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AQEval Example data

Source: R/AQEval.data.R
AQEval.data.Rd

Data packaged with AQEval for use with example code.

Usage

aq.data

Format

(26280x6) 'tbl_df' objects

date

Time-series of POSIX class date and time records.

no2

Time-series of nitrogen dioxide measurements from local site.

bg.no2

Time-series of nitrogen dioxide measurements from nearby background site.

ws

Time-series of local wind speed measurements.

wd

Time-series of local wind direction measurements.

air_temp

Time-series of local air temperature measurements.

Source

Air quality and meteorological data packaged for use with AQEval Examples.

Time-series sources:

  • date Date-and-time-stamp of POSIX class (DateTimeClasses).

  • no2 Nitrogen dioxide downloaded from King's College London Archive using importKCL function in openair.

  • bg.no2 Nitrogen dioxide downloaded from the Automatic Urban and Rural Network Archive using importAURN function in openair.

  • ws, wd, air_temp Wind speed, wind direction and air temperature downloaded from NOAA's Integrated Surface Database using importNOAA function in worldmet.

Details

Most of functions in AQEval adopt the openair convention of assuming supplied data is a single data.frame or similar. The data frame was initially adopted for two reasons:

  • Firstly, air quality data collected and archived in numerous formats and keeping the import requirements simple minimises the frustrations associated with data importation.

  • Secondly, restricting the user to work with a single data format greatly simplifies data management for those less familiar with programming environments.

As part of this work several openair coding conventions were adopted, most importantly that data sets should include a column named date of POSIX class data-and-time-stamps (DateTimeClasses). This and other conventions, such as the use of ws and wd for numeric wind speed and direction data-series, and site and code for character or factor monitoring site name and identifier code, are now commonplace for many working with R in the air quality research community, and many air quality archives provide data in (or support import functions that convert their own data structures to) this openair-friendly structure.

References

Regarding openair and openair-friendly data structuring, see:

Carslaw, D. C. and K. Ropkins (2012), openair --- an R package for air quality data analysis. Environmental Modelling & Software. Volume 27-28, 52-61, DOI doi:10.1016/j.envsoft.2011.09.008

Ropkins, K. and D.C. Carslaw (2012), openair-Data Analysis Tools for the Air Quality Community. R Journal, 4(1). URL https://journal.r-project.org/archive/2012/RJ-2012-003/RJ-2012-003.pdf

Regarding worldmet, see:

David Carslaw (2021), worldmet: Import Surface Meteorological Data from NOAA Integrated Surface Database (ISD). R package version 0.9.5. URL https://CRAN.R-project.org/package=worldmet

See also

DateTimeClasses

openair: functions importAURN and importKCL

worldmet: function importNOAA (See References)

Examples

#data set used in AQEval Examples
dim(aq.data)
#> [1] 26280     6
head(aq.data)
#> # A tibble: 6 × 6
#>   date                  no2 bg.no2    ws    wd air_temp
#>   <dttm>              <dbl>  <dbl> <dbl> <dbl>    <dbl>
#> 1 2001-01-01 00:00:00  5.77     NA  8.5   170      5.55
#> 2 2001-01-01 01:00:00  6.50     NA  6.95  170      6.5 
#> 3 2001-01-01 02:00:00 11.0      NA  5.95  170      7.5 
#> 4 2001-01-01 03:00:00  7.38     NA  6.2   181.     8.4 
#> 5 2001-01-01 04:00:00  5.77     NA  7.45  190      8.8 
#> 6 2001-01-01 05:00:00  5.77     NA  7.45  190      9   
with(aq.data, plot(date, no2, type="l"))