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 addiscatterPlot.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. See openair.generics for
further details.
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