Get ERA5 country-level temperature data

Convenience function to download and aggregate ERA5 temperature data for a country. Resolves the country boundary, downloads monthly data via era5ify_geojson(), and returns area-weighted (cosine-latitude) country-level averages by year and month.

Usage

GetERA5CountryTemperature(...)

get_era5_country_temperature(
  country,
  start_date,
  end_date,
  variables = "mean",
  request_id = NULL,
  resolution = 0.25,
  verbose = FALSE,
  ...
)

Arguments

...

Additional arguments passed to era5ify_geojson().

country

One of: a country name string (resolved via maps::map()), a path to a GeoJSON file, or an sf object. Common aliases like "USA" and "UK" are handled automatically.

start_date

Start date in "YYYY-MM-DD" format.

end_date

End date in "YYYY-MM-DD" format.

variables

Character vector of temperature shorthand names or ERA5 variable names. Shorthands: "mean" (2m_temperature), "max" (maximum_2m_temperature_since_previous_post_processing), "min" (minimum_2m_temperature_since_previous_post_processing). Default: "mean".

request_id

Optional request identifier. Auto-generated from the country name if not provided.

resolution

Spatial resolution in degrees (default: 0.25).

verbose

Whether to print detailed progress messages.

Value

A data.frame with columns year, month, and one column per requested variable (e.g., temperature_mean, temperature_max, temperature_min). Temperature values are in Celsius.

Examples

if (FALSE) { # \dontrun{
# Monthly mean temperature for India
get_era5_country_temperature("India", "2023-06-01", "2023-06-30")

# Mean and max temperature for USA
get_era5_country_temperature("USA", "2023-01-01", "2023-12-31",
  variables = c("mean", "max")
)

# Using an sf object directly
library(sf)
poly <- st_read("my_country.geojson")
get_era5_country_temperature(poly, "2023-01-01", "2023-06-30")
} # }