getClimateWizardData {chillR}

Extract climate data from the ClimateWizard database

Description

This function makes use of an API provided by the International Center for Tropical Agriculture (CIAT) to access climate scenario data for a location of interest. Climate model runs are queried and data returned and summarized according to the specified parameters. A number of metrics are available for several climate models, which are listed in the API repository. Refer to this document for details on what can be downloaded. This function provides the additional option of automatically retrieving all data referring to changes in daily temperature extremes (by month), by setting the “'metric“' parameter to "monthly_min_max_temps". It also offers the option to automatically obtain data for all climate models included in the database (as of January 2018).

Usage

getClimateWizardData(
  coordinates,
  scenario,
  start_year,
  end_year,
  baseline = c(1950, 2005),
  metric = "monthly_min_max_temps",
  GCMs = "all",
  temperature_generation_scenarios = FALSE
)

Arguments

coordinates

position of the point of interest, specified by a vector with two elements that are called longitude and latitude (e.g. c(longitude = 10, latitude = 20)).

scenario

representative concentration pathway scenario. Can only be "historical", "rcp45" or "rcp85".

start_year

start year of the interval, for which data is to be summarized.

end_year

end year of the interval, for which data is to be summarized.

baseline

numeric vector of length 2 indicating the time interval to be used as baseline for the climate scenario. The function then returns projected values relative to this baseline. Defaults to c(1950, 2005) for the standard baseline of the ClimateWizard dataset. This can also assume different values, but it must span an interval of at least 20 years within the [1950; 2005] interval. Needs to be set to NA for the function to return absolute values.

metric

vector of metrics to output, from a list specified in the reference provided above. This can also be "monthly_min_max_temps", which returns all mean monthly minimum and maximum temperatures, or "precipitation" for precipitation data for all months, or "monthly_tmean" for the mean monthly temperatures of all months.

GCMs

vector of GCMs to be accessed, from a list specified in the above reference. This can also be "all" for all available GCMs (as of January 2018).

temperature_generation_scenarios

parameter to indicate whether the scenarios to be generated should be formatted in such a way that they are directly usable by chillR's temperature_generation function. This is only applicable, when metric == 'monthly_min_max_temps'.

Value

data.frame containing the requested information.

Author(s)

Eike Luedeling

References

Girvetz E, Ramirez-Villegas J, Navarro C, Rodriguez C, Tarapues J, undated. ClimateWizard REST API for querying climate change data. https://github.com/CIAT-DAPA/climate_wizard_api

Examples

# the example is #d out, since the download request sometimes times out, and that
# causes problems with CRAN approval of the package

# getClimateWizardData(coordinates=c(longitude=10.613975,latitude=34.933439),
#   scenario="rcp45", start_year=2020, end_year=2050,
#   metric=c("CD18","R02"), GCMs=c("bcc-csm1-1","BNU-ESM"))