Atmospheric Sources Research Articles

Comparison of Identified Ice Supersaturated Regions for Contrail Avoidance Using Three Standard Weather Forecast Databases

Contrails form as a result of water vapor bonding with soot emitted from jet engines at cruise altitudes, leading to contrail formation in Ice Supersaturated Regions (ISSRs). Contrails are estimated to contribute approximately 2% to total anthropogenic global warming. Some researchers have developed simulation models to estimate the frequency, duration, and spatial distribution of contrails. Other researchers have identified issues with the accuracy of the data for predicting the timing and precise geographic positioning of ISSRs. This study presents a systematic review of 22 peer-reviewed articles that included detailed models of ISSR identification, identifying three atmospheric data sources, four parameters, and two equations for calculating the parameters derived. A further analysis revealed differences in the temperature and RHW readings across the three databases, resulting in differences in the RHI calculations and the identification of ISSRs. Over an 18-month period in Sterling, Virginia, USA, the radiosonde data and two atmospheric forecast databases identified the ISSR conditions on 44%, 47%, and 77% of days, respectively. Broken down by a flight level between 30,000 and 39,999 feet in altitude, these differences are highlighted further. The forecast databases overestimated the presence of ISSRs compared to the radiosonde data. These findings underscore the variability inherent in atmospheric datasets and the conversion methods, highlighting potential areas for refinement in ISSR prediction, notably in the development of ensemble forecasts based on several atmospheric databases. The implications of these results, the limitations of this study, and future work are discussed.

Imprint of incomplete combustion processes on the water column of the anthropogenic-pressured Baltic Sea.

This study evaluates the distribution and sources of thermogenic organic matter in the Baltic Sea water column, focusing on polycyclic aromatic hydrocarbons (PAH), dissolved black carbon (DBC), and the imprint of thermogenic organic matter on the dissolved organic matter (DOM) pool. The spatial patterns and complex interactions between land-based and atmospheric sources were assessed from Kiel Bay to Pomeranian Bight within the water column with the combined targeted and untargeted approaches. The findings emphasize the significant influence of terrestrial inputs from the Oder River and autochthonous production composing DOM. In the Pomeranian Bight, PAH and DBC concentrations strongly correlate with land-based discharge, while shipping emissions play a more prominent role in the Arkona Sea. The sea surface microlayer shows unique characteristics in DOM composition, with potential combustion products as an important source revealed by PAH and DOM analyses. Ultrahigh-resolution mass spectrometry identified combustion products, in the DOM pool, providing insights into anthropogenic impacts. This research contributes to a better understanding of the complex dynamics of thermogenic organic matter in coastal environments, highlighting the interplay between land-based sources, shipping emissions, and in-situ processes in the Baltic Sea region.

Reactive species emission characteristics of a cold atmospheric pressure plasma source for biomedical applications operated in a test chamber

This study investigates the potentials and limitations of a novel methodology to characterize the reactive species emission dynamics of cold atmospheric plasma sources for biomedical applications. The time-resolved concentrations of ozone and nitrogen oxides during operation of a modified medical device are sampled in a test chamber environment equipped with a stirring fan for effective mixing of species. The interpretation of experimental data is supported by results from a numerical model solving the diffusion-convection equation. From the linear profiles of O3 and NO2 concentrations, emission rates of 1.3−6.4 μgs-1 for O3 and 0.07-0.1μgs-1 for NO2, depending primarily on plasma input power and fan volume flow rate, were determined for the plasma source. The conversion of these rates into geometry-specific source terms for use in the numerical model led to excellent agreement between experimental and numerical results thus validating the methodology. Finally, empirical equations describing the ozone emission rate dependence on the air flow velocity are presented. The outcomes of this study may stimulate new strategies for assessment of health risks associated with reactive species emission by medical devices based on cold plasma technology.Graphic

Distribution and Source-specific Ecological Risk Analysis of Soil Heavy Metals in South Hunan Province

To identify the spatial distribution patterns and assess the ecological risks associated with soil heavy metal pollution in the southern region of Hunan Province, a total of 362 surface soil samples were collected from the studied area. This study employed multivariate statistics and geographic information systems （GIS） to investigate the spatial distribution pattern of soil metals （Cd, Hg, As, Pb, Zn, Ni, Mn, Tl, and Sb）. Furthermore, the pollution sources and source-specific ecological risk of heavy metals were quantified by combining the positive matrix factorization （PMF） model and the comprehensive ecological risk index model. The results suggested that the mean concentration of soil metals in the study area exceeded the mean background values. Specifically, Cd, Hg, Pb, and Sb showed significant pollution levels and substantial spatial variability, with their concentrations reaching the background values by factors of 8.31, 9.12, 5.09, and 2.79, respectively. The spatial distribution of these heavy metals exhibited discernible patterns, with a higher concentration observed in western Chenzhou and a noticeable trend of increasing concentrations from the central region towards the periphery. The clusters with high concentrations of heavy metals were predominantly situated near industrial zones engaged in black metal smelting and processing and nonferrous metal mining and processing enterprises. Source apportionment indicated that the primary sources of soil heavy metals in the area were industrial activities associated with black metal mining and metallurgy （29.06%）, atmospheric deposition （22.05%）, nonferrous metal mining and processing （20.65%）, a combination of industrial and transportation sources （14.73%）, and natural sources （13.50%）. Moreover, the source-ecological risk assessment model specifically identified Cd and Hg as crucial elements requiring prioritized control measures to mitigate soil ecological risks. Industrial activities, including black metal smelting and processing and atmospheric deposition sources, were identified as the priority sources for health risks in the study region. These results provide an important theoretical basis for the development of effective strategies aimed at managing and diminishing the risks associated with heavy metal contamination in the southern region of Hunan Province.

Intraseasonal Oscillation Intensity Variations of the Atmospheric Heat Source over the Tibetan Plateau and Their Relationship with Summer Precipitation

Intraseasonal Oscillation Intensity Variations of the Atmospheric Heat Source over the Tibetan Plateau and Their Relationship with Summer Precipitation

Inferring atmospheric sources of gaseous organophosphate esters from spatial patterns

Abstract Organophosphate esters (OPEs) have emerged as pervasive environmental contaminants, with concentrations often exceeding those of traditional flame retardants and plasticizers by orders of magnitude. Here, we present concentrations of OPEs in the atmospheric gas phase collected using passive air samplers deployed in the coastal regions of Quebec and British Columbia in Southern Canada. Four OPEs, ie, tri-n-butyl phosphate (TBP), tris(2‑chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris (phenyl) phosphate (TPhP) were reliably and ubiquitously detected, with TCPP showing the highest level, followed by TBP. Concentration levels of TCPP and TCEP are correlated with each other and with population, possibly indicating emission from consumer products. Spatial patterns of TBP and TPhP are more indicative of industrial usage, with airports possibly being a major source for TBP. The positive relationships between atmospheric OPEs and population are influenced by ambient temperature, whereby the size of the populated area around a sampling site influencing the air concentration appears to be decreasing at higher temperatures.

A Review of Sources, Hazards, and Removal Methods of Microplastics in the Environment

The prevalence of microplastics in a wide range of environmental media has attracted increasing attention worldwide. This review article provides a comprehensive and systematic review of the nature, sources, hazards, and removal methods of microplastics in the environment. In contrast to previous studies focusing on the sources and risks of microplastics in a single environment, this article comprehensively analyses atmospheric, terrestrial runoff, marine and freshwater sources of microplastics and explores the hazards they pose to the environment and the health of humans and other organisms. Microplastics cause multiple adverse effects on aquatic and terrestrial organisms through accumulation, including growth inhibition, oxidative stress, inflammation, organ damage, and germ cell abnormalities. They may also enter the food chain and affect human health. This article summarizes the latest research progress on microplastic removal technologies from biological, physical, and chemical perspectives, with high efficiency, sustainability, and degradability for biological removal and adsorption and filtration being more effective for physical removal. This provides valuable information for future research related to microplastics. We advocate for a reduction in the use of microplastics and provide references for solving the problem of microplastic pollution.

Recent advances in atmospheric water harvesting technology and its development.

Water scarcity is a pressing issue worldwide. Given the ample atmospheric water sources, water harvesting from the atmosphere presents a promising solution to this challenge. In recent years, the solar-driven atmospheric water harvesting technology utilizing an adsorption-desorption process has garnered considerable interest. This is attributed to the abundant availability of solar energy, advanced adsorbents, improved photothermal materials, sophisticated interface heating system designs, and efficient thermal management techniques, all of which collectively enhance conversion efficiency. This article provides an overview of the advancements in atmospheric water collection, specifically focusing on hygroscopic water harvesting driven by solar energy. The discussion also encompasses the roles of materials, surfaces, equipment, and systems in enhancing water collection efficiency. By outlining both the advantages and challenges of atmospheric water collection, this study aims to shed light on future research directions in this research field.

Design of an adjustable low-temperature linear microwave plasma source for atmospheric pressure applications

Linear plasmas, compared to small-area low-temperature plasma jets, offer a larger single-treatment area with a brush-like pattern, making them highly promising for various applications. This paper introduces the design of an adjustable low-temperature linear plasma source that operates under atmospheric pressure at 2.45 GHz. The design integrated microwave theory with dielectric barrier discharge principles, utilizing a resonant structure based on a microstrip power divider with one end open and the other shorted. The ground plane of the microstrip structure was replaced by a metal plate featuring a large groove. Argon gas was introduced from the short-circuited end and exited through the groove at the open end, where plasma excitation occurred. Experimental results demonstrated that the device, operating at atmospheric pressure, can achieve adjustable linear plasma widths ranging from 10 mm to 50 mm by varying the incident power between 30 and 100 W. Optical emission measurements confirmed the uniformity of the linear plasma, and the gas temperature 5 mm away from the discharge area remained at only 65 °C, even with a microwave incident power of 100 W. This study offers a novel approach to designing linear atmospheric pressure microwave plasma sources, with significant potential for diverse material treatment applications.

Non-lethal sampling of phalanges for heavy metal bioaccumulation in Pelophylax nigromaculatus from historical mercury mining areas in Southwestern China

The Wanshan mercury mining area (WMMA) in Guizhou Province, China, has been identified as a region at high ecological risk owing to heavy metal contamination. This study employed non-lethal sampling methods, using the phalanges of Pelophylax nigromaculatus in the WMMA as analytical material. Ten heavy metal (metalloid) elements were selected for analysis, including Hg, Cr, Mn, Ni, Cu, Zn, Cd, Pb, As, and Se. These elements were measured using inductively coupled plasma mass spectrometry (ICP-MS), while Hg was determined using atomic fluorescence spectrometry (AFS). The bioaccumulation characteristics of heavy metals in P. nigromaculatus were analyzed through the bioaccumulation factor (BAF), and the extent of heavy metal pollution along with potential ecological risk was assessed using the potential ecological risk index (RI). The scaled mass index (SMI) was utilized to evaluate the body condition of P. nigromaculatus. Additionally, a combination of Spearman correlation analysis and non-negative matrix factorization (NMF) was employed to identify the sources and contributions of heavy metal elements. The results indicated that the distribution characteristics of heavy metal elements in the phalanges of P. nigromaculatus varied. Except for Pb, the concentrations of essential trace elements were significantly higher than those of non-essential elements. The bioaccumulation potential of P. nigromaculatus for heavy metal elements in the soil was found to be low, whereas the exposure risk from heavy metals in the water was high. The presence of heavy metal elements poses a significant potential ecological risk to P. nigromaculatus, with Hg, Cd, and As identified as the primary contributors to this risk. The environmental sources of heavy metals were identified as follows: Hg, Pb, Zn, and Se mainly originated from mining pollution sources; As and Cd primarily came from atmospheric pollution sources; Cr and Cu were mainly from natural activities sources; and Mn and Ni had multiple composite sources. Although heavy metal pollution negatively impacted the physical condition of P. nigromaculatus, no significant differences in SMI were observed across different regions. We believe that this is primarily attributable to the high levels of Se, which effectively mitigate the toxicity of heavy metals. The study demonstrated that using frog phalanges for heavy metal bioaccumulation analysis and SMI for physical condition assessment are simple, safe, and non-lethal methods, which can serve as useful indicators of environmental pollution and help trace the sources of environmental pollutants.

Rapid N2O Formation from N2 on Water Droplet Surfaces

Nitrogen (N2) has long been considered as stable atmospheric reservoir for N element and has a persistence time of hundreds of years. This study reveals that oxygen (O2) at typical tropospheric concentrations can rapidly activate N2, leading to substantial production of nitrous oxide (N2O), the third most impactful greenhouse gas, at rates approaching 2.83 ± 0.41 ppmv hour‐1 catalyzed by ubiquitous water droplets in experimental systems. Notably, ozone (O3), typically consumed by N2O in the stratosphere, can further accelerate N2O formation. In contrast, the produced N2O concentration is below detection limits in the absence of O2/O3 or water droplets. A novel reduction‐then‐oxidation (RTO) mechanism was proposed to account for the rapid formation of N2O on the water droplet surfaces facilitated by the cooperation of water droplets and O2/O3. Further extrapolation indicates that the RTO pathway contributes several Tg N N2O annually, far exceeding the most known sources of N2O. These findings have broad implications for tracing atmospheric N2O sources, enhancing understanding of climate‐O2/O3 interactions, and paving avenues for developing new methodologies for N2O synthesis.

Rapid N2O Formation from N2 on Water Droplet Surfaces.

Nitrogen (N2) has long been considered as stable atmospheric reservoir for N element and has a persistence time of hundreds of years. This study reveals that oxygen (O2) at typical tropospheric concentrations can rapidly activate N2, leading to substantial production of nitrous oxide (N2O), the third most impactful greenhouse gas, at rates approaching 2.83 ± 0.41 ppmv hour-1 catalyzed by ubiquitous water droplets in experimental systems. Notably, ozone (O3), typically consumed by N2O in the stratosphere, can further accelerate N2O formation. In contrast, the produced N2O concentration is below detection limits in the absence of O2/O3 or water droplets. A novel reduction-then-oxidation (RTO) mechanism was proposed to account for the rapid formation of N2O on the water droplet surfaces facilitated by the cooperation of water droplets and O2/O3. Further extrapolation indicates that the RTO pathway contributes several Tg N N2O annually, far exceeding the most known sources of N2O. These findings have broad implications for tracing atmospheric N2O sources, enhancing understanding of climate-O2/O3 interactions, and paving avenues for developing new methodologies for N2O synthesis.

A novel atmospheric microwave plasma source based on circular waveguide with double ridges for nitrogen fixation

Abstract The rectangular tapered waveguide is the most widely used atmospheric microwave plasma source because of its simple structure, reliable performance, and low cost. However, due to the small generated plasma volume and short residence time, this plasma source has low energy efficiency in gas conversion applications such as nitrogen fixation and methane reforming. This paper proposes a novel atmospheric-pressure microwave plasma source based on a circular waveguide to enlarge the plasma volume. Firstly, the microwave working mode in the circular waveguide is analyzed based on the electromagnetic theory. By optimizing the waveguide dimension and loading double metal ridges into the waveguide, the electric field will work in a superposition mode of TE111 and TM010 modes, focus on the discharge area, and reach its maximum intensity there. Secondly, this device is manufactured and used to generate plasma in different conditions. Compared with the rectangular tapered waveguide, this device can generate larger plasmas under the same conditions. Finally, an atmospheric microwave plasma experimental system is built for nitrogen fixation. Measured results show that the proposed device has higher nitrogen fixation production and lower energy cost compared to the rectangular tapered waveguide. Moreover, the proposed device is easy to cascade, thereby it has great potential for promotion in industrial applications.

Health-Oriented Strategy for Clean Air and Climate Actions: Differential Health Effects of Atmospheric Components.

Health is at the forefront of clean air and climate action. However, most existing studies of health impacts were based on additive single-exposure effects, which often oversimplify the relationships between atmospheric components and health outcomes. This review examines various atmospheric components' common sources and differential health effects, including greenhouse gases and major air pollutants such as fine particulate matter (PM2.5). It emphasizes the need for a comparative assessment of health impacts across various atmospheric components. We further highlight black carbon as an illustrative example, given its higher toxicity compared with other major PM2.5 components. By integrating the best available findings on the differential effects of particulate matter components with multiple gridded estimates of air pollution concentrations and population data, we conducted a risk assessment to quantify the health benefits of particulate matter reductions associated with China's clean air actions (2013-2020) and future climate mitigation scenarios (2020-2060). Our assessments indicate that, in regions or during periods where black carbon accounts for a higher proportion of exposure reduction relative to other PM2.5 components, reducing per-unit concentrations of PM2.5 can prevent more premature deaths. We propose a conceptual framework for a health-oriented strategy to enhance the effectiveness of clean air and climate initiatives.

Long-range atmospheric transport of organochlorine pesticides from China to South Korea: Evidence from Deokjeok Island.

The influence of transboundary air pollutants originating from the Asian continent on South Korea has been a major concern. Although organochlorine pesticides (OCPs) have been banned for several decades, they continue to be detected in the Korean environment. However, studies on the long-range atmospheric transport (LRAT) of OCPs in South Korea, particularly in background areas, remain limited. This study investigated the atmospheric levels, sources, and behavior of OCPs at Deokjeok Island, a background site near the west coast of the Korean Peninsula. Total concentrations of 24 OCPs ranged from 53.6 to 325pg/m3, which are lower than those reported by the national POPs monitoring network of South Korea and similar to levels found in other background regions in Northeast Asia. HCB (62.7pg/m3, 45%) and PeCB (46.6pg/m3, 33%) were the most dominant OCPs in the gaseous phase, whereas DDTs were predominant (1.65pg/m3, 44%) in the particulate phase. Gaseous OCPs were strongly influenced by past use and re-emissions, while ongoing emissions and LRAT were the major sources of particulate OCPs. The consistent detection of mirex provides strong evidence of LRAT. In addition, correlation analysis and the Clausius-Clapeyron equation indicated that DDTs were significantly influenced by LRAT. Concentration-weighted trajectory maps identified East, North, and Northeast China as the major source regions for gaseous OCPs, driven by re-emissions, while the primary source areas for particulate OCPs were Beijing, Hebei, Tianjin, and Shandong. Air/soil fugacity fractions showed equilibrium or net deposition for most OCPs (except PeCB), indicating the dynamic environmental behavior of OCPs influenced by past use and LRAT. This study provides evidence of LRAT of OCPs to South Korea, demonstrating the significant impact of transboundary pollution. These results highlight the importance of ongoing monitoring of both historically and currently used pesticides at receptor sites in Northeast Asia.

Historical inventories and future scenarios of multiple hazardous air pollutants (HAPs) emissions from the iron and steel production industry in China.

Iron and steel production (ISP) is one of significant atmospheric pollution emission sources in China. With the implementation of ultra-low emission (ULE) standards, a detailed and new updated emission inventory is urgently needed for better understanding of the temporal trends and spatial variation of emission characteristics. In this study, a unit-based comprehensive emission inventory of multiple hazardous air pollutants (HAPs) for the Chinese ISP spanned from 2012 to 2021, including the conventional pollutants, 13 kinds of Trace elements as well as 2 unconventional but toxic pollutants (PCDD/Fs, F), was dedicatedly developed by integrating dynamic localized emission factors with unit-based information of both the detailed activity level and abatement technology application. Scenario analyses were also conducted to forecast future emission trends up to 2050. The results showed that the lower emission factors owing to ULE retrofits had resulted in different spatial-temporal emission characteristics between outputs and HAPs emissions. The atmospheric emissions of SO2, NOX, PM2.5, PM10, TSP, F and PCDD/Fs from Chinese ISP in 2021 were estimated at about 414.4, 450.5, 1044.3, 2001.6, 3958.8, 9.42 kt and 9.35kg-TEQ, respectively. And most HAPs emissions were lower than those in 2012. Regarding the spatial distribution, Hebei, Jiangsu, Shanxi, ranked as the top 3 emission provinces. Moreover, different manufacturing processes (sintering, blast furnace, steel making, etc.) contributed with different magnitude for specific species, and the future trends estimation showed a great reducing potential caused by the implementation of ULE abatement measures and structure adjustment in future.

A dataset for 15N natural abundance of soil ammonia volatilization

Investigating the sources of ammonia (NH3) in the atmosphere and the contribution of each source is essential for environmental pollution control. The presented dataset aims to provide 15N natural abundance (δ15N) data collected from different controlled treatments to fill the knowledge gap between insufficient data of soil δ15N-NH3 and accurately identifying atmospheric NH3 source apportionments. Our results showed that the overall δ15N-NH3 values emitted from soil ranged from −46.09 to 10.22‰, with an average of −26.81 ± 11.17‰. The mean δ15N-NH3 values under different nitrogen (N) application rates, N fertilizer types, air temperatures, soil moisture, soil pH, soil types, and land use types were −29.41 ± 10.91, −32.43 ± 6.86, −29.10 ± 10.04, −30.31 ± 6.18, −24.84 ± 13.76, −23.53 ± 7.66, and −14.57 ± 12.54‰, respectively. Significant correlations were observed between δ15N-NH3 values and soil pH, soil NO3−-N concentration, and NH3 volatilization. This unique database provides basic data and evidence for the qualification of atmospheric NH3 source apportionments under different study area conditions.

Influence of Early Spring Arctic Sea Ice on Midsummer Precipitation in Northeast China: The Intermediate Links and Temporal‐Spatial Channels

AbstractPrevious studies revealed that the Arctic sea ice in March can influence the July–August (JA) precipitation over northeast China (NEC). We are curious about what happens in the atmosphere during the intermediate months of April, May, and June. In this study, we use atmospheric heat source as an intermediate quantity to link the sea ice and precipitation, and aim to find the intermediate stations where atmospheric heat source can well link to both March Arctic sea ice and the JA precipitation in NEC. The stations can appear in different locations and different intermediate months. Lagged correlations are calculated to infer the response of the heat source to sea ice and the response of precipitation to the heat source. Results show that there exist two spatial‐temporal channels. The first is a direct path over high latitudes, with intermediate station appearing in April at a location between Arctic and NEC. The second is a circuitous path, with intermediate station appearing in June over the equatorial Indian Ocean, which can excite a wave train that finally affects the JA precipitation in NEC. The influence of March Arctic sea ice on the JA precipitation in NEC can be contributed jointly by these two temporal‐spatial channels.

Surface Passivation of Silicon Nanoparticles Monitored by In Situ FTIR

ABSTRACTA setup consisting of two atmospheric plasma sources is used for the combined synthesis and passivation of nanoparticles. The silicon nanoparticles synthesized in the first source are analyzed for their chemical composition, morphology, and photoluminescence. The particles are then treated with a second plasma to induce surface passivation. The passivation process of the particles is monitored in real time using in situ infrared absorption spectroscopy. The results indicate that this treatment induces methylation of the silicon nanocrystals, which is further supported by XPS analysis. This surface passivation shifts the maximum of the photoluminescent signal to blue in the visible spectral region. Further optimization of the reported nanoparticle passivation process can provide a flexible tool for tuning nanoparticle properties.

Exploring Sources of Gravity Waves in the Southern Winter Stratosphere Using 3‐D Satellite Observations and Backward Ray‐Tracing

AbstractDuring austral winter, the southern high latitudes has some of the most intense stratospheric gravity wave (GW) activity globally. However, producing accurate representations of GW dynamics in this region in numerical models has proved exceptionally challenging. One reason for this is that questions remain regarding the relative contributions of orographic and non‐orographic sources of GWs here. We use three‐dimensional (3‐D) satellite GW observations from the Atmospheric Infrared Sounder in austral winter 2012 in combination with the Gravity‐wave Regional Or Global Ray Tracer to backward trace GW rays to their sources. We trace over 14.2 million rays, through ERA5 reanalysis background atmosphere, to their lower atmospheric sources. We find that GWs observed thousands of km downstream can be traced back to key orographic regions, and that on average, all waves (orographic and non‐orographic) converge meridionally over the Southern Ocean. We estimate that across this winter, orographic sources contribute around 5%–35% to the total momentum flux (MF) observed near 60S. The remaining proportion consists of waves from non‐orographic sources, which although typically carry lower MF, the large spatial extent of non‐orographic sources leads to a higher overall contribution. We also quantify the proportion of MF traced back to different regions across the whole southern high latitudes area in order to measure the relative importance of these different regions. These results provide the important insights needed to advance our knowledge of the atmospheric momentum budget in the southern high latitudes.