Variability Of Nitrogen Dioxide Research Articles

Combined Effect of High-Resolution Land Cover and Grid Resolution on Surface NO2 Concentrations

High-resolution air quality simulations are often performed using different nested domains and resolutions. In this study, the variability of nitrogen dioxide (NO2) concentrations estimated from two nested domains focused on Portugal (D2 and D3), with 5 and 1 km horizontal grid resolutions, respectively, was investigated by applying the WRF-Chem model for the year 2015. The main goal and innovative aspect of this study is the simulation of a whole year with high resolutions to analyse the spatial variability under the simulation grids in conjunction with detailed land cover (LC) data specifically processed for these high-resolution domains. The model evaluation was focused on Portuguese air quality monitoring stations taking into consideration the station typology. As main results, it should be noted that (i) D3 urban LC categories enhanced pollution hotspots; (ii) generally, modelled NO2 was underestimated, except for rural stations; (iii) differences between D2 and D3 estimates were small; (iv) higher resolution did not impact model performance; and (v) hourly D2 estimates presented an acceptable quality level for policy support. These modelled values are based on a detailed LC classification (100 m horizontal resolution) and coarse spatial resolution (approximately 10 km) emission inventory, the latter suitable for portraying background air pollution problems. Thus, if the goal is to characterise urban/local-scale pollution patterns, the use of high grid resolution could be advantageous, as long as the input data are properly represented.

Spatial variability of nitrogen dioxide and formaldehyde and residential exposure of children in the industrial area of Viadana, Northern Italy

Chipboard production is a source of ambient air pollution. We assessed the spatial variability of outdoor pollutants and residential exposure of children living in proximity to the largest chipboard industry in Italy and evaluated the reliability of exposure estimates obtained from a number of available models. We obtained passive sampling data on NO2 and formaldehyde collected by the Environmental Protection Agency of Lombardy region at 25 sites in the municipality of Viadana during 10 weeks (2017–2018) and compared NO2 measurements with average weekly concentrations from continuous monitors. We compared interpolated NO2 and formaldehyde surfaces with previous maps for 2010. We assessed the relationship between residential proximity to the industry and pollutant exposures assigned using these maps, as well as other available countrywide/continental models based on routine data on NO2, PM10, and PM2.5. The correlation between NO2 concentrations from continuous and passive sampling was high (Pearson’s r = 0.89), although passive sampling underestimated NO2 especially during winter. For both 2010 and 2017–2018, we observed higher NO2 and formaldehyde concentrations in the south of Viadana, with hot-spots in proximity to the industry. PM10 and PM2.5 exposures were higher for children at < 1 km compared to the children living at > 3.5 km to the industry, whereas NO2 exposure was higher at 1–1.7 km to the industry. Road and population densities were also higher close to the industry. Findings from a variety of exposure models suggest that children living in proximity to the chipboard industry in Viadana are more exposed to air pollution and that exposure gradients are relatively stable over time.

A land use regression model for ambient nitrogen dioxide concentration nearby a commercial airport for low-cost flights (Rome-Ciampino)

Background: Several studies suggest that airport emissions could worse air quality in theneighbourhoods. Aims: To evaluate the spatial variability of nitrogen dioxide (NO2) concentrations in relati...

Short‐term variability of nitrogen dioxide in the winter stratosphere

Measurements of limb radiance from the Solar Mesosphere Explorer (SME) satellite are used to infer the NO2 density at the 10‐ and 16‐mbar pressure levels from January 1 to March 31 of 1982. A photochemical‐dynamical model is developed using the presently accepted chemistry of the NOx family. The dynamical model produces isentropic trajectories which simulate the history of air parcels. From the trajectories the photochemical model calculates NO2 densities, which are compared to those observed by SME. Although the model generally reproduces the spatial and temporal variations rather well, some disagreement was noted for conditions of exceptionally low temperatures. Further analysis indicates that the temperature sensitivity of the N2O5 photolysis cross sections may be overestimated at low temperatures.

Stratospheric Nitrogen Dioxide in the Vicinity of Soufriere, St. Vincent

In April 1979, measurements of nitrogen dioxide in the upper atmosphere were made near Soufriere Volcano by twilight optical-absorption techniques. The derived value of 5 x 10(15) molecules per square centimeter column implies an enhancement of 25 percent over earlier abundances measured in the same latitudinal regions. This enhancement may represent the normal stratospheric variability of nitrogen dioxide in the equatorial region but in any case may be considered an upper limit to the volcano's effect on the total nitrogen dioxide abundance.