving meltwater pulses and ocean circulation perturbations is widely acknowledged. What is less clear is the role of these processes in driving changes in past atmospheric dust activity, and possible wider links between dust and climate. Terrestrial windblown dust (loess) deposits along the northern fringe of the European loess belt potentially record past atmospheric dust emission from regions close to the former Eurasian Ice Sheet (EIS) and provide a means to evaluate the role of ice sheet fluctuations in the past dust cycle. Numerical loess chronologies across this region generally agree on greatly enhanced dust deposition rates during MIS 2, when the EIS reached its maximum extent. Yet, uncertainties over the sources of this material prevent understanding of the precise causes of this greatly enhanced atmospheric dustiness, and any potential link to ice sheet fluctuations and climate. In southeast England, loess accumulation dominantly occurred in two phases centered on 25–23.5 ka and 20–19 ka, matching the timing of coalescence of the Fennoscandian and British-Irish ice sheets and specifically advances and retreats of nearby ice lobes in the western North Sea. As such, these deposits provide an ideal test of the role of ice sheet fluctuations in atmospheric dust dynamics. Here we undertake such a test through a detailed provenance study of loess in southeast England and potential dust source sediments across the North Sea region. We group extensive new and published data sets of detrital zircon U–Pb ages from basement rocks and Cenozoic sediments in the North Sea area, which not only provide new insight into both loess source, but also the nature of sediment transport over NW Europe into the North Sea basin more widely. Multi-proxy evidence allows us to unambiguously identify ice sheet derived sediments in the exposed North Sea basin as the dominant source of loess in southeast England, while fluvial sediments delivered by rivers draining Continental Europe possibly contributed additional source material to the first loess accumulation phase. We propose that sudden retreats of the North Sea Lobe released substantial amounts of sediment rich meltwater into the southern North Sea and Channel basins, driving accelerated dust emission, loess deposition and provenance variability in NW Europe during MIS 2. Moreover, we propose that this model of dust activity driven by proglacial sediment availability may be applicable for EIS marginal regions more widely, even where resultant loess cover is rarely preserved due to extensive erosion and reworking along the ice marginal spillway. This implies the role of ice sheets in controlling wider dust emission may be underestimated. In addition to driving changes in ocean circulation through meltwater pulses, ice sheet dynamics in the Quaternary may have also driven substantial and abrupt changes in atmospheric dust activity. This mechanism may in part explain the coupling between dust and climate events widely seen in Quaternary dust sediment records and suggests a possible major role of high latitude dust emission in MIS 2 dustiness across Europe and beyond.

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.

Application of the high spatiotemporal resolution soil fugitive dust emission inventory compilation method based on CAMx model

The compilation of high spatiotemporal resolution soil fugitive dust (SFD) emission inventories is significant for air pollution prevention and control. This study applied our recently compilated SFD emission inventory of “2 + 26” cities in north China to the CAMx model to estimate the contribution of SFD to the urban ambient particulate, and to simultaneously verify the accuracy of the emission inventory compilation method. Typical periods in spring and summer were selected to represent the highest and lowest levels of annual SFD pollution characteristics, respectively. Beijing, Tianjin, Shijiazhuang, Jinan, and Taiyuan were selected as representative cities. The simulation results of PM were consistent with the observations in terms of the concentration trend. In four of the five cities, the simulation results were significantly correlated with the observation results, with a Pearson correlation between 0.26 and 0.69. The contribution of SFD sources to PM2.5 and PM10 in the five cities were 4–12% and 18–36% in spring, and 1–3% and 4–12% in summer, respectively. The SFD contribution results in this study were not obviously different from earlier source apportionment researches. The relative proportions of SFD and industrial source contributions were reasonable in different seasons for different cities. Simultaneously, this study analyzed the regional contribution characteristics of SFD sources. Contributions to the PM in each city, amounting to ~30–65% of the SFD came from outside the city, including ~1–16% from the nearest city. The results of the high spatiotemporal resolution SFD emission inventory used in this study are accurate, proving that the compilation method is reasonable. Thus, this work provides an example for places with arid climates where suffered SFD pollution to estimate dust emission.

Environmental Particulate Matter (PM) Exposure Assessment of Construction Activities Using Low-Cost PM Sensor and Latin Hypercubic Technique

Dust generation is generally considered a natural process in construction sites; ergo, workers are exposed to health issues due to fine dust exposure during construction work. The primary activities in the execution of construction work, such as indoor concrete and mortar mixing, are investigated to interrogate and understand the critical high particulate matter concentrations and thus health threats. Two low-cost dust sensors (Sharp GP2Y1014AU0F and Alphasense OPC N2) without implementing control measures to explicitly evaluate, compare and gauge them for these construction activities were utilized. The mean exposures to PM10, PM2.5 and PM1 during both activities were 3522.62, 236.46 and 47.62 µg/m3 and 6762.72, 471.30 and 59.09 µg/m3, respectively. The results show that PM10 and PM2.5 caused during the concrete mixing activity was approximately double compared to the mortar. The Latin Hypercube Sampling method is used to analyze the measurement results and to predict the exposure concentrations. The high dust emission and exposure from mixing activities fail to meet the World Health Organization and Health and Safety Commission standards for environmental exposure. These findings will leverage the integration of low-cost dust sensors with Building Information Modelling (BIM) to formulate a digital twin for automated dust control techniques in the construction site.

Optimized approach for developing soil fugitive dust emission inventory in "2+26" Chinese cities

Based on the wind erosion equation and the use of moderate resolution imaging spectroradiometer (MODIS) satellite remote sensing data combined with parameter normalization processing, an optimized high spatial-temporal resolution soil fugitive dust (SFD) emission inventory compiling method was proposed in this study. The "2 + 26" cities in northern China, where heavy pollution frequently occurs, were used as a case study. Using the optimized method, we estimated that the PM50, PM10, and PM2.5 emissions from SFD of "2 + 26" cities in 2018 were 2,014,927, 1,007,463, and 151,120 tons, respectively. The dust emissions and emission factors of each city presented significant differences and were generally of a greater level in high-latitude areas (such as cities in Hebei Province) than in low-latitude areas (such as cities in Henan and Shandong Province). Moreover, with an increase in latitude, vegetation cover factors generally exhibit an upward trend, while temperature and rainfall exhibit a downward trend. The dust emissions in the different months showed significant differences. The total dust emission reached the highest level in "late winter–early spring" season (February to April), and the monthly emission accounted for 15–17% of the annual emissions. While in the "summer–autumn" season (July to November), it is the lowest level of the whole year, monthly emissions accounted for 3–5% of the annual emissions. The emission inventory method proposed in this study can provide a reference for dust emission assessment and further pollution prevention and control work.

Dust‐Drought Nexus in the Southwestern United States: A Proxy‐Model Comparison Approach

AbstractThe U.S. Southwest is naturally prone to dust and drought. With a high risk of unprecedented drought in the future due to climate change, changes in the dust cycle are expected. Whereas paleo records of dust deposition from the region suggest that past megadroughts did not coincide with elevated dust levels, modern studies indicate higher dust during drier conditions. To examine this disagreement, we compare regional paleo records to output from the Community Earth System Model Last Millennium Ensemble experiment. We investigate the role of hydroclimate on dust emissions in the model and analyze how modeled dust during megadroughts compares to all other years. We find that bare ground, as directly modulated by the density of vegetation cover and indirectly by hydroclimate, is the primary control on simulated dust emissions in the Southwest. Furthermore, we find slightly (but significantly) higher dust emission during megadroughts than during years without megadroughts in the model. Using a simple forward modeling approach to assess the impact of age uncertainty in the regional dust records, we find that age uncertainty can explain most of the paleo data/model disagreement. The remaining difference could be related to processes that are not included in the model that inhibit dust emissions during drought, including brown vegetation and soil crusts. Our results suggest the dust‐drought nexus is a continuum and that the impact of drought on dust cycling is subtle.

Simulated regional dust cycle in the Carpathian Basin and the Adriatic Sea region during the Last Glacial Maximum

The climate and environmental conditions in the Carpathian Basin and the adjacent northern Italy/Adriatic region during the Last Glacial Maximum (LGM) exhibit some major differences, as compared to present-day conditions. For instance, high accumulation rates recorded in loess deposits point to an active dust cycle during the LGM. Here, we investigate the climate conditions and provide new insights into the regional dust cycle based on regional climate simulations for both LGM and present-day boundary conditions. The high-resolution model output (grid spacing of ~8.5 km) is in good agreement with available proxy data, showing much colder (particularly during winter) and drier conditions during the LGM over the model domain. Further, the simulated aeolian dust cycle of small grain size particles (<20 μm) is investigated in more detail for LGM conditions. Highest dust emissions are simulated to the east of the Alpine ice sheet and in the Kvarner Bay region. In the northern Carpathian Basin, dust deposition plumes indicate prevailing northerly (NW, N and NE) winds. Strong Bora winds flowing down the slopes of the Dinaric Alps appear to play a major role in the local to regional dust cycle in the northern Adriatic region. From a seasonal perspective, the dust cycle is most active during winter and spring. A closer look at climate and environmental conditions at key areas reveals that high mean wind speeds and low precipitation rates correlate well with the high dust emissions during winter and spring. In contrast, lower wind speeds, increasing precipitation and the greening of vegetation prevent high dust emissions during summer and autumn. An additional analysis of the occurrence frequency of cyclonic circulation patterns in the Adriatic shelf region reveals that individual passing cyclones played an important role in the transport of dust particles from the alluvial Po plain towards the eastern Adriatic loess stacks.

Characterization, optimization, and acoustic emission monitoring of airborne dust emission during wood sawing

This study investigates the airborne dust generation during the wood sawing process. It also develops an intelligent framework for airborne dust monitoring using acoustic emission (AE) sensor during the sawing process of green Douglas-fir wood. It uses AE signals and artificial neural networks to predict the dust emission at different cutting conditions. Also, the statistical effect of cutting parameters on the mass concentration of airborne dust was analyzed. The study investigates sustainable wood manufacturing by considering the effect of airborne dust emission alongside the power consumption and product quality index. It was observed that the mass concentration of the airborne dust is linearly increased with the rotation speed but inversely proportional to the depth of cut, feed speed, and the average chip thickness. The role of the depth of cut and uncut average chip thickness in the generated dust is complex and is more significant when having a small depth of cut. The generated dust emission at different conditions was then compared with its corresponding cutting power and product quality index. The results indicated that developing an AE monitoring system is a reliable method of predicting the amount of inhalable dust that typically measured by an airborne dust detector. This could enable manufacturers to identify the source of high dust emission when different machines are simultaneously operated and adjust their respective cutting parameters to lower the generated airborne dust. A multi-objective optimization should be considered to identify the condition resulting in a low dust emission while having a high product quality and energy-efficient process.

Increased Dust Aerosols in the High Troposphere Over the Tibetan Plateau From 1990s to 2000s

AbstractDust aerosols are a major type of aerosol over the Tibetan Plateau (TP) and influence climate at local to regional scales through their effects on thermal radiation and snow‐albedo feedback. Based on the Modern‐Era Retrospective Analysis for Research and Applications, Version 2 (MERRA‐2) aerosol data set, we report an increase of 34% in the atmospheric dust in the high troposphere over the TP during the spring season in the 2000s in comparison to the 1990s. This result is supported by an increase of 157% (46%) in the dust deposition flux in the Mugagangqiong (Tanggula) ice cores and an increase of 69% in the aerosol index (AI) from Earth Probe (EP) Total Ozone Mapping Spectrometer (TOMS), as well as by increases of simulated dust aerosols over the TP derived from the Community Earth System Model (CESM) and models from the Coupled Model Intercomparison Project Phase 6 (CMIP6). The increased atmospheric dust over the TP is caused by two aspects: (1) There was a higher dust emission over the Middle East during the 2000s than during the 1990s, which is explained by less precipitation and 25.8% higher cyclone frequency over the Middle East. The increased cyclone frequency uplift more dust from the surface over the Middle East to the central Asia in the middle troposphere. (2) Enhanced midlatitude zonal winds help transport more dust in the middle troposphere from central Asia to Northwest China, and thereafter, an increase in northerly winds over Northwest China propels dust southward to the TP.

Simulated regional transport structures and budgets of dust aerosols during a typical springtime dust storm in the Tarim Basin, Northwest China

Abstract Occupying an area of about 1,020,000 km2 with the sparse vegetation and the Taklimakan Desert(TD), The Tarim Basin (TB) is isolated by the surrounding mountains and plateaus, especially to the north of the Tibetan Plateau (TP) with a large drop in elevation. An intense dust storm occurring over TB, Northwest China from April 27 to May 1, 2015 was simulated by using the Weather Research and Forecasting model with chemistry (WRF-Chem v3.8.1). The sources of dust emissions were centered over the northeastern TB with the high dust emission flux reaching 24μgm−2 s−1 injected by strong near-surface northeasterly winds from basin mouth invading the TD. A large amount of dust aerosols accumulated in the windward northern slope of the TP. Dry deposition is the dominant removal process of dust aerosols from the atmosphere over the arid TB. The spatial distribution of dust dry deposition in the TB was similar to the columnar dust loading pattern during this dust storm event. With the impacts of the TB deep terrain structures on atmospheric circulation, the high column loading of dust aerosols was concentrated over the southeastern TB, where dust aerosols mainly accumulated at the lower troposphere below 3000 m. Once dust aerosols were lifted at a high elevation (>3500 m), they were exported from the TB driven by the westerlies in the free troposphere, and the zonal transport flux of dust aerosols (>3000 μgm−2 s−1) peaked at an elevation of approximately 4000 m along 41° N over the TB. The eastern border of TB was found to be the largest contributors to dust export from the TB. It was estimated for this intense dust storm that among the dust aerosols emitted from the dust emission sources over the TD, about 22.28% of dust aerosols were relatively inefficiently exported for the downwind dust regional transport from the TB compared to about 27.17% dust aerosols deposited on the basin surface, and a high fraction of about 50.54% dust aerosols suspending in the atmosphere over the TB, implying a significant implication of dust aerosols from the TD for climate and environment over the central Asian region.

Environmental Impact Assessment of Banagrass-Based Cellulosic Ethanol Production on Hawaii Island: A Spatial Analysis of Re-Suspended Soil Dust and Carbon Dioxide Emission

Environmental impacts from the development of banagrass (Pennisetum purpureum)-based ethanol production on Hawaii Island may create air quality problems. Air pollutants considered in this study include re-suspended soil dust (also known as PM2.5 and PM10) and carbon dioxide (CO2) emission. The resulting pollutant emissions are then compared against the Federal Prevention of Significant Deterioration (PSD) significant standard for the environmental impact assessment. This study combines GIS and a mathematical computational model to logically and effectively examine potential spatial impacts of ethanol development on air quality on Hawaii Island. This study found that mechanical harvesting of banagrass generates higher dust emission than other agricultural crops. The total PM10 emission of 248.18 tons per year was found statistically equivalent to the PSD significant permitting requirement limit of 250 tons per year (tpy) and thus considered as a major stationary source of fugitive dust pollution. The annual CO2 emission amount of 19,371.72 tons is less than the PSD significant permitting requirement of 75,000 tons of CO2 per year. As a result, this estimated amount is not considered as a major stationary source of pollution.

Wind tunnel experiments on dust emissions from different landform types

The measurement and assessment of dust emissions from different landforms are important to understand the atmospheric loading of PM10 (particulate matter ≤10 μm aerodynamic diameter) and to assess natural sources of dust; however, the methodology and technique for determining the dust still present significant research challenges. In the past, specialized field observation and field wind tunnel studies have been used to understand the dust emission. A series of wind tunnel tests were carried out to identify natural sources of dust and measure the magnitudes of dust emissions from different landforms. The method used in this study allowed the measurement of the PM10 emission rate using a laboratory based environmental boundary layer wind tunnel. Results indicated that PM10 emissions demonstrated strong temporal variation and were primarily driven by aerodynamic entrainment. Sand dunes, playa, and alluvial fans had the largest dust emission rates (0.8–5.4 mg/(m2•s)) while sandy gravel, Gobi desert and abandoned lands had the lowest emission rates (0.003–0.126 mg/(m2•s)). Dust emissions were heavily dependent on the surface conditions, especially the availability of loose surface dust. High dust emissions were a result of the availability of dustparticle materials for entrainment while low dust emissions were a result of surface crusts and gravel cover. Soil surface property (surface crusts and gravel cover) plays an important role in controlling the availability of dust-sized particles for entrainment. The dust emission rate depended not only on the surface conditions but also on the friction velocity. The emission rate of PM10 varies as a power function of the friction velocity. Although dynamic abrasion processes have a strong influence on the amount of dust entrainment, aerodynamic entrainment may provide an important mechanism for dust emissions. Large volumes of dust entrained by aerodynamic entrainment cannot only occur at low shear velocity without saltation, but may dominate the entrainment process in many arid and semi-arid environments. So it may also be responsible for large magnitude dust storms. Playa and alluvial fan landforms, prior to developing a surface crust, may be the main sources of dust storms in Qinghai Province.