Atmosphere

18 pages, 5075 KiB

Open AccessArticle

Investigating Equatorial Plasma Depletions through CSES-01 Satellite Data

by Paola De Michelis, Giuseppe Consolini, Tommaso Alberti, Alessio Pignalberi, Igino Coco, Roberta Tozzi, Fabio Giannattasio and Michael Pezzopane

Atmosphere 2024, 15(7), 868; https://doi.org/10.3390/atmos15070868 - 22 Jul 2024

Viewed by 610

Abstract

Ionospheric plasma density irregularities, which are one of the primary sources of disturbance for the Global Navigation Satellite System, significantly impact the propagation of electromagnetic signals, leading to signal degradation and potential interruptions. In the equatorial ionospheric F region after sunset, certain plasma [...] Read more.

Ionospheric plasma density irregularities, which are one of the primary sources of disturbance for the Global Navigation Satellite System, significantly impact the propagation of electromagnetic signals, leading to signal degradation and potential interruptions. In the equatorial ionospheric F region after sunset, certain plasma density irregularities, identified as equatorial plasma bubbles, encounter optimal conditions for their formation and development. The energy spectra of electron density fluctuations associated with these irregularities exhibit a power-law scaling behavior qualitatively similar to the Kolmogorov power law observed in fluid turbulence theory. This intriguing similarity raises the possibility that these plasma density irregularities may possess turbulent characteristics. In this study, we analyzed electron density, temperature, and pressure data obtained from the China Seismo-Electromagnetic Satellite (CSES-01) to delve into the spectral properties of equatorial plasma depletions in the ionospheric F region at an altitude of about 500 km. This research marks the first exploration of these properties utilizing CSES-01 data and focuses on 14 semi-orbits that crossed the equator after midnight (01:00–03:00 LT), characterized by a geomagnetic quiet condition (Kp < 1). The analysis of electron temperature, density and pressure within equatorial plasma depletions revealed power-law scaling behavior for all the selected parameters. Notably, the spectral index values of these parameters are different from each other. The significance of these findings in terms of investigating plasma depletions via magnetic field signatures, as well as their relationship to the occurrence of Rayleigh–Taylor convective turbulence, is examined and discussed. Full article

(This article belongs to the Section Atmospheric Techniques, Instruments, and Modeling)

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16 pages, 17736 KiB

Open AccessArticle

Multi-Year Continuous Observations of Ambient PM_2.5 at Six Sites in Akure, Southwestern Nigeria

by Sawanya Saetae, Francis Olawale Abulude, Mohammed Mohammed Ndamitso, Akinyinka Akinnusotu, Samuel Dare Oluwagbayide, Yutaka Matsumi, Kenta Kanegae, Kazuaki Kawamoto and Tomoki Nakayama

Atmosphere 2024, 15(7), 867; https://doi.org/10.3390/atmos15070867 - 22 Jul 2024

Viewed by 750

Abstract

The spatial–temporal variations of fine particulate matter (PM_2.5) in Akure, a city in southwestern Nigeria, are examined based on multi-year continuous observations using low-cost PM_2.5 sensors at six different sites. The average annual concentration of PM_2.5 across these sites [...] Read more.

The spatial–temporal variations of fine particulate matter (PM_2.5) in Akure, a city in southwestern Nigeria, are examined based on multi-year continuous observations using low-cost PM_2.5 sensors at six different sites. The average annual concentration of PM_2.5 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. PM_2.5 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 PM_2.5 originating from local/regional open burning activities played crucial roles in increased PM_2.5 concentrations during the dry season. Further, site-to-site variations in the PM_2.5 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 PM_2.5 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. Full article

(This article belongs to the Section Air Quality)

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25 pages, 13003 KiB

Open AccessArticle

Assessing the Potential Impacts of Climate Change on Drought in Uzbekistan: Findings from RCP and SSP Scenarios

by Natella Rakhmatova, Bakhriddin E. Nishonov, Bakhtiyar M. Kholmatjanov, Valeriya Rakhmatova, Kristina N. Toderich, Gulchekhra M. Khasankhanova, Lyudmila Shardakova, Temur Khujanazarov, Akmal N. Ungalov and Dmitry A. Belikov

Atmosphere 2024, 15(7), 866; https://doi.org/10.3390/atmos15070866 - 22 Jul 2024

Viewed by 640

Abstract

Future climate change and its impact on drought is critical for Uzbekistan, located in Central Asia, the world’s largest arid zone. This study examines the evolving intensity of climate change and drought events using multi-model ensembles (MMEs) derived from the Coupled Model Intercomparison [...] Read more.

Future climate change and its impact on drought is critical for Uzbekistan, located in Central Asia, the world’s largest arid zone. This study examines the evolving intensity of climate change and drought events using multi-model ensembles (MMEs) derived from the Coupled Model Intercomparison Project Phase 5 and 6 (CMIP5 and CMIP6) simulated under the Representative Concentration Pathway and Shared Socioeconomic Pathway (RCP and SSP) scenarios. The projections show different rates of increase in temperature and precipitation under the RCPs and SSPs. Projected temperature increases are expected to reach up to 2–2.5 °C under SSP1-2.6, SSP2-4.5, and SSP3-7.0, by mid-century. By 2080–2099, an increase is projected of 2–3 °C in monthly mean temperatures throughout the year (SSP1-2.6), and a more pronounced increase in summer up to 3–4 °C (SSP2-4.5) and 4–6 °C (SSP3-7.0), with a marked contrast in conditions between the mountainous and desert regions of Uzbekistan. Regional changes in precipitation over the study periods show relatively little variability, except for FD, where notable trends are found. Under SSP1-2.6 and SSP2-4.5, the increase in precipitation is relatively modest, whereas the changes in SSP3-7.0 are more substantial, with some regions experiencing variations of up to 10–20 mm per period. The Standardized Precipitation Evapotranspiration Index (SPEI), calculated based on the projected temperature and precipitation, provides an estimate of future drought trends. Our results show increasing aridity under all scenarios by mid-century, with longer-term projections indicating stabilization around different SPEI values by 2100: RCP2.6 and SSP1-1.9 stabilize around −1.0; RCP4.5, RCP6.0, SSP2-4.5, and SSP3-7.0 stabilize around −1.5; while RCP8.5 and SSP5-8.5 scenarios project values of −2 or less by 2100. Notable differences in the SPEI index are found between lowland and foothill regions. In view of Uzbekistan’s heavy reliance on agriculture and irrigation, which are the sectors that are expected to be mostly affected by climate change, our study provides a scientific basis for informed policy decision-making. This includes various aspects such as planning and management water resources, as well as the broader socioeconomic development of the country. Full article

(This article belongs to the Section Climatology)

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15 pages, 5045 KiB

Open AccessArticle

Frequency of Italian Record-Breaking Floods over the Last Century (1911–2020)

by Attilio Castellarin, Andrea Magnini, Kay Khaing Kyaw, Filippo Ciavaglia, Miriam Bertola, Gunter Blöschl, Elena Volpi, Pierluigi Claps, Alberto Viglione, Alberto Marinelli and Richard M. Vogel

Atmosphere 2024, 15(7), 865; https://doi.org/10.3390/atmos15070865 - 22 Jul 2024

Viewed by 728

Abstract

This study provides an in-depth analysis of the frequency of extreme streamflow in Italy, adopting the innovative perspective of the theory of records, and focusing on record-breaking floods. (i.e., annual maximum series, AMS) observed in Italy between 1911 and 2020. Our research employs [...] Read more.

This study provides an in-depth analysis of the frequency of extreme streamflow in Italy, adopting the innovative perspective of the theory of records, and focusing on record-breaking floods. (i.e., annual maximum series, AMS) observed in Italy between 1911 and 2020. Our research employs an extensive dataset of 522 annual maximum series (AMS) of streamflow observed across Italy between 1911 and 2020. We consider three time intervals (1911–2020, 1911–1970, and 1971–2020), and we define pooling-groups of AMSs based on (a) hydrological (e.g., catchment size, mean annual precipitation, etc.) and (b) spatial proximities of the gauged sites. First, within each group and for each time period, we compute the regional average number of record-breaking events (NRbins). Second, with a series of resampling experiments that preserve the spatial correlation among the AMSs, we test the hypothesis that NRbins result from a group of stationary sequences. Our results show spatially coherent patterns of an increasing number of record-breaking floods in central and in northeastern Italy over the last 50 years. In the same time interval, significant deviations in the regional number of record-breaking events from what would be expected for stationary flood sequences seem to be more common in drier climates or at higher altitudes, while the catchment size does not seem to be a meaningful descriptor. Full article

(This article belongs to the Special Issue Impacts of Climate Change on Basin Hydrology)

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14 pages, 5127 KiB

Open AccessArticle

A High-Precision Sub-Grid Parameterization Scheme for Clear-Sky Direct Solar Radiation in Complex Terrain—Part II: Considering Atmospheric Transparency Differences in Sub-Grid; Pre-Research for Application

by Changyi Li, Bin Chen, Wei Wu, Yanan Chen, Guili Feng and Xiaopei Wen

Atmosphere 2024, 15(7), 864; https://doi.org/10.3390/atmos15070864 - 22 Jul 2024

Viewed by 525

Abstract

Existing sub-grid parameterization schemes for clear-sky direct solar radiation (SPS-CSDSR) assume that the sub-grid cells have the same atmospheric transparency. This study shows that in undulating terrain, significant errors can occur when the sub-grid is in turbid weather or partly above the cloud [...] Read more.

Existing sub-grid parameterization schemes for clear-sky direct solar radiation (SPS-CSDSR) assume that the sub-grid cells have the same atmospheric transparency. This study shows that in undulating terrain, significant errors can occur when the sub-grid is in turbid weather or partly above the cloud top. A correction factor was proposed. It can effectively eliminate errors under a cloudless sky and can reduce some errors when part of the sub-grid is above the cloud or fog top. For atmospheric models with high horizontal resolution, example test verification shows that the cast shadowless coverage method can lead to large errors. It should no longer be used based on current computing power. These improvements and the high-precision fast terrain occlusion algorithm in Part I will allow SPS-CSDSR to achieve unprecedented high accuracy. Based on the proposed daily interpolation method, the high-precision SPS-CSDSR is also feasible for regional climate simulation. The analysis pointed out that the sub-grid terrain radiative effect (STRE) is distributed over inclined surfaces with larger areas and at different heights. Existing methods of coupling STRE on one flat surface have certain physical drawbacks. This paper suggests introducing parameterization of STRE at different altitudes and improving the coupling of land–air. Full article

(This article belongs to the Section Air Quality)

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18 pages, 336 KiB

Open AccessReview

Occurrence of Microplastics in the Atmosphere: An Overview on Sources, Analytical Challenges, and Human Health Effects

by Fabiana Carriera, Cristina Di Fiore and Pasquale Avino

Atmosphere 2024, 15(7), 863; https://doi.org/10.3390/atmos15070863 - 21 Jul 2024

Viewed by 1052

Abstract

The rapid spread and accumulation of microplastics (MPs) in environmental ecosystems result from extensive plastic usage. MPs have been found in both indoor and outdoor air. Outdoor MP levels vary widely across global cities, with reported ranges from 36 to 118 MPs m [...] Read more.

The rapid spread and accumulation of microplastics (MPs) in environmental ecosystems result from extensive plastic usage. MPs have been found in both indoor and outdoor air. Outdoor MP levels vary widely across global cities, with reported ranges from 36 to 118 MPs m⁻² day⁻¹. However, differing measurement units complicate comparisons. Indoor MPs are particularly concerning due to the significant amount of time people spend indoors. For instance, MP concentrations in workplaces like reception areas and nail salons were found to be 309 ± 214 and 46 ± 55 MPs m⁻³, respectively. Technological limitations hinder the identification of MPs, with methods like µ-ATR-FTIR, µ-FTIR, and µ-Raman identifying MPs of different sizes. MPs smaller than 0.3 µm pose a health risk as they can be internalized in lung cells, while MPs larger than 10 µm are too large to enter alveolar macrophages. This review highlights the current understanding of airborne MPs, focusing on their sources, transport, and deposition mechanisms. It aims to provide a foundation for further studies to deeply assess the presence, abundance, and occurrence of MPs in aerosols, a subject that remains underexplored. Full article

(This article belongs to the Special Issue Urban Air Pollution Exposure and Health Vulnerability)

15 pages, 10073 KiB

Open AccessEditor’s ChoiceArticle

Deciphering East Atlantic Low-Pressure System Formations: Exploring the Nexus of Tropical Jet Streams and Active Monsoon Phases

by Vinay Kumar, Dipak K. Sahu, Katelyn Simonsen and Sabrina Gonzalez

Atmosphere 2024, 15(7), 862; https://doi.org/10.3390/atmos15070862 - 21 Jul 2024

Viewed by 786

Abstract

The formation of low-pressure systems (LPSs) over the eastern Atlantic Ocean, near the coast of West Africa, is an exceptional meteorological/climatological feature that can lead to the development of hurricanes. The upper level diffluence induced by the Tropical Easterly Jet (TEJ) plays a [...] Read more.

The formation of low-pressure systems (LPSs) over the eastern Atlantic Ocean, near the coast of West Africa, is an exceptional meteorological/climatological feature that can lead to the development of hurricanes. The upper level diffluence induced by the Tropical Easterly Jet (TEJ) plays a crucial role in the formation of LPSs over the eastern Atlantic Ocean, off the coast of West Africa. However, the exact influence of the enhanced TEJ and diffluence in relation to cyclogenesis remains unclear. An active precipitation period over the Indian subcontinent and Africa induces an intensification of the TEJ, African Easterly Jet, and the bifurcation of diffluence off the coast of Africa. Over the past five years (2019–2023), a delayed correlation has been observed between the formation of LPSs over the eastern Atlantic Ocean (7.5° N–20° N, 15° W–41° W), the TEJ over the Indian subcontinent (approximately 2 to 3 days), and the AEJ over Africa (approximately 1 day). This correlation is further linked to the bifurcation of diffluence at the 200 mb level. Full article

(This article belongs to the Section Meteorology)

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17 pages, 8480 KiB

Open AccessArticle

Characteristics of Atmospheric Diabatic Heating of the Southwest China Vortex That Induces Extreme Rainstorms in Sichuan

by Chunhua Zhou and Yueqing Li

Atmosphere 2024, 15(7), 861; https://doi.org/10.3390/atmos15070861 - 21 Jul 2024

Viewed by 575

Abstract

In this study, we aimed to demonstrate the importance of diabatic heating in extreme rainstorm weather events induced by the Southwest China vortex (SWCV) in different precipitation regions with a similar circulation background. The results showed that atmospheric diabatic heating had indicative significance [...] Read more.

In this study, we aimed to demonstrate the importance of diabatic heating in extreme rainstorm weather events induced by the Southwest China vortex (SWCV) in different precipitation regions with a similar circulation background. The results showed that atmospheric diabatic heating had indicative significance for the intensity evolution of the SWCV and the precipitation area. Changes in the diabatic heating intensity preceded the intensity evolution of the SWCV, and the diabatic heating region was consistent with the heavy precipitation region. The variation in diabatic heating was mainly due to the positive contribution of its vertical transport term. The two types of spatially non-uniform heating effects were similar; however, the western type was located southeast of the SWCV, with an asymmetric distribution on the southeastern and northwestern sides. The eastern type was located in the northeast of the SWCV, with an asymmetric distribution on the northeastern and southwestern sides. The vertically non-uniform heating effect played a decisive role in the distribution and evolution of the spatially non-uniform heating terms. The vertically non-uniform heating effect affected the intensity evolution of the SWCV. In contrast, the horizontally non-uniform heating effect, in opposition to the vertically non-uniform heating effect, had a slightly weaker intensity than the vertically non-uniform heating effect. For the SWCV system, which induces extreme rainstorms, the magnitude of the horizontally non-uniform heating effect could reach that of vertically non-uniform heating; thus, the possible impact of horizontally non-uniform heating should be considered. Full article

(This article belongs to the Special Issue Advances in Rainfall-Induced Hazard Research)

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18 pages, 3966 KiB

Open AccessArticle

Pilot Study on the Production of Negative Oxygen Ions Based on Lower Voltage Ionization Method and Application in Air Purification

by Haotian Weng, Yaozhong Zhang, Xiaolu Huang, Xuan Liu, Yunhui Tang, Hewei Yuan, Yang Xu, Kun Li and Yafei Zhang

Atmosphere 2024, 15(7), 860; https://doi.org/10.3390/atmos15070860 - 20 Jul 2024

Viewed by 746

Abstract

In the current highly industrialized living environment, air quality has become an increasing public health concern. Natural environments like forests have excellent air quality due to high concentrations of negative oxygen ions originating from low-voltage ionization, without harmful ozone. Traditional negative oxygen ion [...] Read more.

In the current highly industrialized living environment, air quality has become an increasing public health concern. Natural environments like forests have excellent air quality due to high concentrations of negative oxygen ions originating from low-voltage ionization, without harmful ozone. Traditional negative oxygen ion generators require high voltage for corona discharge to produce ions. However, high voltage can increase electron collisions and excitations, leading to more dissociation and recombination of oxygen molecules and consequently higher ozone production. To address the challenge of generating negative oxygen ions without accompanying ozone production, this study designed and constructed a low-voltage negative oxygen ion generator based on nanometer-tip carbon fiber electrodes. The advantage of this device lies in the high curvature radius of carbon fibers, which provides high local electric field strength. This allows for efficient production of negative oxygen ions at low operating voltages without generating ozone. Experiments demonstrated that the device can efficiently generate negative oxygen ions at a working voltage as low as 2.16 kV, 28% lower than the lowest voltage reported in similar studies. The purification device manufactured in this study had a total decay constant for PM_2.5 purification of 0.8967 min⁻¹ within five minutes, compared to a natural decay constant of only 0.0438 min⁻¹, resulting in a calculated Clean Air Delivery Rate (CADR) of 0.1535 m³/min. Within half an hour, concentrations of PM_2.5, PM₁, PM₁₀, formaldehyde, and TVOC were reduced by 99.09%, 99.40%, 99.37%, 94.39%, and 99.35%, respectively, demonstrating good decay constants and CADR. These findings confirm its effectiveness in improving indoor air quality, highlighting its significant application value in air purification. Full article

(This article belongs to the Special Issue Indoor Air Quality Control)

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15 pages, 3099 KiB

Open AccessArticle

Air Monitoring in Operating Rooms: Results from a Comprehensive Study in the Campania Region

by Paolo Montuori, Immacolata Russo, Elvira De Rosa, Fabiana Di Duca, Bruna De Simone and Maria Triassi

Atmosphere 2024, 15(7), 859; https://doi.org/10.3390/atmos15070859 - 20 Jul 2024

Viewed by 573

Abstract

Ensuring air quality in operating rooms is crucial for the health and safety of healthcare professionals and patients. This study, focused on 141 operating theatres in the Campania Region from 2015 to 2022, highlights the importance of air monitoring in operating rooms. Microclimatic [...] Read more.

Ensuring air quality in operating rooms is crucial for the health and safety of healthcare professionals and patients. This study, focused on 141 operating theatres in the Campania Region from 2015 to 2022, highlights the importance of air monitoring in operating rooms. Microclimatic parameters, air exchanges, thermal comfort indices, air pressure differences, and anesthetic gas concentrations were measured using standardized procedures. Results indicate that 19% of microclimatic checks exceeded acceptable limits, with significant non-compliance in air velocity (0.01–0.04 m/s, mean 0.03 m/s) and air changes (1–14 h⁻¹, mean 6 h⁻¹). Additionally, levels of anesthetic gases such as nitrous oxide (54.7–197.31 ppm, mean 142.92 ppm) and sevoflurane (2.05–19.45 ppm, mean 5.90 ppm) frequently exceeded recommended exposure limits, raising health concerns. These findings underscore the importance of rigorously adhering to environmental standards and continuously monitoring for optimal conditions in operating rooms. The study also stresses the necessity of ongoing education and training for healthcare personnel on preventive measures to reduce risks. In conclusion, maintaining optimal environmental conditions not only safeguards the comfort and safety of healthcare professionals and patients, but also improves team productivity and clinical outcomes. The study advocates for regularly updating national guidelines and rigorously enforcing safety protocols in healthcare facilities. Full article

(This article belongs to the Section Air Quality and Health)

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21 pages, 5512 KiB

Open AccessEditor’s ChoiceArticle

Assessing Multi-Scale Atmospheric Circulation Patterns for Improvements in Sub-Seasonal Precipitation Predictability in the Northern Great Plains

by Carlos M. Carrillo and Francisco Muñoz-Arriola

Atmosphere 2024, 15(7), 858; https://doi.org/10.3390/atmos15070858 - 20 Jul 2024

Viewed by 726

Abstract

This study leverages the relationships between the Great Plains low-level jet (GP-LLJ) and the circumglobal teleconnection (CGT) to assess the enhancement of 30-day rainfall forecast in the Northern Great Plains (NGP). The assessment of 30-day simulated precipitation using the Climate Forecast System (CFS) [...] Read more.

This study leverages the relationships between the Great Plains low-level jet (GP-LLJ) and the circumglobal teleconnection (CGT) to assess the enhancement of 30-day rainfall forecast in the Northern Great Plains (NGP). The assessment of 30-day simulated precipitation using the Climate Forecast System (CFS) is contrasted with the North American Regional Reanalysis, searching for sources of precipitation predictability associated with extended wet and drought events. We analyze the 30-day sources of precipitation predictability using (1) the characterization of dominant statistical modes of variability of 900 mb winds associated with the GP-LLJ, (2) the large-scale atmospheric patterns based on 200 mb geopotential height (HGT), and (3) the use of GP-LLJ and CGT conditional probability distributions using a continuous correlation threshold approach to identify when and where the forecast of NGP precipitation occurs. Two factors contributing to the predictability of precipitation in the NGP are documented. We found that the association between GP-LLJ and CGT occurs at two different scales—the interdiurnal and the sub-seasonal, respectively. The CFS reforecast suggests that the ability to forecast sub-seasonal precipitation improves in response to the enhanced simulation of the GP-LLJ and CGT. Using these modes of climate variability could improve predictive frameworks for water resources management, governance, and water supply for agriculture. Full article

(This article belongs to the Special Issue Prediction and Modeling of Extreme Weather Events)

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18 pages, 3190 KiB

Open AccessArticle

A High-Precision Sub-Grid Parameterization Scheme for Clear-Sky Direct Solar Radiation in Complex Terrain—Part I: A High-Precision Fast Terrain Occlusion Algorithm

by Changyi Li, Wei Wu, Yanan Chen, Guili Feng, Bin Chen and Xiaopei Wen

Atmosphere 2024, 15(7), 857; https://doi.org/10.3390/atmos15070857 - 19 Jul 2024

Cited by 1 | Viewed by 540

Abstract

In atmospheric modeling, sub-grid parameterization is an important method for studying the topographic effects of solar radiation using high-resolution Digital Elevation Model (DEM) data. For reducing the amount of computation, some approximate methods that can lead to errors are used in existing sub-grid [...] Read more.

In atmospheric modeling, sub-grid parameterization is an important method for studying the topographic effects of solar radiation using high-resolution Digital Elevation Model (DEM) data. For reducing the amount of computation, some approximate methods that can lead to errors are used in existing sub-grid parameterization schemes for clear-sky direct solar radiation (SPS-CSDSR). The lack of a high-precision fast terrain occlusion algorithm (HPFTOA) remains one of the biggest constraints in this field. This study proposed an HPFTOA. It mainly uses two kinds of acceleration algorithms. One method is to use a dynamic, lossless, and fast occlusion search radius. Another way is to use the rectangular grid for calculations within the accuracy of DEM data to avoid coordinate projection conversions. The test results indicate that the HPFTOA can carry out large-scale computation based on DEM data with a resolution of 90 m. Because it rarely uses approximation algorithms and considers the curvature of the Earth, SPS-CSDSR can achieve unprecedented precision. The HPFTOA can also be used in the fields of mountain solar energy assessment, remote sensing, and telemetry, including terrain-obscuring the probe. As computer performance improves and algorithms and execution code are optimized, the application prospects will be very broad. Full article

(This article belongs to the Section Atmospheric Techniques, Instruments, and Modeling)

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14 pages, 29945 KiB

Open AccessArticle

Improving Air Quality Prediction via Self-Supervision Masked Air Modeling

by Shuang Chen, Li He, Shinan Shen, Yan Zhang and Weichun Ma

Atmosphere 2024, 15(7), 856; https://doi.org/10.3390/atmos15070856 - 19 Jul 2024

Viewed by 628

Abstract

Presently, the harm to human health created by air pollution has greatly drawn public attention, in particular, vehicle emissions including nitrogen oxides as well as particulate matter. How to predict air quality, e.g., pollutant concentration, efficiently and accurately is a core problem in [...] Read more.

Presently, the harm to human health created by air pollution has greatly drawn public attention, in particular, vehicle emissions including nitrogen oxides as well as particulate matter. How to predict air quality, e.g., pollutant concentration, efficiently and accurately is a core problem in environmental research. Developing a robust air quality predictive model has become an increasingly important task, holding practical significance in the formulation of effective control policies. Recently, deep learning has progressed significantly in air quality prediction. In this paper, we go one step further and present a neat scheme of masked autoencoders, termed as masked air modeling (MAM), for sequence data self-supervised learning, which addresses the challenges posed by missing data. Specifically, the front end of our pipeline integrates a WRF-CAMx numerical model, which can simulate the process of emission, diffusion, transformation, and removal of pollutants based on atmospheric physics and chemical reactions. Then, the predicted results of WRF-CAMx are concatenated into a time series, and fed into an asymmetric Transformer-based encoder–decoder architecture for pre-training via random masking. Finally, we fine-tune an additional regression network, based on the pre-trained encoder, to predict ozone (O

_{3}

) concentration. Coupling these two designs enables us to consider the atmospheric physics and chemical reactions of pollutants while inheriting the long-range dependency modeling capabilities of the Transformer. The experimental results indicated that our approach effectively enhances the WRF-CAMx model’s predictive capabilities and outperforms pure supervised network solutions. Overall, using advanced self-supervision approaches, our work provides a novel perspective for further improving air quality forecasting, which allows us to increase the smartness and resilience of the air prediction systems. This is due to the fact that accurate prediction of air pollutant concentrations is essential for detecting pollution events and implementing effective response strategies, thereby promoting environmentally sustainable development. Full article

(This article belongs to the Special Issue Applications of Artificial Intelligence in Atmospheric Sciences)

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22 pages, 4005 KiB

Open AccessArticle

Assessing PM_2.5 Dynamics and Source Contributions in Southwestern China: Insights from Winter Haze Analysis

by Hui Guan, Ziyun Chen, Jing Tian and Huayun Xiao

Atmosphere 2024, 15(7), 855; https://doi.org/10.3390/atmos15070855 - 19 Jul 2024

Viewed by 616

Abstract

Despite enhancements in pollution control measures in southwestern China, detailed assessments of PM_2.5 dynamics following the implementation of the Clean Air Action remain limited. This study explores the PM_2.5 concentrations and their chemical compositions during the winter haze period of 2017 [...] Read more.

Despite enhancements in pollution control measures in southwestern China, detailed assessments of PM_2.5 dynamics following the implementation of the Clean Air Action remain limited. This study explores the PM_2.5 concentrations and their chemical compositions during the winter haze period of 2017 across four major urban centers—Chengdu, Chongqing, Guiyang, and Kunming. Significant variability in mean PM_2.5 concentrations was observed: Chengdu (71.8 μg m⁻³) and Chongqing (53.3 μg m⁻³) recorded the highest levels, substantially exceeding national air quality standards, while Guiyang and Kunming reported lower concentrations, suggestive of comparatively milder pollution. The analysis revealed that sulfate, nitrate, and ammonium (collectively referred to as SNA) constituted a substantial portion of the PM_2.5 mass—47.2% in Chengdu, 62.2% in Chongqing, 59.9% in Guiyang, and 32.0% in Kunming—highlighting the critical role of secondary aerosol formation. The ratio of NO₃⁻/SO₄²⁻ and nitrogen oxidation ratio to sulfur oxidation ratio (NOR/SOR) indicate a significant transformation of NO₂ under conditions of heavy pollution, with nitrate formation playing an increasingly central role in the haze dynamics, particularly in Chengdu and Chongqing. Utilizing PMF for source apportionment, in Chengdu, vehicle emissions were the predominant contributor, accounting for 33.1%. Chongqing showed a similar profile, with secondary aerosols constituting 36%, followed closely by vehicle emissions. In contrast, Guiyang’s PM_2.5 burden was heavily influenced by coal combustion, which contributed 46.3%, reflecting the city’s strong industrial base. Kunming presented a more balanced source distribution. Back trajectory analysis further confirmed the regional transport of pollutants, illustrating the complex interplay between local and distant sources. These insights underscore the need for tailored, region-specific air quality management strategies in southwestern China, thereby enhancing our understanding of the multifaceted sources and dynamics of PM_2.5 pollution amidst ongoing urban and industrial development. Full article

(This article belongs to the Special Issue Air Pollution in China (3rd Edition))

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12 pages, 4643 KiB

Open AccessArticle

Three-Dimensional Lightning Characteristics Analysis over the Tibetan Plateau Based on Satellite-Based and Ground-Based Multi-Source Data

by Jie Zhu, Shulin Zhi, Dong Zheng and Zhengguo Yuan

Atmosphere 2024, 15(7), 854; https://doi.org/10.3390/atmos15070854 - 19 Jul 2024

Viewed by 626

Abstract

Based on the data from the Chinese national ground-based (LFEDA: Low-frequency E-field Detection Array) and satellite-based lightning-detection systems (LMI: Lightning Mapping Imager), the spatial and temporal distribution statistical properties of all types of lightning over the Tibetan Plateau in the summer of 2022 [...] Read more.

Based on the data from the Chinese national ground-based (LFEDA: Low-frequency E-field Detection Array) and satellite-based lightning-detection systems (LMI: Lightning Mapping Imager), the spatial and temporal distribution statistical properties of all types of lightning over the Tibetan Plateau in the summer of 2022 and 2023 are analyzed, and were compared with those in Hainan, which are under quite different geographical conditions. The discrepancy between ground-based and space-borne lightning detection was also discussed. The main results show the following: (1) the characteristics of lightning activities over the Tibetan Plateau based on multi-source data: Most of the high-value lightning areas were located in the transition zone between lower and higher terrain; the diurnal variation of lightning activity was significant, and the most active period concentrated around 15:00 LST (Local Standard Time, the same below). In addition, lightning activities were significantly increased at 21:00 and 0:00, which was related to the unique topography and night rain phenomenon of the plateau. In terms of lightning types, the number of IC (Intra-Cloud) lightning was more than that of CG (Cloud-to-Ground). The study of IC changes is of great significance to the early warning of the plateau DCSs. The spatial distribution of IC at different altitudes was quite different. (2) Comparison of lightning activities between the Tibetan Plateau and Hainan: The hourly variation of lightning activities in Nagqu showed a single peak, while that in Hainan was characterized by a primary peak and a secondary peak, affected by the enhancement of the boundary stream in the low latitude and altitude area of China. At the peak of convection, the lightning activities in Nagqu were less than 1/3 of that in Hainan. However, the duration of high-frequency lightning activities in Nagqu (15–19:00) was about 2 h longer than that in Hainan (15–17:00), which may be related to the fact that the Tibetan Plateau is located in the west of China, where the sunset is later, and solar radiation and convective activities last longer. (3) Analysis of features of LMI: LMI has more advantages in IC detection; LMI has higher detection efficiency for the lightning in the range of 4–6 KM altitude, which is partly related to the stronger convective process and the higher proportion of IC. This work will provide deeper understanding of the characteristics of all types of lightning over the Tibetan Plateau, to reveal the indication significance of lightning for DCSs, and help to promote the development of Chinese satellite-based lightning-detection technology, the optimization of subsequent instruments and the fusion application of ground-based and satellite-based lightning data. Full article

(This article belongs to the Section Atmospheric Techniques, Instruments, and Modeling)

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22 pages, 3788 KiB

Open AccessArticle

Developmental Ambient Air Pollution Exposure in Mice Alters Fronto-Striatal Neurotransmitter System Function: Male-Biased Serotonergic Vulnerability

by Deborah A. Cory-Slechta, Katherine Conrad, Elena Marvin, David Chalupa, Gunter Oberdörster and Marissa Sobolewski

Atmosphere 2024, 15(7), 853; https://doi.org/10.3390/atmos15070853 - 19 Jul 2024

Viewed by 599

Abstract

Air pollution (AP) exposures have been associated with autism (ASD), schizophrenia (SCZ), and attention deficit hyperactivity disorder (ADHD), male-biased neurodevelopmental disorders that are linked to alterations in brain fronto-striatal neurotransmitter systems. The current study sought to assess how developmental exposures of mice to [...] Read more.

Air pollution (AP) exposures have been associated with autism (ASD), schizophrenia (SCZ), and attention deficit hyperactivity disorder (ADHD), male-biased neurodevelopmental disorders that are linked to alterations in brain fronto-striatal neurotransmitter systems. The current study sought to assess how developmental exposures of mice to inhaled ambient ultrafine particle (UFP) air pollution, considered its most reactive component, alters fronto-striatal functional correlations. Mice were exposed via inhalation to concentrated ambient UFPs from postnatal days (PND) 4–7 and 10–13. Frontal cortex, striatum, and serum were collected at PND14 and PND50 to evaluate both acute and persistent effects. UFP-induced changes, more extensive and persistent in males, included elimination of frontal cortical kynurenine correlations with striatal neurotransmitter function, persistent immunosuppression of approximately 50%, and striatal neurotransmitter turnover correlations with serum corticosterone. More limited effects in females did not show persistence. Collectively, these findings depict an apparently physiologically-integrated UFP-induced persistent male-biased vulnerability to brain fronto-striatal system dysfunction that could contribute to behavioral deficits associated with neurodevelopmental disorders. Further studies are needed to ascertain the interactive physiological mechanisms of male fronto-striatal vulnerability and their relation to behavioral impairments, mechanisms of apparent female compensation, and specific contaminants of AP that underlie this vulnerability. Full article

(This article belongs to the Special Issue Air Pollution Exposure and Health Impact Assessment (2nd Edition))

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24 pages, 1236 KiB

Open AccessReview

A Comprehensive Review of Surface Ozone Variations in Several Indian Hotspots

by K. A. Keerthi Lakshmi, T. Nishanth, M. K. Satheesh Kumar and K. T. Valsaraj

Atmosphere 2024, 15(7), 852; https://doi.org/10.3390/atmos15070852 - 19 Jul 2024

Viewed by 1511

Abstract

Ozone at ground level (O₃) is an air pollutant that is formed from primary precursor gases like nitrogen oxides (NOx) and volatile organic compounds (VOCs). It plays a significant role as a precursor to highly reactive hydroxyl (OH) radicals, which ultimately [...] Read more.

Ozone at ground level (O₃) is an air pollutant that is formed from primary precursor gases like nitrogen oxides (NOx) and volatile organic compounds (VOCs). It plays a significant role as a precursor to highly reactive hydroxyl (OH) radicals, which ultimately influence the lifespan of various gases in the atmosphere. The elevated surface O₃ levels resulting from anthropogenic activities have detrimental effects on both human health and agricultural productivity. This paper provides a comprehensive analysis of the variations in surface O₃ levels across various regions in the Indian subcontinent, focusing on both spatial and temporal changes. The study is based on an in-depth review of literature spanning the last thirty years in India. Based on the findings of the latest study, the spatial distribution of surface O₃ indicates a rise of approximately 50–70 ppbv during the summer and pre-monsoon periods in the northern region and Indo-Gangetic Plain. Moreover, elevated levels of surface O₃ (40–70 ppbv) are observed during the pre-monsoon/summer season in the western, southern, and peninsular Indian regions. The investigation also underscores the ground-based observations of diurnal and seasonal alterations in surface O₃ levels at two separate sites (rural and urban) in Kannur district, located in southern India, over a duration of nine years starting from January 2016. The O₃ concentration exhibits an increasing trend of 7.91% (rural site) and 5.41% (urban site), ascribed to the rise in vehicular and industrial operations. This review also presents a succinct summary of O₃ fluctuations during solar eclipses and nocturnal firework displays in the subcontinent. Full article

(This article belongs to the Special Issue Measurement and Variability of Atmospheric Ozone)

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18 pages, 817 KiB

Open AccessArticle

Assessing Worker Exposure to Vehicle Exhaust Emissions and Self-Reported Exposure Symptoms at the Lebombo Port of Entry, in Mpumalanga, South Africa

by Zwelithini M. Makhabane, Kingsley K. Mokoena and Phoka C. Rathebe

Atmosphere 2024, 15(7), 851; https://doi.org/10.3390/atmos15070851 - 19 Jul 2024

Viewed by 641

Abstract

This study assessed workers’ exposure to vehicle exhaust emissions and its health effects at the Lebombo Port of Entry. A quantitative cross-sectional design was adopted, and a structured questionnaire was administered on 209 adult workers to measure their knowledge on vehicle exhaust emissions [...] Read more.

This study assessed workers’ exposure to vehicle exhaust emissions and its health effects at the Lebombo Port of Entry. A quantitative cross-sectional design was adopted, and a structured questionnaire was administered on 209 adult workers to measure their knowledge on vehicle exhaust emissions exposures. Air samples were also collected from the participants using air sampling pumps. Data were analyzed using Statistical Package for Social Sciences, version 27. Logistic regression was performed to examine the association between dependent variables and some sociodemographic factors. Vocational certificates and associate degrees were attributed to workers in the South African Police Services and those in Agriculture: (Odds Ratio) = 2.83%, Confidence Interval (1.41–5.65) and (Odds Ratio) = 4.58%, Confidence Interval (2.10–9.99), respectively. Divorced males had a high level of knowledge and awareness of vehicle exhaust emission and their health effects: (Adjusted Odds Ratio) = 5.31%, Confidence Interval (1.08–26.14). Males had better knowledge of vehicle exhaust emission with carcinogenic effects: (Adjusted Odds Ratio) = 3.28%, Confidence Interval (1.11–9.67). Having an associate’s degree as the highest level of education and irritation of nose and eyes were associated with lower awareness of vehicle exhaust emissions: (Adjusted Odds Ratio) = 0.42%, Confidence Interval (0.19–0.97) and (Adjusted Odds Ratio) = 0.31%, Confidence Interval (0.13–0.76), respectively. The diesel particulate matter concentration was higher during day shifts (0.027 mg/m³) compared to night shifts (0.021 mg/m³), p = 0.001. Seventy-one workers (34%) reported experiencing acute headaches often, and fewer workers (n = 31, 14.8%) reported to have never suffered from an acute headache. A majority of workers (71 (34%)) experienced acute irritation of nose and eyes often compared to a few (33 (16%)) workers who experienced the same less often. In addition, a majority of workers (84 (40.2%)) experienced acute fatigue and nausea often, while fewer workers (37 (17.7%)) experienced fatigue and nausea very often. The majority of workers (n = 116, 55.5%) suffered cough and sneezing more often compared to others. There is an urgent need for improved and effective controls to reduce workers’ exposure to vehicle exhaust emissions. Full article

(This article belongs to the Special Issue Air Pollution Exposure and Health Impact Assessment (2nd Edition))

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12 pages, 18779 KiB

Open AccessArticle

Characteristics of Aerosol Water Content and Its Implication on Secondary Inorganic Aerosol Formation during Sandy Haze in an Inland City in China

by Shiting Zhai, Panru Kang, Shenbo Wang and Ruiqin Zhang

Atmosphere 2024, 15(7), 850; https://doi.org/10.3390/atmos15070850 - 19 Jul 2024

Viewed by 593

Abstract

Sand events continue to occur frequently and affect the North China region. Under unfavorable meteorological conditions, they can easily combine with haze pollution, forming sandy haze events that have a significant impact on human health. Aerosol water content (AWC) is known to have [...] Read more.

Sand events continue to occur frequently and affect the North China region. Under unfavorable meteorological conditions, they can easily combine with haze pollution, forming sandy haze events that have a significant impact on human health. Aerosol water content (AWC) is known to have a significant impact on PM_2.5, but its effect is still unclear in sandy haze. In this work, sandy haze and haze periods were observed in Zhengzhou using a series of high-time-resolution instruments. The AWC calculated by the ISORROPIA-II model reached 11 ± 5 μg m⁻³, accounting for 10% of the PM_2.5, in the sandy haze period. Sensitivity tests show that AWC was mainly relative humidity (RH)-dependent. Additionally, elevated SO₄²⁻, TNO_3, and TNH₄ were crucial in the increase in AWC. The increase in Ca²⁺ ions in the sandy haze led to lower AWC than that in the haze periods. Specifically, (NH₄)₂SO₄ was the major contributor to the AWC when the RH was between 30 and 46% in the sandy haze period, and NH₄NO₃ gradually became the main contributor with the increase in RH. In turn, AWC could enhance the formation of sulfate and nitrate, even during the sandy haze period. Therefore, the emergency control of gaseous precursors should also be implemented before the sand events. Full article

(This article belongs to the Special Issue Atmospheric Pollution in Highly Polluted Areas)

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16 pages, 9526 KiB

Open AccessArticle

High-Resolution Characterization of Aerosol Optical Depth and Its Correlation with Meteorological Factors in Afghanistan

by Sayed Esmatullah Torabi, Muhammad Amin, Worradorn Phairuang, Hyung-Min Lee, Mitsuhiko Hata and Masami Furuuchi

Atmosphere 2024, 15(7), 849; https://doi.org/10.3390/atmos15070849 - 19 Jul 2024

Viewed by 1267

Abstract

Atmospheric aerosols pose a significant global problem, particularly in urban areas in developing countries where the rapid urbanization and industrial activities degrade air quality. This study examined the spatiotemporal variations and trends in aerosol optical depth (AOD) at a 550 nm wavelength, alongside [...] Read more.

Atmospheric aerosols pose a significant global problem, particularly in urban areas in developing countries where the rapid urbanization and industrial activities degrade air quality. This study examined the spatiotemporal variations and trends in aerosol optical depth (AOD) at a 550 nm wavelength, alongside key meteorological factors, in Kabul, Afghanistan, from 2000 to 2022. Using the Google Earth Engine geospatial analysis platform, daily AOD data were retrieved from the Moderate Resolution Imaging Spectroradiometer to assess monthly, seasonal, and annual spatiotemporal variations and long-term trends. Meteorological parameters such as temperature (T), relative humidity (RH), precipitation (PCP), wind speed (WS), wind direction, and solar radiation (SR) were obtained from the Modern Era Retrospective Analysis for Research and Applications. The Mann–Kendall test was employed to analyze the time-series trends, and a Pearson correlation matrix was calculated to assess the influence of the meteorological factors on AOD. Principal component analysis (PCA) was performed to understand the underlying structure. The results indicated high AOD levels in spring and summer, with a significant upward trend from 2000 to 2022. The findings revealed a positive correlation of AOD value with T, RH, WS, and PCP and a negative correlation with SR. The PCA results highlighted complex interactions among these factors and their impact on the AOD. These insights underscore the need for stringent air quality regulations and emission control measures in Kabul. Full article

(This article belongs to the Special Issue Aerosols Pollution: Characteristics, Impacts, Projections and Mitigation)

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10 pages, 1781 KiB

Open AccessArticle

Exposure to Acid Aerosols in the Visiting Areas of the Poás Volcano National Park, Costa Rica

by Christian Vargas Jiménez, José Pablo Sibaja Brenes, Rosa Alfaro Solís, Henry Borbón Alpízar, Mónica Brenes Ortiz and Maricruz Arguedas González

Atmosphere 2024, 15(7), 848; https://doi.org/10.3390/atmos15070848 - 19 Jul 2024

Viewed by 610

Abstract

Poás Volcano made a magmatic eruption in April 2017. The volcanic outburst resulted in an ash and vapor column towering over three kilometers high. Since that time, there has been a continual release of gases, aerosols, and more recently, ash, posing potential issues [...] Read more.

Poás Volcano made a magmatic eruption in April 2017. The volcanic outburst resulted in an ash and vapor column towering over three kilometers high. Since that time, there has been a continual release of gases, aerosols, and more recently, ash, posing potential issues for visitors and park rangers. In this work, the potential for exposure to acid gases and aerosols faced by park rangers, officials, and visitors to the Poás Volcano National Park was evaluated, and the concentrations found were compared with the exposure limits established by the Occupational Safety and Health Administration (OSHA). The study was conducted between October 2021 and November 2022. the concentrations of HCl(g), HNO₃(ac), HF(g), and H₂SO₄(ac) were determined at three strategic points: the ranger station, the visitor center, and the main crater viewpoint. The maximum concentrations obtained were (7.0 ± 1.6) ppb for HCl(g), (6.2 ± 2.8) ppb for HNO₃(ac), and (0.029 ± 0.044) ppm for H₂SO₄(ac). There were no concentration values above the detection limit (0.94 μg/m³) for HF_(g). By comparing the data obtained with similar studies, it is concluded that the measured values in Poás Volcano National Park are low and only show similarities to the results found in volcanoes within the national territory. The exposure limit established by OSHA (0.02 ppm) was only surpassed by H₂SO_4(ac), and could be the cause of health effects experienced over the years by park rangers. To minimize these risks, the use of personal protective equipment and air quality monitoring is essential. Full article

(This article belongs to the Special Issue Impact of Volcanic Eruptions on the Atmosphere)

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19 pages, 823 KiB

Open AccessReview

Trends in the Use of Air Quality Indexes in Asthma Studies

by Angie Daniela Barrera-Heredia, Carlos Alfonso Zafra-Mejía, Alejandra Cañas Arboleda, María José Fernández Sánchez, Liliana López-Kleine and Adriana Rojas Moreno

Atmosphere 2024, 15(7), 847; https://doi.org/10.3390/atmos15070847 - 18 Jul 2024

Viewed by 915

Abstract

International air quality indexes (AQIs) are derived from air pollution and are essential global tools for mitigating diseases such as asthma, as they are used to reduce exposure to triggers. The aim of this article is to systematically review the global literature on [...] Read more.

International air quality indexes (AQIs) are derived from air pollution and are essential global tools for mitigating diseases such as asthma, as they are used to reduce exposure to triggers. The aim of this article is to systematically review the global literature on the use of AQIs in asthma-related studies. To evaluate the importance of the variables considered, a citation frequency index (Q) was used. The results suggest that the most frequently reported air pollutants related to asthma are PM (Q3) > NO₂ (Q3) > O₃ (Q3) > CO (Q3) > NO (Q3) > SO₂ (Q3). In addition, climate variables play a relevant role in asthma research. Temperature (Q4) emerged as the most relevant climate variable, followed by atmospheric pressure (Q3) > wind direction (Q3) > solar radiation (Q3) > precipitation (Q3) > wind speed (Q3). AQIs, specifically the U.S.EPA Air Quality Index and the Air Quality Health Index, are directly associated with air pollution and the prevalence, severity and exacerbation of asthma. The findings also suggest that climate change presents additional challenges in relation to asthma by influencing the environmental conditions that affect the disease. Finally, this study provides a comprehensive view of the relationships among air quality, air pollutants and asthma and highlights the need for further research in this field to develop public health policies and environmental regulations. Full article

(This article belongs to the Special Issue New Insights into Ambient Air Pollution and Human Health)

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8 pages, 488 KiB

Open AccessArticle

Italian National Radon Action Plan: New Challenges for Risk Assessment

by Giuseppe La Verde, Giuseppe Della Peruta, Chiara Imparato, Fabrizio Ambrosino, Rocco Mottareale, Gaetano Gagliardo and Mariagabriella Pugliese

Atmosphere 2024, 15(7), 846; https://doi.org/10.3390/atmos15070846 - 18 Jul 2024

Viewed by 937

Abstract

Radon gas is one of the chemical pollutants with one of the most significant physical effects due to its impact on human health: it is a radioactive noble gas which, if inhaled, can stochastically induce lung cancer. For this reason, it is classified [...] Read more.

Radon gas is one of the chemical pollutants with one of the most significant physical effects due to its impact on human health: it is a radioactive noble gas which, if inhaled, can stochastically induce lung cancer. For this reason, it is classified as a category A substance and is the second cause of cancer after tobacco smoking. The monitoring and management of indoor radon is based on international recommendations but also national regulations, which, in recent years, have been updated by lowering the reference levels. In this work, some radon activity concentration data were evaluated by comparing the criteria of old and new legislation to highlight how the radiation protection approach has completely changed. Specifically, this study focuses on measurements in Campania, which, due to its originally volcanic geological structure, requires crucial attention in the context of radon risk assessment, given the considerable number of dwellings built in tuff. This initial data processing enabled the identification of potential high-priority radon risk areas, serving as an important reference point for the extension of the monitoring activities in Campania. Full article

(This article belongs to the Special Issue Air Pollution in Italy: Effects, Sources and Control)

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22 pages, 2622 KiB

Open AccessArticle

Particulate and Gaseous Emissions from a Large Two-Stroke Slow-Speed Marine Engine Equipped with Open-Loop Scrubber under Real Sailing Conditions

by Achilleas Grigoriadis, Nikolaos Kousias, Anastasios Raptopoulos-Chatzistefanou, Håkan Salberg, Jana Moldanová, Anna-Lunde Hermansson, Yingying Cha, Anastasios Kontses, Zisimos Toumasatos, Sokratis Mamarikas and Leonidas Ntziachristos

Atmosphere 2024, 15(7), 845; https://doi.org/10.3390/atmos15070845 - 17 Jul 2024

Viewed by 941

Abstract

Particulate and gaseous emissions were studied from a large two-stroke slow-speed diesel engine equipped with an open-loop scrubber, installed on a 78,200 metric tonnes (deadweight) containership, under real operation. This paper presents the on-board emission measurements conducted upstream and downstream of the scrubber [...] Read more.

Particulate and gaseous emissions were studied from a large two-stroke slow-speed diesel engine equipped with an open-loop scrubber, installed on a 78,200 metric tonnes (deadweight) containership, under real operation. This paper presents the on-board emission measurements conducted upstream and downstream of the scrubber with heavy fuel oil (HFO) and ultra-low sulfur fuel oil (ULSFO). Particle emissions were examined under various dilution ratios and temperature conditions, and with two thermal treatment setups, involving a thermodenuder (TD) and a catalytic stripper (CS). Our results show a 75% SO₂ reduction downstream of the scrubber with the HFO to emission-compliant levels, while the use of the ULSFO further decreased SO₂ levels. The operation of the scrubber produced higher particle number levels compared to engine-out, attributed to the condensational growth of nanometer particle cores, salt and the formation of sulfuric acid particles in the smaller size range, induced by the scrubber. The use of a TD and a CS eliminates volatiles but can generate new particles when used in high-sulfur conditions. The results of this study contribute to the generally limited understanding of the particulate and gaseous emission performance of open-loop scrubbers in ships and could feed into emission and air quality models for estimating marine pollution impacts. Full article

(This article belongs to the Special Issue Engine Emissions: Assessment and Control)

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11 pages, 7224 KiB

Open AccessEditor’s ChoiceArticle

Connection between Winter East Asia Flow Patterns and Stratospheric Polar Vortex Anomalies

by Masakazu Taguchi

Atmosphere 2024, 15(7), 844; https://doi.org/10.3390/atmos15070844 - 17 Jul 2024

Viewed by 540

Abstract

Using a reanalysis dataset, this work investigates the possible connection of winter East Asia (EA) flow patterns to stratospheric polar vortex (SPV) anomalies. Cluster analysis is performed on the principal components of daily 500 hPa geopotential height fields to identify five distinct flow [...] Read more.

Using a reanalysis dataset, this work investigates the possible connection of winter East Asia (EA) flow patterns to stratospheric polar vortex (SPV) anomalies. Cluster analysis is performed on the principal components of daily 500 hPa geopotential height fields to identify five distinct flow patterns. SPV anomalies are considered in terms of the occurrence of major sudden stratospheric warmings (MSSWs). The results reveal that for the 15 days before the MSSWs, one of the five patterns occurs more frequently than usual, whereas another occurs less frequently. The former constructively interferes with the climatological EA trough in the troposphere and strengthens the planetary wave activity (heat flux) in the extratropical troposphere and stratosphere. It has a similar pattern in the 500 hPa height to the composite leading to the MSSWs, implying that such strengthening can contribute to the forcing of the MSSWs. The latter is in the opposite sense (destructive interference) and is disadvantageous before the MSSWs. Evidence of a stratospheric downward influence on the five flow patterns is relatively unclear. These results suggest a potential coupling between flow patterns or weather regimes in different regions through the SPV, as well as warrant further investigation of the downward influence on EA weather regimes. Full article

(This article belongs to the Section Meteorology)

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20 pages, 11831 KiB

Open AccessArticle

Evolution of Soil Pore Structure and Shear Strength Deterioration of Compacted Soil under Controlled Wetting and Drying Cycles

by Kanishka S. Turrakheil, Syed Samran Ali Shah and Muhammad Naveed

Atmosphere 2024, 15(7), 843; https://doi.org/10.3390/atmos15070843 - 17 Jul 2024

Viewed by 607

Abstract

This study investigates the evolution of soil pore structure and shear strength deterioration in compacted clayey soil under controlled wetting and drying (wd) cycles, which are expected to become more frequent due to climate change. Thirty soil samples were compacted at optimal moisture [...] Read more.

This study investigates the evolution of soil pore structure and shear strength deterioration in compacted clayey soil under controlled wetting and drying (wd) cycles, which are expected to become more frequent due to climate change. Thirty soil samples were compacted at optimal moisture content and 90% maximum dry density. These samples were then subjected to 0, 1, 5, 10, and 15 controlled wd cycles from saturation to the wilting point, and volumetric changes were recorded during each cycle. After the wd treatment, the soil samples were scanned using X-ray computed tomography (CT) at 50 μm resolution and then sheared under unconsolidated–undrained and consolidated–undrained conditions in a triaxial test. Significant shrinkage and swelling of soil samples were observed during wd cycles, with average volumetric strain fluctuating between +12% at saturation and −5% at the wilting point. X-ray CT visualisation and analysis revealed higher porosity, more prominent pores, and increased pore length in soil samples with increasing wd cycles. Both undrained and effective soil shear strength markedly decreased with increasing wd cycles. CT-derived macroporosity and pore length were significant predictors of the soil’s undrained and effective shear strength when exposed to wd cycles. The findings emphasise the considerable impact of climate change, specifically wd cycles, on clayey soil, highlighting the need for consideration in the design of earth-based infrastructure. Full article

(This article belongs to the Special Issue Land-Atmosphere Interactions)

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17 pages, 7021 KiB

Open AccessArticle

by Clare Walter, Peter D. Sly, Brian W. Head, Diane Keogh and Nina Lansbury

Atmosphere 2024, 15(7), 842; https://doi.org/10.3390/atmos15070842 - 17 Jul 2024

Viewed by 1168

Abstract

Childhood asthma is a major health issue in Australia, and traffic emissions play a causative role. Two urban planning policies that impact children’s exposure to traffic emissions are considered in terms of the potential health risks to children in a Melbourne suburb with [...] Read more.

Childhood asthma is a major health issue in Australia, and traffic emissions play a causative role. Two urban planning policies that impact children’s exposure to traffic emissions are considered in terms of the potential health risks to children in a Melbourne suburb with high truck volumes and hospital attendances for childhood asthma. Firstly, the health impact assessment component of the state planning approval of a major road project, and secondly, local government placement of childcare centres and schools in relation to freight routes. Three sources of air quality monitoring data were examined: (i) a Victorian EPA reference site; (ii) a site with planning approval for development into a childcare centre; and (iii) five sites within the boundary of the West Gate Tunnel Project, an AUD 10 billion road and tunnel project. The Australian Urban Research Infrastructure Network data was utilised to assess distances of childcare centres and schools from major truck routes. A range of cconcentration–response functions for childhood asthma (0–18 years) from international systematic meta-analyses and a smaller Australian cross-sectional study were applied to comparative elevations in fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) concentrations between the EPA reference monitor (used for project risk assessment) and local roadside data. It was found that comparative elevations in NO₂ concentrations were associated with the following risk increases: developing asthma 13%, active asthma 12%, and lifetime asthma 9%. Overall, 41% of childcare centres (n = 51) and 36% of schools (n = 22) were ≤150 m to a high-density truck route. Truck emissions likely make a substantial contribution to childhood asthma outcomes in the project area. This study exemplifies how current practices may not be commensurate with guiding policy objectives of harm minimisation and equitable protection. Full article

(This article belongs to the Special Issue Climate Change, Air Pollution and Human Health: Past, Present and Future)

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24 pages, 4737 KiB

Open AccessArticle

COAT Project: Intercomparison of Thermometer Radiation Shields in the Arctic

by Carmen García Izquierdo, Sonia Hernandez, Marina Parrondo, Alberto Casas, Angelo Viola, Mauro Mazzola, Andrea Merlone and Yves-Alain Roulet

Atmosphere 2024, 15(7), 841; https://doi.org/10.3390/atmos15070841 - 16 Jul 2024

Cited by 1 | Viewed by 636

Abstract

A metrological field intercomparison of thermometer radiation shields in the Arctic was conducted with the aim of obtaining information to increase the worldwide comparability of air temperature measurements. Air temperature measurements are performed by different combinations of thermometers and shields. The response of [...] Read more.

A metrological field intercomparison of thermometer radiation shields in the Arctic was conducted with the aim of obtaining information to increase the worldwide comparability of air temperature measurements. Air temperature measurements are performed by different combinations of thermometers and shields. The response of each system (thermometer + shield) to local meteorological conditions depends on the system itself, limiting the comparability of air temperature measurements. Ten different models of radiation shields were included in the intercomparison, involving two campaigns: (1) the laboratory campaign, where all the instrumentation was calibrated just before and just after the field campaign, and (2) the field campaign that lasted 14 months where 41 thermometers were sampled every 2 min. All the delivered data were subjected to quality control to assure the robustness of the conclusions. A reference shield was defined, and the other shields were compared to the reference one for the conditions where maximum divergences were expected, solar irradiance being the highest impact factor. A maximum divergence value of 1.29 °C was derived for one of the shields and, for all the shields, the difference from the reference one decreases with wind speed. Finally, the uncertainties associated with the shields intercomparison were calculated. Full article

(This article belongs to the Special Issue Problems of Meteorological Measurements and Studies (2nd Edition))

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25 pages, 12283 KiB

Open AccessArticle

Southerly Surge Impact on Rainfall Patterns in Southern Indonesia during Winter Monsoon and Madden–Julian Oscillation (MJO)

by Trismidianto, Didi Satiadi, Wendi Harjupa, Ibnu Fathrio, Risyanto, Elfira Saufina, Robi Muharsyah, Danang Eko Nuryanto, Fadli Nauval, Dita Fatria Andarini, Anis Purwaningsih, Teguh Harjana, Alfan Sukmana Praja, Adi Witono, Ina Juaeni and Bambang Suhandi

Atmosphere 2024, 15(7), 840; https://doi.org/10.3390/atmos15070840 - 16 Jul 2024

Viewed by 732

Abstract

The impact of the southerly surge’s interaction with the MJO on rainfall in this study was investigated using daily rainfall data from 2140 weather-observation stations. The southern surge, which coincided with the MJO, enhanced rainfall in the western research region, with Yogyakarta seeing [...] Read more.

The impact of the southerly surge’s interaction with the MJO on rainfall in this study was investigated using daily rainfall data from 2140 weather-observation stations. The southern surge, which coincided with the MJO, enhanced rainfall in the western research region, with Yogyakarta seeing the greatest increase at 4.69 mm/day. Meanwhile, the southern surge that occurred without the MJO increased rainfall in the eastern region, with West Nusa Tenggara seeing the greatest rise at 3.09 mm/day. However, the southerly surge has the effect of lowering rainfall in Jakarta, reaching −2.21 mm/day when the MJO is active and −1.58 mm/day when the MJO is inactive. The southerly surge causes extreme rainfall to only occur in a small part of certain areas, so it tends to significantly reduce the possibility of extreme rainfall. In the southern part of the Indonesian maritime continent, the southerly surge predominates over the MJO, supporting increased water vapor transport. Rainfall mostly increases in the afternoon and decreases in the morning when the southerly surge occurs, whether there is the MJO or not. Convective instability analysis indicates that SS increases precipitation, most likely by raising vertically integrated moisture flux convergence, with a correlation coefficient value of 0.82. Full article

(This article belongs to the Section Meteorology)

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20 pages, 2824 KiB

Open AccessEditor’s ChoiceArticle

The Effect of Wood Species on Fine Particle and Gaseous Emissions from a Modern Wood Stove

by Henna Rinta-Kiikka, Karna Dahal, Juho Louhisalmi, Hanna Koponen, Olli Sippula, Kamil Krpec and Jarkko Tissari

Atmosphere 2024, 15(7), 839; https://doi.org/10.3390/atmos15070839 - 16 Jul 2024

Cited by 1 | Viewed by 913

Abstract

Residential wood combustion (RWC) is a significant source of gaseous and particulate emissions causing adverse health and environmental effects. Several factors affect emissions, but the effects of the fuel wood species on emissions are currently not well understood. In this study, the Nordic [...] Read more.

Residential wood combustion (RWC) is a significant source of gaseous and particulate emissions causing adverse health and environmental effects. Several factors affect emissions, but the effects of the fuel wood species on emissions are currently not well understood. In this study, the Nordic wood species (named BirchA, BirchB, Spruce, SpruceDry, Pine and Alder) were combusted in a modern stove, and the emissions were studied. The lowest emissions were obtained from the combustion of BirchA and the highest from Spruce and Alder. The fine particle mass (PM_2.5) was mainly composed of elemental carbon (50–70% of PM_2.5), which is typical in modern appliances. The lowest PAH concentrations were measured from BirchA (total PAH 107 µg/m³) and Pine (250 µg/m³). In the ignition batch, the PAH concentration was about 4-fold (416 µg/m³). The PAHs did not correlate with other organic compounds, and thus, volatile organic compounds (VOCs) or organic carbon (OC) concentrations cannot be used as an indicator of PAH emissions. Two birch species from different origins with a similar chemical composition but different density produced partially different emission profiles. This study indicates that emission differences may be due more to the physical properties of the wood and the combustion conditions than to the wood species themselves. Full article

(This article belongs to the Special Issue Aerosols Pollution: Characteristics, Impacts, Projections and Mitigation)

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Atmosphere, Volume 15, Issue 7 (July 2024) – 130 articles

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