Atmosphere

15 pages, 13248 KiB

Open AccessArticle

Pseudo-Invariant Feature-Based Linear Regression Model (PIF-LRM): An Effective Normalization Method to Evaluate Urbanization Impacts on Land Surface Temperature Changes

by Zhengwu Cai, Chao Fan, Falin Chen and Xiaoma Li

Atmosphere 2021, 12(11), 1540; https://doi.org/10.3390/atmos12111540 - 22 Nov 2021

Cited by 4 | Viewed by 2254

Abstract

The Landsat land surface temperature (LST) product is widely used to understand the impact of urbanization on surface temperature changes. However, directly comparing multi-temporal Landsat LST is challenging, as the observed LST might be strongly affected by climatic factors. This study validated the [...] Read more.

The Landsat land surface temperature (LST) product is widely used to understand the impact of urbanization on surface temperature changes. However, directly comparing multi-temporal Landsat LST is challenging, as the observed LST might be strongly affected by climatic factors. This study validated the utility of the pseudo-invariant feature-based linear regression model (PIF-LRM) in normalizing multi-temporal Landsat LST to highlight the urbanization impact on temperature changes, based on five Landsat LST images during 2000–2018 in Changsha, China. Results showed that LST of PIFs between the reference and the target images was highly correlated, indicating high applicability of the PIF-LRM to relatively normalize LST. The PIF-LRM effectively removed the temporal variation of LST caused by climate factors and highlighted the impacts of urbanization caused land use and land cover changes. The PIF-LRM normalized LST showed stronger correlations with the time series of normalized difference of vegetation index (NDVI) than the observed LST and the LST normalized by the commonly used mean method (subtracting LST by the average, respectively for each image). The PIF-LRM uncovered the spatially heterogeneous responses of LST to urban expansion. For example, LST decreased in the urban center (the already developed regions) and increased in the urbanizing regions. PIF-LRM is highly recommended to normalize multi-temporal Landsat LST to understand the impact of urbanization on surface temperature changes from a temporal point of view. Full article

(This article belongs to the Special Issue Remote Sensing and GIS Applications in Urban Climate Research)

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15 pages, 2736 KiB

Open AccessArticle

Improving Lidar Windshear Detection Efficiency by Removal of “Gentle Ramps”

by Kai Kwong Hon and Pak Wai Chan

Atmosphere 2021, 12(11), 1539; https://doi.org/10.3390/atmos12111539 - 22 Nov 2021

Cited by 4 | Viewed by 2566

Abstract

The Doppler Lidar windshear alerting system at the Hong Kong International Airport (HKIA), the first of its kind in the world, has been in operation since 2006. This paper reports on an enhancement to the automatic windshear detection algorithm at HKIA, which aims [...] Read more.

The Doppler Lidar windshear alerting system at the Hong Kong International Airport (HKIA), the first of its kind in the world, has been in operation since 2006. This paper reports on an enhancement to the automatic windshear detection algorithm at HKIA, which aims at filtering out alerts associated with smoother headwind changes spread over longer distances along the aircraft glide path (called “gentle ramps”) which may nonetheless exceed the well-established alerting threshold. Real-time statistics are examined over a 46-month study period between March 2016 and December 2019, covering a total of 2,017,440 min and over 1500 quality-controlled pilot reports of windshear (PIREP). The “gentle ramp removal” (GRR) function is able to effectively cut down the alert duration over the 5 major runway corridors, inclusive of both landing and take-off, which together account for over 98% of the PIREP received at HKIA during the study period. In all 5 runway corridors this is achieved with a proportionately smaller decrease—even with no changes in 2 cases—in the hit rate, highlighting the efficiency of the GRR function. The difference in statistical behaviour across the runway corridors also echo literature findings about the differences in length scale of wind disturbances at different locations within HKIA. This study serves as a unique documentation of the state-of-the-art in operational Lidar windshear detection and can provide useful reference to airports and aviation meteorologists around the world. Full article

(This article belongs to the Special Issue Low Level Windshear and Turbulence for Aviation Safety)

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11 pages, 1408 KiB

Open AccessArticle

A Multi-Site Evaluation of Winter Hardiness in Indigenous Alfalfa Cultivars in Northern China

by Lijun Xu, Qian Liu, Yingying Nie, Feng Li, Guixia Yang, Ya Tao, Shijie Lv, Xinjia Wu and Liming Ye

Atmosphere 2021, 12(11), 1538; https://doi.org/10.3390/atmos12111538 - 21 Nov 2021

Cited by 8 | Viewed by 2204

Abstract

Integration of perennial grass species into the current food production systems, especially in the agropastoral regions worldwide, may produce multiple benefits including, among others, a more stable productivity and a smaller eco-environmental footprint. However, one of the fundamental challenges facing the large-scale adoption [...] Read more.

Integration of perennial grass species into the current food production systems, especially in the agropastoral regions worldwide, may produce multiple benefits including, among others, a more stable productivity and a smaller eco-environmental footprint. However, one of the fundamental challenges facing the large-scale adoption of such grass species is their ability to withstand the vagaries of winter in these regions. Here, we present a comprehensive evaluation of the winter hardiness of 50 indigenous Chinese cultivars of alfalfa, a high-quality leguminous perennial grass, in comparison with six introduced U.S. cultivars in a multi-site field experiment in northern China. Our results reveal that indigenous cultivars have stronger winter hardiness than introduced cultivars. Cultivars native in the north performed better than southern cultivars, suggesting that suitability evaluation is an unavoidable step proceeding any regional implementations. Our results also show that the metric we used to assess alfalfa’s winter hardiness, the average score index (ASI), produced more consistent results than another more-widely used metric of winter survival rate (WSR). These findings offer a systematic field evidence that supports regional cropping system adjustment and production system betterment to ensure food security under climate change in the region and beyond. Full article

(This article belongs to the Special Issue Global Climate Change and Food Security: Recent Trends, Current Progress and Future Directions)

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16 pages, 3491 KiB

Open AccessArticle

Storm Naming in the Eastern Mediterranean: Procedures, Events Review and Impact on the Citizens Risk Perception and Readiness

by Vassiliki Kotroni, Konstantinos Lagouvardos, Antonis Bezes, Stavros Dafis, Elisavet Galanaki, Christos Giannaros, Theodore Giannaros, Athanasios Karagiannidis, Ioannis Koletsis, Theodora Kopania, Katerina Papagiannaki, Georgios Papavasileiou, Vasilis Vafeiadis and Eustratios Vougioulas

Atmosphere 2021, 12(11), 1537; https://doi.org/10.3390/atmos12111537 - 21 Nov 2021

Cited by 8 | Viewed by 4729

Abstract

This paper is devoted to the discussion of the practice of storm naming that has been initiated in January 2017 for the first time in the Eastern Mediterranean Region. Namely the METEO Unit at NOA, taking into consideration that storm naming facilitates meteorologists, [...] Read more.

This paper is devoted to the discussion of the practice of storm naming that has been initiated in January 2017 for the first time in the Eastern Mediterranean Region. Namely the METEO Unit at NOA, taking into consideration that storm naming facilitates meteorologists, researchers, authorities, civil protection officers, the media and citizens to communicate the forecasts of high-impact weather events, started storm naming in January 2017 and has named 35 storms up to September 2021. The criteria of storm naming are discussed, and a synopsis of the events is presented. The monthly distribution shows that 57% of the named storms occurred during the winter period, with January being the month with the highest percentage of occurrence of named storms (28%). The impact of storm naming on citizens risk perception and increased awareness has been also assessed through an internet-based questionnaire that was launched on the fourth year of the storm naming practice in Greece. Overall, results indicate a significant impact of storm naming on the readiness of citizens through the activation of perceptual and cognitive mechanisms. Full article

(This article belongs to the Special Issue Climate Extremes and Their Impacts)

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23 pages, 13239 KiB

Open AccessArticle

Precipitation in the Czech Republic in Light of Subjective and Objective Classifications of Circulation Types

by Jan Řehoř, Rudolf Brázdil, Ondřej Lhotka, Miroslav Trnka, Jan Balek, Petr Štěpánek and Pavel Zahradníček

Atmosphere 2021, 12(11), 1536; https://doi.org/10.3390/atmos12111536 - 21 Nov 2021

Cited by 14 | Viewed by 2777

Abstract

Many studies in Europe have investigated the relationship between climatological variables and circulation patterns expressed by various classifications of circulation types. This study provides new insights based on an analysis of precipitation in the western (Bohemia—BOH) and eastern (Moravia and Silesia—M&S) parts of [...] Read more.

Many studies in Europe have investigated the relationship between climatological variables and circulation patterns expressed by various classifications of circulation types. This study provides new insights based on an analysis of precipitation in the western (Bohemia—BOH) and eastern (Moravia and Silesia—M&S) parts of the Czech Republic with respect to the subjective classification of the Czech Hydrometeorological Institute and objective classification based on the flow strength, flow direction, and vorticity during the 1961–2020 period. Circulation types are investigated in regard to their contributions to the total precipitation, mean daily precipitation totals, and precipitation probability (daily totals ≥ 1.0 mm). Types with a westerly airflow and a trough over Central Europe exhibit the highest proportions in precipitation totals. Types with a cyclone over Central Europe, especially combined with a northwestern (BOH) or northeastern (M&S) airflow, result in the highest daily mean totals and precipitation probability. Types with a southwestern airflow transport more precipitation to BOH, while those with a northeastern airflow transport more precipitation to M&S, with a slight seasonal shift in the gradient axis between winter and summer. Circulation types under both classifications are examined from the perspective of their precipitation representation in BOH and M&S and the differences between these two regions. In addition, the suitability of both classifications for precipitation analysis is investigated. Full article

(This article belongs to the Special Issue Climate Variability and Human Impacts in Central Europe Based on Documentary and Instrumental Data)

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21 pages, 5763 KiB

Open AccessArticle

An Object-Based Method for Tracking Convective Storms in Convection Allowing Models

by Fan Han and Xuguang Wang

Atmosphere 2021, 12(11), 1535; https://doi.org/10.3390/atmos12111535 - 21 Nov 2021

Cited by 1 | Viewed by 1769

Abstract

The steady-state assumption commonly used in object-based tracking algorithms may be insufficient to determine the right track when a convective storm goes through a complicated evolution. Such an issue is exacerbated by the relatively coarse output frequency of current convection allowing model (CAM) [...] Read more.

The steady-state assumption commonly used in object-based tracking algorithms may be insufficient to determine the right track when a convective storm goes through a complicated evolution. Such an issue is exacerbated by the relatively coarse output frequency of current convection allowing model (CAM) forecasts (e.g., hourly), giving rise to many spatially well resolved but temporally not well resolved storms that steady-state assumption could not account for. To reliably track simulated storms in CAM outputs, this study proposed an object-based method with two new features. First, the method explicitly estimated the probability of each probable track based on either its immediate past and future motion or a reliable “first-guess motion” derived from storm climatology or near-storm environmental variables. Second, object size was incorporated into the method to help identify temporally not well resolved storms and minimize false tracks derived for them. Parameters of the new features were independently derived from a storm evolution analysis using 2-min Multi-Radar Multi-Sensor (MRMS) data and hourly CAM forecasts produced by the University of Oklahoma (OU) Multiscale data Assimilation and Predictability Laboratory (MAP) from May 2019. The performance of the new method was demonstrated with hourly MRMS and CAM forecast examples from May 2018. A systematic evaluation of four severe weather events indicated 99% accuracy achieved for over 600 hourly MRMS tracks derived with the proposed tracking method. Full article

(This article belongs to the Special Issue Advances in Hazardous Weather Prediction: Data Assimilation, Numerical Model and Tools)

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14 pages, 1710 KiB

Open AccessArticle

Study on Icing Environment Judgment Based on Radar Data

by Jinhu Wang, Binze Xie, Jiahan Cai, Yuhao Wang and Jiang Chen

Atmosphere 2021, 12(11), 1534; https://doi.org/10.3390/atmos12111534 - 20 Nov 2021

Viewed by 2411

Abstract

As a major threat to aviation flight safety, it is particularly important to make accurate judgments and forecasts of the ice accumulation environment. Radar is widely used in civil aviation and meteorology, and has the advantages of high timeliness and resolution. In this [...] Read more.

As a major threat to aviation flight safety, it is particularly important to make accurate judgments and forecasts of the ice accumulation environment. Radar is widely used in civil aviation and meteorology, and has the advantages of high timeliness and resolution. In this paper, a variety of machine learning methods are used to establish the relationship between radar data and icing index (Ic) to determine the ice accumulation environment. The research shows the following. (1) A linear model was established, based on the scattering rate factor (Zh), radial velocity (v), spectral width (w), velocity standard deviation (σ) detected by 94 GHz millimeter wave radar, and backward attenuation coefficient (β) detected by 905 nm lidar, so linear regression was carried out. After principal component analysis (PCA), the correction determination coefficient of the linear equation was increased from 0.7127 to 0.7240. (2) Ice accumulation was unlikely for samples that were significantly off-center. By clustering the data into three or four categories, the proportion of icing lattice points could be increased from 18.81% to 33.03%. If the clustering number was further increased, the ice accumulation ratio will not be further increased, and the increased classification is reflected in the classification of pairs of noises and the possibility of omission is also increased. (3) Considering the classification and nonlinear factors of ice accumulation risk, the neural network method was used to judge the ice accumulation environment. Two kinds of neural network structures were established for quantitative calculation: Structure 1 first distinguished whether there was ice accumulation, and further calculated the icing index for the points where there was ice accumulation; Structure 2 directly calculated the temperature and relative humidity, and calculated the icing index according to definition. The accuracy of the above two structures could reach nearly 60%, but the quantitative judgment of the ice accumulation index was not ideal. The reasons for this dissatisfaction may be the small number of variables and samples, the interval between time and space, the difference in instrument detection principle, and the representativeness of the ice accumulation index. Further research can be improved from the above four points. This study can provide a theoretical basis for the diagnosis and analysis of the aircraft ice accumulation environment. Full article

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

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19 pages, 6144 KiB

Open AccessArticle

Monthly Rainfall Signatures of the North Atlantic Oscillation and East Atlantic Pattern in Great Britain

by Harry West, Nevil Quinn and Michael Horswell

Atmosphere 2021, 12(11), 1533; https://doi.org/10.3390/atmos12111533 - 20 Nov 2021

Cited by 9 | Viewed by 2965

Abstract

Atmospheric-oceanic circulations (teleconnections) have an important influence on regional climate. In Great Britain, the North Atlantic Oscillation (NAO) has long been understood as the leading mode of climate variability, and its phase and magnitude have been found to influence regional rainfall in previous [...] Read more.

Atmospheric-oceanic circulations (teleconnections) have an important influence on regional climate. In Great Britain, the North Atlantic Oscillation (NAO) has long been understood as the leading mode of climate variability, and its phase and magnitude have been found to influence regional rainfall in previous research. The East Atlantic Pattern (EA) is also increasingly recognised as being a secondary influence on European climate. In this study we use high resolution gridded rainfall and Standardised Precipitation Index (SPI) time series data for Great Britain to map the monthly rainfall signatures of the NAO and EA over the period January 1950–December 2015. Our analyses show that the influence of the two teleconnections varies in space and time with distinctive monthly signatures observed in both average rainfall/SPI-1 values and incidences of wet/dry extremes. In the winter months the NAO has a strong influence on rainfall and extremes in the north-western regions. Meanwhile, in the southern and central regions stronger EA-rainfall relationships are present. In the summer months opposing positive/negative phases of the NAO and EA result in stronger wet/dry signatures which are more spatially consistent. Our findings suggest that both the NAO and EA have a prominent influence on regional rainfall distribution and volume in Great Britain, which in turn has implications for the use of teleconnection forecasts in water management decision making. We conclude that accounting for both NAO and EA influences will lead to an enhanced understanding of both historic and future spatial distribution of monthly precipitation. Full article

(This article belongs to the Special Issue Atmospheric Teleconnection)

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14 pages, 695 KiB

Open AccessArticle

Assessing Health Impacts of Winter Smog in Lahore for Exposed Occupational Groups

by Fatima Jabeen, Zulfiqar Ali and Amina Maharjan

Atmosphere 2021, 12(11), 1532; https://doi.org/10.3390/atmos12111532 - 20 Nov 2021

Cited by 9 | Viewed by 11763

Abstract

The goal of this research was to investigate the health effects of winter pollution on various occupations in Lahore and its neighboring peri-urban areas. A questionnaire survey, key informants, and focused group discussions were employed to collect data, which included demographic, socioeconomic, and [...] Read more.

The goal of this research was to investigate the health effects of winter pollution on various occupations in Lahore and its neighboring peri-urban areas. A questionnaire survey, key informants, and focused group discussions were employed to collect data, which included demographic, socioeconomic, and health-related information. Descriptive statistics and the multivariate logistic regression model (MLRM) were used to examine the effects of pollution on exposed occupational groups who experienced symptoms such as coughing, shortness of breath, and eye discomfort. According to data from interviews, MLRM revealed that individuals working in various occupations with outdoor and indoor environments are equally affected by winter smog, but being middle-aged (odds ratio OR = 5.73), having a history of a respiratory ailment (OR = 4.06), and location (OR = 2.26) all play important roles in determining health. However, less educated people, elders, and people who already live in polluted areas are more likely to develop respiratory health symptoms. During the smog incident, it was determined that diverse health and socioeconomic factors exacerbate an individual’s negative health impact more than others. Full article

(This article belongs to the Special Issue Urban Air Pollution Exposure and Related Diseases)

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16 pages, 2156 KiB

Open AccessArticle

Estimation of Emission Factors for Hazardous Air Pollutants from Petroleum Refineries

by Elisa Polvara, Luca Roveda, Marzio Invernizzi, Laura Capelli and Selena Sironi

Atmosphere 2021, 12(11), 1531; https://doi.org/10.3390/atmos12111531 - 20 Nov 2021

Cited by 6 | Viewed by 3276

Abstract

The hazardous air pollutants (HAPs) group is composed of 187 chemicals that are known to be potentially carcinogenic and dangerous for human health. Due to their toxicological impact, HAPs are an increasingly studied class of compounds. Of the different HAPs sources, refineries are [...] Read more.

The hazardous air pollutants (HAPs) group is composed of 187 chemicals that are known to be potentially carcinogenic and dangerous for human health. Due to their toxicological impact, HAPs are an increasingly studied class of compounds. Of the different HAPs sources, refineries are one of the major sources. In order to obtain a preliminary assessment of the impact of a refinery in terms of emissions, a useful instrument is the determination of the emission factor (EF). For this reason, this work, focusing on the USA refining scenario, aims to provide evidence for a generic trend in refinery emissions to evaluate a correlation between the plant size and the amount of its emissions, in particular the HAPs emissions. Based on the analysis of the data collected from the U.S. Environmental Protection Agency (US EPA), a general trend in the emissions from refinery plants was established, showing a positive correlation between the HAPs emissions and the refinery size, represented by a value of the Pearson correlation coefficient r close to 1. Once this correlation was highlighted, a purpose of this work became the estimation of an organic HAPs emission factor (EF): from a whole refining plant, the EF of the total organic HAPs is equal to 10 g emitted for each ton of crude oil processed. Moreover, it was also possible to undertake the same evaluation for two specific HAP molecules: benzene and formaldehyde. The benzene and formaldehyde EFs are equal to, respectively, 0.8 g and 0.2 g for each ton of processed crude oil. This work provides a simple rule of thumb for the estimation of hazardous substances emitted from petroleum refineries in their mean operating conditions. Full article

(This article belongs to the Special Issue Air Pollution, Air Quality and Human Health)

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13 pages, 6657 KiB

Open AccessArticle

VOCs Fugitive Emission Characteristics and Health Risk Assessment from Typical Plywood Industry in the Yangtze River Delta Region, China

by Kun Hu, Zhiqiang Liu, Ming Wang, Bingjie Zhang, Haotian Lin, Xingdong Lu and Wentai Chen

Atmosphere 2021, 12(11), 1530; https://doi.org/10.3390/atmos12111530 - 20 Nov 2021

Cited by 7 | Viewed by 2660

Abstract

Volatile organic compounds (VOCs) emissions from the plywood manufacturing industry in China have received concerns during recent years. A total of 115 VOCs were measured in the adhesive-making, adhesive-coating, and hot-pressing workshops of the plywood manufacturing industry to investigate fugitive emission characteristics of [...] Read more.

Volatile organic compounds (VOCs) emissions from the plywood manufacturing industry in China have received concerns during recent years. A total of 115 VOCs were measured in the adhesive-making, adhesive-coating, and hot-pressing workshops of the plywood manufacturing industry to investigate fugitive emission characteristics of VOCs and assess their health risks to workers. The average concentration of total VOCs in workshops of the plywood manufacturing industry is 467 ± 359 μg/m³, whereas the value for ambient air is 81.4 μg/m³. For specific processes, the adhesive-coating and hot-pressing processes show higher VOCs concentrations (501 μg/m³–519 μg/m³) than the adhesive-making process (340 μg/m³). Formaldehyde, ethyl acetate, and dichloromethane are the three most abundant VOCs in workshops, with relative contributions to total VOCs of 55.9–63.1%, 4.3–11.0%, and 1.7–4.4%, respectively. For ozone formation potential (OFP) of VOCs, formaldehyde is the largest contributor (86.1%), followed by toluene, xylenes, and propanal. The non-cancer toxic risks (HI) and cancer risks of total VOCs (T-LCR) for three processes are calculated as 2.93–3.94 and 2.86–4.17 × 10⁻⁴ using the US EPA recommended methods, both significantly higher than threshold values (1.0 for HI and 10⁻⁴ for LCR), suggesting the highly toxic and cancer risks to workers. Formaldehyde contributes 68.1–78.2% and 91.4–93.9% of HI and T-LCR, respectively. The designed risk reduction scheme of VOCs based on air ventilation suggests that air ventilation rates of formaldehyde need to reach 4–5 times in 8 h in three processes to reduce T-LCR to 10⁻⁵. These results are useful for developing VOCs control measures and evaluating VOCs occupational health risk for workers in the plywood manufacturing industry. Full article

(This article belongs to the Special Issue VOC Sensing and Measurements)

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14 pages, 1540 KiB

Open AccessArticle

Dominant Contributions of Secondary Aerosols and Vehicle Emissions to Water-Soluble Inorganic Ions of PM_2.5 in an Urban Site in the Metropolitan Hangzhou, China

by Chun Xiong, Shaocai Yu, Xue Chen, Zhen Li, Yibo Zhang, Mengying Li, Weiping Liu, Pengfei Li and John H. Seinfeld

Atmosphere 2021, 12(11), 1529; https://doi.org/10.3390/atmos12111529 - 19 Nov 2021

Cited by 9 | Viewed by 2248

Abstract

Water soluble inorganic ions (WSIIs) are important components in PM_2.5 and could strongly affect the acidity and hygroscopicity of PM_2.5. In order to achieve the seasonal characteristics and determine the potential sources of WSIIs in PM_2.5 in Hangzhou, online [...] Read more.

Water soluble inorganic ions (WSIIs) are important components in PM_2.5 and could strongly affect the acidity and hygroscopicity of PM_2.5. In order to achieve the seasonal characteristics and determine the potential sources of WSIIs in PM_2.5 in Hangzhou, online systems were used to measure hourly mass concentrations of WSIIs (SO₄²⁻, NO₃⁻, NH₄⁺, Cl⁻, Na⁺, K⁺, Ca²⁺ and Mg²⁺) as well as PM_2.5, NO₂ and SO₂ at an urban site for one month each season (May, August, October, December) in 2017. Results showed that the hourly mass concentrations of PM_2.5 during the whole campaign varied from 1 to 292 μg·m⁻³ with the mean of 56.03 μg·m⁻³. The mean mass concentration of WSIIs was 26.49 ± 20.78 μg·m⁻³, which contributed 48.28% to averaged PM_2.5 mass. SNA (SO₄²⁻, NO₃⁻ and NH₄⁺) were the most abundant ions in PM_2.5 and on average, they comprised 41.57% of PM_2.5 mass. PM_2.5, NO₂, SO₂ and WSIIs showed higher mass concentrations in December, possibly due to higher energy consumption emissions, unfavorable meteorological factors (e.g., lower wind speed and temperature) and regional transport. Results from PCA models showed that secondary aerosols and vehicle emissions were the dominant sources of WSIIs in the observations. Our findings highlight the importance of stronger controls on precursor (e.g., SO₂ and NO₂) emissions in Hangzhou, and show that industrial areas should be controlled at local and regional scales in the future. Full article

(This article belongs to the Special Issue Advances in Air Quality Data Analysis and Modeling)

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14 pages, 28314 KiB

Open AccessEditor’s ChoiceArticle

Analysis of Symptomology, Infectiveness, and Reinfections between Male and Female COVID-19 Patients: Evidence from Japanese Registry Data

by Meng-Hao Li, Abu Bakkar Siddique, Ali Andalibi and Naoru Koizumi

Atmosphere 2021, 12(11), 1528; https://doi.org/10.3390/atmos12111528 - 19 Nov 2021

Viewed by 2414

Abstract

Background: Hokkaido was the first Japanese prefecture to be affected by COVID-19. Since the beginning of the pandemic, the Japanese government has been publishing the information of each individual who was tested positive for the virus. Method: The current study analyzed the 1269 [...] Read more.

Background: Hokkaido was the first Japanese prefecture to be affected by COVID-19. Since the beginning of the pandemic, the Japanese government has been publishing the information of each individual who was tested positive for the virus. Method: The current study analyzed the 1269 SARS-CoV-2 cases confirmed in Hokkaido in order to examine sex-based differences in symptomology and infectiveness, as well as the status of reinfections and the viral transmission networks. Results: The majority of asymptomatic patients were females and older. Females were 1.3-fold more likely to be asymptomatic (p < 0.001) while a decade of difference in age increased the likelihood of being asymptomatic by 1% (p < 0.001). The data contained information up to quaternary viral transmission. The transmission network revealed that, although asymptomatic patients are more likely to transmit the virus, the individuals infected by asymptomatic cases are likely to be asymptomatic (p < 0.001). Four distinct co-occurrences of symptoms were observed, including (i) fever/fatigue, (ii) pharyngitis/rhinitis, (iii) ageusia/anosmia, and (iv) nausea/vomiting/diarrhea. The presences of diarrhea (p = 0.05) as well as nausea/vomiting (p < 0.001) were predictive of developing dyspnea, i.e., severe disease. About 1% of the patients experienced reinfection. Conclusions: Sex and symptomatology appear to play important roles in determining the levels of viral transmission as well as disease severity. Full article

(This article belongs to the Special Issue Spreading of Novel Coronavirus (COVID-19) in Ambient Air: Modeling, Prediction and Mitigation Strategies)

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20 pages, 6874 KiB

Open AccessArticle

Spatio-Temporal Variability of Hydroclimatology in the Upper Cauca River Basin in Southwestern Colombia: Pre- and Post-Salvajina Dam Perspective

by Wilmar L. Cerón, Mary T. Kayano, Camilo Ocampo-Marulanda, Teresita Canchala, Irma Ayes Rivera, Alvaro Avila-Diaz, Rita V. Andreoli and Itamara Parente de Souza

Atmosphere 2021, 12(11), 1527; https://doi.org/10.3390/atmos12111527 - 19 Nov 2021

Cited by 3 | Viewed by 3573

Abstract

The Cauca River rises in the Colombian Andes and is the main tributary of the Magdalena River, which drains to the Caribbean Sea. The La Balsa station monitors the Upper Cauca basin and is located just downstream of La Salvajina hydroelectric facility. At [...] Read more.

The Cauca River rises in the Colombian Andes and is the main tributary of the Magdalena River, which drains to the Caribbean Sea. The La Balsa station monitors the Upper Cauca basin and is located just downstream of La Salvajina hydroelectric facility. At this station, the discharge time series for November–January during 1950–2019 shows a statistically significant downward break, and change of distribution after 1986 has been documented after La Salvajina started operation. We assessed the spatio-temporal variability of hydroclimatology in the upper Cauca River basin during the pre- and post-Salvajina dam periods to better understand this break. Post-Salvajina, low (high) discharge events are linked to negative (positive) precipitation and soil moisture anomalies that are greater in magnitude and extension than those recorded in the pre-Salvajina period in response to the more intense El Niño events (more intense and frequent central La Niña events) after 1986. Therefore, it is necessary to consider possible future rainfall scenarios and non-infrastructure measures (i.e., reforestation, territorial planning, integrated watershed management, etc.) to mitigate floods and droughts impacts. The contribution of this study is to provide evidence for the need for foresight in the design of any structural or non-structural flood measures. Full article

(This article belongs to the Special Issue ENSO: Dynamics, Predictability, Modelling and Teleconnection)

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18 pages, 9614 KiB

Open AccessArticle

Impact of Solar Activity on Global Atmospheric Circulation Based on SD-WACCM-X Simulations from 2002 to 2019

by Chen-Ke-Min Teng, Sheng-Yang Gu, Yusong Qin and Xiankang Dou

Atmosphere 2021, 12(11), 1526; https://doi.org/10.3390/atmos12111526 - 19 Nov 2021

Cited by 3 | Viewed by 3340

Abstract

In this study, a global atmospheric model, Specified Dynamics Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension (SD-WACCM-X), and the residual circulation principle were used to study the global atmospheric circulation from the lower to upper atmosphere (~500 km) from 2002 [...] Read more.

In this study, a global atmospheric model, Specified Dynamics Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension (SD-WACCM-X), and the residual circulation principle were used to study the global atmospheric circulation from the lower to upper atmosphere (~500 km) from 2002 to 2019. Our analysis shows that the atmospheric circulation is clearly influenced by solar activity, especially in the upper atmosphere, which is mainly characterized by an enhanced atmospheric circulation in years with high solar activity. The atmospheric circulation in the upper atmosphere also exhibits an ~11 year period, and its variation is highly correlated with the temporal variation in the F10.7 solar index during the same time series, with a maximum correlation coefficient of up to more than 0.9. In the middle and lower atmosphere, the impact of solar activity on the atmospheric circulation is not as obvious as in the upper atmosphere due to some atmospheric activities such as the Quasi-Biennial Oscillation (QBO), El Niño–Southern Oscillation (ENSO), sudden stratospheric warming (SSW), volcanic forcing, and so on. By comparing the atmospheric circulation in different latitudinal regions between years with high and low solar activity, we found the atmospheric circulation in mid- and high-latitude regions is more affected by solar activity than in low-latitude and equatorial regions. In addition, clear seasonal variation in atmospheric circulation was detected in the global atmosphere, excluding the regions near 10⁻⁴ hPa and the lower atmosphere, which is mainly characterized by a flow from the summer hemisphere to the winter hemisphere. In the middle and low atmosphere, the atmospheric circulation shows a quasi-biennial oscillatory variation in the low-latitude and equatorial regions. This work provides a referable study of global atmospheric circulation and demonstrates the impacts of solar activity on global atmospheric circulation. Full article

(This article belongs to the Special Issue Links between Solar Activity and Atmospheric Circulation)

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21 pages, 1740 KiB

Open AccessArticle

Blockchain-Aware Distributed Dynamic Monitoring: A Smart Contract for Fog-Based Drone Management in Land Surface Changes

by Abdullah Ayub Khan, Zaffar Ahmed Shaikh, Asif Ali Laghari, Sami Bourouis, Asif Ali Wagan and Ghulam Ali Alias Atif Ali

Atmosphere 2021, 12(11), 1525; https://doi.org/10.3390/atmos12111525 - 19 Nov 2021

Cited by 26 | Viewed by 3268

Abstract

In this paper, we propose a secure blockchain-aware framework for distributed data management and monitoring. Indeed, images-based data are captured through drones and transmitted to the fog nodes. The main objective here is to enable process and schedule, to investigate individual captured entity [...] Read more.

In this paper, we propose a secure blockchain-aware framework for distributed data management and monitoring. Indeed, images-based data are captured through drones and transmitted to the fog nodes. The main objective here is to enable process and schedule, to investigate individual captured entity (records) and to analyze changes in the blockchain storage with a secure hash-encrypted (SH-256) consortium peer-to-peer (P2P) network. The proposed blockchain mechanism is also investigated for analyzing the fog-cloud-based stored information, which is referred to as smart contracts. These contracts are designed and deployed to automate the overall distributed monitoring system. They include the registration of UAVs (drones), the day-to-day dynamic captured drone-based images, and the update transactions in the immutable storage for future investigations. The simulation results show the merit of our framework. Indeed, through extensive experiments, the developed system provides good performances regarding monitoring and management tasks. Full article

(This article belongs to the Special Issue Application of Remote Sensing Cloud Computing in Land Surface Change)

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34 pages, 14199 KiB

Open AccessReview

An Overview of Experiences Made and Tools Used to Inform the Public on Ambient Air Quality

by Alessandra Fino, Francesca Vichi, Cristina Leonardi and Krishnendu Mukhopadhyay

Atmosphere 2021, 12(11), 1524; https://doi.org/10.3390/atmos12111524 - 18 Nov 2021

Cited by 6 | Viewed by 3978

Abstract

Legislative regulations on atmospheric pollution have been established in different parts of the world for addressing air quality management. An important public commitment, common among all nations, is to ensure environmental safety and health protection, particularly for the most fragile population groups. Each [...] Read more.

Legislative regulations on atmospheric pollution have been established in different parts of the world for addressing air quality management. An important public commitment, common among all nations, is to ensure environmental safety and health protection, particularly for the most fragile population groups. Each country has its own rules and practices to provide adequate and timely information on ambient air quality. Information is given either through easily accessible media, including websites and apps, or by traditional means of telecommunication. An air quality index (AQI) is definitely a valuable tool for disseminating data on the main regulated pollutants and represents a readable indicator of the prevailing situation of air quality in the area. Several calculating expressions were formulated to combine, in a unique value, different parameters, and a few methods were created to determine and compare different AQIs. This paper gives almost a global overview of approaches and tools used to inform the public about the status of the ambient air quality. Different AQIs are analyzed to contribute to the sharing of air quality management practices and information to raise public awareness and to help policymakers to act accordingly. Full article

(This article belongs to the Special Issue Air Quality Assessment and Management)

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11 pages, 426 KiB

Open AccessArticle

Reduction in Indoor Airborne Endotoxin Concentration by the Use of Air Purifier and Its Relationship with Respiratory Health: A Randomized Crossover Intervention Study

by Yoshiko Yoda, Kenji Tamura, Naruhito Otani, Hideki Hasunuma, Shoji F. Nakayama and Masayuki Shima

Atmosphere 2021, 12(11), 1523; https://doi.org/10.3390/atmos12111523 - 18 Nov 2021

Cited by 4 | Viewed by 2807

Abstract

Endotoxins are biological components of particulate matter that cause adverse respiratory system effects. Recently, air purifiers have been widely used; however, their effects on endotoxins are not fully understood. We conducted a randomized crossover intervention study to evaluate the effects of air purifiers [...] Read more.

Endotoxins are biological components of particulate matter that cause adverse respiratory system effects. Recently, air purifiers have been widely used; however, their effects on endotoxins are not fully understood. We conducted a randomized crossover intervention study to evaluate the effects of air purifiers on indoor endotoxins and occupants’ respiratory health. Thirty-two healthy subjects were randomly assigned to two groups; each group spent four weeks using either a true or sham (filter removed) air purifier. Subsequently, the subjects spent an additional four weeks using the alternative air purifier. The indoor endotoxins in fine (PM_2.5) and coarse (PM_10–2.5) particulate matter were continuously collected, and pulmonary function was tested repeatedly during the study period. Household characteristics were assessed using a questionnaire. The geometric mean of the PM_2.5 endotoxin concentrations was 0.13 EU/m³, which was significantly lower with true purifiers compared with sham purifiers, after adjusting for household characteristics (0.17 EU/m³). In addition, the PM_2.5 endotoxin concentrations were significantly greater in reinforced concrete houses than in wooden houses. The PM_10–2.5 endotoxin concentrations were significantly greater in homes with two or more household members, and in those with pets. No association was found between endotoxin concentration and respiratory health among the subjects. Full article

(This article belongs to the Topic Assessing Indoor Pollution and Its Impacts on the Human Health)

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14 pages, 3892 KiB

Open AccessArticle

Changes of Extreme Precipitation and Possible Influence of ENSO Events in a Humid Basin in China

by Xiaoxia Yang, Juan Wu, Jia Liu and Xuchun Ye

Atmosphere 2021, 12(11), 1522; https://doi.org/10.3390/atmos12111522 - 18 Nov 2021

Cited by 11 | Viewed by 2464

Abstract

In this study, 11 extreme precipitation indices were selected to examine the spatiotemporal variation of extreme precipitation in the Poyang Lake Basin during 1960–2017. The responses of extreme precipitation indices to El Nino/Southern Oscillation (ENSO) events of different Pacific Ocean areas were further [...] Read more.

In this study, 11 extreme precipitation indices were selected to examine the spatiotemporal variation of extreme precipitation in the Poyang Lake Basin during 1960–2017. The responses of extreme precipitation indices to El Nino/Southern Oscillation (ENSO) events of different Pacific Ocean areas were further investigated. The results show that the temperature in the Poyang Lake Basin has increased significantly since the 1990s, and the inter-decadal precipitation fluctuated. Most extreme precipitation indices showed an increasing trend with abrupt changes occurring around 1991. Spatially, most of the extreme precipitation indices decreased from northeast to southwest. The increasing trend of most indices in the center and south of the basin was relatively prominent. The linear correlations between the extreme precipitation indices and Nino 1 + 2 were the most significant. On the timescale of 2–6 years, a common oscillation period between the extreme precipitation of the basin and the four ENSO indices can be observed. After 2010, the positive correlation between the precipitation of the Poyang Lake Basin and the SST (sea surface temperature) anomalies in the equatorial Pacific increased significantly. Additionally, annual total wet–day precipitation in most areas of the Poyang Lake Basin increased with varying degrees in warm ENSO years. The results of this study will improve the understanding of the complex background and driving mechanism of flood disasters in the Poyang Lake Basin. Full article

(This article belongs to the Special Issue Meteorological Extremes in China)

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22 pages, 13490 KiB

Open AccessArticle

Evaluation of a Prototype Broadband Water-Vapour Profiling Differential Absorption Lidar at Cardington, UK

by Catherine Gaffard, Zhihong Li, Dawn Harrison, Raisa Lehtinen and Reijo Roininen

Atmosphere 2021, 12(11), 1521; https://doi.org/10.3390/atmos12111521 - 18 Nov 2021

Cited by 6 | Viewed by 2074

Abstract

For a one-month period in summer 2020, a prototype Vaisala broadband differential absorption lidar (BB-DIAL) was deployed at a Met Office research site. It was compared with in-situ observations of humidity (93 radiosonde ascents and 27 of uncrewed aerial vehicle flights) and the [...] Read more.

For a one-month period in summer 2020, a prototype Vaisala broadband differential absorption lidar (BB-DIAL) was deployed at a Met Office research site. It was compared with in-situ observations of humidity (93 radiosonde ascents and 27 of uncrewed aerial vehicle flights) and the Met Office 1.5 km resolution numerical weather prediction (NWP) model: UK Variable resolution model (UKV). The BB-DIAL was able to collect data up to the cloud base, in all-weather situations including rain, when it was possible to reach 3 km. The average maximum height was 1300 m, with 75% of the data reaching 1000 m and 35% extending to 1500 m. Compared with radiosondes, the standard deviation for the water vapour is between 5% and 10%. The comparison with the UKV is very encouraging, with a correlation of 0.90. The error against the radiosonde is smaller than against the UKV, which is encouraging for assimilation the BB-DIAL data in UKV. Some data quality issues, such as an increase in error and variable bias in the region of overlap between the far field and close field, spurious oscillations and an unrealistic dry layer above fog are identified. Despite these issues, the overall results from this assessment are promising in terms of potential benefit, instrument reliability and capturing significant humidity changes in the boundary layer. Full article

(This article belongs to the Special Issue Atmospheric Water Vapor Observation, Simulation, Prediction and Responses to Climate Change)

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22 pages, 10722 KiB

Open AccessArticle

Turbulence in Large-Scale Two-Dimensional Balanced Hard Sphere Gas Flow

by Rafail V. Abramov

Atmosphere 2021, 12(11), 1520; https://doi.org/10.3390/atmos12111520 - 18 Nov 2021

Cited by 5 | Viewed by 1794

Abstract

In recent works, we developed a model of balanced gas flow, where the momentum equation possesses an additional mean field forcing term, which originates from the hard sphere interaction potential between the gas particles. We demonstrated that, in our model, a turbulent gas [...] Read more.

In recent works, we developed a model of balanced gas flow, where the momentum equation possesses an additional mean field forcing term, which originates from the hard sphere interaction potential between the gas particles. We demonstrated that, in our model, a turbulent gas flow with a Kolmogorov kinetic energy spectrum develops from an otherwise laminar initial jet. In the current work, we investigate the possibility of a similar turbulent flow developing in a large-scale two-dimensional setting, where a strong external acceleration compresses the gas into a relatively thin slab along the third dimension. The main motivation behind the current work is the following. According to observations, horizontal turbulent motions in the Earth atmosphere manifest in a wide range of spatial scales, from hundreds of meters to thousands of kilometers. However, the air density rapidly decays with altitude, roughly by an order of magnitude each 15–20 km. This naturally raises the question as to whether or not there exists a dynamical mechanism which can produce large-scale turbulence within a purely two-dimensional gas flow. To our surprise, we discover that our model indeed produces turbulent flows and the corresponding Kolmogorov energy spectra in such a two-dimensional setting. Full article

(This article belongs to the Special Issue Structure of Atmospheric Turbulence)

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14 pages, 8191 KiB

Open AccessArticle

Regional Air Pollutant Characteristics and Health Risk Assessment of Large Cities in Northeast China

by Chunsheng Fang, Hanbo Gao, Zhuoqiong Li and Ju Wang

Atmosphere 2021, 12(11), 1519; https://doi.org/10.3390/atmos12111519 - 18 Nov 2021

Cited by 3 | Viewed by 2006

Abstract

This study systematically investigated the pollution characteristics of atmospheric O₃ and PM_2.5, regional transport, and their health risks in three provincial capitals in northeast China during 2016–2020. The results show that O₃ concentrations showed a trend of high summer [...] Read more.

This study systematically investigated the pollution characteristics of atmospheric O₃ and PM_2.5, regional transport, and their health risks in three provincial capitals in northeast China during 2016–2020. The results show that O₃ concentrations showed a trend of high summer and low winter, while PM_2.5 concentrations showed a trend of high winter and low summer during these five years. The results of the correlation analysis indicate that external sources contribute more O₃, while PM_2.5 is more from local sources. The backward trajectory clustering analysis results showed that Changchun had the highest share of northwest trajectory with a five-year average value of 67.89%, and the city with the highest percentage of southwest trajectory was Shenyang with a five-year average value of 23.95%. The backward trajectory clustering analysis results showed that the share of the northwest trajectory decreased and the share of the southwest trajectory increased for all three cities in 2020 compared to 2016. The results of the potential source contribution function (PSCF) and concentration weighting trajectory (CWT) analysis showed that the main potential source areas and high concentration contribution areas for PM_2.5 in the northeast were concentrated in Mongolia, Inner Mongolia, Shandong Province, and the northeast, and for O₃ were mainly located in Shandong, Anhui, and Jiangsu Provinces, and the Yellow Sea and Bohai Sea. The non-carcinogenic risk of PM_2.5 in Harbin was high with a HQ of 2.04, while the other cities were at acceptable levels (HQ < 0.69) and the non-carcinogenic risk of O₃ was acceptable in all three cities (HQ < 0.22). However, PM_2.5 had a high carcinogenic risk (4 × 10⁻⁴ < CR < 0.44) and further treatment is needed to reduce the risk. Full article

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

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9 pages, 5207 KiB

Open AccessEditor’s ChoiceArticle

A Novel Composite Coding Method for Incoherent Scatter Radar

by Haoyi Chen, Kai Yuan, Ming Yao and Jiawei Xiong

Atmosphere 2021, 12(11), 1518; https://doi.org/10.3390/atmos12111518 - 18 Nov 2021

Cited by 2 | Viewed by 1804

Abstract

Many modern ionospheric studies rely on incoherent scatter radars (ISR) since this kind of radar is able to detect various ionospheric parameters over very long ranges. The performance of ISR significantly depends on its coding system. In recent decades, a new type of [...] Read more.

Many modern ionospheric studies rely on incoherent scatter radars (ISR) since this kind of radar is able to detect various ionospheric parameters over very long ranges. The performance of ISR significantly depends on its coding system. In recent decades, a new type of coding system, which is the so-called composite coding, was presented. It used to be constructed by using a certain code to modulate alternating code to achieve better detection resolution and anti-noise performance for ISRs. In the present study, a new composite coding system was presented, which is constructed based on complementary codes and alternating codes. In this paper, the performance of the new composite code will be compared with that of several traditional codes to show that the new composite code can help to improve the detection performance of the ISR. According to the analysis based on the ambiguity function, the present composite coding system helps to improve the range resolution and detection range for ISR detections. In addition, numerical tests on anti-noise performance show that the complementary composite coding system has a good anti-noise performance and helps to reduce the necessary times of incoherent integration. As a result, the composite coding system can improve the time resolution. Full article

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

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13 pages, 3476 KiB

Open AccessArticle

The Characteristics of Heavy Ozone Pollution Episodes and Identification of the Primary Driving Factors Using a Generalized Additive Model (GAM) in an Industrial Megacity of Northern China

by Liuli Diao, Xiaohui Bi, Wenhui Zhang, Baoshuang Liu, Xuehan Wang, Linxuan Li, Qili Dai, Yufen Zhang, Jianhui Wu and Yinchang Feng

Atmosphere 2021, 12(11), 1517; https://doi.org/10.3390/atmos12111517 - 17 Nov 2021

Cited by 6 | Viewed by 2449

Abstract

Tropospheric ozone is the only normal pollutant with a continuously increasing annual average concentration worldwide. In this study, data were monitored at the Nankai University Air Quality Research Supersite (NKAQRS) (38.99° N, 117.33° E) between 1 April, and 31 August from 2018 to [...] Read more.

Tropospheric ozone is the only normal pollutant with a continuously increasing annual average concentration worldwide. In this study, data were monitored at the Nankai University Air Quality Research Supersite (NKAQRS) (38.99° N, 117.33° E) between 1 April, and 31 August from 2018 to 2020, 33 O₃ episodes from 2018 to 2020 were analyzed to reveal the characteristics of O₃, VOCs and OFP during O₃ episodes and to evaluate the driving factors. The O₃ episodes showed a decreasing trend in terms of pollution frequency, days, heavy pollution duration and peak concentration. Ethane, acetylene, cyclopentane, and methylcyclopentane were the major types in 2020, while 1-hexene was the main component in 2019. The main ozone-contributing species in 2020 were propene cyclopentane methylcyclopentane and ethylene. Alkenes were important contributors to ozone formation. Using generalized additive models (GAMs), the explanatory variables in the study are divided into environmental and meteorological factors, and 16 impact factors are selected as explanatory variables. We found that the influence of these meteorological factors on O₃ pollution was nonlinear and impacted by the interaction between variables. O₃ episodes were mainly driven by meteorological and precursor (NO) factors in 2018, while meteorological conditions (T), followed by precursor (NO₂) were the driving factors in 2019 and 2020, suggesting that O₃ episodes were mainly driven by meteorological conditions. Full article

(This article belongs to the Special Issue Tropospheric Ozone in China: Current Situation, Formation Mechanism and Control Measures)

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19 pages, 5436 KiB

Open AccessArticle

An Overall Uniformity Optimization Method of the Spherical Icosahedral Grid Based on the Optimal Transformation Theory

by Fuli Luo, Xuesheng Zhao, Wenbin Sun, Yalu Li and Yuanzheng Duan

Atmosphere 2021, 12(11), 1516; https://doi.org/10.3390/atmos12111516 - 17 Nov 2021

Viewed by 2134

Abstract

The improvement of overall uniformity and smoothness of spherical icosahedral grids, the basic framework of atmospheric models, is a key to reducing simulation errors. However, most of the existing grid optimization methods have optimized grid from different aspects and not improved overall uniformity [...] Read more.

The improvement of overall uniformity and smoothness of spherical icosahedral grids, the basic framework of atmospheric models, is a key to reducing simulation errors. However, most of the existing grid optimization methods have optimized grid from different aspects and not improved overall uniformity and smoothness of grid at the same time, directly affecting the accuracy and stability of numerical simulation. Although a well-defined grid with more than 12 points cannot be constructed on a sphere, the area uniformity and the interval uniformity of the spherical grid can be traded off to enhance extremely the overall grid uniformity and smoothness. To solve this problem, an overall uniformity and smoothness optimization method of the spherical icosahedral grid is proposed based on the optimal transformation theory. The spherical cell decomposition method has been introduced to iteratively update the grid to minimize the spherical transportation cost, achieving an overall optimization of the spherical icosahedral grid. Experiments on the four optimized grids (the spring dynamics optimized grid, the Heikes and Randall optimized grid, the spherical centroidal Voronoi tessellations optimized grid and XU optimized grid) demonstrate that the grid area uniformity of our method has been raised by 22.60% of SPRG grid, −1.30% of HR grid, 38.30% of SCVT grid and 38.20% of XU grid, and the grid interval uniformity has been improved by 2.50% of SPRG grid, 2.80% of HR grid, 11.10% of SCVT grid and 11.00% of XU grid. Although the grid uniformity of the proposed method is similar with the HR grid, the smoothness of grid deformation has been enhanced by 79.32% of grid area and 24.07% of grid length. To some extent, the proposed method may be viewed as a novel optimization approach of the spherical icosahedral grid which can improve grid overall uniformity and smoothness of grid deformation. Full article

(This article belongs to the Special Issue Recent Advances and Future Prospects of Machine Learning in Predictive Modeling of Atmospheric Sciences)

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14 pages, 2250 KiB

Open AccessArticle

Utility and Triggers in Uptake of Agricultural Weather and Climate Information Services in Senegal, West Africa

by Issa Ouedraogo, Ndèye Seynabou Diouf, Gnalenba Ablouka, Robert B. Zougmoré and Anthony Whitbread

Atmosphere 2021, 12(11), 1515; https://doi.org/10.3390/atmos12111515 - 17 Nov 2021

Cited by 9 | Viewed by 2460

Abstract

Weather and climate information services (WCIS) are gaining recognition among scientists and governments as an essential adaptation tool for agriculture, especially in the drylands of Africa. In Senegal, the widespread production and dissemination of WCIS was initiated in 2015 to cover the agricultural, [...] Read more.

Weather and climate information services (WCIS) are gaining recognition among scientists and governments as an essential adaptation tool for agriculture, especially in the drylands of Africa. In Senegal, the widespread production and dissemination of WCIS was initiated in 2015 to cover the agricultural, pastoral and fishing sectors. This paper analyzes the types of decisions made by WCIS users, their preferences and level of satisfaction, and explores the triggers of agricultural WCIS adoption. We collected data during the onset and cessation of the rainy seasons to understand the utility and reliability of WCIS by farmers across all stages of the growing season. Data were analyzed using descriptive statistics. A binary logistic regression was tested to understand the socio-economic triggers in uptake of WCIS. Results showed that rainfall forecast is the most preferred WCIS (49% of the respondents) followed by extreme wind forecast. At the beginning of the rainy season, nearly 80% of the respondents have chosen the sowing date and about 60% have chosen crop varieties based on disseminated WCIS. In the middle of the growing season, about 70% of the respondents used WCIS to decide on fertilizer application dates. Results also showed that age and level of education, being trained on WCIS use, membership to farmers’ organizations, owning a radio have a significant effect on WCIS-based decision-making. These factors are essential for triggering the uptake of WCIS, and therefore are required to improve the implementation of existing weather climate services in Africa. Full article

(This article belongs to the Section Biometeorology and Bioclimatology)

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26 pages, 980 KiB

Open AccessArticle

Innovative Carbon Mitigation Techniques to Achieve Environmental Sustainability Agenda: Evidence from a Panel of 21 Selected R&D Economies

by Muhammad Khalid Anser, Shujaat Abbas, Abdelmohsen A. Nassani, Mohamed Haffar, Khalid Zaman and Muhammad Moinuddin Qazi Abro

Atmosphere 2021, 12(11), 1514; https://doi.org/10.3390/atmos12111514 - 16 Nov 2021

Cited by 8 | Viewed by 2935

Abstract

Technological innovation in the energy sector is highly needed to reduce carbon emission costs, which requires knowledge spillovers, financial development, and carbon pricing to achieve a green developmental agenda. The current study examines the role of knowledge innovations in achieving the environmental sustainability [...] Read more.

Technological innovation in the energy sector is highly needed to reduce carbon emission costs, which requires knowledge spillovers, financial development, and carbon pricing to achieve a green developmental agenda. The current study examines the role of knowledge innovations in achieving the environmental sustainability agenda under financial development and carbon pricing in a panel of 21 selected R&D economies from 1990 to 2018. The study constructed a composite index of financial development and knowledge innovation in the carbon pricing model. The results show that carbon pricing, a financial development index, innovation index, and energy demand fail to achieve stringent carbon reduction targets. A U-shaped relationship is found between carbon emissions and per capita income in the absence of a financial development index and trade openness. At the same time, this study shows the monotonic decreasing function in the presence of all factors. The causality estimates confirmed the feedback relationship between carbon pricing and carbon emissions, carbon pricing and the financial index, and the financial development index and innovation index. Further, the causality results established the carbon-led financial development and innovation, growth-led carbon emissions, and trade-led emissions, pricing, and financial development in a panel of selected countries. The estimates of the innovation accounting matrix (forecasting mechanism) confirmed the viability of the environmental sustainability agenda through carbon pricing, knowledge innovation, and financial development over a time horizon. However, these factors are not achievable carbon reduction targets in a given period. The study concludes that carbon pricing may provide a basis for achieving an environmental sustainability agenda through market-based innovations, green financing options, and improved energy resources. This would ultimately help desensitize carbon emissions across countries. Full article

(This article belongs to the Special Issue Greenhouse Gas Emissions Measurement)

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15 pages, 3220 KiB

Open AccessArticle

Grey Correlation Analysis of Haze Impact Factor PM2.5

by Jiayi Xu, Zhixin Liu, Lirong Yin, Yan Liu, Jiawei Tian, Yang Gu, Wenfeng Zheng, Bo Yang and Shan Liu

Atmosphere 2021, 12(11), 1513; https://doi.org/10.3390/atmos12111513 - 16 Nov 2021

Cited by 25 | Viewed by 2578

Abstract

In recent years, frequent severe haze weather has formed in China, including some of the most populated areas. We found that these smog-prone areas are often relatively a “local climate” and aim to explore this series of scientific problems. This paper uses remote [...] Read more.

In recent years, frequent severe haze weather has formed in China, including some of the most populated areas. We found that these smog-prone areas are often relatively a “local climate” and aim to explore this series of scientific problems. This paper uses remote sensing and data mining methods to study the correlation between haze weather and local climate. First, we select Beijing, China and its surrounding areas (East longitude 115°20′11″–117°40′35″, North latitude 39°21′11″–41°7′51″) as the study area. We collected data from meteorological stations in Beijing and Xianghe from March 2014 to February 2015, and analyzed the meteorological parameters through correlation analysis and a grey correlation model. We study the correlation between the six influencing factors of temperature, dew point, humidity, wind speed, air pressure and visibility and PM2.5, so as to analyze the correlation between haze weather and local climate more comprehensively. The results show that the influence of each index on PM2.5 in descending order is air pressure, wind speed, humidity, dew point, temperature and visibility. The qualitative analysis results confirm each other. Among them, air pressure (correlation 0.771) has the greatest impact on haze weather, and visibility (correlation 0.511) is the weakest. Full article

(This article belongs to the Special Issue Study of Mitigation of PM2.5 and Surface Ozone Pollution)

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12 pages, 89687 KiB

Open AccessArticle

A Method for Estimating the Cloud Adjacency Effect on the Ground Surface Reflectance Reconstruction from Passive Satellite Observations through Gaps in Cloud Fields

by Mikhail V. Tarasenkov, Matvei N. Zonov, Marina V. Engel and Vladimir V. Belov

Atmosphere 2021, 12(11), 1512; https://doi.org/10.3390/atmos12111512 - 16 Nov 2021

Cited by 6 | Viewed by 1937

Abstract

A method for estimating the cloud adjacency effect on the reflectance of ground surface areas reconstructed from passive satellite observations through gaps in cloud fields is proposed. The method allows one to estimate gaps of cloud fields in which the cloud adjacency effect [...] Read more.

A method for estimating the cloud adjacency effect on the reflectance of ground surface areas reconstructed from passive satellite observations through gaps in cloud fields is proposed. The method allows one to estimate gaps of cloud fields in which the cloud adjacency effect can be considered small (the increment of the reflectance

Δ r_{s u r f} \leq

0.005). The algorithm is based on statistical simulation by the Monte Carlo method of radiation transfer in stochastic broken cloudiness with a deterministic cylindrical gap. An interpolation formula is obtained for the radius of the cloud adjacency effect that can be used for the reconstruction the ground surface reflectance in real time without calculations by the Monte Carlo method. Full article

(This article belongs to the Special Issue Atmospheric and Ocean Optics: Atmospheric Physics III)

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18 pages, 12661 KiB

Open AccessArticle

Observational Analysis of a Wind Gust Event during the Merging of a Bow Echo and Mini-Supercell in Southeastern China

by Hui Zheng, Yuchun Zhao, Yipeng Huang, Wei Zhang, Changrong Luo, Ming Wei and Xinfa Qiu

Atmosphere 2021, 12(11), 1511; https://doi.org/10.3390/atmos12111511 - 16 Nov 2021

Viewed by 2161

Abstract

The merging of a fast-moving bow echo with a convective cell of a hook-echo signature was studied by using polarimetric radar detections. Gusts with wind speeds near 35 m s⁻¹ were recorded by the surface station, which caused significant damage. A convective [...] Read more.

The merging of a fast-moving bow echo with a convective cell of a hook-echo signature was studied by using polarimetric radar detections. Gusts with wind speeds near 35 m s⁻¹ were recorded by the surface station, which caused significant damage. A convective cell with a mesovortex signature, which is hereafter referred to as a mini-supercell, was observed over the northeast of the bow echo before the convective merging. It was found that the mesovortex possessed cyclonic circulation and resembled a supercell-like feature. The merging of the bow echo and the mini-supercell strengthened the updraft near the apex of the bow echo. The enhanced updraft was also demonstrated by the appearance of a differential reflectivity (Z_DR) column with a topmost height of 4 km above the melting layer (~4 km). The bow was separated into northern and southern sectors after merging with the mini-supercell, leading to the gusty wind over the surface of the south sector. Full article

(This article belongs to the Special Issue Moist Atmospheric Convection)

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