Pollution modelling with openair



Overview

The R openair package provides functions to import pre-calculated back trajectories using the NOAA HYSPLIT model. The trajectories have been calculated for a select range of locations which will expand over time. Data is available covering the last 20 years for some sites.

Rotterdam, 2013 Trajectory

traject3 <- importTraj(site = "rotterdam", year = 2013)
trajPlot(selectByDate(traject3, start = "01/07/2013", end = "11/07/2013"), 
  method = "density", col = "increment", xlim = c(-40, 20))
## (loaded the KernSmooth namespace)

London, 2013 Trajectory

trajectory <- importTraj(site = "london", year = 2013)
trajPlot(selectByDate(trajectory, start = "01/09/2013", end = "11/09/2013"), 
  method = "density", col = "increment", xlim = c(-40, 20))

trajPlot(selectByDate(trajectory, start = "01/08/2013", end = "10/08/2013"), 
  method = "density", col = "increment", xlim = c(-40, 20))

Data are also available for other sites, including oslo, wuhan china, sao paulo, etc but the length of timeseries vary. Data is available for London for over 20 years, but for others only a couple of years data is available.

The importTraj() function imports pre-calculated back trajectories using the HYSPLIT trajectory model (Hybrid Single Particle Lagrangian Integrated Trajectory Model http://ready.arl.noaa.gov/HYSPLIT.php). Back trajectories provide some very useful information for air quality data analysis.

Trajectories are run at 3-hour intervals and stored in annual, yearly files.

The data can be examined using the head method in R, or alternatively using the kable method. 

head(trajectory)
##   receptor year month day hour hour.inc    lat    lon height pressure
## 1        1 2013     1   1    0        0 51.500 -0.100   10.0    986.3
## 2        1 2012    12  31   23       -1 51.557 -0.607   10.1    985.9
## 3        1 2012    12  31   22       -2 51.581 -1.105   10.1    985.6
## 4        1 2012    12  31   21       -3 51.573 -1.592   10.0    985.3
## 5        1 2012    12  31   20       -4 51.532 -2.068    9.7    984.9
## 6        1 2012    12  31   19       -5 51.458 -2.536    9.3    984.6
##                 date2       date
## 1 2013-01-01 00:00:00 2013-01-01
## 2 2012-12-31 23:00:00 2013-01-01
## 3 2012-12-31 22:00:00 2013-01-01
## 4 2012-12-31 21:00:00 2013-01-01
## 5 2012-12-31 20:00:00 2013-01-01
## 6 2012-12-31 19:00:00 2013-01-01


Alan
CTO Tendron Systems Ltd

References

The openair package is available via CRAN
https://cran.r-project.org/web/packages/openair/README.html

The NOAA Hysplit model is described here NOAA HYSPLIT http://ready.arl.noaa.gov/HYSPLIT.php