brassens

The development of this library is in progress.

A package to deal with Citizen Weather Stations temperature data

• calls to PurpleAir API from R session to recover timeseries of temperature on a given spatial area
• formatting data
• cleaning non-conventional measurements of temperature with statistical tools (CrowdQC+ library)
• calibration with reference stations (GHCNh dataset used by default)

Pipeline tutorial

Prepare all parameters

pa_file parameter can be NULL: in this case, you need to provide an API key to download data from PurpleAir API to load_pa(). wu_inv refers to an inventory of WeatherUnderground files in your local machine. Once you have WU files, you can create this inventory by using create_wu_inventory() function.

> config <- list(
  ts = as.POSIXct("2021-07-22 00:00:00", tz = "UTC"),
  te = as.POSIXct("2021-07-23 23:59:59", tz = "UTC"),
  area = your_polygon,
  wu_inv = your_wu_inventory,
  pa_file = path_to_your_pa_file
)

Load GHCNh data

This reference dataset is used for calibration step. You can also use another reference network for calibration.

ghcnh <- download_ghcnh(config$ts, config$te, config$area)

Open and process citizen weather stations from WeatherUnderground and PurpleAir.

You can tune maximum distance.

wu_list <- load_wu(config$ts, config$te, config$area, config$wu_inv) |>
  format_wu() |>
  clean_cws() |>
  calib_cws(ref = ghcnh, max_dist = 20000)

pa_list <- load_pa(
  ts = config$ts,
  te = config$te,
  area = config$area,
  storage_file = config$pa_file
) |>
  format_pa() |>
  clean_cws() |>
  calib_cws(ref = ghcnh, max_dist = 20000)

References

CrowdQC+ library
Fenner, D., Bechtel, B., Demuzere, M., Kittner, J. and Meier, F. (2021): CrowdQC+ – A quality-control for crowdsourced air-temperature observations enabling world-wide urban climate applications. Frontiers in Environmental Science 9: 720747. DOI: 10.3389/fenvs.2021.720747.

Global Historical Climatology Network - hourly
Menne, Matthew J.; Noone, Simon; Casey, Nancy W.; Dunn, Robert H.; McNeill, Shelley; Kantor, Diana; Thorne, Peter W.; Orcutt, Karen; Cunningham, Sam; Risavi, Nicholas. 2023. Global Historical Climatology Network-Hourly (GHCNh). NOAA National Centers for Environmental Information. [accessed on 2024/06/12]

PurpleAir data download functions adapted from
Callahan J, Martin H, Wilson K, Brasel T, Miller H (2023). AirSensor: Process and Display Data from Air Quality Sensors. R package version 1.1.1, https://CRAN.R-project.org/package=AirSensor.

PurpleAir: https://www2.purpleair.com
WeatherUnderground: https://www.wunderground.com