Maximum Concentrations In Winter Research Articles

A six-year measurement-based analysis of traffic-related particulate matter pollution in urban areas: the case of Warsaw, Poland (2016-2021)

This study used PM10 and PM2.5 measurements from the State Environmental Monitoring stations in Warsaw and its suburban areas. Analysis of variability characteristics at the traffic and urban background stations was carried out for 2016-2021. A six-year analysis (2016-2021) of air quality in Warsaw, Poland, focusing highlights the persistent impact of transportation on particulate matter concentrations. Comparing a city centre traffic station with urban background locations reveals consistently higher PM10 concentrations at the traffic station throughout the year, with an annual traffic-related increase of 12.6 μg/m³ (32%). PM2.5 concentrations at the traffic station are also consistently about 1.5 μg/m³ (7%) higher. For monthly averages, the highest PM10 concentrations at the traffic station were noted in March, which may be related to the resuspention of sand and salt left over from winter snow removalp rocesses. In the case of PM2.5, the typical annual cycle with maximum concentrations in winter and minimum concentrations in summer was not observed. Diurnal variability patterns show elevated PM10 concentrations at the traffic station from 8:00 a.m. to 10:00 p.m., attributed to the resuspension process. PM2.5 patterns exhibit a smaller amplitude at the traffic station, with nighttime accumulation due to inflow. This study emphasizes the lasting impact of transportation on air quality, providing insights into pollution control strategies in urban areas.

Characteristics of water-soluble inorganic aerosol pollution and its meteorological response in Wuhan, Central China

Due to the rapid economic development in Central China, PM2.5 (particles not larger than 2.5 μm) pollution is serious in recent years. To fully understand the causes of PM2.5 in this region, we conducted a long-term tracking (2015–2018) on water-soluble inorganic ions (WSIIs) in PM2.5, including sulfate (SO42−), nitrate (NO3−), ammonium (NH4+), chlorine (Cl−), potassium (K+), calcium (Ca2+), sodium (Na+), and magnesium (Mg2+). Results indicate that each ion has significant seasonal variations, with the maximum concentration in winter and minimum in summer. The secondary inorganic aerosols (SIAs) have remarkably higher concentrations in haze periods than non-haze periods, which indicates that the outbreak of haze is closely related to the massive generation of SIAs. Moreover, each ion shows a different response to the variation of meteorology, implying the different formation mechanisms. Generally, high pollution levels of Ca2+, Mg2+, K+, Cl−, and Na+ are correlated to prevailing winds, suggesting the significant contribution of regional transport. High concentrations of SIAs are usually accompanied by the low temperature (T < 15 °C), high relative humidity (RH > 60%), and calm wind, which means they are mainly locally generated. Under conditions with low T and high RH, more gaseous sulfur and nitrogen tend to be converted into solid inorganic salts, proved by the higher oxidation efficiency. Different to NO3−, SO42− is also easily generated at high T through photochemical oxidization. This study interprets fine particle pollution from the perspective of particle composition, and the results provide an reference for regional air pollution prevention.

Correlations between 7Be, 210Pb, dust and PM10 concentrations in relation to meteorological conditions in northern Poland in 1998–2018

Analysis of a twenty-year (1998–2018) data series on 7Be concentrations in weekly collected aerosol samples in northern Poland showed a clear pattern of seasonal changes in 7Be with a maximum in the summer period associated with the most intensive thermal convection and vertical mixing. Activity concentrations of 7Be ranged from 480 μBq m−3 to 9370 μBq m−3. A strong relationship has been shown between 7Be concentrations observed in years and the activity of the Sun related to the sunspot number. Activity concentrations of 210Pb in aerosol ranged from 17 μBq m−3 to 1490 μBq m-3 with maximum occurring in the winter. The difference in the seasonal pattern in 7Be and 210Pb concentrations were directly related to the different sources of both isotopes, as an additional source of 210Pb was the products of combustion during the heating season. Similar pattern with maximum concentrations in winter was observed for PM10, as the main source is the same as in the case 210Pb. A content of PM10 was in the range from 6.5 to 81.7 μg m−3. A statistically significant correlation between both isotopes occurs. At the same time, 7Be, 210Pb and PM10 are visibly related to the dust concentrations ranged from 7.3 μg m−3 in winter to 134.8 μg m−3 in spring. Statistical analysis carried out with simple regression model, stepwise multiple regression, and Random Forest models showed that the sunspots number, air temperature and sunshine duration have the most substantial impact on transport, and hence the concentration of 7Be in the surface layer of the atmosphere. The increase in relative humidity and precipitation and higher wind speed have a statistically significant effect on the reduction of 7Be concentrations in surface air.

Temporal variability of chlorophyll distribution in the Gulf of Mexico: bio-optical data from profiling floats

Abstract. Chlorophyll concentration is a key oceanic biogeochemical variable. In the Gulf of Mexico (GOM), its distribution, which is mainly obtained from satellite surface observations and scarce in situ experiments, is still poorly understood. In 2011–2012, eight profiling floats equipped with biogeochemical sensors were deployed for the first time in the GOM and generated an unprecedented dataset that significantly increased the number of chlorophyll vertical distribution measurements in the region. The analysis of these data, once calibrated, permits us to reconsider the spatial and temporal variability of the chlorophyll concentration in the water column. At a seasonal scale, results confirm the surface signal seen by satellites, presenting maximum concentrations in winter and low values in summer. It is shown that the deepening of the mixed layer is the primary factor triggering the chlorophyll surface increase in winter. In the GOM, a possible interpretation is that this surface increase corresponds to a biomass increase. However, the present dataset suggests that the basin-scale climatological surface increase in chlorophyll content results from a vertical redistribution of subsurface chlorophyll and/or photoacclimation processes, rather than a net increase of biomass. One plausible explanation for this is the decoupling between the mixed-layer depth and the deep nutrient reservoir since mixed-layer depth only reaches the nitracline in sporadic events in the observations. Float measurements also provide evidence that the depth and the magnitude of the deep chlorophyll maximum is strongly controlled by the mesoscale variability, with higher chlorophyll biomass generally observed in cyclones rather than anticyclones.

Seasonal dynamics of nutrients concentration and dissolved oxygen content in the rivers of southern Primorye

Rivers are the main source of terrigenous nutrients to the coastal sea which could be responsible for such adverse impacts as red tides or hypoxia in the estuarine areas. To evaluate the rivers influence on chemical environments in the coastal zone, monitoring of water properties in the rivers of southern Primorye was conducted in 2016 (and continues till nowadays). Retrospective data of chemical measurements on the Razdolnaya, Artemovka, Knevichanka and Ryazanovka rivers in different seasons of 1985 were used for comparison with modern data. Prominent seasonal dynamics of chemical parameters is revealed that generally corresponds to seasonal changes of freshwater discharge caused by monsoon cycle of precipitations. The seasonal dynamics of water temperature is conditioned by climate features of the region and geographic location of the rivers: the temperature at the surface is about 0 о C in February, then rises in spring-summer and decreases in autumn, with the maximum values in August as 26-27 о С for the flat rivers and 18-20 о С for the mountain rivers. The pH variations are conditioned by the carbon dioxide saturation in water, so its level is 6.1-7.2 in winter and 7.4-8.2 in summer. Nutrients, except iron, have the maximum concentration in winter (DIN ~2.5 µM/L, DIP ~0.5 µM/L, silicates ~115.0 µM/L) but the iron concentration is the highest in spring (~0.1 mg/L). However, natural seasonal variation of nutrients is distorted by anthropogenic load for some rivers with industrial and agricultural activity in the basins, including the territories of P.R. China (Suifen/Razdolnaya River): their waters are the richest by nitrogen and phosphorus in summer (DIN ~45.0 µM/L, DIP ~0.5 µM/L) and by dissolved iron in autumn-winter (~0.9-1.3 mg/L). Spatial variability is very similar between all nutrients in any season (correlation coefficients between DIN and Fe concentrations are 0.75-0.99, between DIP and Fe - 0.83-0.99) that means that their growth in the polluted rivers has common nature, presumably a decomposition of organic wastes Being transferred. Transferred to the sea, the nutrient elements of terrestrial origin are converted back to organic matter enhancing the coastal waters productivity, but consequences of this impact are principally different for the natural regime with the winter-spring maximum and for the distorted regime with the summer-fall maximum. Huge oxygen demand determines the lowered DO in the Suyfen/Razdolnaya and Knevichanka in winter. Other rivers of southern Primorye (Ryazanovka, Barabashevka, Kievka, Partizanskaya, Sokolovka, Artemovka) could be considered as «clean» ones, following to Russian standards of water quality. Seasonal variability of oxygen content in their waters is driven by changes of water temperature and photosynthesis. Comparison of the long-term changes in water quality for the rivers Razdolnaya, Artemovka, Knevichanka and Ryazanovka over the last 30 years (relative to 1985) has revealed unfavorable changes of dissolved oxygen content for the Razdolnaya and Knevichanka, whereas the changes are not significant for the Artemovka and the oxygen content has increased for the Ryazanovka. The latter indicates the Ryazanovka water quality improvement that is important since a fish farm is located on the river.

STUDY OF RADON AND THORON CONCENTRATION IN ENVIRONMENT OF MORADABAD DISTRICT OF UTTAR PRADESH, INDIA

Purpose: A study of indoor radon and thoron has been carried out in the dwelling of Moradabad, Uttar Pradesh, India. Radon is an invisible radioactive gas that occurs naturally in the indoor atmosphere. It comes from the natural breakdown of uranium in soils and rocks. Lung cancer risk depends upon the concentration of radon, thoron and their decay product in the air.&#x0D; Methodology: The measurements of radon and thoron concentration were carried out by using LR-115 type II plastic track detectors (SSNTD Technique). &#x0D; Findings: In the present study the value of radon concentration from10.5 Bq/m3to 30Bq/m3 with an average19.9Bq/m3and thoron concentration from 5.6 Bq/m3 to 24 Bq/m3 with an average of 14.9 Bq/m3. It is observed that radon and thoron concentration is maximum in winter and minimum during summer. The maximum concentration in winter is essentially influenced by the intense temperature inversion, which occurs in the winter season when the wind velocity is low.&#x0D; The maximum concentration in winter is also the result of decreased ventilation because in this season the houses are closed for a long time and radon/thoron accumulated inside the room and a weak positive correlation was observed between radon and thoron.&#x0D; Social Implications: There are some difficulties in assessing the exact risks of radon in the home. Most studies have used data from miners who will have had far more exposure to radon than is likely in any building.&#x0D; Originality/ Novelty: This study is done at Moradabad City and Research Lab present in S.S.P. G. College Shajhanapur. Data of radon and thoron concentration has been taken from twin cup radon-thoron Dosimeter and Spark Counter.

Quantifying importance and scaling effects of atmospheric deposition of inorganic fixed nitrogen for the eutrophic Black Sea

Abstract. Wet atmospheric depositions have been collected in a rural (Katsiveli) and urban (Sevastopol) location at the Crimean coast of the Black Sea from 2003 to 2008. Samples, 217 from Katsiveli and 228 from Sevastopol, have been analysed for inorganic fixed nitrogen (nitrate, nitrite, and ammonium). Data have revealed almost equal contributions of ammonium (44–45 %) and nitrate (52–53 %) and minor contribution of nitrite (2–4 %) for both rural and urban samples. The volume weight mean concentration of inorganic fixed nitrogen (IFN) in urban samples (2.51 mg N L−1) is about 2-fold of that content in rural samples (1.16 mg N L−1). Seasonal variations in volume weight mean monthly concentrations have been revealed for both locations with maximum concentrations in winter and minimum values in summer, but intra-annual variations are statistically significant for only urban samples. The average annual deposition of IFN with atmospheric precipitations on the surface of the Black Sea is about 0.31 × 106 t N yr−1 (0.75 t N km−2 yr−1), which is on average 39 % of the riverine input. It does vary in space and time. The relative importance of the atmospheric input increases from coastal to open areas and from winter to summer. Deposition of IFN with wet atmospheric precipitations proportionally increases the concentration of chlorophyll a, as it is traced from satellite data. The traced increase in the concentration of chlorophyll a has reached 1.5-fold for mesoscale processes. In case of individual rain events supporting up to 50–60 mg N m−2, the influence of IFN deposition is up to 5 % at the north-western shelf of the Black Sea, where most of the river-born IFN is loaded. In the central areas of the sea, where the amount of IFN in summer is low, the contribution of individual rainfall can reach 35 %. The input of IFN to the Black Sea has potential to enhance 2-fold the level of primary production.

Long term climatology of particulate matter and associated microphysical and optical properties over Dibrugarh, North-East India and inter-comparison with SPRINTARS simulations

The long term climatology of PM10 and PM2.5 concentrations for the five year period from June 2007–March 2012 is studied using measurements made with a Quartz Crystal Microbalance Impactor over Dibrugarh, North-East India. The PM10 and PM2.5 exhibit similar seasonal variability with maximum concentration in winter and minimum in monsoon seasons. The PM10 concentration is mainly attributed to PM2.5 with minimal contribution from PM10–2.5. The long term monthly mean PM10 and PM2.5 concentrations shows maximum value in late winter and early pre-monsoon. This temporal variability is positively correlated with the MODIS retrieved fire counts associated mostly with the biomass burning activities and negatively correlated with rainfall. PM10 and PM2.5 gradually increased from 2007 to 2010 and decreased thereafter. An overall slow decreasing trend in PM10 and PM2.5 concentrations together with black carbon (BC) concentrations has been observed. The examination of microphysical and optical properties also reveals the dominance of PM2.5 aerosols. Higher percentage contributions of BC to both PM10 and PM2.5 are observed in post-monsoon season followed by winter. The inter-comparison of measured PM and BC concentrations with SPRINTARS simulation reveals that model underestimates the measurements except in pre-monsoon. The discrepancy might have arisen due to the topography of the location and inadequate emission inventory for the climate zone.

Seasonal Variation of Cistus ladanifer L. Diterpenes.

The exudate of Cistus ladanifer L. consists mainly of two families of secondary metabolites: flavonoids and diterpenes. The amount of flavonoids present in the leaves has a marked seasonal variation, being maximum in summer and minimum in winter. In the present study, we demonstrate that the amount of diterpenes varies seasonally, but with a different pattern: maximum concentration in winter and minimum in spring-summer. The experiments under controlled conditions have shown that temperature influences diterpene production, and in particular, low temperatures. Given this pattern, the functions that these compounds perform in C. ladanifer are probably different.

Comparison of BTX Profiles and Their Mutagenicity Assessment at Two Sites of Agra, India

In the present study, the concentrations of three volatile organic compounds (VOCs), namely, acronym for benzene, toluene, and xylenes (BTX) were assessed because of their role in the tropospheric chemistry. Two representative sites, a roadside and a petrol pump, were chosen for sample collection. VOCs were collected using SKC-activated charcoal tubes and SKC personal sampler and characterized by gas chromatograph using flame ionization detector. Among BTX, benzene had the highest concentration. At the roadside, mean concentration of benzene, toluene, o-,m-xylene, and p-xylene were 14.7 ± 2.4 μgm−3, 8.1 ± 1.2 μgm−3, 2.1 ± 0.8 μgm−3, and 5.1 ± 1.2 μgm−3, respectively. At the petrol pump, the mean concentrations of benzene, toluene, o-,m-xylene and p-xylene were 19.5 ± 3.7 μgm−3, 12.9 ± 1.1 μgm−3, 3.6 ± 0.5 μgm−3 and 11.1 ± 1.5 μgm−3, respectively, and were numerically higher by a fraction of 2. Monthly variation of BTX showed maximum concentration in winter. Inter-species ratios and inter-species correlation indicated traffic as the major source of BTX. Extracts of samples were positive in both Salmonella typhimurium tester strains TA98 and TA100 without metabolic activation suggesting the presence of direct mutagens in ambient air that can cause both frame-shift and base-pair mutation. The mutagenic response was greater for TA100 than TA98 suggesting greater activity for base-pair mutagenicity than frame-shift mutagenicity and was found to be statistically significant.

Spatial and temporal changes in non-structural carbohydrate reserves in eelgrass (Zostera marina L.) in Danish coastal waters

Abstract The spatial and seasonal changes of total non-structural carbohydrate (TNC) reserves in above- and belowground tissues in eelgrass (Zostera marina) were assessed at four different sampling sites in Danish waters. The study consisted of annual field sampling, where sites differed in water depth and nutrient content in sediments. The TNC concentrations varied considerably in all tissues, and rhizomes generally represented the major storage organ. Sucrose was the main sugar contributing to TNC whilst starch represented the minor (&lt;15%) reserves. Trehalose, which is reported in Z. marina here for the first time, due to the use of a recently developed HPLC method, was found in low concentrations (up to ∼2%) and showed a reverse seasonal variation compared to other sugars, with maximum concentrations in winter. Plants growing near depth limits (5.5 m) had significantly higher reserves, whereas no significant effect of sediment nutrient contents on the TNC concentrations was observed, reflecting the ability of Z. marina to tolerate a range of different growth conditions.

Seasonal variability of total and easily leachable element contents in topsoils (0–5 cm) from eight catchments in the European Arctic (Finland, Norway and Russia)

Frozen topsoil samples (0–5 cm) were collected during March/April 1994 in eight Arctic catchments in northern Europe (4 in Russia, 3 in Finland, 1 in Norway) at varying distances and wind directions from the emissions of the Russian nickel ore mining, roasting and smelting industry on the Kola Peninsula. Between 14 and 25 sites were sampled in catchment basins ranging in size from 12 to 35 km 2. Sampling was repeated in spring immediately after the snow melted, in summer and in autumn to study seasonal variability and the fate of elements when the snow melts. The <2 mm fraction of air-dried topsoils was analysed for total (aqua regia extraction) and easily leachable (in 1 m ammonium acetate, buffered at pH 4.5) element concentrations using ICP-AES and GFAAS for up to 35 elements. Results for selected elements are presented here. Soil organic matter can be shown to be the controlling factor determining element contents and fate. In catchments close to the Russian nickel industry, the topsoils have low carbon and nitrogen contents. Using both extraction methods most elements reach maximum concentrations in winter; lowest concentrations are observed in midsummer. Soil organic matter and elements associated with it are thus leached out of the soils together with soluble elements when the snow melts. This process continues in summer. Elements will enrich surface waters, the lower layers of podzol profiles, or reach the groundwater. The use of the two extractions described provides a simple method to study the mobilities and pathways of elements in the topsoils during the arctic year. Using the proportions of easily leachable to total concentration, a good estimation of the status of the topsoil in the study area can be given.

Seasonal variation of atmospheric nonmethane hydrocarbons on the western coast of Brittany, France

Continuous measurements of NMHCs were made at the TOR station of Porspoder, located in western Brittany (France), on the Atlantic shore. Twelve samples per day have been performed since February 1992. Four-day spanned, three-dimensional back-trajectories reaching 913 mbar at Porspoder site at 0 and 12 h, have been used to differentiate the air parcels according to their origin and directions. The outcome of this analysis shows that such air parcels can fall within five classes: continental air masses, North Sea air masses, England air masses, stagnant oceanic air masses and oceanic air masses. The general trend of the seasonal variation shows a maximum concentration in winter and a minimum in summer, regardless of the air mass origin. The low concentrations are obtained when the site is influenced by oceanic air masses. With few exceptions, the composition of the four other classes are similar and largely have higher concentrations than the previous class. A variation of the winter-summer ratio, as a function of the rate constants of reaction of light hydrocarbons with hydroxyl radicals, shows that, in the case of continental air masses, hydroxyl chemistry is the main process involved which removes hydrocarbons in the troposphere, and in the case of oceanic air masses, a signature of previous continental passages was observed when air masses were sampled at Porspoder. Other oxidation pathways in addition to reaction with hydroxyl chemistry and NO3 radical are suspected for the branched-chain alkanes.

Variations of tropospheric ozone concentration over Syowa Station, Antarctica

Aircraft measurements of the tropospheric O 3 concentration were made over Syowa Station (69°00′S, 39°35′E), Antarctica from May 1989 to January 1990, except during the polar night months of June and July. The O 3 concentration increased with height for the whole period of the measurements. Lower tropospheric O 3 showed a prominent seasonal variation with maximum concentration in winter and minimum concentration in summer, which is very close to the result of continuous O 3 measurements initiated at Syowa Station in February 1988. In the upper troposphere, the concentration reached high values in winter, decreased gradually until late spring and then increased again. As a result, the height-dependent difference of the concentration was reduced from late autumn to early spring and enhanced in remaining seasons of the year. The seasonal variation of upper tropospheric O 3 was similar to those of the lower stratospheric O 3 concentration measured by ozonesondes and the total amount of O 3 by a Dobson spectrophotometer over Syowa Station. Inspection of TOMS (Total Ozone Mapping Spectrometer) data also suggested that the temporal variations of the upper tropospheric O 3 measured in this study are closely related to those of the lower stratospheric O 3 over Syowa Station. Comparison of the results of surface O 3 measurements in the southern hemisphere showed that the concentration increase going southward, and appearance of the minimum concentration of the seasonal variation is delayed by almost 1 month at the South Pole compared to Syowa Station and Cape Grim, Tasmania. Taking into account these results, it is suggested that the intrusion of stratospheric O 3 into the troposphere occurs over Syowa Station throughout the year, and that air with low O 3 concentrations is transported from subpolar or middle latitudes to the station through the lower troposphere from spring to early autumn, in addition to the photochemical destruction of O 3 near the station. DOI: 10.1034/j.1600-0889.1992.t01-3-00004.x

Fluctuations of element concentrations during the growing season of Polytrichum formosum (Hedw.)

Fourteen elements (Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Ni, Pb, Sr, Ti, and Zn) were quantitatively determined by AES/ICP in aboveground parts of the endohydric moss Polytrichum formosum (Hedw.) after sampling over regular intervals from 1985 to 1987. With the exception of K, Mg, and Zn all elements showed a large continuous fluctuation (> 30%) during the growing season. Four different patterns of seasonal variation were found: (1) large seasonal variations of element concentrations (∼80%) with maximum concentrations in winter and lowest concentrations in the summer months (Al, Fe, Cr, Mg, Pb, and Ti), (2) smaller seasonal variations (∼50%) with maximum concentrations in winter and lowest concentrations in summer (Ba, Ca, Cd, Cu, Sr), (3) slight seasonal variations (∼30%) with maximum concentrations in the summer (K), and (4) slight seasonal changes (∼30%) with maximum concentrations in the winter (Mg and Zn). The relative biological variance of element concentrations between 9 different stands of Polytrichum formosum decreases in the following sequence: Ti, Al, Pb, Fe, Cr, Ni, Ba, Ca, Cu, Cd, K, Mg, Sr, Zn. The relative biological variance of individual elements is generally lower than the variance in element concentrations caused by seasonal changes. Because of its high biological variance for most elements investigated (seasonal as well as between different stands of Polytrichum formosum) this moss should only be used as a passive bioindicator, if all other environmental parameters are standardized.