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We report state-of-the-art first-principles molecular dynamics results on the heterogeneous chemical uptake of NO2, a major anthropogenic pollutant, on the dry and wet hydroxylated surface of α-quartz, which is a significant component of silica-based catalysts and atmospheric dust aerosols. Our investigation spotlights an unexpected chemical pathway by which NO2 (i) can be adsorbed as HONO by deprotonation of interfacial silanols (i.e., –Si–OH group) on silica, (ii) can be barrierless converted to nitric acid, and (iii) can finally dissociated to surface bounded NO and hydroxyl gas phase radicals. This chemical pathway does not invoke any previously experimentally postulated NO2 dimerization, dimerization that is less likely to occur at low NO2 concentrations. Moreover, water significantly catalyzes the HONO formation and the dissociation of nitric acid into surface-bounded NO and OH radicals, while visible light adsorption can further promote these chemical transformations. This work highlights how water-restricted solvation regimes on common mineral substrates are likely to be a source of reactive oxygen species, and it offers a theoretical framework for further and desirable experimental efforts, aiming to better constrain trace gases/mineral interactions at different relative humidity conditions. [ABSTRACT FROM AUTHOR]

Several studies highlight the environmental and human health impacts of outdoor air pollution. However, a significant gap exists in understanding indoor air pollution in urban households. The current work aims to characterize the fan dust samples collected from households in Chandigarh, India. The five composite samples were collected from different areas, including the dining room, drawing room, bedroom, kitchen, and worship room, of different households in the same location. Samples were characterized using various analytical techniques like X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The concentration of all the measured elements was found to be relatively lower when compared with other similar studies. Ca and Fe showed a high household fraction. XRD confirmed the high fraction of calcite and quartz particles in household dust samples. In SEM analysis, circular, irregular flakes and fibrous particles indicated coal combustion particles in the household dust. Additionally, sharp edge particles showed the enrichment of minerals in the dust samples. Health risk assessment results indicated that the hazard index values for children and adult populations were within limits for non-carcinogenic and carcinogenic health risks from three exposure pathways, revealing insignificant health risks. Besides, the microbiological examination identifies Paebacillus barcinonensis and Bacillus megaterium in dining room dust, Bacillus megaterium and Bacillus circulans in dining and drawing room dust, Lysinibacillus boronitolerans in Bedroom dust, Paenibacillus species. and Bacillus species. in worship room dust, Bacillus circulance and Bacillus megaterium in the kitchen area. Human activities were strongly found to be associated with microbial and metal existence in the dust samples. Household dust, contaminated with biological and inorganic pollutants, has the potential to pose health risks to occupants. Hence, the study briefly discusses the approaches to minimize household dust and indoor air pollutants. Therefore, improving indoor air quality should be a vital component of public health protection policies for urban and rural households. [ABSTRACT FROM AUTHOR]

Knowledge of the chemical composition and mixing state of aerosols at a single-particle level is critical for gaining insights into atmospheric processes. One common tool to make these measurements is single-particle mass spectrometry. There remains a need to compare the performance of different single-particle mass spectrometers (SPMSs). An intercomparison of SPMSs was conducted at the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) chamber at the Karlsruhe Institute of Technology (KIT) in November 2014, as part of the first phase of the Fifth International Workshop on Ice Nucleation (FIN-01). In this paper we compare size distributions and mass spectra of atmospherically relevant particle types measured by five SPMSs. These include different minerals, desert and soil dusts, soot, bioaerosol (Snomax; protein granule), secondary organic aerosol (SOA), and SOA-coated mineral particles. Most SPMSs reported similar vacuum aerodynamic diameter (dva) within typical instrumental ranges from ∼100 –200 nm (lower limit) to ∼2 –3 µm (upper limit). In general, all SPMSs exhibited a wide dynamic range (up to ∼103) and high signal-to-noise ratio (up to ∼104) in mass spectra. Common spectral features with small diversities in mass spectra were found with high average Pearson's correlation coefficients, i.e., for average positive spectra ravg-pos=0.74 ± 0.12 and average negative spectra ravg-neg=0.67 ± 0.22. We found that instrument-specific detection efficiency (DE) was more dependent on particle size than particle type, and particle identification favored the use of bipolar, rather than monopolar, instruments. Particle classification from "blind experiments" showed that all instruments differentiated SOA, soot, and soil dust and detected subtle changes in the particle internal mixing but had difficulties differentiating among specific mineral types and dusts. This study helps to further understand the capabilities and limitations of the single-particle mass spectrometry technique in general and the specific performance of the instrument in characterizing atmospheric aerosol particles. [ABSTRACT FROM AUTHOR]

European Space Agency's Mars Express (MEX) has been orbiting Mars for 20 years and its instruments have provided a plethora of observations of atmospheric dust and clouds. These observations have been analysed to produce many unique views of the processes leading to dust lifting and cloud formation, and a full picture of the climatologies of dust and clouds has emerged. Moreover, the orbit of MEX enables viewing the planet at many local times, giving a unique access to the diurnal variations of the atmosphere. This article provides an overview of the observations of dust and clouds on Mars by MEX, complemented by the Trace Gas Orbiter that has been accompanying MEX on orbit for some years. [ABSTRACT FROM AUTHOR]

This study aims to investigate the seasonal variation and source identification of fluorescent aerosol particles at the monitoring site of the University of Salento in Lecce, southeastern Italy. Utilizing a wideband integrated bioaerosol sensor (WIBS), this research work analyzes data from two specific monitoring days: one in winter (10 January 2024), marked by significant transport of anthropogenic particles from Eastern Europe, and another in early spring (6 March 2024), characterized by marine aerosol sources and occasional desert dust. This study focuses on the seven WIBS particle categories (A, B, C, AB, AC, BC, ABC), which exhibited distinct characteristics between the two days, indicating different aerosol compositions. Winter measurements revealed a predominance of fine-mode particles, particularly soot and bacteria. In contrast, spring measurements showed larger particles, including fungal spores, pollen fragments, and mineral dust. Fluorescence intensity data further emphasized an increase in biological and organic airborne material in early spring. These results highlight the dynamic nature of fluorescent aerosol sources in the Mediterranean region and the necessity of continuous monitoring for air quality assessments. By integrating WIBS measurements with air mass back-trajectories, this study effectively identifies fluorescent aerosol sources and their seasonal impacts, offering valuable insights into the environmental and health implications of aerosol variability in the investigated Mediterranean area. [ABSTRACT FROM AUTHOR]

This article introduces the notions of asymptotic dust and asymptotic radiation equations of state. With these non-linear generalizations of the well known dust or (incoherent) radiation equations of state the perfect-fluid equations lose any conformal covariance or privilege. We analyse the conformal field equations induced with these equations of state. It is shown that the Einstein- λ -perfect-fluid equations with an asymptotic radiation equation of state allow for large sets of Cauchy data that develop into solutions which admit smooth conformal boundaries in the future and smooth extensions beyond. In the case of asymptotic dust equations of state sharp results on the future asymptotic behaviour are not available yet. [ABSTRACT FROM AUTHOR]

Oceanic suspended particulate matter (SPM) plays important roles in the coupling of climate and biogeochemical cycles via ocean–atmosphere interactions. However, methods for quantifying the properties of SPM in seawater have not yet been well established. Here we present the application of the recently developed complex amplitude sensor (CAS) for analyzing the complex forward-scattering amplitude of individual SPM (0.2–5.0 µm in diameter) obtained at depths of 0–100 m during a research cruise in the western North Pacific. The measured distribution of the complex amplitude indicated that the CAS-derived SPM data could be roughly classified into five major types. Comparison with reference sample's complex amplitude data and scanning electron microscopy analysis suggested that these types could be attributed mainly to diatom fragments, carbonaceous materials (likely organic matter), mineral dusts, iron oxides, or black carbon. Depth profiles revealed that relatively high concentrations of SPM, presumably dominated by diatom fragments and carbonaceous materials with peak diameters of 0.7–1.0 µm, were typically associated with elevated turbidities and chlorophyll a concentrations. Based on this case study, we discuss the practical advantages and limitations of using the CAS to measure size-resolved concentrations of SPM in seawater and to characterize its composition. [ABSTRACT FROM AUTHOR]

In this study, prominent dust source areas are identified along with their plume extent using high temporal frequency satellite observations. Hourly dust plume observations of the Dust Belt from geostationary‐orbit satellites are analyzed for the 2017‐12–2022‐11 period. To identify dust source areas and their extents, we back‐track plumes to their source, assessing source areas in terms of emission frequency, contribution, and plume extent patterns. This method advances over traditional source allocation techniques that rely on polar‐orbiting satellites based on a few daily passes and meteorological wind fields for backtracking. Our findings indicate that Boreal summer is the most intense season for most sources, except in the Southern Sahara, which experiences winterly winds. Our analysis also reveals significant contributions from regions within the Sahara that experience expansive but infrequent dust storms, highlighting the importance of considering both frequency and magnitude in understanding dust emissions. Plain Language Summary: This study focuses on the role of mineral dust, a significant climate constituent originating mainly from arid regions. Identifying where dust comes from and where it goes is essential for understanding how it affects the climate. To do so, we employ high temporal frequency satellite data to backtrack dust plumes to their sources, revealing key dust‐emitting regions and their seasonal variations. We also quantify each source area's frequency and magnitude of emissions and the spatial distribution of emanating dust plumes. Our findings show that summer is the peak season for most areas, except for the strongest dust sources, located in Southern Sahara, which peak in winter driven by seasonal winds. Additionally, some Saharan source areas exhibit severe storms but have been under‐emphasized because they were measured by the frequency of their storms. Key Points: High‐temporal‐resolution images from geostationary‐orbit satellites enable precise back‐tracking of dust source areasDust source areas are analyzed in terms of their emission frequency, contribution to the regional atmosphere, and corresponding plume extentSummer is the peak dust emission season for most sources in West Asia and Sahara and ephemeral lake beds are active during the dry season [ABSTRACT FROM AUTHOR]

The Atacama Desert is amongst the driest places on Earth yet large dust outbreaks seem rare. We present the first quantitative assessment of dust events in the Atacama for 1950–2021 based on station observations. A total of 1920 dust days were recorded with less than 10% being classified as dust storms. We calculated the wind speeds at 5%, 25% and 50% of the dust‐event frequency distribution. The mean wind speed for the threshold of 5% is 10.9 ± 1.6 ms−1 which is twice as large as the values in the Taklamakan, Western Sahel, and Sudan, and consistent with the perceptually infrequent dust activity despite the exceptional aridity. We see no overall long‐term trend but increased dust activity for 1970–1978, 1984–1988 and 2013–2017. A combination of changes in the wind speed statistics and soil conditions, possibly including anthropogenic land‐use changes have led to the variability in dust activity. Plain Language Summary: Little is known about the dust activity in the Atacama Desert in Chile. Our study provides the first assessment of dust events in the past 72 years using dust and meteorological observations from stations in the Atacama. Dust activity is low but we found three periods in the past with more dust activity than today, possibly linked to past changes in soil conditions. The minimum wind speeds required for dust events are much higher than those previously determined for North African and East Asian Deserts, consistent with the rareness of large dust outbreaks from the Atacama. Key Points: Dust activity is rare with dust reports on 1,920 days in 72 yearsThere is no long‐term trend but enhanced activity during three periods, dominated by dust reports from the station Chañaral, is foundMean threshold wind speeds for dust‐event occurrence is 10.9 ± 1.6 ms−1, and is higher than that for North African and East Asian Deserts [ABSTRACT FROM AUTHOR]

The source of dust in the global atmosphere is an important factor to better understand the role of dust aerosols in the climate system. However, it is a difficult task to attribute the airborne dust over the remote land and ocean regions to their origins since dust from various sources are mixed during long‐range transport. Recently, a multi‐model experiment, namely the AeroCom‐III Dust Source Attribution (DUSA), has been conducted to estimate the relative contribution of dust in various locations from different sources with tagged simulations from seven participating global models. The BASE run and a series of runs with nine tagged regions were made to estimate the contribution of dust emitted in East‐ and West‐Africa, Middle East, Central‐ and East‐Asia, North America, the Southern Hemisphere, and the prominent dust hot spots of the Bodélé and Taklimakan Deserts. The models generally agree in large scale mean dust distributions, however models show large diversity in dust source attribution. The inter‐model differences are significant with the global model dust diversity in 30%–50%, but the differences in regional and seasonal scales are even larger. The multi‐model analysis estimates that North Africa contributes 60% of global atmospheric dust loading, followed by Middle East and Central Asia sources (24%). Southern hemispheric sources account for 10% of global dust loading, however it contributes more than 70% of dust over the Southern Hemisphere. The study provides quantitative estimates of the impact of dust emitted from different source regions on the globe and various receptor regions including remote land, ocean, and the polar regions synthesized from the seven models. Plain Language Summary: As the most abundant aerosol type in the Earth's atmosphere, mineral dust plays an important role in global climate by interacting with incoming and outgoing radiation, providing liquid and ice cloud nuclei, and affecting atmospheric stability. The global dust sources are relatively well characterized by the remote sensing and modeling studies as the majority of dust is emitted from the so‐called dust belt which expands from North Africa to East Asia. However, it is challenging to attribute dust sources over the remote land and ocean regions, since dust is mixed during long‐range transport, where it experiences complex atmospheric processes, including horizontal and vertical‐advection, wet deposition, and dry deposition. Using the multi‐model simulations in the Aerocom/Dust Source Attribution experiment, the present study (a) examines the model diversity in dust source attribution and (b) estimates the contribution of dust sources to various receptor regions, including remote land/ocean and the polar regions in different altitudes, from the multi‐model statistics. Beyond dust sources, many remote land, ocean, and polar regions are affected by a mixture of dust from various sources around the globe. Key Points: Contributions of various dust sources are quantitatively estimated in a multi‐model experimentContributions of various sources have different horizontal and vertical distributions and seasonalityDust near source regions are dominated by dust emitted in the upwind source regions; however many remote land, ocean, and polar regions are affected by a mixture of dust from various sources around the globe [ABSTRACT FROM AUTHOR]

Hydrogen is an important energy source for achieving energy transition and carbon neutrality. Underground salt caverns are ideal for large-scale and long-term underground hydrogen storage (UHS). The hydrogen diffusivity in the rock of a salt cavern gas storage is an important parameter for evaluating the hydrogen tightness of UHS. In this study, hydrogen diffusivity was investigated and the effects of the rock microstructure in a UHS on hydrogen diffusivity were analyzed by using experiments and numerical modeling. Core samples were drilled from the Chuzhou Salt Cavern Gas Storage in the Huai'an salt mine and tested for hydrogen diffusivity using a newly developed setup. A core hydrogen diffusion coefficient model was constructed using the time-domain diffusion method to examine the effects of the complex microstructure and mineral distribution of salt rocks and mudstones. The results indicated the following: (1) the diffusion coefficient of the interlayer mudstone were approximately two orders of magnitude larger than those of salt rocks, and the mudstone showed obvious bidisperse diffusion behavior; (2) high temperature and pressure facilitated hydrogen diffusivity in the cores; (3) the diffusion coefficient of mineral particles was of the order of 10−11 m2/s, which was significantly lower than that of core samples; (4) microscale modeling of hydrogen diffusion using the digital rock method revealed that the discrete microfractures and pores in the cores contributed considerably to the hydrogen diffusion process in tight rocks. • Hydrogen diffusivity of rocks in a salt cavern was analyzed via experimental and numerical modeling. • Diffusion coefficient of salt rock cores was lower than that of interlayer mudstones. • Diffusion coefficient of core plugs was significantly larger than that of particles. • Microcracks and pores considerably contributed to the hydrogen diffusivity of tight rocks. [ABSTRACT FROM AUTHOR]

Humans have occupied the Alps over most of the Holocene. Yet, continuous records on the impact of using montane resources and landscapes are scarce or confined to segregated areas or periods. We present a high-resolution geochemical record of the last 4800 years from the ombrotrophic peatland Piller Moor in the Central Alps (Tyrolean Oberland, western Austria), using inductively coupled mass plasma spectrometry (ICP-MS) and highly efficient inter-calibrated portable X-ray fluorescence analysis (pXRF). Fluctuations of metal enrichment factors (EF) for lead (Pb), copper (Cu), zinc (Zn) and antimony (Sb), accumulation rates of anthropogenic lead (Pb anth AR) and mineral matter (MAR), based on titanium (Ti), are in line with archaeological and pollen evidence for human presence and environmental change. Periods of intensified, erosive land use are indicated by MAR around 4400 cal BP, 3400 cal BP and, very prominently, at 2400 cal BP. After low MAR in the early Middle Ages, soil disturbances reappear around 1200 cal BP (750 AD), after 200 cal BP (1750 AD) and during the 20th century AD. We found evidence that metallurgy was practised in the area as early as 4450 cal BP, again from 3500 to 2900 cal BP and episodically between 2400 and 1400 cal BP. The Central Alps were presumably a source of increased Pb-emissions in the post-Roman period from 1500 to 1400 cal BP (450–550 AD). Generally, our findings suggest that mining predates archaeological and historical evidence. Following a continuous increase since the Middle Ages, atmospheric Pb EF and Pb anth AR peak around 1980 AD. The record of mineral atmospheric input illustrates the notable impact of human activities on soil erosion and dust entrainment in the Central Alps. Furthermore, links between Little Ice Age cold phases and reduced human impact and mining are established. Our high-resolution peat-geochemistry data quantifies atmospheric deposition of mineral matter and Pb, which act as proxies for landscape evolution and metallurgy on a local and regional scale. It provides new insights and a deeper understanding of the interaction of climate, environment and humans in mountainous landscapes like the Central Alps. [ABSTRACT FROM AUTHOR]

We explore the dynamical behaviour of dust particles that populate the surface of inner optically thick protoplanetary discs. This is a disc region with the hottest dust and is of a great importance for planet formation and dust evolution, but we still struggle to understand all the forces that shape this environment. In our approach, we combine results from two separate numerical studies, one is the wind velocity and density distributions obtained from magnetohydrodynamical simulations of accretion discs, and the other is a high-resolution multigrain dust radiation transfer. In our previous paper in the series, we described the methodology for utilizing these results as an environmental input for the integration of dust trajectories driven by gravity, gas drag, and radiation pressure. Now we have two improvements, we incorporate time changes in the wind density and velocity, and we implement the non-radial radiation pressure force. We applied our analysis on the Herbig Ae and T Tau stars. We confirm that the radiation pressure force can lead to dust outflow, especially in the case of more luminous stars. Additionally, it opposes dust accretion at the inner disc edge and reduces dust settling. These effects are enhanced by the disc wind, especially in the zone where the stellar and the disc magnetic fields meet. Our results suggest that dust grains can stay in the hottest disc region for an extended period and then end up ejected into the outer disc regions. [ABSTRACT FROM AUTHOR]

This work analyses 10 years (from 2009 to 2018) of long‐range Saharan dust advections (SDAs) and their correlation with the precipitation and radiative budget over the Central Mediterranean region. The identification of the SDAs is based on back‐trajectories (BTs) of air mass and complementary measurements of the dust deposited at the site of Monte Martano in Central Italy. The associated synoptic circulation weather types (CWT), precipitation and radiation variables have been estimated by using ERA5 and CAMS reanalysis, satellite data and raingauge observations. It is found that the 50% of all SDAs occur under a CWT characterized by an upper level trough over the Western Mediterranean and a high‐pressure system over the Eastern Mediterranean. Strong southerly winds, large vertical integral of water vapour transport and a positive anomaly of 2 m temperature are associated with dust uplift and transport. The effect of dust on rainfall intensity puts forward the important modulation of the aerosol effects on the radiative budget with a latitudinal dependence. On dusty days, intense rainfall increases over the northern Central Mediterranean and light rainfall is suppressed in the southern Central Mediterranean, pointing out a relevant correlation between dust and the intensification of extreme events. Other than affecting rainfall intensity, the stronger surface heating over the southern Central Mediterranean, which is correlated to a higher dust optical depth, causes a local maximum of sea surface temperature (SST) and near‐surface temperature anomaly. [ABSTRACT FROM AUTHOR]

The availability of dissolved iron (Fe) limits primary production over some regions of the surface ocean, especially in regions such as the subarctic North Pacific. In this work, we use Fe stable isotope ratios (δ56Fe) in bulk and size-fractionated marine aerosol particles and dissolved Fe of surface seawater in the subarctic North Pacific on Japanese GEOTRACES cruise GP02 (Summer 2017) as a tracer to clarify the relative contribution of combustion and natural Fe in both marine aerosol particles and surface seawater. The bulk aerosols collected in the coastal regions of both East Asia and western North Pacific have total δ56Fe values that are as low as −0.5 ‰ when compared to crustal (+0.1 ‰), with both the water-soluble phase and the fine particles even more fractionated (as low as −1.9 and −2.8 ‰, respectively). The negative correlation between the aerosol δ56Fe signatures and the enrichment factors of Fe and other elements dominated by anthropogenic sources (e.g., lead and cadmium) in these coastal regions indicates the presence of Fe emitted from high-temperature combustion sources, such as coal combustion and metal smelting. In these regions, combustion Fe accounts for 4–13 and 13–45 % of the total and water-soluble aerosol Fe, respectively. The results demonstrate that soluble aerosol Fe sourced from combustion Fe can be equivalent to that sourced from natural dust Fe in these coastal regions. By contrast, the aerosol particles in pelagic regions were near crustal δ56Fe in all particle size fractions, indicating the dominance of natural Fe and little to no combustion Fe. The relationships among the fractional Fe solubility, major ion concentration, Fe species, and δ56Fe indicate that the presence of combustion Fe is the dominant reason for the solubility increase in the coastal regions and that the atmospheric processing of mineral dust during transport is more important in the pelagic regions. The dissolved Fe of the surface seawater at 10 m depth had a consistently higher δ56Fe by up to +1.5 ‰ than that of the simultaneously collected water-soluble aerosol Fe. The pattern of the elevated δ56Fe in the surface seawater corresponds to decreasing Fe concentrations and can be approximated by Rayleigh fractionation; we attribute these elevated surface δ56Fe values to the effect of biological uptake. New Fe fluxes from both the atmosphere and deeper depths are limited at least in summer compared with the biological uptake in the open ocean of the subarctic North Pacific. [ABSTRACT FROM AUTHOR]

This study aimed to assess the effects of rock dust on Meloidogyne javanica in soybean grown in autoclaved and non-autoclaved soil and investigate the impacts on plant foliar nutrition. The nematode reproduction experiment was conducted in two periods (Trials 1 and 2) in a 5 × 2 factorial design (rock dust rates of 0, 1000, 2000, 3000, and 4000 kg ha−1 × autoclaved and non-autoclaved soil). Soybean were inoculated with 2000 eggs + second-stage juveniles (J2) of M. javanica, and nematode and vegetative variables were evaluated at 60 days after inoculation (DAI). The penetration experiment followed a 2 × 2 factorial design (rock dust rates of 0 and 2500 kg ha−1 × autoclaved and non-autoclaved soil). Soybean were inoculated with 2000 eggs + J2 of M. javanica and evaluated at 5, 10, 15, 20, and 25 DAI. The shoot dry biomass from the reproduction experiment (Trial 1) was analyzed for macro- and micronutrients. In Trial 1, nematode reproduction decreased proportionally to the increase in rock dust rate in non-autoclaved soil. In Trial 2, the lowest nematode numbers were predicted to be achieved with rates of 2213 to 2309 kg ha−1, and nematode numbers were lower in autoclaved than in non-autoclaved soil. Rock dust reduced J2 penetration at 10 and 15 DAI, and there was no formation of females in treated plants. Rock dust application increased foliar levels of Fe, B, and Cu. Rock dust reduced M. javanica reproduction, penetration, and development in soybean and promoted gains in Fe, Cu, and B foliar contents. [ABSTRACT FROM AUTHOR]

The results of studies of a basaltic andesite sample (complicated by the mineralized fracture and voids, as well as fracture and gas voids filled with secondary mineralization) dredged on the submarine Esmeralda Volcano are presented. A detailed comparative study of the mineral composition of the substance lining the fracture, the near-fracture space, and the basaltic andesite part unaffected by secondary alterations made it possible to discover the presence of a mineral assemblage, which is atypical for the unaltered volcanic rocks, in the submarine Esmeralda Volcano. In the intra-fracture space and adjacent basaltic andesite zones, wide variation ranges of the plagioclase composition are recorded; isomorphism in the Fe–Ca pyroxene series is studied; REE oxides, hydroxides, and fluorohydroxides are studied; and variability in the composition of minerals of the magnetite–hematite series is shown. Tectonic movements in the previously formed basaltic andesites likely promoted the emergence of permeable zones, through which new portions of the melt leaked. In a limited space, high fluid gas saturation, temperature, and pressure fostered the extraction of metal compounds from the melt and host rocks. [ABSTRACT FROM AUTHOR]

​​​​​​​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. [ABSTRACT FROM AUTHOR]

This source apportionment research was one of the first attempts to quantify the contributions of pollution sources to ambient particulate matter (PM2.5) in the urban area of Skopje. The sampling was conducted at two locations in the city of Skopje, with permanent, year-round coverage. The elemental composition of PM2.5 aerosols was analyzed with non-destructive energy dispersive X-ray fluorescence spectroscopy, water-soluble ions were analyzed photometrically, and black carbon was assessed with an optical transmissometer. Positive Matrix Factorization was used for data modelling, and the contribution of each source to total particulate mass (PM2.5) was calculated. Seven main pollution sources were identified for both sites including biomass burning, open fire burning, traffic, fuel/residual oil burning, industry, and soil/mineral dust. Biomass combustion continues to be the largest single source of ambient air pollution and, due to its particular temporal distribution, is most likely the primary cause of extreme wintertime pollution episodes. Despite being fully seasonal, biomass burning provides the greatest annual relative contribution, reaching 32% for the Novo Lisiche site and 33% for the Karposh site, and during the winter months, this source alone contributes beyond the annual PM2.5 limit levels. Traffic is the second most important source. The annual relative contribution of traffic to the total particle mass at the Novo Lisiche site was 23%, and at the Karposh site, it was 18%. Other notable sources include the combustion of fuel/residual oil, soil dust, and open fires burning. [ABSTRACT FROM AUTHOR]

Understanding large desert formation/evolution contributing to regional‐to‐global dust cycles remains a challenge. This study presents the geochemical and Sr‐Nd isotope compositions of 51 surface sediment samples collected from the widespread hyper‐arid Thar Desert in northwestern India. The major objective is to determine sediment provenance for a better understanding of the formation/evolution mechanism of this Great Indian Desert as well as downwind dust contributions toward the Himalayas. The compositionally immature sandy Thar sediments (CIA ∼50 ± 4, WIP ∼49 ± 12, and EuN/Eu* ∼0.80 ± 0.13) are recycled materials derived from the Himalayan orogen and later modified by quartz addition and heavy mineral depletion/sorting processes. The 87Sr/86Sr (0.7259 ± 0.0012 and εNd (−12.5 ± 2.7) in the bulk of these Thar sediments are different from the earlier published compositions of the eolian sand deposits in northwestern India. The subcategories of Thar materials collected from different dune types exposed over different lithologies (Quaternary alluvium vs. Tertiary and Mesozoic sedimentary formations) are geochemically and isotopically indistinguishable, which indicates their cogenetic sources and/or sediment reworking. Thar sediments collected in this study have a predominant Indus origin along with significant contributions from the upwind Ghaggar‐Hakra paleochannels. The Indus sediments are most likely wind‐eroded from the shelf region exposed during the low sea stand of LGM and afterward deglaciation. Considering the new and published data sets, the Sr‐Nd isotope budget of dust deposited in the Himalayan frontal glaciers indicates that atmospheric mineral dust contribution from the upwind Indo‐Gangetic Plain proximal to the Himalayas is at par with dust parcels from distant natural deserts. Plain Language Summary: This provenance study aims to explore the eolian versus fluvial/alluvial mode of sediment delivery to the Thar Desert and its significance to the downwind dust dispersal toward the Himalayas. For this purpose, we characterized several Thar sediment samples collected from a widespread hyper‐arid area in southwest Rajasthan. The sampled area has a variety of Thar dune types and underlying lithologies but a poor river drainage system in modern times. This new data set provides evidence for the Thar surface sediments as predominantly derived from the Indus shelf region during the low sea stand of the Last Glacial Maxima (LGM ∼18–22 ka BP) and afterward deglaciation. The upwind Ghaggar‐Hakra paleochannels also seem to be a significant source of sandy Thar surface sediments in the sampled area of southwest Rajasthan. Further, a literature data comparison indicates a competitive role of downwind sediment source regions (Indo‐Gangetic Plain, IGP) more proximal to the Himalayas at par with the dust delivery from remote natural deserts including Thar. This new data set has the potential to serve as the Thar sediment signatures in regional provenance studies. Key Points: Sandy Thar sediments collected from different dune types exposed over key lithologies are geochemically/isotopically indistinguishableThar sediments have a predominantly Indus provenance with significant contributions from upwind Ghaggar‐Hakra paleochannelsProximal Indo‐Gangetic Plain has dust contributions to the Himalayan frontal glaciers at par with that from the Thar Desert [ABSTRACT FROM AUTHOR]

Mineral dust from the Sahara desert can travel long distances at high altitudes, perturbing the energy budget of the atmosphere. Charging of dust has been observed to occur near the surface through triboelectric charging during dust lofting, potentially affecting particle coagulation, fall speeds, and the lofting process itself. Apart from near-surface studies, measurements at elevated dust layers, where charge may play a role in particle long-range transport, are rare. This study presents new observations from an uncrewed aircraft system (UAS) of type MASC-3, through an elevated Saharan dust layer over Cyprus on 6 April 2022. The dust layer ranged from 1500 to 2500 meters above sea level (a.s.l), with maximum particle number concentrations (PNC) of 80–100 cm − 3 , primarily consisting of particles up to 2.5 µm in size. Measurements showed elevated charge within the dust layer, with magnitude proportional to PNC. It was concluded that there was a small influence of aircraft charge on the measurements, which was handled by developing a PNC-based correction factor. Corrected charge within the dust layer ranged from 0.2 to 3 pC m − 3 , with most of the charge at the upper and lower dust layer boundaries. The magnitude and location of the charge was consistent with predictions of ion-particle attachment. This suggests that most of the measured charge did not originate from the lofting process, but dust particles were charged on site through ion-particle attachment processes. [ABSTRACT FROM AUTHOR]

Mineral dust plays an important role in Earth's climate system, yet it is difficult to identify dust imprints in paleofluvial sediments, especially on orbital timescales. Here, we present high‐resolution authigenic carbonate Ca–Mg–Sr compositions in a fluvial sequence under the transport pathway of Asian dust. The Mg/Ca, Sr/Ca, and Mg/Sr ratios exhibit distinct transitions in both secular trends and orbital cycles at ∼8 Ma. Before ∼8 Ma, given similar Mg and Sr partitioning behaviors during carbonate formation, hydroclimate changes yielded strong orbital signals in the Sr/Ca and Mg/Ca ratios but no detectable signals in the Mg/Sr ratios. After ∼8 Ma, given the strengthened input of Mg‐rich dust during cold‒dry periods, the Mg/Sr and Mg/Ca ratios clearly exhibited orbital signals, but the Sr/Ca ratio did not. Such transitions in carbonate composition corroborate the dust‐induced changes in fluvial hydrochemistry, offering an innovative methodology for detecting orbital dust cycles in paleofluvial systems. Plain Language Summary: A set of criteria, that is, transport and sedimentation dynamics, the surface morphology of quartz grains and provenance indices, were employed to recognize eolian deposits in past fluvial sediments. However, distinguishing eolian dust at orbital scales poses a challenge, as high‐resolution records that meet these criteria are difficult to reconstruct. Here, we present high‐resolution records of authigenic carbonate compositions from Neogene fluvial sediments in the Linxia Basin, a key downwind catchment area for Asian dust. The carbonate elemental compositions, in conjunction with sedimentary Sr‒Nd isotopes, exhibit a long‐term two‐stage evolution marked by a pivotal shift at ∼8 Ma. This transition is most likely attributed to an increase in Asian dust deposition since that time. On orbital timescales, the periodic fluctuations in extrabasinal dust flux, characterized by Mg‐rich but Sr‐poor components (mostly dolomite), have led to pronounced alterations in the orbital patterns of carbonate Ca‐Mg‐Sr compositions since ∼8 Ma. Our findings indicate that carbonate Ca‐Mg‐Sr compositions can offer a straightforward and innovative approach for pinpointing eolian dust activity on orbital timescales when extrabasinal dust can be appropriately distinguished. Key Points: A close examination of carbonate compositions offers a new method for identifying orbital dust cycles within continental fluvial systemsThe authigenic carbonate composition in a fluvial sequence in NE Tibet shows a distinct orbital transition at ∼8 MaMg‐rich dust markedly altered the river chemistry during the cold/arid stages, with a less pronounced effect during the warm/humid stages [ABSTRACT FROM AUTHOR]

In order to evaluate the beneficiation plant environment in a more scientific and reasonable way, this paper took the workshop environment of the beneficiation plant as the research object. This paper divided the beneficiation plant into 7 evaluation units according to its functions. The evaluation indices are dust, noise, light environment, microclimate, benzene, toluene and xylene. This paper combines the G1 method and the entropy weight method to evaluate the weight of each evaluation index, the element extension model of the concentrator working environment is established by the element analysis method, and the matter element analysis method is used to establish an evaluation index system of a beneficiation plant in East China. The results show that the evaluation level of the breaking workshop and the auxiliary facilities are unqualified, the auxiliary facility is qualified, the culling workshop, culled yard and accessory building are medium, the screening workshop and grinding workshop are good. [ABSTRACT FROM AUTHOR]

A new version of the CHIMERE model is presented. This version contains both computational and physico-chemical changes. The computational changes make it easy to choose the variables to be extracted as a result, including values of maximum sub-hourly concentrations. Performance tests show that the model is 1.5 to 2 times faster than the previous version for the same setup. Processes such as turbulence, transport schemes and dry deposition have been modified and updated. Optimization was also performed for the management of emissions such as anthropogenic and mineral dust. The impact of fires on wind speed, soil properties and leaf area index (LAI) was added. Pollen emissions, transport and deposition were added for birch, ragweed, olive and grass. The model is validated with a simulation covering Europe with a 60 km × 60 km resolution and the entire year of 2019. Results are compared to various measurements, and statistical scores show that the model provides better results than the previous versions. [ABSTRACT FROM AUTHOR]

In the confined spaces of underground mines, the exposure of over 10,000 miners in the U.S. to diesel exhaust and diesel particulate matter (DPM) is an occupational inevitability, particularly in metal and nonmetal mineral extraction. These workers routinely operate amidst diesel-powered equipment, often outdated and highly polluting, extracting resources such as limestone, gold, and salt. The acute health effects of such exposure are significant, leading to symptoms like headaches and flu-like conditions, with the impact being more pronounced in these closed work environments. This review scrutinizes DPM's hazard in the mining sector, consolidating the extant knowledge and exploring ongoing research. It encapsulates our understanding of DPM's physicochemical properties, existing sampling methods, health ramifications, and mitigation technologies. Moreover, it underscores the necessity for further study in areas such as the evolution of DPM's physicochemical attributes, from its genesis at high-pressure, high-temperature conditions within diesel engines to its emission into the mine atmosphere. A key research gap is the intricate interaction of DPM with specific characteristics of the mine environment—such as relative humidity, ambient temperature, the presence of other mineral dust, and the dynamics of ventilation air. These factors can significantly alter the physicochemical profile of DPM, influencing both its in-mine transport and its deposition behavior. Consequently, this can affect the respiratory health of miners, modifying the toxicity and the respiratory deposition of DPM particles. Identified research imperatives include (1) the advancement of instrumentation for accurate number measurement of DPM to replace or supplement traditional gravimetric methods; (2) the development of long-lasting, cost-effective control technologies tailored for the mining industry; (3) an in-depth investigation of DPM interactions within the unique mine microclimate, considering the critical components like humidity and other aerosols; and (4) understanding the differential impact of DPM in mining compared to other industries, informing the creation of mining-specific health and safety protocols. This review's findings underscore the urgency to enhance emission control and exposure prevention strategies, paving the way for a healthier underground mining work environment. [ABSTRACT FROM AUTHOR]

Ice nucleating particles (INPs) are rare particles that initiate primary ice formation, a critical step required for subsequent important cloud microphysical processes that ultimately govern cloud phase and cloud radiative properties. Laboratory studies have found that organic‐rich dusts, such as those found in soils, are more efficient INPs compared to mineral dust. However, the atmospheric relevance of these organic‐rich dusts are not well understood, particularly in regions with significant agricultural activity. The Agricultural Ice nuclei at the Southern Great Plains field campaign (AGINSGP) was conducted in rural Oklahoma to investigate how soil dusts contribute to INP populations in the Great Plains. We present chemical characterization of ambient and ice crystal residual particles from a single day of sampling, using single particle mass spectrometry (SPMS) and scanning microscopy. Ambient particles were primarily carbonaceous or secondary aerosol, while the fraction of dust particles was higher in the residual particles. We also observed an unusual particle type consisting of a carbonaceous core mixed with dust fragments on the surface, which was found in higher proportion in residuals. Dust particles measured during residual sampling contained greater proportions of phosphate (63PO2− ${\text{PO}}_{2}^{-}$ and 79PO3− ${\text{PO}}_{3}^{-}$) and lead (206Pb+). Strong sulfate signals were not seen in the residual dust particles measured by the SPMS, while nitrate was slightly depleted relative to ambient dust. This study shows that organic‐rich soils may be important contributors to the ambient INP population in agricultural regions. Plain Language Summary: Ice nucleating particles (INPs) affect climate by causing clouds to freeze at warmer temperatures. However, they are very rare which this means that they are challenging to characterize. Agricultural soils have exhibited high ice nucleation activity in lab studies though their relevance to ambient INP populations is unknown. In this work, we directly measure INP composition in a field campaign at a site in the middle of farmlands to determine whether they are an important source of INPs. We show that dust particles, along with carbonaceous particles mixed with dust, are enriched in INP samples relative to ambient particles. We also show that phosphate (presumed to come from biological fragments) and lead may enhance the IN activity of dust particles. Key Points: Ice nucleating particle composition was directly measured with the ice crystal residual method using two characterization techniquesDust residual particles contained greater phosphate and lead relative to ambient dust particlesCarbonaceous particles internally mixed with dust fragments were found in residual particles measured by SEM/EDX [ABSTRACT FROM AUTHOR]

In this study we present data collected between August 2017 and December 2018 from submarine sediment trap M1 located in the eastern tropical North Atlantic and determine lithogenic and biogenic fluxes, and grain-size distributions of aerosol dust. An unprecedented high sampling resolution of four days in combination with satellite imagery allowed the identification of thirteen major dust events of two types within the 468-day series. Seven dust events were classified as high-flux events identified by a deposition of >=25 mg m-2 d-1. The average dust deposition rate increased by 461.3% during these types of events. The remaining six events were characterized by a high composition of giant particles (>7.3 vol%). Seasonal variations of dust flux were recorded, with highest fluxes observed in spring at an average deposition rate of 14.8 mgm-2 d-1, and lowest fluxes in fall with an average rate of 8.6 mg m-2 d-1. The estimated total dust flux in the tropical North Atlantic was 4040.02 mg m-2 y-1. We suggest that most of the summer dust was likely transported over the sampling site at high altitudes while winter transport occurred closer to the sea surface, resulting in generally higher background fluxes. Grain-size distributions exhibited seasonal variations with increased occurrences of giant particles (>62.5 mm) in fall 2017 and spring, and less occurrences in winter and fall 2018. Grain-size sorting was high in spring and most variable in summer. Precipitation did not affect depositional fluxes or grain-size distributions of the aeolian dust significantly. Organic matter was deposited continuously at the sampling site with a deposition rate ranging from 14.4-862.25 mg m-2 d-1. Organic matter fluxes increased by 199.5% during high-flux dust events but decreased by 13.6% during anomalous grain-size events. Spring experienced the highest number of dust events (n=5). This unprecedented high-resolution dataset of dust deposition in marine sediment-traps enabled the distinction of dust events and their relation to organic matter flux. This suggests the possibility of a dust fertilization or mineral ballasting effect. [ABSTRACT FROM AUTHOR]

Assessment of the concentrations of dust pollution resulting from both measurements at reference stations and those determined using mathematical modelling requires accurate identification of the sources of emission. Although the concentration of dust results from several complex transport processes, as well as chemical and microphysical transformations of aerosols, sources of emissions may have a significant impact on the local level of pollution. This pilot study aimed to use measurements of the concentrations of dust (with the specification of the PM10 and PM2.5 fractions) made over a heap/excavation and its surroundings using an airship equipped with equipment for testing the optical and microphysical properties of atmospheric aerosols, and a ground station located at the facility. On the basis of the measurements, the function of the source of emissions of dust was estimated. According to our study, the yearly emission of dust varies between 42,470 and 886,289 kg for PM10, and between 42,470 and 803,893 for PM2.5 (minimum and maximum values). A model of local air quality was also used, which allowed us to verify the parameterization of emissions of dust pollutants for the PM10 and PM2.5 fractions from heaps and excavations based on the modelling results. [ABSTRACT FROM AUTHOR]

This study analyses the trends of total aerosol and the main aerosol species over nine capitals in the Baltic Sea basin from 1989 to 2019 based on the Modern-Era Retrospective Analysis for Research and Applications, Version 2 Reanalysis. Aerosol speciation includes mineral dust, sea salt, sulphate (SO4), organic carbon (OC), and black carbon (BC). The mean total aerosol optical depth (AOD) values were the highest (up to 0.216) over the continental capitals (i.e., Warsaw, Berlin, and Vilnius). For each capital, the mean SO4 AOD was the main aerosol species, with a trend specular to total AOD. Apart from Warsaw, the mean BC AOD was the aerosol species with the lowest level. The composition of aerosols changed with respect to the species of anthropogenic origins (i.e., SO4, OC, and BC), with the percentage contribution to the total AOD decreasing for the SO4 AOD and increasing for the BC AOD. Also, the OC AOD showed an increase in the percentage contribution to total AOD for Copenhagen, Oslo, Stockholm, and the continental capitals. Anthropogenic aerosols contributed up to 90.3% of the total AOD, with the highest values over the continental capitals. For each capital, the minimum in the percentage contribution of anthropogenic AOD was between 2007 and 2008, likely due to the global financial crisis. Anthropogenic AOD as a percentage of the total AOD decreased from 1989 to 2008. Both the total and the SO4 AODs decreased over each capital. By contrast, the BC AOD increased over Stockholm, and both the OC and BC AODs increased over Berlin, Copenhagen, and Oslo. The decoupling of carbonaceous aerosols and the SO4 AOD trends was likely due to concurrent factors such as biomass burning and low-sulphur fuel policies. From 2000 to 2019, the inverse relationships between gross domestic products and SO4 AODs suggest a relative decoupling of economic growth from fossil fuels for Oslo, Stockholm, Tallinn, and Vilnius. [ABSTRACT FROM AUTHOR]

The spatial–temporal variations of fine particulate matter (PM2.5) in Akure, a city in southwestern Nigeria, are examined based on multi-year continuous observations using low-cost PM2.5 sensors at six different sites. The average annual concentration of PM2.5 across these sites was measured at 41.0 µg/m3, which surpassed both the Nigerian national air quality standard and the World Health Organization air quality guideline level. PM2.5 levels were significantly higher during the dry season (November–March), often exceeding hazardous levels (over 350 µg/m3), than during the wet season. The analyses of trends in air mass trajectories and satellite data on fire occurrences imply that the transport of dust and accumulation of PM2.5 originating from local/regional open burning activities played crucial roles in increased PM2.5 concentrations during the dry season. Further, site-to-site variations in the PM2.5 levels were observed, with relatively high concentrations at less urbanized sites, likely due to high local emissions from solid fuel combustion, waste burning, and unpaved road dust. Diurnal patterns showed morning and evening peaks at less urbanized sites, accounting for an estimated 51–77% of local emissions. These results highlight the importance of local emission sources in driving spatial–temporal PM2.5 variations within the city and the need for targeted mitigation strategies to address the significant air pollution challenges in Akure and similar regional cities in West Africa. [ABSTRACT FROM AUTHOR]

The Solar Resource estimate (SolaRes) tool based on the Speed-up Monte Carlo Advanced Radiative Transfer code using GPU (SMART-G) has the ambition to fulfil both research and industrial applications by providing accurate, precise, and high-time-resolution simulations of the solar resource. We investigate the capacity of SolaRes to reproduce the radiation field, relying on 2 years of ground-based measurements by pyrheliometers and pyranometers acquired in northern France (Lille and Palaiseau). Our main objective is to provide, as a first step in clear-sky conditions, a thorough regional validation of SolaRes, allowing us to investigate aerosol impacts on solar resource. We perform comparisons between SolaRes-simulated and clear-sky-measured global horizontal irradiance (GHI), direct normal irradiance (DNI), diffuse horizontal irradiance (DifHI), and global and diffuse irradiance on a tilted plane (GTI, DifTI), and we even consider the circumsolar contributions. Using spectral aerosol optical thickness (AOT) data sets as input, which are delivered by the AErosol RObotic NETwork (AERONET) and the Copernicus Atmosphere Monitoring Service (CAMS), we examine the influence of aerosol input data sets in SolaRes on the comparison scores. Two aerosol models are mixed to compute aerosol optical properties. We also perform a sensitivity study on the aerosol parametrisation and investigate the influence of applying more or less strict cloud-screening methods to derive ground-based proof data sets of clear-sky moments. SolaRes is validated with the (relative) root mean square difference (RMSD) in GHI as low as 1 % and a negligible mean bias difference (MBD). The impact of the cloud-screening method in GHI is 0.5 % of RMSD and 0.3 % of MBD. SolaRes also estimates the circumsolar contribution, which improves MBD in DNI and DifHI by 1 % and 4 %, respectively, and RMSD by ∼ 0.5 %. MBD in DNI is around - 1 % and RMSD around 2 %, and MBD in DifHI is 2 % and RMSD around 9 %. RMSD and MBD in both DNI and DifHI are larger than in GHI because they are more sensitive to the aerosol and surface properties. DifTI measured on a vertical plane facing south is simulated by SolaRes with an RMSD of 8 %, comparable to that obtained for DifHI. Our results suggest a strong influence of reflection by not only ground surface but also surrounding buildings. The sensitivity studies on the aerosol parameterisation show that the spectral AOT contains enough information for high performance in DNI simulations, with low influence of the choice of the aerosol models on the RMSD. However, choosing a model with smaller aerosol single scattering albedo significantly decreases SolaRes DifHI and GHI. The best combination in Lille and Palaiseau consists of continental clean mixed with desert dust. Also, complementary information on angular scattering and aerosol absorption provided by the AERONET-inverted model further improves simulated clear-sky GHI by reducing RMSD by ∼ 0.5 % and MBD by ∼ 0.8 %. Eventually, the choice of the data source has a significant influence. Indeed, using CAMS AOT instead of AERONET AOT increases the RMSD in GHI by ∼ 1 % and MBD by ∼ 0.4 % and RMSD in DNI by 5 %. The RMSD in GHI remains slightly smaller than state-of-the-art methods. [ABSTRACT FROM AUTHOR]

Maize is a major staple food in Africa, its production and post-harvest generally occurs on smallholder farmers' properties, where significant food losses occur in the field during harvesting, processing and storage. Most smallholder farmers lack access to modern methods of harvesting, processing and storage. Generally, the storage structures used are ineffective against storage pests, leading to postharvest losses due to insect pests that, in some cases, can reach about 40% of the total production. Pest control is generally scarce, and when adopted, it is based on local knowledge-based pest control alternatives or on the application of synthetic pesticides known to be harmful to the environment and human and animal health. So, alternative pest control methods commonly found include the use of inert dust as an integrated pest management approach, without residual effects and ideal for food safety. This study aimed to determine the efficacy of charcoal powder (CP) and rock dust (RD) alone or combined with diatomaceous earth (DE) in the control of rice weevil (Sitophilus oryzae). Maize grains were treated and infested by the addition of Sitophilus oryzae, on the day they were treated and, 30 and 60 days after treatment. Mortality was assessed at 10 and 20 days after each infestation. Emerged insects were counted 40 days after the second mortality assessment for each infestation period. At 90 days after treatment, the seed germination test was performed. The best treatments for Sitophilus oryzae control (mortality) and F1 emergence reduction were RD (0.5, 0.25 and 0.10 g/kg), RD+DE (0.5+0.05, 0.25+0.05 and 0.10+0.05 g/kg), and CP+DE (1.0+0.05, 0.50+0.05 and 0.25+0.05 g/kg). The RD and RD+DE remained efficient in maize treated and stored for 60 days. The treatments did not interfere with seed germination. Rock Dusts, RD+DE, and CP have the potential to be used as stored grain protectants, providing economically and environmentally friendly pest control alternatives, especially in small-scale agriculture. In developing countries, especially in sub-Saharan Africa, studies for optimization and introduction of inert dusts tested in this research, have the potential to reduce post-harvest losses, improving food security. [ABSTRACT FROM AUTHOR]

Atmospheric mineral dust aerosol constitutes a threat to aircraft engines from deterioration of internal components. Here we fulfil an overdue need to quantify engine dust ingestion at airports worldwide. The vertical distribution of dust is of key importance since ascent/descent rates and engine power both vary with altitude and affect dust ingestion. We use representative jet engine power profile information combined with vertically and seasonally varying dust concentrations to calculate the "dust dose" ingested by an engine over a single ascent or descent. Using the Copernicus Atmosphere Monitoring Service (CAMS) model reanalysis, we calculate climatological and seasonal dust dose at 10 airports for 2003–2019. Dust doses are mostly largest in Northern Hemisphere summer for descent, with the largest at Delhi in June–August (JJA; 6.6 g) followed by Niamey in March–May (MAM; 4.7 g) and Dubai in JJA (4.3 g). Holding patterns at altitudes coincident with peak dust concentrations can lead to substantial quantities of dust ingestion, resulting in a larger dose than the take-off, climb, and taxi phases. We compare dust dose calculated from CAMS to spaceborne lidar observations from two dust datasets derived from the Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP). In general, seasonal and spatial patterns are similar between CAMS and CALIOP, though large variations in dose magnitude are found, with CAMS producing lower doses by a factor of 1.9 to 2.8, particularly when peak dust concentration is very close to the surface. We show that mitigating action to reduce engine dust damage could be achieved, firstly by moving arrivals and departures to after sunset and secondly by altering the altitude of the holding pattern away from that of the local dust peak altitude, reducing dust dose by up to 44 % and 41 % respectively. We suggest that a likely low bias of dust concentration in the CAMS reanalysis should be considered by aviation stakeholders when estimating dust-induced engine wear. [ABSTRACT FROM AUTHOR]

Temperature and mineral dust records serve as valuable palaeoclimatic indicators for studying atmospheric variability across different temporal scales. In this study, we employed Haar fluctuations to analyse global spatiotemporal atmospheric variability over the Last Glacial Cycle, capturing both high- and low-frequency information within the records, regardless of uniform or non-uniform sampling. Furthermore, we utilised Haar fluctuations to compute fluctuation correlations, thereby enhancing our understanding of palaeoclimate dynamics. Our findings reveal a latitudinal dependency in the transition from macroweather to climate regimes (τc), with polar regions experiencing shorter transitions compared to the tropics and mid-latitudes. These transitions occur at approximately 1/100 th of glacial cycle length scales, suggesting a dominant forcing mechanism beyond Milankovitch cycles. Additionally, our analysis shows that polar regions have larger fluctuation amplitudes than lower latitudes as a consequence of the polar amplification effect. Furthermore, fluctuation correlations demonstrate faster synchronisation between the poles themselves compared to lower-latitude sites, achieving high correlation values within 10 kyr. Therefore, our findings suggest a consistent climate signal propagating from the poles to the Equator, representing the first empirical evidence supporting the hypothesis that the poles play a pivotal role as climate change drivers, influencing the variability in climatic transitions worldwide. [ABSTRACT FROM AUTHOR]

Various fire emission estimates for southern Africa during 2019, derived with multiple burned area data sets with resolutions ranging from 500 to 20 m, are evaluated using satellite carbon monoxide (CO) observations. Southern African emissions derived from burned area generated by 20 m Sentinel‐2 satellite imagery are up to 120% higher than other estimates because small fires are better detected with a higher‐resolution satellite instrument. A comprehensive comparison between simulated and observed atmospheric CO indicates that the Sentinel‐2 burned area data significantly improves emission estimates, with up to 15% reduction in CO concentration biases in comparison to emissions based on coarser resolution burned area data. We also found that the temporal lag between emissions and atmospheric CO concentrations during the peak fire month was related to atmospheric transport. These findings emphasize the importance of utilizing higher‐resolution satellite instruments in accurately estimating emissions and understanding the impact of small fires on global climate. Plain Language Summary: We studied how much carbon monoxide (CO) was released into the air in southern Africa due to fires. To derive CO emissions we used different remotely sensed data of area burned, with varying levels of detail, from 500 to 20 m, and used these emissions in a model to mimic atmospheric transport and chemistry of CO. We found that emissions derived from the very detailed 20‐m satellite images from Sentinel‐2 produced a similar large amount of CO in the atmosphere over southern Africa as seen by CO satellite observations. This is because the smaller fires, which are harder to spot, were detected with the 20‐m burned area satellite observations. We also found that the air movement and inflow of polluted air from outside Africa impacted the peak of air pollution. Key Points: Sentinel‐2 burned area detects small fires, resulting in up to 120% higher fire emissions compared to conventional resolution estimatesImproved fuel load modeling and new emission factors yield more trustworthy fire emissions that can be evaluated with top‐down constraintsAtmospheric modeling and TROPOMI CO observations indicate a 15% bias reduction using Sentinel‐2 burned area compared with coarser fire data [ABSTRACT FROM AUTHOR]

Aerosol optical depth (AOD) is a vital parameter in atmospheric research. Using observations of the Visible Infrared Imaging Radiometer Suite (VIIRS), onboard Suomi National Polar‐orbiting Partnership (Suomi‐NPP) and NOAA‐20 satellites, National Oceanic and Atmospheric Administration (NOAA) produces near‐real time AOD product with high pixel resolution (750 m), wide swath width (3,040 km), and a 16‐day repeat cycle. Here we report the evaluation of the NOAA/VIIRS AOD using a comprehensive aerosol data set, derived from a global‐scale, multi‐seasonal airborne mission, the NASA Atmospheric Tomography Mission (ATom). This data set includes rich physical and chemical information, such as size distributions, chemical compositions, optical properties, and hygroscopicities of major aerosol types, including dust, sea salt, smoke, internally mixed sulfate/nitrate/organics particles (non‐smoke), black carbon, etc. Globally, VIIRS AOD (Suomi‐NPP and NOAA‐20) shows good agreement with the ATom AOD in the moderate to high AOD range (>0.3), with respect to measurement uncertainties (orthogonal distance regression fitting slope: 1.5 ± 0.2 for Suomi‐NPP and 1.6 ± 0.5 for NOAA‐20; correlation coefficient: 0.85 for Suomi‐NPP and 0.73 for NOAA‐20). There is a persistent bias in the low AOD range (<0.3) on the order of 0.03, likely reflecting systematic errors on VIIRS and/or the ATom AOD product. Ångström exponent reported by VIIRS shows excellent agreement with ATom results within expected uncertainties. Given the unique insights revealed by the ATom AOD and aerosol property data set, it is desirable to have ATom‐like comprehensive payloads in future airborne satellite validation programs. Plain Language Summary: Aerosol optical depth (AOD) plays a crucial role in air quality and climate. Satellites have been used to retrieve AOD and other aerosol properties for decades; but satellite retrievals are indirect measurements and need validation using direct measurements. Visible Infrared Imaging Radiometer Suite (VIIRS) is the state‐of‐the‐art instrument that retrieves AOD along with other aerosol properties. In this work, we use the comprehensive aerosol data set from the recent global‐scale, multi‐seasonal ATom field campaign, to evaluate the operational VIIRS AOD product on two satellites (NOAA‐20 and SNPP). This data set includes rich physical and chemical information, such as size distributions, chemical compositions, optical properties, and hygroscopicities of major aerosol types, including dust, sea salt, smoke, internally mixed sulfate/nitrate/organics particles, black carbon, etc. Our analysis shows that the operational VIIRS AOD product is generally accurate and robust. A small bias in the low AOD range has been identified, which could be partially explained by the atmospheric variability, but likely reflects systematic errors on VIIRS and/or the ATom AOD product. Our effort further justifies the global scale suborbital airborne missions (such as HIPPO and ATom) and its unique role in atmospheric/climate research as well as operations. Key Points: National Oceanic and Atmospheric Administration (NOAA)/Visible Infrared Imaging Radiometer Suite (VIIRS) Aerosol optical depth (AOD) (Suomi National Polar‐orbiting Partnership [Suomi‐NPP] and NOAA‐20) generally shows good agreement with the AOD product derived from global‐scale airborne observationsThere is a persistent bias in the low AOD range (<0.3), likely reflecting systematic errors on VIIRS and/or the ATom AOD productComprehensive aerosol observations offer invaluable information for satellite validation and model evaluation [ABSTRACT FROM AUTHOR]

A comprehensive analysis of aerosol characteristics over Saudi Arabia from 2005 to 2022, utilizing high-resolution satellite-based observations and reanalysis datasets, examining the distribution of aerosols and their subtypes across the three dimensions (temporal, spatial, and altitude based) for March, April, and May. This study focuses on the analysis of parameters such as aerosol optical depth (AOD), angstrom exponent (AE), absorption aerosol optical depth (AAOD), and Ultraviolet Aerosol Index (UVAI), revealing significant spatial disparities, with elevated aerosol concentrations in the central and eastern regions and comparatively lower concentrations along the western coastal areas. In this study, the spatial patterns and temporal trends are analyzed through trajectory modeling. The study also investigates the composition of aerosols in various Saudi cities. Aerosols prevailing in a dozen Saudi Arabian cities were systematically categorized into six sub-types, considering their particle size and UV-absorbing properties. Notably, two major aerosol sub-types, absorbing coarse (AC) aerosols (UVAI > 0.25, AE < 0.70) treated as mineral dust and absorbing mixed (AM) aerosols (0.70 < AE < 1.25) along with neutral fine (NF) particles (− 0.5 < UVAI < 0.25, AE > 1.25) treated as urban, predominate across the Kingdom of Saudi Arabia. [ABSTRACT FROM AUTHOR]

A new four-dimensional, multiyear, and near-global climate data record of the fine-mode (submicrometer in terms of diameter) and coarse-mode (supermicrometer in terms of diameter) components of atmospheric pure dust is presented. The separation of the two modes of dust in detected atmospheric dust layers is based on a combination of (1) the total pure-dust product provided by the well-established European Space Agency (ESA) "LIdar climatology of Vertical Aerosol Structure" (LIVAS) database and (2) the coarse-mode component of pure dust provided by the first step of the two-step POlarization LIdar PHOtometer Networking (POLIPHON) technique, developed in the framework of the European Aerosol Research Lidar Network (EARLINET). Accordingly, the fine-mode component of pure dust is extracted as the residual between the LIVAS total pure dust and the coarse-mode component of pure dust. Intermediate steps involve the implementation of regionally dependent lidar-derived lidar ratio values and AErosol RObotic NETwork (AERONET)-based climatological extinction-to-volume conversion factors, facilitating conversion of dust backscatter into extinction and subsequently extinction into mass concentration. The decoupling scheme is applied to observations from the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) at 532 nm. The final products consist of the fine mode and coarse mode of atmospheric pure dust, quality-assured profiles of backscatter coefficient at 532 nm, extinction coefficient at 532 nm, and mass concentration for each of the two components. The datasets are established primarily with the original L2 horizontal (5 km) and vertical (60 m) resolution of the Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) along the CALIPSO orbit path and secondly in averaged profiles of seasonal–temporal resolution, 1° × 1° spatial resolution, and the original vertical resolution of CALIPSO, focusing on the latitudinal band extending between 70° S and 70° N and covering more than 15 years of Earth observations (June 2006–December 2021). The quality of the CALIPSO-based fine-mode and coarse-mode dust products is assessed through the use of AERONET fine-mode and coarse-mode aerosol optical thickness (AOT) interpolated to 532 nm and the AERosol properties – Dust (AER-D) campaign airborne in situ particle size distributions (PSDs) as reference datasets during atmospheric conditions characterized by dust presence. The near-global fine-mode and coarse-mode pure-dust climate data record is considered unique with respect to a wide range of potential applications, including climatological, time series, and trend analysis over extensive geographical domains and temporal periods, validation of atmospheric dust models and reanalysis datasets, assimilation activities, and investigation of the role of airborne dust in radiation and air quality. [ABSTRACT FROM AUTHOR]

Mineralogical composition drives dust impacts on Earth's climate systems. However, most climate models still use homogeneous dust, without accounting for the temporal and spatial variation in mineralogy. To quantify the radiative impact of resolving dust mineralogy on Earth's climate, we implement and simulate the distribution of dust minerals (i.e., illite, kaolinite, smectite, hematite, calcite, feldspar, quartz, and gypsum) from Claquin et al. (1999) (C1999) and activate their interaction with radiation in the GFDL AM4.0 model. Resolving mineralogy reduces dust absorption compared to the homogeneous dust used in the standard GFDL AM4.0 model that assumes a globally uniform hematite volume content of 2.7 % (HD27). The reduction in dust absorption results in improved agreement with observation-based single-scattering albedo (SSA), radiative fluxes from CERES (the Clouds and the Earth's Radiant Energy System), and land surface temperature from the CRU (Climatic Research Unit) compared to the baseline HD27 model version. It also results in distinct radiative impacts on Earth's climate over North Africa. Over the 19-year (from 2001 to 2019) modeled period during JJA (June–July–August), the reduction in dust absorption in AM4.0 leads to a reduction of over 50 % in net downward radiation across the Sahara and approximately 20 % over the Sahel at the top of the atmosphere (TOA) compared to the baseline HD27 model version. The reduced dust absorption weakens the atmospheric warming effect of dust aerosols and leads to an alteration in land surface temperature, resulting in a decrease of 0.66 K over the Sahara and an increase of 0.7 K over the Sahel. The less warming in the atmosphere suppresses ascent and weakens the monsoon inflow from the Gulf of Guinea. This brings less moisture to the Sahel, which combined with decreased ascent induces a reduction of precipitation. To isolate the effect of reduced absorption compared to resolving spatial and temporal mineralogy, we carry out a simulation where the hematite volume content of homogeneous dust is reduced from 2.7 % to 0.9 % (HD09). The dust absorption (e.g., single-scattering albedo) of HD09 is comparable to that of the mineralogically speciated model on a global mean scale, albeit with a lower spatial variation that arises solely from particle size. Comparison of the two models indicates that the spatial inhomogeneity in dust absorption resulting from resolving mineralogy does not have significant impacts on Earth's radiation and climate, provided there is a similar level of dust absorption on a global mean scale before and after resolving dust mineralogy. However, uncertainties related to emission and distribution of minerals may blur the advantages of resolving minerals to study their impact on radiation, cloud properties, ocean biogeochemistry, air quality, and photochemistry. On the other hand, lumping together clay minerals (i.e., illite, kaolinite, and smectite), but excluding externally mixed hematite and gypsum, appears to provide both computational efficiency and relative accuracy. Nevertheless, for specific research, it may be necessary to fully resolve mineralogy to achieve accuracy. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated that the amount of specific airborne mold types and their concentrations increase during dust events. This study investigates the seasonal variation of airborne mold concentrations before, during, and after the dust transport in an eastern Mediterranean coastal area, Izmir city, Turkey. A total of 136 airborne mold samples were collected between September 2020 and May 2021. Two different culture media, namely Potato Dextrose Agar (PDA) and Malt-Extract Agar (MEA), were used for enumeration and genus-based identification of the airborne mold. In addition to culture media, the influences of air temperature, relative humidity, and particulate matter equal to or less than 10 µm (PM10) were also investigated seasonally. The HYSPLIT trajectory model and web-based simulation results were mainly used to determine dusty days. The mean total mold concentrations (TMC) on dusty days (543 Colony Forming Unit (CFU)/m3 on PDA and 668 CFU/m3 on MEA) were approximately 2–2.5 times higher than those on non-dusty days (288 CFU/m3 on PDA and 254 CFU/m3 on MEA) for both culture media. TMC levels showed seasonal variations (p < 0.001), indicating that meteorological parameters influenced mold concentrations and compositions. Some mold genera, including Cladosporium sp., Chrysosporium sp., Aspergillus sp., Bipolaris sp., Alternaria sp., and yeast, were found higher during dusty days than non-dusty days. Thus, dust event impacts levels and types of airborne molds and has implications for regions where long-range dust transport widely occurs. [ABSTRACT FROM AUTHOR]

Airborne mineral dust significantly impacts air quality, human health, and the global climate. Due to sparse ground sensors, particularly in source regions, dust monitoring relies mainly on remote sensing through Aerosol Optical Depth (AOD) retrievals from polar-orbiting satellite optical instruments. These are valuable but lack the temporal resolution for precise plume tracking and source characterization. We introduce DustSCAN, a five-year, hourly dust plume dataset derived from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) images on geostationary-orbit Meteosat satellites. Using multi-channel infrared images, we detect atmospheric dust and track hourly dust-affected pixels. These are clustered into discrete plumes using the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm. DustSCAN includes 9950 discrete plumes over 2018-2022 across the Sahara, the Arabian Desert, and Western and Central Asia. It complements existing resources and provides a framework for detailed analysis of dust sources, trajectories, and impacts. Its distinctive event-based and spatio-temporal detail offers an advancement in unraveling the complexities of dust storm dynamics. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effect of rock types, i.e., granite, conglomerate rock, limestone, and crushing mechanism, i.e., Vertical Shaft Impact (VSI) crusher, Horizontal Shaft Impact (HSI) crusher, on the morphology of manufactured sands. By combining the 3D scanning and spherical harmonic analysis, the morphological parameters of manufactured sands such as elongation ratio (EL), flatness ratio (Fl), aspect ratio (AR), edge angle (EA), sphericity (SH), and fractal dimension were quantified. The results indicate limestone is more readily broken into blade-shaped particles without being able to blunt sharp edges through constant abrasion. The proportion of bladed particles in manufactured sand prepared from limestone is 1.91 times higher than the proportion of bladed particles in conglomerates. Additionally, the HSI crusher has a more significant effect on rocks with smaller strength. For the same parent rock, manufactured sand from a VSI crusher contains 30% more spherical and oblate particles than from an HSI crusher. [ABSTRACT FROM AUTHOR]

To investigate air pollution in the kerbside environment and its associated human health risks, a study was conducted in Lanzhou during December 2018, as well as in April, June, and September 2019. The research aimed to characterize the composition of PM10 and PM2.5, including elements, ions, and carbonaceous components, at both rooftop and kerbside locations. Additionally, source apportionment and health risk assessment were conducted. The results showed that the average mass concentrations of PM10 on the rooftop were 176.01 ± 83.23 μg/m3, and for PM2.5, it was 94.07 ± 64.89 μg/m3. The PM10 and PM2.5 levels at the kerbside are 2.21 times and 1.79 times, respectively, greater than those on the rooftop. Moreover, the concentrations of elements, ions, and carbonaceous components in kerbside PM were higher than those at the rooftop location. Chemical mass closure analysis identified various sources, including organic matter, mineral dust, secondary ions, other ions, elements, and other components. In comparison to rooftop particulate matter (PM), mineral dust makes a more substantial contribution to kerbside PM. Secondary ions show an opposite trend, making a greater contribution to rooftop PM. The contribution of organic components within PM of the same particle size remains relatively consistent. The outcome of the health risk assessment indicates that Co, Cd, and As in PM within the kerbside and rooftop environments do not pose a notable carcinogenic risk. However, Al and Mn do present specific non-carcinogenic risks, particularly in the kerbside environment. Furthermore, children experience elevated non-carcinogenic risk compared to adults. These findings can serve as a scientific foundation for formulating policies within the local health department. [ABSTRACT FROM AUTHOR]

WRF-Chem is widely used to assess regional aerosol radiative feedback. However, in current version, aerosol optical properties are only calculated in four shortwave bands, and only two of them are used to "interpolate" optical properties towards 14 shortwave bands used in the Rapid Radiative Transfer Model (RRTMG) scheme. In this study, we use a "Resolved" algorithm to estimate aerosol radiative feedback in WRF-Chem, in which aerosol optical properties are calculated in all 14 shortwave bands. The impacts of changing this calculation algorithm are then evaluated. The simulation results of aerosol optical properties are quite different using the new "Resolved" algorithm, especially for dust aerosols. The alteration of aerosol optical properties result in considerably different aerosol radiative effects: the dust radiative forcing in the atmosphere simulated by the "Resovled" algorithm is about two times larger than the original "Interpolated" algorithm; The dust radiative forcing at top of the atmosphere (TOA) simulated by the "Interpolated" algorithm is negative in all Sahara region, while the "Resolved" algorithm simulates positive forcing at TOA and can exceed 10 W/m2 in the Sahara desert, which is more consistent with previous studies. The modification also leads to changes in meteorological fields due to alterations in radiative feedback effects of aerosols. The surface temperature is changed due to the difference in radiation budget at the bottom of the atmosphere (BOT) and the heating effects by aerosols at the surface. Furthermore, the amendment of algorithm partially corrects the wind field and temperature simulation bias compared to the reanalysis data. The difference in planet boundary layer height can reach up to ~100 m in China and ~200 m in Sahara, further resulting in a greater surface haze considerably. The results show that correcting the estimation algorithm of aerosol radiative effects is necessary in WRF-Chem model. [ABSTRACT FROM AUTHOR]

The chronic exposure to particulate matter (PM) pollution causes societal and environmental issues, in particular in urban areas where most citizen are regularly exposed to vehicular traffic. Since almost two decades, environmental magnetic monitoring has demonstrated its efficiency to successfully map relative concentrations of airborne particle deposition on accumulative surfaces. A better understanding of the magnetic results requires discriminating the main traffic-related sources of the observed signal on particle collectors. To meet this objective, we investigated a sample set of exhaust and non-exhaust sources with respect to their magnetic fingerprints inferred from hysteresis loops, first-order reversal curve (FORC) diagrams, temperature dependency of initial susceptibility and unmixing of isothermal remanent magnetization acquisition curves. The source sample set comprises 14 diesel and gasoline exhaust smoke residues, 12 abrasive-fatigue wear test pieces from worn brake-pads, brake powders, worn tire-tread and three resuspension products: asphalt concrete, street dust and Saharan mineral dust deposited by precipitation after long-range eolian transport. Magnetic properties of the source samples were compared to those from various accumulative surfaces exposed to urban traffic (passive collectors, filters of facemasks for cycling, plant leaves and tree barks). We found some fingerprints of exhaust pipes and brake wear products on these collectors. The findings highlight the relevance of environmental magnetism tools to characterize different traffic-related source signals in accumulative surfaces in urban environment. [ABSTRACT FROM AUTHOR]

The detection and evaluation of biomass burning and dust events are critical for understanding their impact on air quality, climate, and human health, particularly in the Mediterranean region. This research pioneers an innovative methodology that uses Sentinel-2 multispectral (MS) imagery to meticulously pinpoint and analyze long-transport dust outbreaks and biomass burning phenomena, originating both locally and transported from remote areas. We developed the dust/biomass burning (DBB) composite normalized differential index, a tool that identifies clear, dusty, and biomass burning scenarios in the selected region. The DBB index jointly employs specific Sentinel-2 bands: B2-B3-B4 for visible light analysis, and B11 and B12 for short-wave infrared (SWIR), exploiting the specificity of each wavelength to assess the presence of different aerosols. A key feature of the DBB index is its normalization by the surface reflectance of the scene, which ensures independence from the underlying texture, such as streets and buildings, for urban areas. The differentiation involves the comparison of the top-of-atmosphere (TOA) reflectance values from aerosol events with those from clear-sky reference images, thereby constituting a sort of calibration. The index is tailored for urban settings, where Sentinel-2 imagery provides a decametric spatial resolution and revisit time of 5 days. The average values of DBB achieve a 96% match with the coarse-mode aerosol optical depths (AOD), measured by a local station of the AERONET network of sun-photometers. In future studies, the map of DBB could be integrated with that achieved from Sentinel-3 images, which offer similar spectral bands, albeit with much less fine spatial resolution, yet benefit from daily coverage. [ABSTRACT FROM AUTHOR]

Melting polar and alpine ice sheets in response to global warming pose ecological and societal risks but will also hamper our ability to reconstruct past climate and atmospheric composition across the globe. Since polar ice caps are crucial environmental archives but highly sensitive to ongoing climate warming, the Arctic and Antarctic research community is increasingly faced with melt-affected ice cores, which are already common in alpine settings of the lower latitudes. Here, we review the characteristics and effects of near-surface melting on ice-core records, focusing on a polar readership and making recommendations for melt-prone study regions. This review first covers melt layer formation, identification and quantification of melt, and structural characteristics of melt features. Subsequently, it discusses effects of melting on records of chemical impurities, i.e. major ions, trace elements, black carbon, and organic species as well as stable water isotopic signatures, gas records, and applications of melt layers as environmental proxies. Melting occurs during positive surface energy balance events, which are shaped by global to local meteorological forcing, regional orography, glacier surface conditions and subsurface characteristics. Meltwater flow ranges from homogeneous wetting to spatially heterogeneous preferential flow paths and is determined by temperature, thermal conductivity and stratigraphy of the snowpack. Melt layers and lenses are the most common consequent features in ice cores and are usually recorded manually or using line scanning. Chemical ice-core proxy records of water-soluble species are generally less preserved than insoluble particles such as black carbon or mineral dust due to their strong elution behaviour during percolation. However, high solubility in ice as observed for ions like F - , Cl - , NH 4+ or ultra-trace elements can counteract the high mobility of these species due to burial in the ice interior. Stable water isotope records like δ18 O are often preserved but appear smoothed if significant amounts of meltwater are involved. Melt-affected ice cores are further faced with questions about the permeability of the firn column for gas movement, and gas concentrations can be increased through dissolution and in situ production. Noble gas ratios can be useful tools for identifying melt-affected profile sections in deep ice. Despite challenges for ice-core climate reconstruction based on chemical records, melt layers are a proxy of warm temperatures above freezing, which is most sensitive in the dry snow and percolation zone. Bringing together insights from snow physics, firn hydrology, and ice-core proxy research, we aim to foster a more comprehensive understanding of ice cores as climate and environmental archives, provide a reference on how to approach melt-affected records, and raise awareness of the limitations and potential of melt layers in ice cores. [ABSTRACT FROM AUTHOR]

In the present study, tests were carried out on composite samples on a polylactide matrix containing 25% by weight of mineral filler in the form of diatomaceous earth, base, and silanized with GPTMOS (3-glycidoxypropyltrimethoxysilane), OTES (n-octyltriethoxysilane), and MTMOS (methyltrimethoxysilane) silanes. The addition of two types of waxes, synthetic polyamide wax and natural beeswax, were used as a factor to increase the rheological properties of the composites. The obtained samples were characterized in terms of the effect of filler silanization on the degradation rate of the composites. The tests were conducted under different conditioning conditions, i.e., after exposure to strong UV radiation for 250 and 500 h, and under natural sunlight for 21 days. The conditioning carried out under natural conditions showed that the modified samples exhibit up to twice the degradation rate of pure polylactide. The addition of synthetic wax to the composites increases the tendency to agglomerate diatomaceous earth, while natural wax has a positive effect on filler dispersion. For composites modified with GPTMOS and OTES silanes, it was noted that the addition of natural wax inhibited the degree of surface degradation, compared to the addition of synthetic wax, while the addition of MTMOS silane caused the opposite effect and samples with natural wax degraded more strongly. It was shown that, despite the high degree of surface degradation, the process does not occur significantly deep into the composite and stops at a certain depth. [ABSTRACT FROM AUTHOR]

Dust resuspension from four typical fabrics (cotton, linen, silk, and polyester) exposed to airflow with common velocities within 0–10 m/s, including a moving fabric case and a fixed fabric case, was experimentally studied in this article. A set of empirical correlations, involving air velocity, fabric motion mode, fabric type, and airflow duration was developed to describe and predict the moving fabric case. It was found that a stronger-than-expected resuspension was triggered by short-term accelerating airflow. The resuspension enhancement of over 90% was reported for the moving fabrics compared with the fixed ones. Fabric motion induced by airflow was proposed to account for these resuspension findings. Fabric acceleration was then demonstrated to be a key factor in evaluating the resuspension for such a scenario. This article not only reveals an inconspicuous phenomenon of dust resuspension from fabrics under the impact of airflow and consequent fabric motion, but also provides a theoretical basis for particulate matter assessment and regulation. Copyright © 2024 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]