Nitrogen oxides and ozone in Portugal: trends and ozone estimation in an urban and a rural site

Fernández‐Guisuraga, José Manuel; Castro, Amaya; Alves, Célia; Calvo, Ana; Alonso‐Blanco, Elisabeth; Blanco-Alegre, C.; Fraile, Roberto

doi:10.1007/s11356-016-6888-6

Cited by 19 publications

(18 citation statements)

References 24 publications

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“…Of the seasons, the highest O 3 concentrations in the sites with three kinds of urban forest in Yuanshan Forest Park were observed in summer (Figure 3), in agreement with the results of most previous studies conducted in urban, rural, and forest areas [54][55][56][57][58], and in compliance with the seasonal variation of O 3 levels in Joshua Tree National Park, (Californiam, USA) [59], as well as with the seasonal variation under tree canopies in the urban area of Siena, Italy [37]. This finding can be attributed primarily to the high BVOC levels observed in this period, especially during daytime, when tree activity and the intensity of photochemical reactions are at a maximum [60,61].…”

Section: Seasonal Variation Of O 3 Levelssupporting

confidence: 90%

Spatiotemporal Ozone Level Variation in Urban Forests in Shenzhen, China

Duan

Wang

Pei

et al. 2019

Forests

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This study is among the first to investigate ozone levels in urban forests in China. It establishes that urban forest air quality in Yuanshan Forest Park (Shenzhen) is suitable for recreational activities and identifies spatial, seasonal, and diurnal O3 patterns and relationships with micrometeorological parameters, suggesting the possibility of manipulating relevant forest characteristics to reduce Surface ozone (O3) levels. An understanding of O3 levels of urban forest environments is needed to assess potential effects on human health and recreational activities. Such studies in China are scarce. This study investigated urban forest O3 levels to improve understanding and support residents engaging in forest recreational activities. We monitored O3 levels in 2015–2016 for three urban forests representing common habitats (foothill, valley, and ridge) in Yuanshan Forest Park and for an adjacent square. The overall mean daily and daily maximum 8 h mean (MDA8) O3 concentrations were highest for the ridge forest and lowest for the valley forest. Each forest’s O3 concentrations were highest in summer. Diurnally, forest O3 concentrations peaked between 13:00 and 17:00 and reached a minimum between 03:00 and 09:00. The correlation between forest O3 concentrations and air temperature (AT) was strongly positive in summer and autumn but negative in spring. In each season, O3 concentration was negatively correlated with relative humidity (RH). No MDA8 or hourly O3 concentrations in the forests exceeded National Ambient Air Quality Standard Grade I thresholds (100 and 160 μg m−3, respectively). O3 accumulation is present in ridge urban forest in all seasons. Foothill and valley urban forests have better air quality than ridge forestation. Urban forest air quality is better in spring and autumn than in summer and is better from night-time to early morning than from noon to afternoon.

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Section: Seasonal Variation Of O 3 Levelssupporting

confidence: 90%

Spatiotemporal Ozone Level Variation in Urban Forests in Shenzhen, China

Duan

Wang

Pei

et al. 2019

Forests

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“…Of the seasons, the highest O3 concentrations in the sites with three kinds of urban forest in Yuanshan Forest Park were observed in summer (Figure 3), in agreement with the results of most previous studies conducted in urban, rural, and forest areas [54][55][56][57][58], and in compliance with the seasonal variation of O3 levels in Joshua Tree National Park, USA [59], as well as with the seasonal variation under tree canopies in the urban area of Siena, Italy [60]. This finding can be attributed primarily to the high BVOC levels observed in this period, especially during daytime, when tree activity and the intensity of photochemical reactions are at a maximum [61][62].…”

Section: Seasonal Variation Of O3 Levelssupporting

confidence: 90%

Spatiotemporal Ozone Level Variation in Urban Forests in Shenzhen, China

Duan¹,

Wang²,

Pei³

et al. 2019

Preprint

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Research Highlights: This study is among the first to investigate ozone levels in urban forests in China. It establishes that urban forest air quality in Yuanshan Forest Park, Shenzhen, is suitable for recreational activities and identifies spatial, seasonal, and diurnal O3 patterns and relationships with micrometeorological parameters, suggesting the possibility of manipulating relevant forest characteristics to reduce O3 levels. Background and Objectives: An understanding of O3 levels of urban forest environments is needed to assess potential effects on human health and recreational activities. Such studies in China are scarce. This study investigated urban forest O3 levels to improve understanding and support residents engaging in forest recreational activities. Materials and Methods: We monitored O3 levels in 2015–2016 for three urban forests representing common habitats (foothill, valley, and ridge) in Yuanshan Forest Park, Shenzhen, and for an adjacent square. Results: The overall mean daily and daily maximum 8-h mean (MDA8) O3 concentrations were highest for the ridge forest and lowest for the valley forest. Each forest’s O3 concentrations were highest in summer. Diurnally, forest O3 concentrations peaked between 13:00 and 17:00 and reached a minimum between 03:00 and 09:00. The correlation between forest O3 concentrations and air temperature (AT) was strongly positive in summer and autumn but negative in spring. In each season, O3 concentration was negatively correlated with relative humidity (RH). No MDA8 or hourly O3 concentrations in the forests exceeded National Ambient Air Quality Standard Grade I thresholds (100 and 160 μg m−3, respectively). Conclusions: O3 accumulation is present in ridge urban forest in all seasons. Foothill and valley urban forests have better air quality than ridge forestation. Urban forest air quality is better in spring and autumn than in summer and is better from night-time to early morning than from noon to afternoon.

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“…NO 2 can then be formed through the oxidation of NO in the atmosphere. It follows that the NO 2 to NO x ratio can provide a measure of the oxidative capacity of the atmosphere (Rao and George, 2014;Fernández-Guisuraga et al, 2016) and it is a measure of the temporal proximity to emission sources. In addition, measurements performed in Milan during different field experiments show that the ratio of NO 2 to NO x anti-correlates with the ratio of black carbon to PM 1 , suggesting that the NO 2 / NO x in these urban areas is an indicator for secondary pollutant formation relative to primary traffic emissions.…”

Section: Primary Pollutants Influencementioning

confidence: 99%

On the functional form of particle number size distributions: influence of particle source and meteorological variables

et al. 2018

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Abstract. Particle number size distributions (PNSDs) have been collected periodically in the urban area of Milan, Italy, during 2011 and 2012 in winter and summer months. Moreover, comparable PNSD measurements were carried out in the rural mountain site of Oga-San Colombano (2250 m a.s.l.), Italy, during February 2005 and August 2011. The aerosol data have been measured through the use of optical particle counters in the size range 0.3-25 µm, with a time resolution of 1 min. The comparison of the PNSDs collected in the two sites has been done in terms of total number concentration, showing higher numbers in Milan (often exceeding 10 3 cm −3 in winter season) compared to Oga-San Colombano (not greater than 2×10 2 cm −3 ), as expected. The skewness-kurtosis plane has been used in order to provide a synoptic view, and select the best distribution family describing the empirical PNSD pattern. The four-parameter Johnson system-bounded distribution (called Johnson SB or JSB) has been tested for this aim, due to its great flexibility and ability to assume different shapes. The PNSD pattern has been found to be generally invariant under site and season changes. Nevertheless, several PNSDs belonging to the Milan winter season (generally more than 30 %) clearly deviate from the standard empirical pattern. The seasonal increase in the concentration of primary aerosols due to combustion processes in winter and the influence of weather variables throughout the year, such as precipitation and wind speed, could be considered plausible explanations of PNSD dynamics.

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Nitrogen oxides and ozone in Portugal: trends and ozone estimation in an urban and a rural site

Cited by 19 publications

References 24 publications

Spatiotemporal Ozone Level Variation in Urban Forests in Shenzhen, China

Spatiotemporal Ozone Level Variation in Urban Forests in Shenzhen, China

Spatiotemporal Ozone Level Variation in Urban Forests in Shenzhen, China

On the functional form of particle number size distributions: influence of particle source and meteorological variables

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