calcFno2(input, tau = 60, user.fno2, main = "", xlab = "year", ...)nox
andno2 (roadside NOX and NO2 concentrations), back_nox,
back_no2 and back_o3 (hourly background concentrations of
each pollutant). In addition scatterPlot.calcFno2 also returns
an object of class ``openair''. The object includes three main
components: call, the command used to generate the plot;
data, the data frame of summarised information used to make the
plot; and plot, the plot itself. If retained, e.g. using
output <- calcFno2(...), this output can be used to recover the
data, reproduce or rework the original plot or undertake further
analysis.An openair output can be manipulated using a number of generic operations,
including print, plot and summary.
linearRelation
for details of how to estimate the primary NO2 fraction.In the absence of roadside O3 measurements, it is rather more problematic
to calculate the fraction of primary NO2. Carslaw and Beevers (2005c)
developed an approach based on linearRelation the analysis of
roadside and background measurements. The increment in roadside NO2
concentrations is primarily determined by direct emissions of NO2 and the
availability of One to react with NO to form NO2. The method aims to
quantify the amount of NO2 formed through these two processes by seeking
the optimum level of primary NO2 that gives the least error.
Test data is provided at
Carslaw, D.C. and N Carslaw (2007). Detecting and characterising small changes in urban nitrogen dioxide concentrations. Atmospheric Environment. Vol. 41, 4723-4733.
Carslaw, D.C., Beevers, S.D. and M.C. Bell (2007). Risks of exceeding the hourly EU limit value for nitrogen dioxide resulting from increased road transport emissions of primary nitrogen dioxide. Atmospheric Environment 41 2073-2082.
Carslaw, D.C. (2005a). Evidence of an increasing NO2/NOX emissions ratio from road traffic emissions. Atmospheric Environment, 39(26) 4793-4802.
Carslaw, D.C. and Beevers, S.D. (2005b). Development of an urban inventory for road transport emissions of NO2 and comparison with estimates derived from ambient measurements. Atmospheric Environment, (39): 2049-2059.
Carslaw, D.C. and Beevers, S.D. (2005c). Estimations of road vehicle primary NO2 exhaust emission fractions using monitoring data in London. Atmospheric Environment, 39(1): 167-177.
Carslaw, D. C. and S. D. Beevers (2004). Investigating the Potential Importance of Primary NO2 Emissions in a Street Canyon. Atmospheric Environment 38(22): 3585-3594.
Carslaw, D. C. and S. D. Beevers (2004). New Directions: Should road vehicle emissions legislation consider primary NO2? Atmospheric Environment 38(8): 1233-1234.
linearRelation if you have roadside ozone
measurements.## Users should see the full openair manual for examples of how
## to use this function.Run the code above in your browser using DataLab