NOx AND O3 VARIABILITY AND ITS RELATION WITH WEATHER CONDITIONS IN IAȘI CITY

The paper presents the temporal variability of surface ozone (O3) and its precursors (oxides of nitrogen - NOx) from January 2012 to December 2015. In the same time, this study is aimed to explore the influence of the weather elements on these two major atmospheric pollutants in the area of Iași city. The maximum record of nitrogen oxides reached during the 4 analyzed years was 1200 μ/m-3 on October 27, 2015, a period of the year when atmospheric stability prevails. During the warm season (considered from May to September) the highest concentration of ozone was recorded at 155 μ/m-3. The winds direction from SSE or NNW and the winds speed greater than 2 m/s can significantly increase the concentration of the O3 and NOx respectively. Also, the stable atmospheric conditions can increase especially the concentration of the nitrogen dioxides. The statistical results illustrate a strong Pearson's correlation of surface ozone with solar radiation/maximum air temperature (r >0.5). The correlations were strongest during the summer months. Using the composite method, between warm season and cold season a difference of the pollutants concentration greater than 30 units for NOx was observed. Synoptic conditions associated with high pollution are also described.

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Ice Nucleating Particles in Southern Chile and their connection to clouds

10.5194/egusphere-egu21-7474 ◽

2021 ◽

Author(s):

Heike Wex ◽

Xianda Gong ◽

Boris Barja ◽

Patric Seifert ◽

Martin Radenz ◽

...

Keyword(s):

Warm Season ◽

Weather Conditions ◽

Chem Phys ◽

Cold Season ◽

Southern Chile ◽

Backscatter Coefficient ◽

Air Masses ◽

North West ◽

The North ◽

Almost All

Concentrations of atmospheric ice nucleating particles (INP) were obtained from weekly filter samples which were collected from May 2019 until March 2020 in southern Chile. Sampling took place at an altitude of 620m above sea level, on top of Cerro Mirador, a mountain directly to the west of Punta Arenas (53&#176;S, 71&#176;W). Additional aerosol properties such as particle number size distributions were measured as well. In parallel, ground-based remote sensing measurements with lidar and cloud radar were made in Punta Arenas.INP concentrations were obtained from washing atmospheric aerosol particles off from deployed polycarbonate filters and subsequent analysis of the samples on two different freezing arrays which were used and described by us earlier (e.g., in Gong et al., 2019 and Hartmann et al., 2020). INP concentrations could be obtained over a broad temperature range from above -5&#176;C down to -25&#176;C.INP concentrations were clearly higher than data obtained for the Southern Ocean region as reported in McCluskey et al. (2018) and Welti et al. (2020). Indeed, they were comparable to concentrations measured at Cape Verde (Gong et al., 2020). INP concentrations obtained during the warm season were spreading over ~ 2 orders of magnitude at any temperature. Data obtained for the cold season almost all were at the upper end of the observed INP concentration range, with only one weekly sample featuring low concentrations.Heating of the samples was also applied, and the heated samples had clearly lower INP concentrations across the examined temperatures, implying a biological fraction among the INP of ~ 80%. Therefore, local terrestrial sources may be the source of the observed INP.The assumption of local terrestrial sources is strengthened by a case study. For that, two subsequent samples obtained during the cold season were examined in more detail. These were the one sample with low INP concentrations which was obtained during the cold season during the week from August 14 to August 22, and the subsequent sample collected from August 22 to August 29, which was amongst the highest samples. Backward trajectories together with an analysis of Lidar data showed that the low INP concentrations were obtained for a time during which air masses predominantly came in from the south with little contact to land and for calm weather conditions. Conditions were not as stable during the following week which featured air masses mostly coming in from the north-west. The aerosol backscatter coefficient at the height level of the in-situ measurements was obtained from lidar observations for both weeks and shows about 50 % lower aerosol load for the first week, when INP concentrations were low.All of this hints to local terrestrial sources for the observed highly ice active biogenic INP.&#160;Literature:Gong et al. (2019), Atmos. Chem. Phys., 19, 10883-10900, doi:10.5194/acp-19-10883-2019.Gong et al. (2020), Atmos. Chem. Phys., 20, 1451-1468, doi:10.5194/acp-20-1451-2020.Hartmann et al. (2020), Geophys. Res. Lett., 47, doi:10.1029/2020GL087770.McCluskey et al. (2018), Geophys. Res. Lett., 45, doi:10.1029/2018gl079981.Welti et a. (2020), Atmos. Chem. Phys. 20, doi:10.5194/acp-2020-466.

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Weather Conditions and Outdoor Fall Injuries in Northwestern Russia

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17176096 ◽

2020 ◽

Vol 17 (17) ◽

pp. 6096 ◽

Cited By ~ 1

Author(s):

Tatiana N. Unguryanu ◽

Andrej M. Grjibovski ◽

Tordis A. Trovik ◽

Børge Ytterstad ◽

Alexander V. Kudryavtsev

Keyword(s):

Air Temperature ◽

Negative Binomial ◽

Ground Surface ◽

Warm Season ◽

Negative Binomial Regression ◽

Weather Conditions ◽

Cold Season ◽

Population Based ◽

Fall Injuries ◽

Northwestern Russia

This study aimed to investigate associations between the weather conditions and the frequency of medically-treated, non-fatal accidental outdoor fall injuries (AOFIs) in a provincial region of Northwestern Russia. Data on all non-fatal AOFIs that occurred from January 2015 through June 2018 (N = 1125) were extracted from the population-based Shenkursk Injury Registry (SHIR). Associations between the weather conditions and AOFIs were investigated separately for the cold (15 October–14 April) and the warm (15 April–14 October) seasons. Negative binomial regression was used to investigate daily numbers of AOFIs in the cold season, while zero-inflated Poisson regression was used for the warm season. The mean daily number of AOFIs was 1.7 times higher in the cold season compared to the warm season (1.10 vs. 0.65, respectively). The most typical accident mechanism in the cold season was slipping (83%), whereas stepping wrong or stumbling over something was most common (49%) in the warm season. The highest mean daily incidence of AOFIs in the cold season (20.2 per 100,000 population) was observed on days when the ground surface was covered by compact or wet snow, air temperature ranged from −7.0 °C to −0.7 °C, and the amount of precipitation was above 0.4 mm. In the warm season, the highest mean daily incidence (7.0 per 100,000 population) was observed when the air temperature and atmospheric pressure were between 9.0 °C and 15.1 °C and 1003.6 to 1010.9 hPa, respectively. Along with local weather forecasts, broadcasting warnings about the increased risks of outdoor falls may serve as an effective AOFI prevention tool.

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METEOROLOGICAL POTENTIAL OF THE ATMOSPHERE OF THE SARNY AND ITS GEOECOLOGICAL SIGNIFICANCE

GEOGRAPHY AND TOURISM ◽

10.17721/2308-135x.2020.59.70-83 ◽

2020 ◽

pp. 70-83

Author(s):

Oksana Romaniv ◽

Larisa Janello

Keyword(s):

Thermal Regime ◽

Urban Areas ◽

Warm Season ◽

Weather Conditions ◽

Cold Season ◽

Practical Significance ◽

Close Relationship ◽

Harmful Substances ◽

The Masses ◽

The City

The purpose of the study is to assess the meteorological potential of the atmosphere of Sarny and to determine the degree of influence of various parameters of the microclimatic system. The research methodology includes a system of methods and techniques: monographic (used to study the materials of literary sources and Internet resources), mathematical (used a number of special indicators: Coefficient of meteorological potential according to VA Baranovsky, Coefficient of weather hardness Arnoldi for the cold season and heat for the warm season), graphic (used to visualize the results of the study). Research results. The processes of accumulation of harmful substances in the atmospheric air of the city of Sarny prevail over the processes of scattering throughout the year. The best processes of dispersion of harmful substances in the air of the city of Sarny occur in the cold season, the processes of accumulation are most active in July-August. The meteorological potential in Sarny is worse than in Rivne and Dubno, which are located in the southern part of Rivne region. A reliable direct close relationship between the concentration of pollutants (sulfur dioxide, formaldehyde) in the air with a meteorological potential of the atmosphere in Sarni been set. This should be considered when monitoring the atmosphere. During the cold period of the year in the thermal regime of the microclimate of the city the severe weather prevails in the winter months, and in March, October, November - mild weather. In the warm period of the year only in summer the indicators of the thermal regime are in the comfort zone. The weather, which is characterized by extreme thermal discomfort and poses a danger and extreme danger to humans, was not formed during 2016-2018. In the cold season, the relationship between the thermal regime and the level of meteorological potential of the geourbosystem of Sarny is closer. But in the warm season, the self-cleaning abilities of the atmosphere tend to deteriorate with increasing average comfort temperature. We assume that the processes of global warming will make the microclimate of the city of Sarny in the warm season more comfortable in terms of its thermal regime, but less attractive in terms of meteorological potential of the atmosphere. Scientific novelty of the work: the meteorological potential of the atmosphere of the city of Sarny by months for 2016-2018 was calculated; regularities of change of these indicators in warm and cold periods of the year were established; the meteorological potential of Sarny was compared with the indicators of other cities of the region (Dubno and Rivne). The correlations between the meteorological potential of the atmosphere of the city of Sarny with the level of air pollution and with the indicators of the thermal regime for cold and warm seasons have been established. The practical significance of the work is that the obtained results can be used in the form of recommendations to local authorities for the improvement of urban areas to protect the air from pollution in conditions of low meteorological potential. The conclusions obtained in the work can be used as a basis for geoplanning projects for the location of industries. Also, the information obtained in the work can be taken into account by the media to inform the masses in order to form a rational behavior of the population in different weather conditions.

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Suspended Particulates Concentration (PM10) under Unstable Atmospheric Conditions over Subtropical Urban Area (Qena, Egypt)

Advances in Meteorology ◽

10.1155/2013/457181 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

M. El-Nouby Adam

Keyword(s):

Urban Area ◽

Air Temperature ◽

Atmospheric Stability ◽

Cold Season ◽

Atmospheric Conditions ◽

Stability Class ◽

Average Value ◽

Suspended Particulates ◽

Monthly Average ◽

Hot Season

The main purpose of this study is to evaluate the suspended particulates (PM10) in the atmosphere under unstable atmospheric conditions. The variation of PM10was investigated and primary statistics were employed. The results show that, the PM10concentrations values ranged from 6.00 to 646.74 μg m−3. The average value of PM10is equal to 114.32 μg m−3. The high values were recorded in April and May (155.17 μg m−3and 171.82 μg m−3, respectively) and the low values were noted in February and December (73.86 μg m−3and 74.05 μg m−3, respectively). The average value of PM10of the hot season (125.35 × 10−6 g m−3) was higher than its value for the cold season (89.27 μg m−3). In addition, the effect of weather elements (air temperature, humidity and wind) on the concentration of PM10was determined. The multiple R between PM10and these elements ranged from 0.05 to 0.47 and its value increased to reach 0.73 for the monthly average of the database used. Finally, the PM10concentrations were grouped depending on their associated atmospheric stability class. These average values were equal to 122.80 ± 9 μg m−3(highly unstable or convective), 109.37 ± 12 μg m−3(moderately unstable) and 104.42 ± 15 μg m−3(slightly unstable).

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Seasonal variation in atmospheric pollutants transport in central Chile: dynamics and consequences

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-6431-2021 ◽

2021 ◽

Vol 21 (8) ◽

pp. 6431-6454

Author(s):

Rémy Lapere ◽

Laurent Menut ◽

Sylvain Mailler ◽

Nicolás Huneeus

Keyword(s):

Particulate Matter ◽

Surface Ozone ◽

Fine Particulate Matter ◽

Warm Season ◽

Atmospheric Pollutants ◽

Capital City ◽

Winter Period ◽

Central Chile ◽

Mixing Ratios ◽

Fine Particulate

Abstract. Central Chile faces atmospheric pollution issues all year long as a result of elevated concentrations of fine particulate matter during the cold months and tropospheric ozone during the warm season. In addition to public health issues, environmental problems regarding vegetation growth and water supply, as well as meteorological feedback, are at stake. Sharp spatial gradients in regional emissions, along with a complex geographical situation, make for variable and heterogeneous dynamics in the localization and long-range transport of pollutants, with seasonal differences. Based on chemistry–transport modeling with Weather Research Forecasting (WRF)–CHIMERE, this work studies the following for one winter period and one summer period: (i) the contribution of emissions from the city of Santiago to air pollution in central Chile, and (ii) the reciprocal contribution of regional pollutants transported into the Santiago basin. The underlying 3-dimensional advection patterns are investigated. We find that, on average for the winter period, 5 to 10 µg m−3 of fine particulate matter in Santiago come from regional transport, corresponding to between 13 % and 15 % of average concentrations. In turn, emissions from Santiago contribute between 5 % and 10 % of fine particulate matter pollution as far as 500 km to the north and 500 km to the south. Wintertime transport occurs mostly close to the surface. In summertime, exported precursors from Santiago, in combination with mountain–valley circulation dynamics, are found to account for most of the ozone formation in the adjacent Andes cordillera and to create a persistent plume of ozone of more than 50 ppb (parts per billion), extending along 80 km horizontally and 1.5 km vertically, and located slightly north of Santiago, several hundred meters above the ground. This work constitutes the first description of the mechanism underlying the latter phenomenon. Emissions of precursors from the capital city also affect daily maxima of surface ozone hundreds of kilometers away. In parallel, cutting emissions of precursors in the Santiago basin results in an increase in surface ozone mixing ratios in its western area.

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On the understanding of surface ozone variability, its precursors and their associations with atmospheric conditions over the Delhi region

Atmospheric Research ◽

10.1016/j.atmosres.2021.105653 ◽

2021 ◽

Vol 258 ◽

pp. 105653

Author(s):

Anshika ◽

Ravi Kumar Kunchala ◽

Raju Attada ◽

Ramesh K. Vellore ◽

Vijay K. Soni ◽

...

Keyword(s):

Surface Ozone ◽

Atmospheric Conditions

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Cold-season atmospheric conditions associated with sudden changes in PM10 concentration over Seoul, Korea

Atmospheric Pollution Research ◽

10.1016/j.apr.2021.03.004 ◽

2021 ◽

Author(s):

Minjeong Cho ◽

Yong-Sang Choi ◽

Ha-Rim Kim ◽

Changhyun Yoo ◽

Seoung-Soo Lee

Keyword(s):

Cold Season ◽

Pm10 Concentration ◽

Atmospheric Conditions

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Radiative Effect and Mixing Processes of a Long-Lasting Dust Event over Athens, Greece, during the COVID-19 Period

Atmosphere ◽

10.3390/atmos12030318 ◽

2021 ◽

Vol 12 (3) ◽

pp. 318

Author(s):

Panagiotis Kokkalis ◽

Ourania Soupiona ◽

Christina-Anna Papanikolaou ◽

Romanos Foskinis ◽

Maria Mylonaki ◽

...

Keyword(s):

Atmospheric Pollutants ◽

Saharan Dust ◽

Radiative Effect ◽

Atmospheric Conditions ◽

Dust Event ◽

Mixing Processes ◽

Hysplit Model ◽

European Continent ◽

Dust Layer ◽

Ground Based Lidar

We report on a long-lasting (10 days) Saharan dust event affecting large sections of South-Eastern Europe by using a synergy of lidar, satellite, in-situ observations and model simulations over Athens, Greece. The dust measurements (11–20 May 2020), performed during the confinement period due to the COVID-19 pandemic, revealed interesting features of the aerosol dust properties in the absence of important air pollution sources over the European continent. During the event, moderate aerosol optical depth (AOD) values (0.3–0.4) were observed inside the dust layer by the ground-based lidar measurements (at 532 nm). Vertical profiles of the lidar ratio and the particle linear depolarization ratio (at 355 nm) showed mean layer values of the order of 47 ± 9 sr and 28 ± 5%, respectively, revealing the coarse non-spherical mode of the probed plume. The values reported here are very close to pure dust measurements performed during dedicated campaigns in the African continent. By utilizing Libradtran simulations for two scenarios (one for typical midlatitude atmospheric conditions and one having reduced atmospheric pollutants due to COVID-19 restrictions, both affected by a free tropospheric dust layer), we revealed negligible differences in terms of radiative effect, of the order of +2.6% (SWBOA, cooling behavior) and +1.9% (LWBOA, heating behavior). Moreover, the net heating rate (HR) at the bottom of the atmosphere (BOA) was equal to +0.156 K/d and equal to +2.543 K/d within 1–6 km due to the presence of the dust layer at that height. On the contrary, the reduction in atmospheric pollutants could lead to a negative HR (−0.036 K/d) at the bottom of the atmosphere (BOA) if dust aerosols were absent, while typical atmospheric conditions are estimated to have an almost zero net HR value (+0.006 K/d). The NMMB-BSC forecast model provided the dust mass concentration over Athens, while the air mass advection from the African to the European continent was simulated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model.

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Temperature and Relative Humidity Profile Retrieval from Fengyun-3D/HIRAS in the Arctic Region

Remote Sensing ◽

10.3390/rs13101884 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1884

Author(s):

Jingjing Hu ◽

Yansong Bao ◽

Jian Liu ◽

Hui Liu ◽

George P. Petropoulos ◽

...

Keyword(s):

Relative Humidity ◽

Real Time ◽

Wide Spectrum ◽

Warm Season ◽

Arctic Region ◽

Cold Season ◽

The Arctic ◽

Practical Applications ◽

A New Technique ◽

The Arctic Region

The acquisition of real-time temperature and relative humidity (RH) profiles in the Arctic is of great significance for the study of the Arctic’s climate and Arctic scientific research. However, the operational algorithm of Fengyun-3D only takes into account areas within 60°N, the innovation of this work is that a new technique based on Neural Network (NN) algorithm was proposed, which can retrieve these parameters in real time from the Fengyun-3D Hyperspectral Infrared Radiation Atmospheric Sounding (HIRAS) observations in the Arctic region. Considering the difficulty of obtaining a large amount of actual observation (such as radiosonde) in the Arctic region, collocated ERA5 data from European Centre for Medium-Range Weather Forecasts (ECMWF) and HIRAS observations were used to train the neural networks (NNs). Brightness temperature and training targets were classified using two variables: season (warm season and cold season) and surface type (ocean and land). NNs-based retrievals were compared with ERA5 data and radiosonde observations (RAOBs) independent of the NN training sets. Results showed that (1) the NNs retrievals accuracy is generally higher on warm season and ocean; (2) the root-mean-square error (RMSE) of retrieved profiles is generally slightly higher in the RAOB comparisons than in the ERA5 comparisons, but the variation trend of errors with height is consistent; (3) the retrieved profiles by the NN method are closer to ERA5, comparing with the AIRS products. All the results demonstrated the potential value in time and space of NN algorithm in retrieving temperature and relative humidity profiles of the Arctic region from HIRAS observations under clear-sky conditions. As such, the proposed NN algorithm provides a valuable pathway for retrieving reliably temperature and RH profiles from HIRAS observations in the Arctic region, providing information of practical value in a wide spectrum of practical applications and research investigations alike.All in all, our work has important implications in broadening Fengyun-3D’s operational implementation range from within 60°N to the Arctic region.

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Influence of Meteorological Conditions and Aerosol Properties on the COVID-19 Contamination of the Population in Coastal and Continental Areas in France: Study of Offshore and Onshore Winds

Atmosphere ◽

10.3390/atmos12040523 ◽

2021 ◽

Vol 12 (4) ◽

pp. 523

Author(s):

Jacques Piazzola ◽

William Bruch ◽

Christelle Desnues ◽

Philippe Parent ◽

Christophe Yohia ◽

...

Keyword(s):

Atmospheric Transport ◽

Weather Conditions ◽

Meteorological Conditions ◽

Sea Spray ◽

Atmospheric Conditions ◽

Virus Transport ◽

Virus Propagation ◽

Viral Particles ◽

The Social ◽

Aerosol Properties

Human behaviors probably represent the most important causes of the SARS-Cov-2 virus propagation. However, the role of virus transport by aerosols—and therefore the influence of atmospheric conditions (temperature, humidity, type and concentration of aerosols)—on the spread of the epidemic remains an open and still debated question. This work aims to study whether or not the meteorological conditions related to the different aerosol properties in continental and coastal urbanized areas might influence the atmospheric transport of the SARS-Cov-2 virus. Our analysis focuses on the lockdown period to reduce the differences in the social behavior and highlight those of the weather conditions. As an example, we investigated the contamination cases during March 2020 in two specific French areas located in both continental and coastal areas with regard to the meteorological conditions and the corresponding aerosol properties, the optical depth (AOD) and the Angstrom exponent provided by the AERONET network. The results show that the analysis of aerosol ground-based data can be of interest to assess a virus survey. We found that moderate to strong onshore winds occurring in coastal regions and inducing humid environment and large sea-spray production episodes coincides with smaller COVID-19 contamination rates. We assume that the coagulation of SARS-Cov-2 viral particles with hygroscopic salty sea-spray aerosols might tend to inhibit its viral infectivity via possible reaction with NaCl, especially in high relative humidity environments typical of maritime sites.

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