Daily, seasonal and monthly variations in ozone levels recorded at the Turia river basin in Valencia (Eastern Spain)

Abstract

Results show a different behaviour of the monthly means and the daily cycles depending on the season of the year and the measuring environment, with summer/winter ratios ranging from 2.4 in cities to 1.6 inland, and mean values always higher in the interior of the basin. Daily cycles show significant summer/winter differences related to the predominant situations of anticyclonic stability in winter, which limit ventilation, and the predominant breeze circulations in summer. Results also show a "weekend effect" at urban and medium-distance stations. At the most inland station, the weekend/weekday behaviour differs according to the season of the year; weekend ozone levels are higher in spring, autumn and winter, and lower in summer, coinciding with the predominance of local wind cycles that favour air mass penetration inland from the coast.

Investigating the background and local contribution of the oxidants in London and Bangkok

“…26 In addition to local sources, ozone precursors (NO x , volatile organic compounds (VOCs)) can also be transported over long distances from the source and cause ozone formation in the downwind locations. 27 The balance between local and long-range transport effects are assumed to depend strongly on regional meteorological and geographical differences. The representation of chemistry and accurate ozone precursor emission inventories in the model is very important to reproduce O 3 globally and regionally.…”

Prediction of hourly ozone concentrations with multiple regression and multilayer perceptron models

“…They studied different time windows and obtained daily predictions with accuracy and robustness. Castell-Balaguer et al [15] applied descriptive methods to analyze the seasonal variations of O 3 in the Turia river basin, including two of these urban sites. They concluded that the average daily and monthly dynamics had summer/winter differences, depending on the location.…”

“…Table 1 gives the characteristics of these sites. The Mediterranean Centre for Environmental Studies Foundation applied quality control methods to the data set used in this work [16]. The report [17] assessed air pollution health impacts in Valencia.…”

“…Daily and weekly seasonalities are included as predictors, in the form of sine and cosine components. These seasonalities were descriptively analyzed by [15] Table 3 gives the number of hourly observations used in analysis, for the three prediction intervals.…”

Circulation‐type classification derived on a climatic basis to study air quality dynamics over the Iberian Peninsula

“…Ganor et al () relate the occurrence of mineral dust outbreaks in the Eastern Mediterranean to the presence of thermal low‐pressure areas over Maghreb. In the Iberian Peninsula ( IP ) under anticyclonic conditions, mesoscale phenomena control O 3 during summer along the Spanish Mediterranean coast (Millán et al , ; Barros et al , ; Gonçalves et al , ; Castell‐Balaguer et al , ). In summer, under a blocking anticyclone over Central Europe, there is a net transport of O 3 and precursors towards NW Spain that increases surface O 3 concentration (Saavedra et al , ).…”