Dust Deposition Research Articles

Effect of Sand and Dust Shading on the Output Characteristics of Solar Photovoltaic Modules in Desertification Areas

Photovoltaic power generation is rapidly developing as a kind of renewable energy that can protect the ecological environment. The establishment of photovoltaic power stations in desertification areas can play a very important role in desert windbreaks and sand fixation as well as improve the ecological environment. The realization of the effective integration of photovoltaics and deserts can have multiple benefits for the economy, society, and ecology. However, the deposition of sand and dust caused by environmental factors in desertification areas can seriously affect the power generation efficiency of PV modules. In this study, the output characteristics of photovoltaic modules were tested under three wind speed conditions (5 m/s, 10 m/s, and 15 m/s), with different sand densities, sand particle sizes, and inclination angles. The experimental study showed that the module’s output power gradually decreased with an increase in the density of accumulated sand; the sand accumulation density on the surface of the photovoltaic module increased from 0 to 40 g/m2, and the maximum output power decreased by 32.2%. As the sand particle size increased, the maximum output power of the module rose and was gradually stabilized in the three wind speed groups. As the sand particle size increased, the maximum output power of the module increased and gradually stabilized in the three wind speed groups. When the wind speed was 15 m/s, the component output power of the angle had the largest drop; the tilt angle was 60° when the relative output power rate reached the minimum (i.e., 86.5%); that is, there was electrical energy loss of approximately 13.7%. The sand particle size and accumulated sand density were the control variables related to the module temperature and the transmittance of the proportion of the impact of the module filling factor differences. According to the curve analysis of the filling factor in different sand accumulation densities, the filling factor first increased and then decreased. In this test, the filling factor at the sand accumulation density of 35 g/m2 (module temperature valley) reached the peak value. The change trend for the component filling factor under different sand particle sizes fluctuated.

African dust transport and deposition modelling verified through a citizen science campaign in Finland

African desert dust is emitted and long-range transported with multiple effects on climate, air quality, cryosphere, and ecosystems. On 21–23 February 2021, dust from a sand and dust storm in northern Africa was transported to Finland, north of 60°N. The episode was predicted 5 days in advance by the global operational SILAM forecast, and its key features were confirmed and detailed by a retrospective analysis. The scavenging of dust by snowfall and freezing rain in Finland resulted in a rare case of substantial mineral dust contamination of snow surfaces over a large area in the southern part of the country. A citizen science campaign was set up to collect contaminated snow samples prepared according to the scientists’ instructions. The campaign gained wide national interest in television, radio, newspapers and social media, and dust samples were received from 525 locations in Finland, up to 64.3°N. The samples were utilised in investigating the ability of an atmospheric dispersion model to simulate the dust episode. The analysis confirmed that dust came from a wide Sahara and Sahel area from 5000 km away. Our results reveal the features of this rare event and demonstrate how deposition samples can be used to evaluate the skills and limitations of current atmospheric models in simulating transport of African dust towards northern Europe.

New design for PVT system with elliptic cooling duct involving nanofluid in existence of MHD and utilizing TEG

This research investigates the integration of a thermoelectric-enhanced cooling elliptic duct into a photovoltaic solar system. Employing the finite volume method, the simulation aims to analyze the system's performance. Furthermore, the introduction of a magnetic field is explored as a strategy to boost electricity generation and overall system efficiency. The study is driven by the pursuit of enhanced energy conversion and a thorough comprehension of the complex dynamics within solar energy configurations. The nanofluid laminar flow within elliptic duct has been affected by magnetic force and better cooling has been achieved. Impacts of Wdust (amount of dust), Vi (inlet velocity into elliptic tube), Ha (Hartmann) and φ (fraction of additives) on thermal (ηth) and electrical (ηe) performance have been discussed in output section. With deposit of dust, ηth and ηe decrease about 9.07 % and 23.5 %. With rise of Ha, the uniformity of temperature over silicon layer improves and amounts of ηe and ηth increase about 1.18 % and 6.85 %.With mixing water with nanoparticles, the performance of panel enhances and positive effect enhances about 65.73 % and 7.35 % with elevate of Vi, in view of ηe and ηth, respectively. The enhancement of ηe and ηth with rise of Ha improves about 80.81 % and 15.1 % for greater Vi. As Vi intensifies, the better cooling occurs and amounts of ηe and ηth enhances about 4.03 % and 30.26 %. Achieving a uniform temperature distribution across the panel is crucial for assessing its performance. Increasing Vi and Ha leads to a substantial improvement in uniformity, with enhancements of approximately 47.35 % and 4.66 %, respectively. This indicates a more balanced heat distribution, which is a positive indicator of the system's efficiency.

3D modeling of the airflow and aerosol deposition in the existence of dust

Annually, more than two million deaths are caused due to the exposure of air pollution which cause damage to the lungs and the respiratory system. Topography, light-textured topsoil, drought, and desert climate make Saudi Arabia vulnerable to sand storms and dust. The study aims to examine the deposition of dust particles in the human airway and its relationship to asthma and investigate the possibility that the dust deposition would be changed with different particle size diameters. An idealized upper respiratory tract 3D model was constructed with computer-aided design software. Later a computational simulation was performed using computational fluid dynamics with 3 different sizes (0.03, 2, and 9 microns) of the dust particles to find out the change in airflow velocity and pressure. Our findings revealed that small size particles will travel more with less inertia, whereas bigger size particles will travel less but with higher inertia at airflow rates of 30 L/min. It was found that dust deposition in the respiratory system determines the probability of inhalation and total deposition in the alveoli greatly varies with particle diameter size. An idealized URT model replicate patient-specific URT geometry which helped in finding real-time airflow velocity and pressure of dust particles. Particles with smaller diameter are capable of 100% deposition and inhalation rate at the alveoli, whereas particles with bigger diameter tend to deposit less and with lower inhalation rates at the alveoli.

The study on the self-cleaning property of hydrophobic polydimethylsiloxane/nano-CaCO3 coating

<p>Dust depositions always degrade the building’s value due to the growth of mold and fungi. Manual cleaning is required to clean the building glass frequently which is time-consuming and costly. Self-cleaning coating is an effective and practical way to reduce dust accumulation. Using the sol-gel method, this study synthesized the self-cleaning polydimethylsiloxane (PDMS)/nano-calcium carbonate (CaCO<sub>3</sub>) coating. The coating recorded the water contact angle (WCA) of 99.5° ± 0.5°, indicating the hydrophobic property. The embedded nanoparticles create air pockets that reduce the adhesion between water droplets and glass surface. The hydrophobic coated glass showed the self-cleaning effect where the coating achieves a low dust haze of about 32% at the sliding angle 25°. The water contact angle (WCA) of the coating system degrades to 98.2° ± 1.2°, indicating the coated glass can maintain its hydrophobic property in the real environment after 1 month of outdoor exposure. In comparison, the bare glass showed large dust haze value above 50% due to the dust accumulation impact.</p>

Dust deposition in agricultural landscapes: Temporal and spatial dynamics along a transect into a natural forest patch

This work presents the results of the deposition rate of aeolian sediments within a forest patch of semiarid Argentina. The goal of this study was to evaluate the spatial and temporal dynamic of the dust deposition rate (Dr), mainly of the mineral fraction. Passive collectors were installed along transects in a forest patch at 5, 15, 25, 50, 100 and 300 m downwind from the border of an agricultural plot. The average Dr during 30 months was 38.3 ± 26.8 g m−2 yr−1. Dr was statistically similar between spring-summer (47.5 ± 30.1 g m−2 yr−1) and the autumn–winter period (29.2 ± 21.7 g m−2 yr−1). The mean diameter of sediment particles was higher in spring-summer (70 µm) than in autumn–winter (50 µm), probably due to the greater contribution of coarser sediments from wind erosion of surrounding agricultural soils (local source) during spring-summer. During both periods silt-sized particles (40 %) and very fine sand (20 %) were the most abundant, while clay content was 3.5 %. Clay and silt contents were higher in autumn–winter, while fine sand content was higher in spring-summer. Dr within the forest patch was highly variable, therefore statistically homogeneous, despite the fact that 300 m inside the forest the average Dr was ≈35 % lower than at 5 m from the agricultural plot. Sediment deposited at the forest border showed higher aggregation than the sediment collected inside the forest. Forest patches are capable of retaining particles that are key for the soil fertility of semiarid areas, highlighting the importance of aeolian source-sink processes and of forest patches for long-term management decisions in agricultural landscapes.

Long‐Term Landscape Evolution in Response to Climate Change, Ecosystem Dynamics, and Fire in a Basaltic Catchment on the Colorado Plateau

AbstractPredicting responses of semi‐arid to montane landscapes in southwestern North America to ongoing anthropogenic changes requires understanding of past interplay among geomorphic, ecologic, and climatic factors. This study utilizes modern weathering and sediment transport processes to inform the interpretation of a 250‐kyr lacustrine sediment record of paleoecology, hydrology, and erosion from a small, closed basin, basaltic catchment on the southwestern edge of the Colorado Plateau. Geochemical and mineralogical analyses of bedrock, colluvium, and lake sediments indicate that clastic sediments in the basin are a mixture of local physical weathering products (albite and ilmenite) and eolian dust (quartz, illite, and zircon). Dust fractions increase during glacial periods coincident with lower overall sedimentation rates, suggesting this pattern results from decreased local erosion rates and not increased dust deposition. Titanium counts from X‐ray fluorescence core scanning, a proxy for ilmenite content, traces past local erosion rates. The highest erosion rates, inferred from the highest Ti counts, follow climatic transitions toward interglacial conditions (Marine Isotope Stage 5e, 3a, and the Holocene), periods characterized by vegetation changeover (observed in the core's palynology), higher temperatures (piñon‐juniper‐oak pollen abundance), lower effective precipitation (shallow lake facies), and increased wildfire activity (microscopic charcoal particle counts and sizes). While brief inferred episodes of erosion occur following abrupt transitions to cooler and wetter conditions, indicated by the abundance of subalpine tree (spruce and fir) pollen and deeper lake facies, landscapes appear more stable during glacial periods. This long‐term perspective suggests that aridification and resulting vegetation succession and increased wildfires will increase erosion rates in similar settings regionwide.

Experimental Study of Particle Transport and Deposition Distribution over Complex Terrains Based on Spherical Alumina

The transport and deposition of atmospheric particulate matter have attracted significant attention recently due to the increasing frequency of extreme disaster events, such as dust storms, volcanic eruptions, and extensive forest fires. The size distribution of the transported material and the conditions of the land–air interface are dominant factors in comprehending the detrimental potential of atmospheric particulate matter. However, it is still a challenge to understand the mechanism of dust deposition, especially over complex terrain. In an effort to investigate the deposition characteristics of particles over complex terrain, a series of experiments were conducted in a multifunctional environmental wind tunnel. The results show that the wind speed directly above the top of the mild slope model is significantly greater than that in the steep slope model, which indicates that a steep slope has a greater blocking effect on wind fields. At low wind speeds, the average wind speed at the top of the mild slope model is 17.8% higher than that at the top of the steep slope model, and at high wind speeds the average wind speed at the top of the mild slope model is 8.6% higher than that at the top of the steep slope model. The influence trend of the steep slope model and the combination model is basically the same, with both decreasing first and then increasing with the direction of wind velocity. The amount of surface deposition is greatly affected by the location of the feeding point and the microscale characteristics of the surface. In the steep slope model, the deposition is mainly distributed on the windward side, while the leeward side has a small amount of deposition. In the mild slope model, particles are deposited not only on the windward side, but also on the leeward side. The average rate of decline in deposition flux in the steep slope model is 88.4% and 75.1% in the mild slope model. The use of the combination model reduces the particle concentration at the back end compared with the single model. In three different models, the deposition on the windward side was shown to be significantly greater than that on the leeward side of the model. Our work increases understanding of the deposition of coarse dust particles over complex terrain and provides basic data for improving the accuracy of large-region particle transport and deposition simulations.

Abundance, distribution and deposition of PM2.5-bound iron in northern China during 2021 dust and dust storm periods

Dust storms have the ability to transport and deposit contaminants and nutrients, such as iron (Fe), to downwind regions through atmospheric processes. However, there is a lack of reported data on the high-resolution variations and deposition of particulate iron in multiple locations during dust storms. This study aimed to address this gap by employing standardized analytical methods to measure the concentrations of PM10, PM2.5, and PM2.5-associated Fe in Taiyuan, Beijing, Tianjin, Ji'nan, and the Bohai Bay of China during the dusty events of 2021. A total of 13 blowing sand or dust storms were recorded, with average PM10 and PM2.5 concentrations of 262 ± 322 and 85 ± 652, 171 ± 403 and 53 ± 448, 153 ± 211 and 57 ± 315, and 207 ± 249 and 63 ± 301 μg/m3 at the above-mentioned sites, respectively. These elevated concentrations were attributed to stronger winds in northern China and severe wind erosion in the sand source areas. During these events, the average concentrations of PM2.5-bound Fe reached 2730.2 ± 4587.9, 2030.2 ± 3877.9, 1342.1 ± 2251.4, and 1785.1 ± 2536.6 ng/m3 in Taiyuan, Beijing, Tianjin, and Ji'nan, respectively, with the highest concentrations recorded as 48.8, 48.0, 29.2, and 22.7 μg/m3. A significant positive correlation was observed between Fe and Si in PM2.5 in the four cities, with higher Fe/Si slopes recorded in or near the source regions, while the homogenized Fe/Si values were observed after long-distance transport. The mean dry deposition fluxes (FFe) of PM2.5-bound Fe were calculated as 0.34 ± 0.64, 0.31 ± 0.91, 0.21 ± 0.56, and 0.17 ± 0.28 mg/m2/d for Taiyuan, Beijing, Tianjin, and Ji'nan, respectively, based on both hourly observation data and model-based calculations of dry deposition velocities. It is worth noting that FFe decreased from west to east in China, consistent with a previous study that showed a decrease in dust deposition rates with increasing transport distances. Peaks in FFe corresponded to the highest concentrations of PM2.5-associated Fe, indicating that these concentrations played a significant role in Fe. Furthermore, the atmospheric deposition of dissolved Fe from blowing sand or dust storm events was found to contribute to carbon fixation in the Bohai region of China, providing a range of 7.8 × 104–3.9 × 106 mol. This research provides valuable insights into the quantitative relationship between atmospheric deposition and marine productivity during dust events.

Dust storms increase the tolerance of phytoplankton to thermal and pH changes.

Aquatic communities are increasingly subjected to multiple stressors through global change, including warming, pH shifts, and elevated nutrient concentrations. These stressors often surpass species tolerance range, leading to unpredictable consequences for aquatic communities and ecosystem functioning. Phytoplankton, as the foundation of the aquatic food web, play a crucial role in controlling water quality and the transfer of nutrients and energy to higher trophic levels. Despite the significance in understanding the effect of multiple stressors, further research is required to explore the combined impact of multiple stressors on phytoplankton. In this study, we used a combination of crossed experiment and mechanistic model to analyze the ecological and biogeochemical effects of global change on aquatic ecosystems and to forecast phytoplankton dynamics. We examined the effect of dust (0-75 mg L-1 ), temperature (19-27°C), and pH (6.3-7.3) on the growth rate of the algal species Scenedesmus obliquus. Furthermore, we carried out a geospatial analysis to identify regions of the planet where aquatic systems could be most affected by atmospheric dust deposition. Our mechanistic model and our empirical data show that dust exerts a positive effect on phytoplankton growth rate, broadening its thermal and pH tolerance range. Finally, our geospatial analysis identifies several high-risk areas including the highlands of the Tibetan Plateau, western United States, South America, central and southern Africa, central Australia as well as the Mediterranean region where dust-induced changes are expected to have the greatest impacts. Overall, our study shows that increasing dust storms associated with a more arid climate and land degradation can reverse the negative effects of high temperatures and low pH on phytoplankton growth, affecting the biogeochemistry of aquatic ecosystems and their role in the cycles of the elements and tolerance to global change.

An experimental study for efficiency modeling of grid-connected photovoltaic system

ABSTRACT As a key factor, it is vital to mathematically model the electrical efficiency of photovoltaic (PV) systems. This paper investigates the efficient modeling of a 2.5 kW grid-connected PV system, located in Mahan, Kerman, Iran, with respect to different factors like solar radiation, humidity, dust deposition, temperature, and shading. For this aim, different nonlinear models are considered and a curve-fitting approach is used to optimally determine the unknown parameters. Over the case study, simulation results show that when the dust deposition is not included in the modeling (solar radiation, ambient temperature, cell temperature, humidity, and shading as inputs), the third-degree polynomial model leads to more accurate result than the other models. By use of the third-degree polynomial model, the value of root mean square error (RMSE) for train and test data sets is obtained 0.0123 and 0.0109, respectively. In this case, the average RMSE value is 0.0116. On the other hand, when dust impact is included in the modeling (solar radiation, ambient temperature, humidity, and number of dusty days as inputs), the accuracy of the exponential model is more than the other ones. In this case, the value of RMSE for both train and test data sets is obtained 0.0018. Sensitivity analysis shows that the system efficiency depends mainly on the radiation, cell temperature, and dust and less on the humidity.

Experimental analysis of dust composition impact on Photovoltaic panel Performance: A case study

Solar Photovoltaic systems are greatly influenced by meteorological conditions of the surrounding area, dust is the most influencing one. Dust deposition on the surface of photovoltaic (PV) panel hinder the penetration of solar radiation to PV cells and eventually reduce the power production of PV system. To overcome dust-based power losses, frequent cleaning is required depending on geographical location, PV integration scheme and size of the PV power plant. In this manuscript, consequences of dust deposition on photovoltaic systems such as drop in radiation and output power operating are studied, and the optimal time interval for cleaning is determined. Airborne dust particles were collected for a month for morphological and meteorological characterization. The average mass concentrations of the sample are 187.63 μgm-3, showcasing an irregular distribution of dust particles having unlike shapes and sizes. In this study, the influence of dust deposition is quantified using temperature and insolation for clean and dirty PV panels. The overall performance of the PV system is studied based on a comparison of quantified and recorded data. Lastly, different cleaning methodologies are studied to procure the best ones. Power losses were brought down to 7% when PV panels were cleaned fortnightly, which is the most feasible interval in terms of balance between cleaning cost and energy wasted due to soiling.

Discrepant mass accumulation rates of sediments in the South Pacific Ocean from 230Th and 3He measurements

A common technique for determining the mass accumulation rates of marine sediments is through measurements of constant flux proxies. These proxies, like unsupported 230Th and extraterrestrial 3He, are buried at a known rate at the seafloor, and thus their concentration in sediments is inversely proportional to the vertical mass accumulation rate of ambient sediments. These two proxies have varied assumptions regarding their behavior that have been difficult to test, particularly in regions of very low sedimentation. We present new measurements of helium and thorium isotopes in coretop sediments from the South Pacific Gyre. Our main finding is that 230Th- and 3He-derived mass accumulation rates of these sediments differ by a factor of 2–10, with 230Th-based mass accumulation rates systematically higher than those derived from 3He. While the final cause of the discrepancy is difficult to elucidate, we suggest that up to a factor of 2 worth of the sedimentary 230Th deficit can be explained by lateral transport of 230Th, while the remainder must be explained by other processes, such as ancient coretops undercorrected for post-depositional 230Th decay. Regardless of the mechanism, our findings have critical implications for the application of constant flux proxies in the South Pacific Gyre, with one example being the calibration of dust deposition models in this region. Ultimately, additional testing is required to determine the accuracy of the 3He and 230Th techniques for estimating sediment accumulation rates in regions of the open ocean with extremely low sedimentation rates.

A numerical study on sedimentation effect of dust, smoke and traffic particle deposition in a realistic human lung

Inhalation of pollutants can be deadly for respiratory health, as toxic pollutants can penetrate the deep lungs which could occur severe respiratory infection and lead to life-threatening respiratory diseases. The excessive presence of pollutants in the environment increases the concern of potential respiratory health hazards. To date, a microscopic understanding of the sedimentation effect on dust, smoke and traffic (pollutant) particles transported to the airways is missing in the literature. This first-ever study aims to analyse the sedimentation effect in various directions of pollutant particle transport in airways. This study also quantitatively explains how particle size, density, and physical exercise impact pollutant particle transport and deposition (TD) in the human lung airways. The contribution of the sedimentation effect is largely independent of particle size. The sedimentation effect can also be found significant at the trachea region when the fluid flow is horizontal. Overall, traffic particles with large diameters and high flow rates are deposited in the upper lung, whereas dust particles with large diameters and high flow rates are deposited in the deep lung. It is expected that 79.1 % of the particles will reach the deep lung. The difference between the deposition rates of the horizontal and vertical lungs reduces if the particle size reduces, the flow rate increases or the particle density reduces. The deposition rate of a horizontal lung for the heaviest particles (traffic) at 15 L/min flow rate is about 4.5 % higher than that of a vertical lung with the same flow rate.

Experimental and theoretical study on effect of dust deposition on frosting characteristics of fin surface

Since dust accumulates on the fin surface of the outdoor heat exchanger all year round, frost formation inevitably occurs on the fin surface with dust deposition when an air source heat pump is used for heating in winter. However, the effect of dust deposition on frosting characteristics of fin surface has not been clarified. Therefore, visualization experiments were carried out in this paper to study the frosting characteristics on bare and superhydrophobic fin surfaces under different dust deposition levels. Meanwhile, the influence mechanism of dust deposition on frost formation was analyzed theoretically based on phase transition dynamics. The experimental results showed that when the dust deposition on the superhydrophobic fin surface was less than 0.2 g, the dust deposition promoted crystal growth at the initial stage of frost formation, while the frost formation was inhibited when the dust deposition was more than 0.4 g. In the case of bare fin surface, dust deposition always inhibited the frost formation. As the dust deposition mass on the fin surface increased, the thickness and density of the frost layer decreased on both bare and superhydrophobic fin surfaces. In addition, it was worth noting that with the increase of dust deposition, the super hydrophobicity of the superhydrophobic surface was gradually lost. This is not conducive to the practical application of superhydrophobic anti-frosting technology.

Aeolian dust movement and deposition under local atmospheric circulation in a desert-oasis transition zone of the northeastern Taklimakan desert

Taklimakan Desert, in the northwest China, is one of the main sources of dust storms in the world. Frequent dust storms have seriously affected the ecological environment of surrounding oases. Quantification of dust deposition on the different underlying surface is vital to understand the local atmospheric cycling and its effect on movement of the dust particles in desert fringe areas. To examine the contribution of airflow from different direction to the dust deposition rate, the desert–oasis transition zone between the Korla oasis and the northeast edge of the Taklimakan desert is selected as the study area. 36 h backward trajectories of air masses arriving at the study site from 1st March to 31st May 2023, were determined by using the HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory Model) model. The trajectories were categorized by k-means clustering into 3 clusters, which show distinct features in terms of the trajectory origins and the entry direction to the site. Dust collection tank were placed on five underlying surfaces from south to north: shifting sand desert, semi-shifting sand desert, desert vegetation, shelter forestland and croplands at the height of 0.2 m, 0.5 m, and 1.5 m. At the each of height, four dust collection tanks were arranged to collect the dust from 4 directions. Results show that, air masses from the south with highest frequency (46 days) and highest dust storm occurrence (91.3 %) is the main contributor of dust particles to the study area. Dust deposition rate on different underlying surfaces showed a significant decreasing trend from the desert to oasis, and the dust deposition on all underlying surfaces decreased with the height. Dust deposition corresponding to the southward wind direction is the highest, and the amount of fine dust particles are increased with the height of the dust collection tank. The results of this study could be helpful to forecast the potential occurrence and mowing pathway of dust storms, which can provide the basis for mitigation of the negative effects on the environment.

Solid dust induced roughening and overheating of TBC-coated superalloy

Thermal barrier coatings (TBC) on superalloy blade/vane enable an increase in turbine inlet temperature (TIT) and aero-engine efficiency. However, the deposition of dust on TBC significantly ablates superalloys and becomes a bottleneck for advanced engine development. This paper presents a comprehensive modeling approach, based on an experiment involving dust deposition on a TBC-coated substrate, aimed at understanding the fundamental cause of substrate ablation. The results show that a significant increase in surface roughness is obtained experimentally with dust accumulation. The temperature field within the TBC-substrate system is disturbed by surface roughening. Consequently, the film cooling is seriously destroyed. While the dust accumulated on the TBC surface also contributes to heat insulation by increasing the effective TBC thickness, localized overheating of the substrate occurs and then leads to ablation and premature failure of the substrate. This elucidation of the overheating mechanism could inform the development of strategies to resist dust accumulation in advanced aero engines.

Aeolian dust and hydro-biological characteristics: Decoding dust storm impacts on phytoplankton in the northern Arabian Gulf

Aeolian dust is an essential source of growth-limiting nutrients for marine phytoplankton. Despite being at the core of the Global Dust Belt, the response of the Arabian Gulf ecosystem to such atmospheric forcing is rarely documented. Here, the hydro-biological effect of mineral dust was studied in the northern Arabian Gulf (NAG) off Kuwait through monthly water sampling (December 2020 to December 2021), dust-storm follow-up sampling, and mineral dust and nutrient addition in-situ experiments. The multivariate analysis of oceanographic data revealed pronounced hydro-biological seasonality. The mineral dust deposition during two severe dust storm events in March and June 2021 showed a spatially varying effect of dust on coastal waters. The dust storms elevated the surface dissolved iron levels by several magnitudes, increased the dissolved inorganic nitrogen and phosphorous levels, changed their stoichiometry, and offset the hydrobiological seasonality. In the microcosms, dust input temporarily reduced phytoplankton phosphorous limitation in a dose-dependent manner when mesozooplankton (copepods) grazing was minimal. The microphytoplankton response to mineral dust inputs was comparable to that with nitrogen and phosphorous treatment. While Both treatments increased diatom size structure and biomass, the abundance of single-celled diatoms was comparatively higher in dust treatment. Multivariate analysis indicated that dust deposition alters the hydrographical properties of the surface ocean during dust storm events. The effects, though transient, were traceable for 3–16 days post-storm in coastal waters. The response of the summer phytoplankton to these changes, if delayed or muted, should be interpreted with caution given the summer water column stratification, the high nitrogen: phosphorous ratio and the low phosphorous solubility of aerosol dust, and the complex pelagic microbial food web interactions in the NAG. This study thus underlines the importance of a multivariate approach in documenting the ecological implications of Aeolian dust storms on marine environments closer to the dust source regions.

Study on the fine particles deposition law in the bronchus of miners affected by dust pollution in the anchor excavation working environment

To study the dust exposure law of the operator in the anchor digging working face, the CFD-DEM method was used to numerically simulate the dust deposition pattern in the bronchus of the anchor digging driver. The results show that the highest dust concentration in the vortex region of the anchor digging working face can reach 2364.76 mg/m3, seriously endangering the health of anchor digging driver. The average dust concentration in the respiratory hemisphere of the driver is 510.57 mg/m3, and the range of inhaled dust diameter is 0–60 μm in the breathing state of moderate labour. Over time, the deposition mass in the bronchial showed a pattern of rapid and then slow increase, which was consistent with the trend of the Boltzmann model. Increasing dust particle diameter was positively correlated with bronchial deposition rate and negatively correlated with alveolar deposition rate. Among them, 0–10 μm particles were deposited throughout the bronchus and a large number of particles were deep into the alveoli, with the alveolar deposition rate as high as 56.3 %, while the alveolar deposition rate for particles of 10–20 μm decreased to 20.4 %, and for particles larger than 30 μm, the effect on the alveoli was smaller.

Fine and Coarse Dust Effects on Radiative Forcing, Mass Deposition, and Solar Devices Over the Middle East

AbstractIn desert regions like the Middle East, dust has a profound impact on the environment, climate, air quality, and solar devices. The size of dust particles determines the extent of these effects. Dust deposition (DD) measurements show that coarse dust particles with geometric radius r > 10 μm comprise most of the deposited mass. Still, these particles are not represented in the current models that are tuned to fit the observed aerosol optical depth (AOD). As a result, the existing models and reanalysis products underestimate DD and dust emission (DE) almost 3 times. This is the first study to constrain the dust simulations by both AOD and DD measurements to quantify the effect of coarse and fine dust using the WRF‐Chem model. We found that, on average, coarse dust contributes less than 10% to dust shortwave radiative forcing (RF) at the surface but comprises more than 70% of DE. Annual mean net RF over the Arabian Peninsula and regional seas locally reaches −25 W m−2. Airborne fine dust particles with radii r < 3 μm are mainly responsible for the significant dimming (5%–10%) of solar radiation, cooling the surface, and hampering solar energy production. However, dust mass deposition is primarily linked to coarse particles, decreasing the efficiency of photovoltaic panels by 2%–5% per day. Therefore, incorporating coarse dust in model simulations and data assimilation would improve the overall description of the dust mass balance and its impact on environmental systems and solar devices.