Atmosphere

20 pages, 20299 KiB

Open AccessArticle

Investigating Future Urbanization’s Impact on Local Climate under Different Climate Change Scenarios in MEGA-urban Regions: A Case Study of the Pearl River Delta, China

by Pak Shing Yeung, Jimmy Chi-Hung Fung, Chao Ren, Yong Xu, Kangning Huang, Jiye Leng and Michael Mau-Fong Wong

Atmosphere 2020, 11(7), 771; https://doi.org/10.3390/atmos11070771 - 21 Jul 2020

Cited by 12 | Viewed by 4890

Abstract

Urbanization is one of the most significant contributing factors to anthropogenic climate change. However, a lack of projected city land use data has posed significant challenges to factoring urbanization into climate change modeling. Thus, the results from current models may contain considerable errors [...] Read more.

Urbanization is one of the most significant contributing factors to anthropogenic climate change. However, a lack of projected city land use data has posed significant challenges to factoring urbanization into climate change modeling. Thus, the results from current models may contain considerable errors in estimating future climate scenarios. The Pearl River Delta region was selected as a case study to provide insight into how large-scale urbanization and different climate change scenarios impact the local climate. This study adopts projected land use data from freely available satellite imagery and applies dynamic simulation land use results to the Weather Research and Forecasting Model (WRF). The simulation periods cover the summer periods in 2010 and 2029–2031, the latter of which is averaged to represent the year 2030. The WRF simulation used the observed local climate conditions in 2010 to represent the current scenario and the projected local climate changes for 2030 as the future scenario. Under all three future climate change scenarios, the warming trend is prominent (around 1–2 °C increase), with a widespread reduction in wind speed in inland areas (1–2 ms⁻¹). The vulnerability of human health to thermal stress was evaluated by adopting the wet-bulb globe temperature (WBGT). The results from the future scenarios suggest a high public health risk due to rising temperatures in the future. This study provides a methodology for a more comprehensive understanding of future urbanization and its impact on regional climate by using freely available satellite images and WRF simulation tools. The simulated temperature and WBGT results can serve local governments and stakeholders in city planning and the creation of action plans that will reduce the potential vulnerability of human health to excessive heat. Full article

(This article belongs to the Section Climatology)

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18 pages, 5188 KiB

Open AccessArticle

Disdrometer, Polarimetric Radar, and Condensation Nuclei Observations of Supercell and Multicell Storms on 11 June 2018 in Eastern Nebraska

by Matthew Van Den Broeke

Atmosphere 2020, 11(7), 770; https://doi.org/10.3390/atmos11070770 - 21 Jul 2020

Cited by 3 | Viewed by 2632

Abstract

Disdrometer and condensation nuclei (CN) data are compared with operational polarimetric radar data for one multicell and one supercell storm in eastern Nebraska on 11 June 2018. The radar was located ~14.3 km from the instrumentation location and provided excellent observation time series [...] Read more.

Disdrometer and condensation nuclei (CN) data are compared with operational polarimetric radar data for one multicell and one supercell storm in eastern Nebraska on 11 June 2018. The radar was located ~14.3 km from the instrumentation location and provided excellent observation time series with new low-level samples every 1–2 min. Reflectivity derived by the disdrometer and radar compared well, especially in regions with high number concentration of drops and reflectivity <45 dBZ. Differential reflectivity also compared well between the datasets, though it was most similar in the supercell storm. Rain rate calculated by the disdrometer closely matched values estimated by the radar when reflectivity and differential reflectivity were used to produce the estimate. Concentration of CN generally followed precipitation intensity for the leading convective cell, with evidence for higher particle concentration on the edges of the convective cell associated with outflow. The distribution of CN in the supercell was more complex and generally did not follow precipitation intensity. Full article

(This article belongs to the Special Issue Measurement and Modeling of the Precipitation Particle Size Distribution)

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16 pages, 2106 KiB

Open AccessArticle

Statistical Analysis of the CO₂ and CH₄ Annual Cycle on the Northern Plateau of the Iberian Peninsula

by Isidro A. Pérez, M. Luisa Sánchez, M. Ángeles García, Nuria Pardo and Beatriz Fernández-Duque

Atmosphere 2020, 11(7), 769; https://doi.org/10.3390/atmos11070769 - 21 Jul 2020

Cited by 5 | Viewed by 2558

Abstract

Outliers are frequent in CO₂ and CH₄ observations at rural sites. The aim of this paper is to establish a procedure based on the lag-1 autocorrelation to form measurement groups, some of which include outliers, and the rest include regular measurements. [...] Read more.

Outliers are frequent in CO₂ and CH₄ observations at rural sites. The aim of this paper is to establish a procedure based on the lag-1 autocorrelation to form measurement groups, some of which include outliers, and the rest include regular measurements. Once observations are classified, a second objective is to determine the number of harmonics in order to suitably describe the annual evolution of both gases. Monthly CO₂ and CH₄ percentiles were calculated over a six-year period. Linear trends for most of the percentiles were around 2.24 and 0.0097 ppm year⁻¹, and the interquartile ranges of residuals calculated from detrended concentrations were 6 and 0.02 ppm for CO₂ and CH₄, respectively. Five concentration groups were proposed for CO₂ and six were proposed for CH₄ from the lag-1 autocorrelation applied to detrended observations. Monthly medians were calculated in each group, and combinations of harmonics were applied in an effort to fit the annual cycle. Finally, adding annual and semi-annual harmonics successfully described the cycle where one step was observed in the concentration decrease in spring, not only for high CO₂ percentiles but also for low CH₄ percentiles. Full article

(This article belongs to the Special Issue Statistical Approaches to Investigate Air Quality)

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21 pages, 5801 KiB

Open AccessArticle

Tornado Risk Climatology in Europe

by Jürgen Grieser and Phil Haines

Atmosphere 2020, 11(7), 768; https://doi.org/10.3390/atmos11070768 - 21 Jul 2020

Cited by 14 | Viewed by 8962

Abstract

Violent tornadoes are rare in Europe but they can have devastating effects. Damage associated with individual tornadoes can reach several billion euros and they have caused hundreds of fatalities. The tornado risk varies considerably over Europe, but so far only a few national [...] Read more.

Violent tornadoes are rare in Europe but they can have devastating effects. Damage associated with individual tornadoes can reach several billion euros and they have caused hundreds of fatalities. The tornado risk varies considerably over Europe, but so far only a few national maps of tornado risk and one Europe-wide map exist. We show several different ways to create quantitative maps of tornado occurrence rates as follows: Kernel smoothing of observations, climatologies of convective parameters from reanalysis, output of a logistic regression model to link convective parameters with observed tornadoes, orography-dependent climatologies and finally the population-bias corrected tornado occurrence rates from the Risk Management Solutions (RMS) Europe Severe Convective Storm Model. We discuss advantages and disadvantages of each approach and compare the results. While the climatologies created from the individual methods show a lot of qualitative similarities, we advocate to combine the methods to achieve the most reliable quantitative climatology. Full article

(This article belongs to the Special Issue Tornadoes in Europe: Climatology, Forecasting, and Impact)

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3 pages, 164 KiB

Open AccessEditorial

Climate Change, Climatic Extremes, and Human Societies in the Past

by Harry F. Lee

Atmosphere 2020, 11(7), 767; https://doi.org/10.3390/atmos11070767 - 20 Jul 2020

Viewed by 2320

Abstract

More people appreciate the importance of global sustainability [...] Full article

(This article belongs to the Special Issue Climate Change, Climatic Extremes, and Human Societies in the Past)

22 pages, 4480 KiB

Open AccessEditor’s ChoiceArticle

Analysis of Pollution Characteristics and Influencing Factors of Main Pollutants in the Atmosphere of Shenyang City

by Jiaqi Tian, Chunsheng Fang, Jiaxin Qiu and Ju Wang

Atmosphere 2020, 11(7), 766; https://doi.org/10.3390/atmos11070766 - 20 Jul 2020

Cited by 20 | Viewed by 3768

Abstract

Air pollution is one of the most concerning environmental problems in cities. Hourly data on pollutant concentrations from 11 automatic atmospheric monitoring stations and meteorological data in Shenyang from 2017 to 2019 were used to analyze the spatio-temporal variation rules of CO (carbon [...] Read more.

Air pollution is one of the most concerning environmental problems in cities. Hourly data on pollutant concentrations from 11 automatic atmospheric monitoring stations and meteorological data in Shenyang from 2017 to 2019 were used to analyze the spatio-temporal variation rules of CO (carbon monoxide), SO₂ (sulfur dioxide), NO₂ (nitrogen dioxide), O₃ (ozone), PM_2.5 and PM₁₀ (PM particles with an aerodynamic diameters of not more than 2.5 µm and 10 µm) and their relationships with meteorological parameters. Meanwhile, the regional transmission route of pollutants was analyzed by the hybrid single particle Lagrangian integrated trajectory (HYSPLIT) model. The results showed that the concentration of O₃ in the northern area of the city was higher than that in the south; CO, SO₂ and NO₂ were relatively high in the urban center; and PM_2.5 and PM₁₀ were relatively high in the southwest. The average concentration of pollutants was lowest in 2019. The concentration of O₃ was the highest in spring, while CO showed no significant variations between different seasons. The remaining pollutant concentrations appeared to be high in winter and low in summer. The cumulative concentrations of the six pollutants were the highest in March, and relatively low in July–September. The diurnal concentration variations of O₃, CO and SO₂ exhibited a “single peak,” while others showed a “double peak and double valley.” Temperature was positively correlated with O₃ concentration and negatively correlated with others. Wind speed was negatively correlated with the concentration of PM_2.5, NO₂, and O₃. The air quality of the main urban area in spring and summer was mainly affected by the coastal air flow, while it was mostly affected by the northwest air flow in autumn and winter. Full article

(This article belongs to the Section Air Quality)

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17 pages, 14007 KiB

Open AccessArticle

Capturing the Variability in Instantaneous Vehicle Emissions Based on Field Test Data

by Zhiqiang Zhai, Ran Tu, Junshi Xu, An Wang and Marianne Hatzopoulou

Atmosphere 2020, 11(7), 765; https://doi.org/10.3390/atmos11070765 - 20 Jul 2020

Cited by 19 | Viewed by 3425

Abstract

Emission models are important tools for traffic emission and air quality estimates. Existing instantaneous emission models employ the steady-state “engine emissions map” to estimate emissions for individual vehicles. However, vehicle emissions vary significantly, even under the same driving conditions. Variability in the emissions [...] Read more.

Emission models are important tools for traffic emission and air quality estimates. Existing instantaneous emission models employ the steady-state “engine emissions map” to estimate emissions for individual vehicles. However, vehicle emissions vary significantly, even under the same driving conditions. Variability in the emissions at a specific driving condition depends on various influencing factors. It is important to gain insight into the effects of these factors, to enable detailed modeling of individual vehicle emissions. This study employs a portable emissions measurement system (PEMS), to collect vehicle emissions including the corresponding parameters of engine condition, vehicle activity, catalyst temperature, geography, and meteorology, to analyze the variability in emission rates as a function of those factors, across different vehicle specific power (VSP) categories. We observe that carbon dioxide, carbon monoxide, nitrogen oxides, and particle number emissions are strongly correlated with engine parameters (engine speed, torque, load, and air-fuel ratio) and vehicle activity parameters (vehicle speed and acceleration). In the same VSP bin, emissions per second on highways and ramps are higher than those on arterial roads, and the emissions when the vehicle is traveling downhill tend to be higher than the emissions during uphill traveling, because of higher observed speeds and accelerations. Morning emissions are higher than afternoon emissions, due to lower temperatures. Full article

(This article belongs to the Special Issue Emissions, Transport and Fate of Pollutants in the Atmosphere)

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12 pages, 1414 KiB

Open AccessArticle

Efficacy of Radiant Catalytic Ionization in Reduction of Enterococcus spp., Clostridioides difficile and Staphylococcus aureus in Indoor Air

by Krzysztof Skowron, Katarzyna Grudlewska-Buda, Sylwia Kożuszko, Natalia Wiktorczyk, Karolina Jadwiga Skowron, Agnieszka Mikucka, Zuzanna Bernaciak and Eugenia Gospodarek-Komkowska

Atmosphere 2020, 11(7), 764; https://doi.org/10.3390/atmos11070764 - 20 Jul 2020

Cited by 4 | Viewed by 3126

Abstract

(1) Background: An aerogenic way is one of main rout of spreading microorganisms (including antibiotic resistant), that cause healthcare-associated infections. The source of microorganisms in the air can be patients, personnel, visitors, outdoor air, hospital surfaces and equipment, and even sink drains. (2) [...] Read more.

(1) Background: An aerogenic way is one of main rout of spreading microorganisms (including antibiotic resistant), that cause healthcare-associated infections. The source of microorganisms in the air can be patients, personnel, visitors, outdoor air, hospital surfaces and equipment, and even sink drains. (2) Methods: The standardized suspensions (0.5 McFarland) of the examined strains (Enterococcus spp., Clostridioides difficile, Staphylococcus aureus) were nebulized in sterile chamber. Then the Induct 750 (ActivTek) device, generating RCI (radiant catalytic ionization) phenomenon, was used for 20 min. Next, the number of bacteria in the air was calculated using collision method. The percentage of reduction coefficient (R) was calculated. (3) Results: In case of enterococci, the R value was >90% and there are no statistically significant differences among tested strains. For C. difficile strains the R value range from 64–95%. The R value calculated for hypervirulent, antibiotic resistant CDI PCR 27 strain was statistically significantly lower than for other examined strains. For S. aureus non-MRSA the R value was 99.87% and for S. aurues MRSA the R value was 95.61%. (4) Conclusions: The obtained results indicate that the use of RCI may contribute to reducing the occurrence of dangerous pathogens in the air, and perhaps transmission and persistence in the hospital buildings environment. Full article

(This article belongs to the Special Issue Health Effects and Exposure Assessment to Bioaerosols in Indoor and Outdoor Environments)

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18 pages, 8160 KiB

Open AccessArticle

Wildfire Pyroconvection and CAPE: Buoyancy’s Drying and Atmospheric Intensification—Fort McMurray

by Atoossa Bakhshaii, Edward A. Johnson and Kiana Nayebi

Atmosphere 2020, 11(7), 763; https://doi.org/10.3390/atmos11070763 - 18 Jul 2020

Cited by 3 | Viewed by 4207

Abstract

The accurate prediction of wildfire behavior and spread is possible only when fire and atmosphere simulations are coupled. In this work, we present a mechanism that causes a small fire to intensify by altering the atmosphere. These alterations are caused by fire-related fluxes [...] Read more.

The accurate prediction of wildfire behavior and spread is possible only when fire and atmosphere simulations are coupled. In this work, we present a mechanism that causes a small fire to intensify by altering the atmosphere. These alterations are caused by fire-related fluxes at the surface. The fire plume and fluxes increase the convective available potential energy (CAPE) and the chance of the development of a strong pyroconvection system. To study this possible mechanism, we used WRF-Fire to capture fire line propagation as the result of interactions between heat and moisture fluxes, pressure perturbations, wind shear development and dry air downdraft. The wind patterns and dynamics of the pyroconvection system are simulated for the Horse River wildfire at Fort McMurray, Canada. The results revealed that the updraft speed reached up to 12 m/s. The entrainment mixed the mid and upper-level dry air and lowered the atmospheric moisture. The mid-level and upper-level dew point temperature changed by 5–10

^{\circ}

C in a short period of time. The buoyant air strengthened the ascent as soon as the nocturnal inversion was eliminated by daytime heating. The 887 J/kg total increase of CAPE in less than 5 h and the high bulk Richardson number (BRN) of 93 were indicators of the growing pyro-cumulus cell. The presented simulation has not improved the original model or supported leading-edge numerical weather prediction (NWP) achievements, except for adapting WRF-Fire for Canadian biomass fuel. However, we were able to present a great deal of improvements in wildfire nowcasting and short-term forecasting to save lives and costs associated with wildfires. The simulation is sufficiently fast and efficient to be considered for a real-time operational model. While the project was designed and succeeded as an NWP application, we are still searching for a solution for the intractable problems associated with political borders and the current liable authorities for the further development of a new generation of national atmosphere–wildfire forecasting systems. Full article

(This article belongs to the Special Issue Wildfire Spread and Weather: Theory, Models and Reality)

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28 pages, 7810 KiB

Open AccessArticle

Impacts of Vegetation and Topography on Land Surface Temperature Variability over the Semi-Arid Mountain Cities of Saudi Arabia

by Ahmed Ali Bindajam, Javed Mallick, Saeed AlQadhi, Chander Kumar Singh and Hoang Thi Hang

Atmosphere 2020, 11(7), 762; https://doi.org/10.3390/atmos11070762 - 18 Jul 2020

Cited by 55 | Viewed by 5687

Abstract

Land surface temperature (LST) can fully reflect the water–heat exchange cycle of the earth surface that is important for the study of environmental change. There is little research on LST in the semi-arid region of Abha-Khamis-Mushyet, which has a complex topography. The study [...] Read more.

Land surface temperature (LST) can fully reflect the water–heat exchange cycle of the earth surface that is important for the study of environmental change. There is little research on LST in the semi-arid region of Abha-Khamis-Mushyet, which has a complex topography. The study used LST data, retrieved from ASTER data in semi-arid mountain areas and discussed its relationship with land use/land cover (LULC), topography and the normalized difference vegetation index (NDVI). The results showed that the LST was significantly influenced by altitude and corresponding LULC type. In the study area, during the summer season, extreme high-temperature zones were observed, possibly due to dense concrete surfaces. LST among different types of land use differed significantly, being the highest in exposed rocky areas and built-up land, and the lowest in dense vegetation. NDVI and LST spatial distributions showed opposite trends. The LST–NDVI feature space showed a unique ABC obtuse-angled triangle shape and showed an overall negative linear correlation. In brief, the LST could be retrieved well by the emissivity derived NDVI TES method, which relied on upwelling, downwelling, and transmittance. In addition, the LST of the semi-arid mountain areas was influenced by elevation, slope zenith angle, aspect and LULC, among which vegetation and elevation played a key role in the overall LST. This research provides a roadmap for land-use planning and environmental conservation in mountainous urban areas. Full article

(This article belongs to the Special Issue Interaction between Urban Microclimates and the Buildings)

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17 pages, 6005 KiB

Open AccessArticle

High-Resolution Solar Climate Atlas for Greece under Climate Change Using the Weather Research and Forecasting (WRF) Model

by Theodoros Katopodis, Iason Markantonis, Nadia Politi, Diamando Vlachogiannis and Athanasios Sfetsos

Atmosphere 2020, 11(7), 761; https://doi.org/10.3390/atmos11070761 - 18 Jul 2020

Cited by 16 | Viewed by 4682

Abstract

In the context of climate change and growing energy demand, solar technologies are considered promising solutions to mitigate Greenhouse Gas (GHG) emissions and support sustainable adaptation. In Greece, solar power is the second major renewable energy, constituting an increasingly important component of the [...] Read more.

In the context of climate change and growing energy demand, solar technologies are considered promising solutions to mitigate Greenhouse Gas (GHG) emissions and support sustainable adaptation. In Greece, solar power is the second major renewable energy, constituting an increasingly important component of the future low-carbon energy portfolio. In this work, we propose the use of a high-resolution regional climate model (Weather Research and Forecasting model, WRF) to generate a solar climate atlas for the near-term climatological future under the Representative Concentration Pathway (RCPs) 4.5 and 8.5 scenarios. The model is set up with a 5 × 5 km² spatial resolution, forced by the ERA-INTERIM for the historic (1980–2004) period and by the EC-EARTH General Circulation Models (GCM) for the future (2020–2044). Results reaffirm the high quality of solar energy potential in Greece and highlight the ability of the WRF model to produce a highly reliable future climate solar atlas. Projected changes between the annual historic and future RCPs scenarios indicate changes of the annual Global Horizontal Irradiance (GHI) in the range of ±5.0%. Seasonal analysis of the GHI values indicates percentage changes in the range of ±12% for both scenarios, with winter exhibiting the highest seasonal increases in the order of 10%, and autumn the largest decreases. Clear-sky fraction f_clear projects increases in the range of ±4.0% in eastern and north continental Greece in the future, while most of the Greek marine areas might expect above 220 clear-sky days per year. Full article

(This article belongs to the Special Issue Climate Modeling for Renewable Energy Resource Assessment)

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Graphical abstract

16 pages, 5918 KiB

Open AccessEditor’s ChoiceArticle

Characterization, Pollution Sources, and Health Risk of Ionic and Elemental Constituents in PM_2.5 of Wuhan, Central China

by Weiqian Wang, Weilin Zhang, Shiyang Dong, Shinichi Yonemachi, Senlin Lu and Qingyue Wang

Atmosphere 2020, 11(7), 760; https://doi.org/10.3390/atmos11070760 - 17 Jul 2020

Cited by 12 | Viewed by 3776

Abstract

Atmospheric PM_2.5 samples from Wuhan, China were collected during a winter period of February and a summer period of August in 2018. The average PM_2.5 mass concentration in winter reached 112 μg/m³—about two-fold higher than that found in summer. [...] Read more.

Atmospheric PM_2.5 samples from Wuhan, China were collected during a winter period of February and a summer period of August in 2018. The average PM_2.5 mass concentration in winter reached 112 μg/m³—about two-fold higher than that found in summer. Eight ionic species constituted 1/3 of PM_2.5, whereas more than 85% represented secondary ionic aerosols (NO₃⁻, SO₄²⁻ and NH₄⁺). Higher ratios of NO₃⁻/SO₄²⁻ (0.95–2.62) occurred in winter and lower ratios (0.11–0.42) occurred in summer showing the different contribution for mobile and stationary sources. Seventeen elemental species constituted about 10% of PM_2.5, with over 95% Na, Mg, Al, Ca, Fe, K and Zn. Higher K-concentration occurred in winter indicating greater contribution from biomass and firework-burning. Carcinogenic risks by Cr, As, Cd, Ni and Pb in PM_2.5 indicated that about 6.94 children and 46.5 adults among per million may risk getting cancer via inhalation during surrounding winter atmospheric sampling, while about 5.41 children and 36.6 adults have the same risk during summer. Enrichment factors (EFs) and elemental ratios showed that these hazardous elements were mainly from anthropogenic sources like coal and oil combustion, gasoline and diesel vehicles. Full article

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

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14 pages, 4054 KiB

Open AccessEditor’s ChoiceArticle

Assessment of Air Pollution with Polychlorinated Dibenzodioxins (PCDDs) and Polychlorinated Dibenzofuranes (PCDFs) in Lithuania

by Vigilija Klima, Renata Chadyšienė, Rūta Ivanec-Goranina, Dainius Jasaitis and Vaida Vasiliauskienė

Atmosphere 2020, 11(7), 759; https://doi.org/10.3390/atmos11070759 - 17 Jul 2020

Cited by 9 | Viewed by 3943

Abstract

Polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDD/F) are highly bioavailable in humans, either through direct inhalation or indirectly by trophic transfer from contaminated food or water. The main sources of pollution with PCDD/F include industrial and non-industrial combustion sources, like domestic contaminated wood burning, [...] Read more.

Polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDD/F) are highly bioavailable in humans, either through direct inhalation or indirectly by trophic transfer from contaminated food or water. The main sources of pollution with PCDD/F include industrial and non-industrial combustion sources, like domestic contaminated wood burning, house fires, burning of leaves from trees, etc. When looking for alternative energy sources and reduced energy costs, solid waste incineration plants are intended to be built in the vicinity of urbanized areas, and thus, the need emerges for examination and prediction of to what extent the solid waste incineration plants might affect the surrounding ecosystem, air pollution, and human health. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) (or simply PCDD/F congeners) belong to the group of semi-volatile organic compounds with environmental stability and long-range transfer in the ambient air. Dioxin isomers are highly toxic and may have carcinogenic and mutagenic effects in humans. PCDD/F is detected in air, water, sediment, plants and animals. PCDD/F is generally distributed in the particulate phase in ambient air. For solid waste incineration plant emissions, the distribution of PCDD/F particles into particles with a diameter of <10 μm is more than 81% of the total particulate matter, and more than 54% of the PCDD/F is distributed into particles with a diameter of <2.5 μm. The aim of this study is to investigate the sources of PCDD/F, emissions and potential hazards, i.e., a toxic equivalent in Lithuania. The measurements were performed in two largest cities of Lithuania Vilnius and Kaunas, where the level of PCDD/F discovered was from 0.015 to 0.52 pg/m³ and from 0.02 to 0.05 pg/m³, respectively. The sites for the monitoring were selected based on their proximity to the locations of the planned cogeneration power plants in these cities. Full article

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

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16 pages, 5076 KiB

Open AccessEditor’s ChoiceArticle

Investigating the Interannual Variability of the Boreal Summer Water Vapor Source and Sink over the Tropical Eastern Indian Ocean-Western Pacific

by Meng Zou, Shaobo Qiao, Liya Chao, Dong Chen, Chundi Hu, Qingxiang Li and Guolin Feng

Atmosphere 2020, 11(7), 758; https://doi.org/10.3390/atmos11070758 - 17 Jul 2020

Cited by 2 | Viewed by 2698

Abstract

Using the four-times daily and monthly-mean reanalysis datasets of NCEP/NCAR for the 1958 to 2018 period, we investigate the interannual variability of the June-July-August (JJA)–mean water vapor source and sink over the tropical eastern Indian Ocean-Western Pacific (TEIOWP) and the underlying mechanism. It [...] Read more.

Using the four-times daily and monthly-mean reanalysis datasets of NCEP/NCAR for the 1958 to 2018 period, we investigate the interannual variability of the June-July-August (JJA)–mean water vapor source and sink over the tropical eastern Indian Ocean-Western Pacific (TEIOWP) and the underlying mechanism. It is found that the two major modes (EOF1 and EOF2) of the water vapor source and sink anomalies over the TEIOWP present a southwest-northeast oriented dipole and a southwest-northeast oriented tripole. Specifically, when the western maritime continent shows an anomalous water vapor source, the northwestern Pacific is characterized by anomalous water vapor sink and source in EOF1 and EOF2 modes, respectively. The EOF1 and EOF2 modes are primarily driven by a single and a double meridional cell anomaly, which corresponds to the in-phase and out-of-phase linkage between evaporation anomalies over the western maritime continent and precipitation anomalies over the northwestern Pacific, respectively. Furthermore, the EOF1 mode is regulated by the quick transition of the El Niño-Southern Oscillation (ENSO) phase, whereas the EOF2 mode probably originates from internal atmospheric variability. Considering that the standard deviation of PC1 is much higher during ENSO years than that during non-ENSO years, it is probable that the water source and sink anomalies over the TEIOWP tend to be dominant by EOF1 mode during ENSO years. In contrast, the EOF2 mode may play an important role in the water source and sink anomalies over the TEIOWP during non-ENSO years. Accordingly, the water vapor source and sink anomalies over the TEIOWP may be well predicted based on the ENSO state in the previous December-January-February. These results are useful for understanding the predictability of water vapor source and sink anomalies over the TEIOWP. Full article

(This article belongs to the Section Meteorology)

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25 pages, 9081 KiB

Open AccessArticle

Evaluation of WRF-Chem Predictions for Dust Deposition in Southwestern Iran

by Mansour A. Foroushani, Christian Opp, Michael Groll and Amirhossein Nikfal

Atmosphere 2020, 11(7), 757; https://doi.org/10.3390/atmos11070757 - 17 Jul 2020

Cited by 13 | Viewed by 4812

Abstract

The relationships between monthly recorded ground deposition rates (GDRs) and the spatiotemporal characteristics of dust concentrations in southwest Iran were investigated. A simulation by the Weather Research and Forecasting Model coupled with the Chemistry modeling system (WRF-Chem) was conducted for dust deposition during [...] Read more.

The relationships between monthly recorded ground deposition rates (GDRs) and the spatiotemporal characteristics of dust concentrations in southwest Iran were investigated. A simulation by the Weather Research and Forecasting Model coupled with the Chemistry modeling system (WRF-Chem) was conducted for dust deposition during 2014–2015. The monthly dust deposition values observed at 10 different gauge sites (G01–G10) were mapped to show the seasonal and spatial variations in dust episodes at each location. An analysis of the dust deposition samples, however, confirmed that the region along the deposition sites is exposed to the highest monthly dust load, which has a mean value of 2.4 mg cm⁻². In addition, the study area is subjected to seasonally varying deposition, which follows the trend: spring > summer > winter > fall. The modeling results further demonstrate that the increase in dust emissions is followed by a windward convergence over the region (particularly in the spring and summer). Based on the maximum likelihood classification of land use land cover, the modeling results are consistent with observation data at gauge sites for three scenarios [S.I, S.II, and S.III]. The WRF model, in contrast with the corresponding observation data, reveals that the rate factor decreases from the southern [S.III—G08, G09, and G10] through [S.II—G04, G05, G06, and G07] to the northern points [S.I—G01, G02, and G03]. A narrower gap between the modeling results and GDRs is indicated if there is an increase in the number of dust particles moving to lower altitudes or an increase in the dust resident time at high altitudes. The quality of the model forecast is altered by the deposition rate and is sensitive to land surface properties and interactions among land and climate patterns. Full article

(This article belongs to the Special Issue Regional Air Quality Modeling)

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16 pages, 2247 KiB

Open AccessArticle

Dependence of Mass–Dimensional Relationships on Median Mass Diameter

by Saisai Ding, Greg M. McFarquhar, Stephen W. Nesbitt, Randy J. Chase, Michael R. Poellot and Hongqing Wang

Atmosphere 2020, 11(7), 756; https://doi.org/10.3390/atmos11070756 - 17 Jul 2020

Cited by 13 | Viewed by 3722

Abstract

Retrievals of ice cloud properties require accurate estimates of ice particle mass. Empirical mass–dimensional (m–D) relationships in the form

m = a D^{b}

are widely used and usually universally applied across the complete range of particle sizes. For [...] Read more.

Retrievals of ice cloud properties require accurate estimates of ice particle mass. Empirical mass–dimensional (m–D) relationships in the form

m = a D^{b}

are widely used and usually universally applied across the complete range of particle sizes. For the first time, the dependence of a and b coefficients in m–D relationships on median mass diameter (D_mm) is studied. Using combined cloud microphysical data collected during the Olympic Mountains Experiment and coincident observations from Airborne Precipitation Radar Third Generation, D_mm-dependent (a, b) coefficients are derived and represented as surfaces of equally plausible solutions determined by some tolerance in the chi-squared difference

χ^{2}

that minimizes the difference between observed and retrieved radar reflectivity. Robust dependences of a and b on D_mm are shown with both parameters significantly decreasing with D_mm, leading to smaller effective densities for larger D_mm ranges. A universally applied constant m–D relationship overestimates the mass of large aggregates when D_mm is between 3–6 mm and temperatures are between −15–0 °C. Multiple m–D relations should be applied for different D_mm ranges in retrievals and simulations to account for the variability of particle sizes that are responsible for the mass and thus for the variability of particle shapes and densities. Full article

(This article belongs to the Special Issue Measurement and Modeling of the Precipitation Particle Size Distribution)

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16 pages, 4333 KiB

Open AccessArticle

Ozone Trends from Two Decades of Ground Level Observation in Malaysia

by Fatimah Ahamad, Paul T. Griffiths, Mohd Talib Latif, Liew Juneng and Chung Jing Xiang

Atmosphere 2020, 11(7), 755; https://doi.org/10.3390/atmos11070755 - 17 Jul 2020

Cited by 11 | Viewed by 3927

Abstract

We examine the change in surface ozone and its precursor behavior over 20 years at four locations in western Peninsular Malaysia which have undergone urban-commercial development. Trend and correlation analyses were carried out on ozone and oxides of nitrogen observation data over the [...] Read more.

We examine the change in surface ozone and its precursor behavior over 20 years at four locations in western Peninsular Malaysia which have undergone urban-commercial development. Trend and correlation analyses were carried out on ozone and oxides of nitrogen observation data over the periods of 1997–2016 as well as the decadal intervals of 1997–2006 and 2007–2016. Diurnal variation composites for decadal intervals were also plotted. Significant increasing ozone concentrations were observed at all locations for the 20-year period, with a range between 0.09 and 0.21 ppb yr⁻¹. The most urbanized location (S3) showed the highest ozone trend. Decadal intervals show that not all stations record significant increasing trends of ozone, with S1 recording decreasing ozone at a rate of −0.44 ppb yr⁻¹ during the latter decade. Correlation analysis showed that only oxides of nitrogen ratios (NO/NO₂) had significant inverse relationships with ozone at all stations corresponding to control of ozone by photostationary state reactions. The diurnal composites show that decadal difference in NO/NO₂ is mostly influenced by change in nitric oxide concentrations. Full article

(This article belongs to the Special Issue Changes in the Composition of the Atmosphere)

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20 pages, 7844 KiB

Open AccessArticle

Inversion Method of Regional Range-Dependent Surface Ducts with a Base Layer by Doppler Weather Radar Echoes Based on WRF Model

by Xiaozhou Liu, Zhensen Wu and Hongguang Wang

Atmosphere 2020, 11(7), 754; https://doi.org/10.3390/atmos11070754 - 16 Jul 2020

Cited by 13 | Viewed by 3458

Abstract

Ground clutter caused by variations of atmospheric refraction environment can occur when the weather radar is observing precipitation systems, especially in the presence of a tropospheric duct. Therefore, the acquisition of duct parameters is very important for evaluating radar performance and improving data [...] Read more.

Ground clutter caused by variations of atmospheric refraction environment can occur when the weather radar is observing precipitation systems, especially in the presence of a tropospheric duct. Therefore, the acquisition of duct parameters is very important for evaluating radar performance and improving data quality. Based on the measured echo data of a Doppler weather radar located at Qingdao and the numerical simulation results of modified refractivity profiles from the Weather Research and Forecasting (WRF) model, an inversion method for regional range-dependent tropospheric duct parameters over the sea area is proposed in this paper. Due to the higher antenna height of up to 169 m, the transmission environment is assumed to be a surface duct with a base layer for locating the antenna in the trapping layer. The Principal Component Analysis (PCA) and Parabolic Equation (PE) methods were used to characterize the horizontal inhomogeneity of duct parameters and the propagation of electromagnetic waves in the tropospheric duct. In the inversion model, duct parameters extracted from WRF outputs were used as the initial values. Additionally, multithread parallel processing was adopted in order to reduce the inversion time based on the characteristics of the optimization algorithm. The overall variation tendencies of the WRF simulation results in the regional distribution of duct parameters were well consistent with the inversion results, but were relatively lower in terms of specific values. Due to the influence of precipitation targets on measured echo data, the inversed echo data had different agreements with the measurements in space, and the absolute error values were less than 5 dB in about 90% of the region of interest. Full article

(This article belongs to the Special Issue Vertical Structure of the Atmospheric Boundary Layer in Coastal Zone)

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34 pages, 6540 KiB

Open AccessArticle

Climate Change and the Future Heat Stress Challenges among Smallholder Farmers in East Africa

by Genesis Tambang Yengoh and Jonas Ardö

Atmosphere 2020, 11(7), 753; https://doi.org/10.3390/atmos11070753 - 16 Jul 2020

Cited by 16 | Viewed by 6425

Abstract

Agricultural production in sub-Saharan Africa remains dependent on high inputs of human labor, a situation associated with direct exposure to daylight heat during critical periods of the agricultural calendar. We ask the question: how is the Wet-Bulb Globe Temperature (WBGT) going to be [...] Read more.

Agricultural production in sub-Saharan Africa remains dependent on high inputs of human labor, a situation associated with direct exposure to daylight heat during critical periods of the agricultural calendar. We ask the question: how is the Wet-Bulb Globe Temperature (WBGT) going to be distributed in the future, and how will this affect the ability of smallholder farmers to perform agricultural activities? Data from general circulation models are used to estimate the distribution of WBGT in 2000, 2050 and 2100, and for high activity periods in the agricultural calendar. The distribution of WBGT is divided into recommended maximum WBGT exposure levels (°C) at different work intensities, and rest/work ratios for an average acclimatized worker wearing light clothing (ISO, 18). High WBGTs are observed during the two periods of the East African. In February to March, eastern and coastal regions of Kenya and Tanzania witness high WBGT values—some necessitating up to 75% rest/hour work intensities in 2050 and 2100. In August to September, eastern and northern Kenya and north and central Uganda are vulnerable to high WBGT values. Designing policies to address this key challenge is a critical element in adaptation methods to address the impact of climate change. Full article

(This article belongs to the Special Issue Plant Adaptation to Global Climate Change)

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26 pages, 6200 KiB

Open AccessArticle

Occurrence and Development of an Extreme Precipitation Event in the Ili Valley, Xinjiang, China and Analysis of Gravity Waves

by Xin Huang, Yushu Zhou and Lu Liu

Atmosphere 2020, 11(7), 752; https://doi.org/10.3390/atmos11070752 - 16 Jul 2020

Cited by 8 | Viewed by 3608

Abstract

We used observational data and the results from a high-resolution numerical simulation model to analyze the occurrence and development of an extreme precipitation event in the Ili Valley, Xinjiang, China on 26 June 2015. We analyzed the horizontal wavelength, period, speed, ducting, energy [...] Read more.

We used observational data and the results from a high-resolution numerical simulation model to analyze the occurrence and development of an extreme precipitation event in the Ili Valley, Xinjiang, China on 26 June 2015. We analyzed the horizontal wavelength, period, speed, ducting, energy propagation and feedback mechanism of inertial gravity waves. A low-level convergence line was formed in the valley by the northerly and westerly winds as a result of Central Asian vortices and the trumpet-shaped topography of the Ili Valley. There was sufficient water vapor in the valley for the precipitation event to develop. A mesoscale vortex formed and developed on the low-level convergence line and the rainfall was distributed either near the convergence line or the mesoscale vortex. The low-level convergence line and the uplift caused by the terrain triggered convection, and then the convection triggered waves at lower levels. The combination of ascending motion induced by the lower level waves and the mesoscale vortex led to the development of convection, causing the precipitation to intensify. When the convection moved eastward to Gongliu County, it was coupled with the ascending phase of upper level waves, causing both the convection and precipitation to intensify again. We applied spectral analysis methods to verify that the waves were inertial gravity waves. The upper level inertial gravity waves propagated westward at a mean speed of −12 m s⁻¹ with periods of 73–179 min and horizontal wavelengths of 50–55 km. The lower level inertial gravity waves propagated eastward at a mean speed of 8 m s⁻¹ with periods of 73–200 min and a horizontal wavelength of 85 km. The more (less) favorable waveguide conditions determined whether the gravity waves persisted for a long (short) time and propagated for a longer (shorter) distance. Based on the mesoscale Eliassen–Palm flux theory, the wave energy of inertial gravity waves had an important effect on the maintenance and development of convection and precipitation by affecting wind strength and wind divergence. Feedback was mainly through the meridional and vertical transport of zonal momentum and the meridional transport of heat. Full article

(This article belongs to the Section Meteorology)

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14 pages, 3611 KiB

Open AccessArticle

Ambient Gaseous Pollutants in an Urban Area in South Africa: Levels and Potential Human Health Risk

by Oyewale Mayowa Morakinyo, Murembiwa Stanley Mukhola and Matlou Ingrid Mokgobu

Atmosphere 2020, 11(7), 751; https://doi.org/10.3390/atmos11070751 - 16 Jul 2020

Cited by 18 | Viewed by 5118

Abstract

Urban air pollution from gaseous pollutants is a growing public health problem in many countries including South Africa. Examining the levels, trends and health risk of exposure to ambient gaseous pollutants will assist in understanding the effectiveness of existing control measures and plan [...] Read more.

Urban air pollution from gaseous pollutants is a growing public health problem in many countries including South Africa. Examining the levels, trends and health risk of exposure to ambient gaseous pollutants will assist in understanding the effectiveness of existing control measures and plan for suitable management strategies. This study determined the concentration levels and non-cancer risk of CO, SO₂, NO₂, and O₃ at an industrial area in Pretoria West, South Africa. We utilised a set of secondary data for CO, NO₂, SO₂, and O₃ that was obtained from a monitoring station. Analysis of the hourly monitored data was done. Their non-cancer risk (HQ) was determined using the human health risk assessment model for different age categories. The annual levels of NO₂ (39.442 µg/m³), SO₂ (22.464 µg/m³)_, CO (722.003 µg/m³) and the 8-hour concentration of CO (649.902 µg/m³) and O₃ (33.556 µg/m³) did not exceed the South African National Ambient Air Quality Standards for each pollutant. The HQ for each pollutant across exposed groups (except children) was less than 1. This indicates that the recorded levels could not pose non-cancer risk to susceptible individuals. Full article

(This article belongs to the Section Air Quality)

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20 pages, 6754 KiB

Open AccessArticle

Poor Air Quality and Its Association with Mortality in Ho Chi Minh City: Case Study

by Hoang Ngoc Khue Vu, Quang Phuc Ha, Duc Hiep Nguyen, Thi Thu Thuy Nguyen, Thoai Tam Nguyen, Thi Thuy Hang Nguyen, Ngoc Dang Tran and Bang Quoc Ho

Atmosphere 2020, 11(7), 750; https://doi.org/10.3390/atmos11070750 - 15 Jul 2020

Cited by 26 | Viewed by 10152

Abstract

Along with its rapid urban development, Ho Chi Minh City (HCMC) in recent years has suffered a high concentration of air pollutants, especially fine particulate matters or PM_2.5. A comprehensive study is required to evaluate the air quality conditions and their [...] Read more.

Along with its rapid urban development, Ho Chi Minh City (HCMC) in recent years has suffered a high concentration of air pollutants, especially fine particulate matters or PM_2.5. A comprehensive study is required to evaluate the air quality conditions and their health impact in this city. Given the lack of adequate air quality monitoring data over a large area of the size of HCMC, an air quality modeling methodology is adopted to address the requirement. Here, by utilizing a corresponding emission inventory in combination with The Air Pollution Model-Chemical Transport Model (TAPM-CTM), the predicted concentration of air pollutants is first obtained for PM_2.5, NOx, and SO₂. Then by associating the pollutants exposed with the mortality rate from three causes, namely Ischemic Heart Disease (IHD), cardiopulmonary, and lung cancer, the impact of air pollution on human health is obtained for this purpose. Spatial distribution has shown a high amount of pollutants concentrated in the central city with a high density of combustion vehicles (motorcycles and automobiles). In addition, a significant amount of emissions can be observed from stevedoring and harbor activities, including ferries and cargo handling equipment located along the river. Other sources such as household activities also contribute to an even distribution of emission across the city. The results of air quality modeling showed that the annual average concentrations of NO₂ were higher than the standard of Vietnam National Technical Regulation on Ambient Air Quality (QCVN 05: 2013 40 µg/m³) and World Health Organization (WHO) (40 µg/m³). The annual average concentrations of PM_2.5 were 23 µg/m³ and were also much higher than the WHO (10 µg/m³) standard by about 2.3 times. In terms of public health impacts, PM_2.5 was found to be responsible for about 1136 deaths, while the number of mortalities from exposure to NO₂ and SO₂ was 172 and 89 deaths, respectively. These figures demand some stringent measures from the authorities to potentially remedy the alarming situation of air pollution in HCM City. Full article

(This article belongs to the Special Issue Future Energy Technologies and Photochemical Smog Formation)

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18 pages, 3655 KiB

Open AccessArticle

Monitoring Excess Exposure to Air Pollution for Professional Drivers in London Using Low-Cost Sensors

by Louise Bøge Frederickson, Shanon Lim, Hugo Savill Russell, Szymon Kwiatkowski, James Bonomaully, Johan Albrecht Schmidt, Ole Hertel, Ian Mudway, Benjamin Barratt and Matthew Stanley Johnson

Atmosphere 2020, 11(7), 749; https://doi.org/10.3390/atmos11070749 - 15 Jul 2020

Cited by 16 | Viewed by 5641

Abstract

In this pilot study, low-cost air pollution sensor nodes were fitted in waste removal trucks, hospital vans and taxis to record drivers’ exposure to air pollution in Central London. Particulate matter (PM

_{2.5}

and PM

_{10}

), CO

_{2}

, NO

_{2}

, [...] Read more.

In this pilot study, low-cost air pollution sensor nodes were fitted in waste removal trucks, hospital vans and taxis to record drivers’ exposure to air pollution in Central London. Particulate matter (PM

_{2.5}

and PM

_{10}

), CO

_{2}

, NO

_{2}

, temperature and humidity were recorded in real-time with nodes containing low-cost sensors, an electrochemical gas sensor for NO

_{2}

, an optical particle counter for PM

_{2.5}

and PM

_{10}

and a non-dispersive infrared (NDIR) sensor for CO

_{2}

, temperature and relative humidity. An intervention using a pollution filter to trap PM and NO

_{2}

was also evaluated. The measurements were compared with urban background and roadside monitoring stations at Honor Oak Park and Marylebone Road, respectively. The vehicle records show PM and NO

_{2}

concentrations similar to Marylebone Road and a higher NO

_{2}

-to-PM ratio than at Honor Oak Park. Drivers are exposed to elevated pollution levels relative to Honor Oak Park: 1.72

μ

g m

^{- 3}

, 1.92

μ

g m

^{- 3}

and 58.38 ppb for PM

_{2.5}

, PM

_{10}

, and NO

_{2}

, respectively. The CO

_{2}

levels ranged from 410 to over 4000 ppm. There is a significant difference in average concentrations of PM

_{2.5}

and PM

_{10}

between the vehicle types and a non-significant difference in the average concentrations measured with and without the pollution filter within the sectors. In conclusion, drivers face elevated air pollution exposure as part of their jobs. Full article

(This article belongs to the Section Air Quality)

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17 pages, 4884 KiB

Open AccessFeature PaperArticle

High-Resolution Temperature Variability Reconstructed from Black Pine Tree Ring Densities in Southern Spain

by Jan Esper, Claudia Hartl, Ernesto Tejedor, Martin de Luis, Björn Günther and Ulf Büntgen

Atmosphere 2020, 11(7), 748; https://doi.org/10.3390/atmos11070748 - 15 Jul 2020

Cited by 10 | Viewed by 6336

Abstract

The presence of an ancient, high-elevation pine forest in the Natural Park of Sierras de Cazorla in southern Spain, including some trees reaching >700 years, stimulated efforts to develop high-resolution temperature reconstructions in an otherwise drought-dominated region. Here, we present a reconstruction of [...] Read more.

The presence of an ancient, high-elevation pine forest in the Natural Park of Sierras de Cazorla in southern Spain, including some trees reaching >700 years, stimulated efforts to develop high-resolution temperature reconstructions in an otherwise drought-dominated region. Here, we present a reconstruction of spring and fall temperature variability derived from black pine tree ring maximum densities reaching back to 1350 Coefficient of Efficiency (CE). The reconstruction is accompanied by large uncertainties resulting from low interseries correlations among the single trees and a limited number of reliable instrumental stations in the study region. The reconstructed temperature history reveals warm conditions during the early 16th and 19th centuries that were of similar magnitude to the warm temperatures recorded since the late 20th century. A sharp transition from cold conditions in the late 18th century (t_1781–1810 = −1.15 °C ± 0.64 °C) to warm conditions in the early 19th century (t_1818–1847 = −0.06 °C ± 0.49 °C) is centered around the 1815 Tambora eruption (t₁₈₁₆ = −2.1 °C ± 0.55 °C). The new reconstruction from southern Spain correlates significantly with high-resolution temperature histories from the Pyrenees located ~600 km north of the Cazorla Natural Park, an association that is temporally stable over the past 650 years (r_1350–2005 > 0.3, p < 0.0001) and particularly strong in the high-frequency domain (r_HF > 0.4). Yet, only a few of the reconstructed cold extremes (1453, 1601, 1816) coincide with large volcanic eruptions, suggesting that the severe cooling events in southern Spain are controlled by internal dynamics rather than external (volcanic) forcing. Full article

(This article belongs to the Special Issue Past Climate Reconstructed from Tree Rings)

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11 pages, 3245 KiB

Open AccessArticle

Modelling the Present Global Terrestrial Climatic Response Due to a Chicxulub-Type Asteroid Impact

by Víctor M. Mendoza, Blanca Mendoza, René Garduño and Marni Pazos

Atmosphere 2020, 11(7), 747; https://doi.org/10.3390/atmos11070747 - 14 Jul 2020

Viewed by 3189

Abstract

A Chicxulub-like asteroid event occurs, on average, approximately every ~27 to 200 million years. Therefore, such an event could happen presently. Here, we simulate the climatic anomalies it may cause with respect to the current conditions, assuming the same target geology of carbonates [...] Read more.

A Chicxulub-like asteroid event occurs, on average, approximately every ~27 to 200 million years. Therefore, such an event could happen presently. Here, we simulate the climatic anomalies it may cause with respect to the current conditions, assuming the same target geology of carbonates and evaporates and a 1 Gt release of sulphate gases. We used a thermodynamic model, including water vapor, cloudiness (by greenhouse and albedo effects), and cryosphere feedback to calculate aerosol cooling. We found that it took nearly 4.5 years for solar radiation to recover its preimpact value—during the first year practically no solar radiation reached the surface. Recovery of the temperature took more than 45 years. The lowest temperatures occurred between 1.5 and 5 years after the impact, being the coldest at −14 °C below the preimpact temperature. July surface temperature anomalies occurred 1.5 years after the impact, becoming one of the largest, compared to preimpact temperatures. Most continents showed temperature anomalies of −45 °C. The least cold places were the polar regions with temperature anomalies between approximately −5 and 0 °C. As for the most remarkable climatic effect, we found that, for ~6 years, the ice extended over almost all the ocean surface and, after ~25 years, it covered nearly half of the surface, remaining so for beyond 45 years. The continental ice remained without reduction beyond 45 years. Sixty years after the impact, the surface oceanic and continental fractions covered by ice were 0.52 and 0.98, respectively. We also modeled the effect of smaller quantities of sulfur released after asteroid impacts, concluding that an instantaneous, large climatic perturbation attributed to a loading range may lead to a semi-permanent shift in the climate system. Full article

(This article belongs to the Section Climatology)

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15 pages, 9873 KiB

Open AccessArticle

Variations in Ozone Concentration over the Mid-Latitude Region Revealed by Ozonesonde Observations in Pohang, South Korea

by Daegeun Shin, Seungjoo Song, Sang-Boom Ryoo and Sang-Sam Lee

Atmosphere 2020, 11(7), 746; https://doi.org/10.3390/atmos11070746 - 14 Jul 2020

Cited by 13 | Viewed by 4733

Abstract

Ozone absorbs harmful UV rays at high elevations but acts as a pollutant gas in the lower atmosphere. It is necessary to monitor both the vertical profile and the total column ozone. In this study, variations in the ozone concentration of Pohang were [...] Read more.

Ozone absorbs harmful UV rays at high elevations but acts as a pollutant gas in the lower atmosphere. It is necessary to monitor both the vertical profile and the total column ozone. In this study, variations in the ozone concentration of Pohang were divided into three vertical layers: the stratospheric layer (STL), the second ozone peak layer (SOPL), and the tropospheric layer (TRL). Our results indicated that the ozone concentration in the STL, SOPL, TRL, and total column ozone increased by 0.45%, 2.64%, 5.26%, and 1.07% decade⁻¹, respectively. The increase in the SOPL during springtime indicates that stratosphere–troposphere exchange is accelerating, while the increase during summertime appears to have been influenced by the lower layers. The growth of tropospheric ozone concentration is the result of both increased ozone precursors from industrialization in East Asia and the influx of stratospheric ozone. Our results reaffirmed the trend of ozone concentration in mid-latitudes of the northern hemisphere from vertical profiles in Pohang and, in particular, suggests that the recent changes of ozone in this region need to be carefully monitored. Full article

(This article belongs to the Section Air Quality)

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17 pages, 6727 KiB

Open AccessArticle

Climatological Large-Scale Circulation Patterns over The Middle Americas Region

by Carlos A. Ochoa-Moya, Yoel A. Cala-Pérez, Yanet Díaz-Esteban, Christopher L. Castro, Paulina Ordoñez-Peréz and Arturo I. Quintanar

Atmosphere 2020, 11(7), 745; https://doi.org/10.3390/atmos11070745 - 14 Jul 2020

Cited by 3 | Viewed by 3266

Abstract

In this study, twenty large-scale circulation patterns are identified to generate a synoptic classification of Weather Types (WT) over a region that comprises Mexico, the Intra-Americas Seas, Central America, and northern South America. This classification is performed using Self-Organizing Maps (SOMs) with mean [...] Read more.

In this study, twenty large-scale circulation patterns are identified to generate a synoptic classification of Weather Types (WT) over a region that comprises Mexico, the Intra-Americas Seas, Central America, and northern South America. This classification is performed using Self-Organizing Maps (SOMs) with mean sea-level pressure standardized anomalies from reanalysis. The influence of quasi-permanent pressure centers over the region, such as North Atlantic Subtropical High (NASH) and North Pacific High (NPH) are well captured. Seasonal variability of high-pressure centers for dry (November–April) and wet (May–October) periods over the entire region are also well represented in amplitude and pattern among the WTs. The NASH influence and intensification of the Caribbean low-level jet and the North American monsoon system is well captured. During the dry period, a strong trough wind advects cold air masses from mid-latitudes to the subtropics over the western Atlantic Ocean. High-frequency transitions among WTs tend to cluster around the nearest neighbors in SOM space, while low-frequency transitions occur along columns instead of rows in the SOM matrix. Low-frequency transitions are related to intraseasonal and seasonal scales. The constructed catalog can identify near-surface atmospheric circulation patterns from a unified perspective of synoptic climate variability, and it is in high agreement with previous studies for the region. Full article

(This article belongs to the Special Issue Central America and Caribbean Hydrometeorology and Hydroclimate)

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26 pages, 11041 KiB

Open AccessArticle

Use of Electronic UV Dosimeters in Measuring Personal UV Exposures and Public Health Education

by Martin W. Allen, Neil Swift, Kathryn M. Nield, Ben Liley and Richard L. McKenzie

Atmosphere 2020, 11(7), 744; https://doi.org/10.3390/atmos11070744 - 14 Jul 2020

Cited by 19 | Viewed by 4494

Abstract

The performance limits of electronic ultraviolet (EUV) dosimeters, which use AlGaN Schottky photodiodes as the ultraviolet radiation (UVR) sensing element to measure personal erythemally weighted UVR exposures, were investigated via a direct comparison with meteorological-grade reference instruments. EUV dosimeters with two types of [...] Read more.

The performance limits of electronic ultraviolet (EUV) dosimeters, which use AlGaN Schottky photodiodes as the ultraviolet radiation (UVR) sensing element to measure personal erythemally weighted UVR exposures, were investigated via a direct comparison with meteorological-grade reference instruments. EUV dosimeters with two types of AlGaN Schottky photodiode were compared to second-generation ‘Robertson–Berger type’ broadband erythemal radiometers. This comparison was done by calculating correction factors for the deviations of the spectral responsivity of each instrument from the CIE erythemal action spectrum and for deviations in their angular response from the ideal cosine response of flat surfaces and human skin. Correction factors were also calculated to convert the output of these instruments to vitamin D-weighted UV irradiances. These comparisons showed that EUV dosimeters can be engineered with spectral responsivities and cosine response errors approaching those of Robertson–Berger type radiometers, making them very acceptable for use in human UVR exposure and sun safety behaviour studies, provided appropriate side-by-side calibrations are performed. Examples of these calibrations and the effect of EUV dosimeter sampling rates on the calculation of received erythemal UVR doses and erythemal UVR dose rates are provided, as well as brief descriptions of their use in primary skin cancer prevention programmes, handheld meters, and public health displays. Full article

(This article belongs to the Special Issue Measuring Personal Exposure to Solar Ultraviolet Radiation Using Dosimetric Techniques)

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14 pages, 674 KiB

Open AccessArticle

The Influence of the Mineral–Microbial Deodorizing Preparation on Ammonia Emission and Growth Performance in Turkey Production

by Remigiusz Gałęcki, Michał Dąbrowski, Tadeusz Bakuła, Kazimierz Obremski, Mirosław Baranowski, Adriana Nowak and Beata Gutarowska

Atmosphere 2020, 11(7), 743; https://doi.org/10.3390/atmos11070743 - 13 Jul 2020

Cited by 2 | Viewed by 2955

Abstract

In our previous in vitro research and also in laying hen production, attempts were made to minimise ammonia emissions in poultry houses with the use of Deodoric^® biopreparation. The objective of the present research was to evaluate the influence of the Deodoric [...] Read more.

In our previous in vitro research and also in laying hen production, attempts were made to minimise ammonia emissions in poultry houses with the use of Deodoric^® biopreparation. The objective of the present research was to evaluate the influence of the Deodoric^® on ammonia (NH₃) emission and turkey growth performance in a semi-industrial production system. Significant differences in NH₃ emission (p-value < 0.001), body weight (p-value < 0.001) and relative humidity (p-value < 0.001) were observed between the control group (C) and the experimental group (E) where Deodoric® was applied. In group C, an increase in ammonia concentration in air could have contributed to a decrease in the body weight of turkeys, but the above correlation was not observed in group E. In the control group, a relatively strong correlation between NH₃ emission and temperature (p-value = 0.0009; r = 0.74) and moderate correlations between NH₃ emission vs. relative humidity (p-value = 0.01; r = 0.59), air speed (p-value = 0.015; r = 0.60) and cooling (p-value = 0.005; r = 0.66) were noted. Studied correlations were not observed in group E. The preparation did not affect microbial levels in manure or body samples. Throughout the experiment, significant differences in the number of mesophilic bacteria (for the model: F = 46.14, p-value = 0.09; for mesophilic microorganisms: F = 3.29, p-value = 0.045) and Campylobacter spp. (for the model: F = 24.96, p-value = 0.008; for Campylobacter spp.: F = 0.25, p-value = 0.64) were not observed between group C and group E. The administration of Deodoric^® to manure decreased NH₃ concentration in the air and increased weight gains in the experimental group of turkeys relative to group C. Preparation may be applied in poultry farms to improve poultry farming conditions. Full article

(This article belongs to the Special Issue Livestock Odor and Air Quality)

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33 pages, 4434 KiB

Open AccessArticle

Retrofit Strategies for Energy Efficiency of Historic Urban Fabric in Mediterranean Climate

by Meltem Ulu and Zeynep Durmuş Arsan

Atmosphere 2020, 11(7), 742; https://doi.org/10.3390/atmos11070742 - 13 Jul 2020

Cited by 16 | Viewed by 4436

Abstract

Energy-efficient retrofitting of historic housing stock requires methodical approach, in-depth analysis and case-specific regulatory system, yet only limited efforts have been realized. In large scale rehabilitation projects, it is essential to develop a retrofit strategy on how to decide energy-efficient solutions for buildings [...] Read more.

Energy-efficient retrofitting of historic housing stock requires methodical approach, in-depth analysis and case-specific regulatory system, yet only limited efforts have been realized. In large scale rehabilitation projects, it is essential to develop a retrofit strategy on how to decide energy-efficient solutions for buildings providing the most energy saving in a short time. This paper presents a pilot study conducted at a neighborhood scale, consisting of 22 pre-, early-republican and contemporary residential buildings in a historic urban fabric in the Mediterranean climate. This study aims to develop an integrated approach to describe case-specific solutions for larger scale historic urban fabric. It covers the building performance simulation (BPS) model and numerical analysis to determine the most related design parameters affecting annual energy consumption. All the case buildings were classified into three main groups to propose appropriate retrofit solutions in different impact categories. Retrofit solutions were gathered into two retrofit packages, Package 1 and 2, and separately, three individual operational solutions were determined, considering a five-levelled assessment criteria of EN 16883:2017 Standard. Energy classes of case buildings were calculated based on National Building Energy Regulations. Changes in building classes were evaluated considering pre- and post-retrofit status of the buildings. For the integrated approach, the most related design parameters on annual energy consumption were specified through Pearson correlation analysis. The approach indicated that three buildings, representing each building group, can initially be retrofitted. For all buildings, while maximum energy saving was provided by Package 2 with 48.57%, minimum energy saving was obtained from Package 1 with 19.8%. Full article

(This article belongs to the Special Issue Assessing the Impact of Climate Change on Urban Cultural Heritage)

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