Attach climate indices to observations

Joins one or more monthly indices by year and month. Because an index has no spatial dimension, every observation in a month receives the same value.

Usage

attach_climate_index(
  dat,
  indices,
  years = NULL,
  year_col = "YEAR",
  month_col = "MONTH"
)

Arguments

dat

a data frame or sf object with year and month columns

indices

index names to attach, or a data frame from fetch_climate_index()

years

years to fetch; defaults to those present in dat

year_col, month_col

names of the year and month columns

Value

dat with one column per index. Months with no published value are NA.

Examples

if (FALSE) { # \dontrun{
observations <- attach_climate_index(observations, c("NAO", "AMO"))
} # }