Calculate meteorological and atmospheric covariates

Extract meteorological and atmospheric values at point locations. Returns a data.frame object containing locs_id, date and hour, vertical pressure level, and meteorological or atmospheric variable. Variable column name reflects variable and circular buffer radius.

Usage

calculate_merra2(
  from,
  locs,
  locs_id = NULL,
  radius = 0,
  fun = "mean",
  weights = NULL,
  .by_time = NULL,
  geom = FALSE,
  ...
)

Arguments

from

SpatRaster(1). Output of process_merra2().

locs

data.frame, characater to file path, SpatVector, or sf object.

locs_id

character(1). Column within locations CSV file containing identifier for each unique coordinate location.

radius

integer(1). Circular buffer distance around site locations. (Default = 0).

fun

character(1). Function used to summarize multiple raster cells within sites location buffer (Default = mean).

weights

NULL, SpatRaster, polygon SpatVector/sf, or file path. Optional weights raster for weighted extraction. If NULL (default), unweighted extraction is performed.

.by_time

NULL or character(1). Optional time grouping key used with .by_time for temporal summaries.

geom

FALSE/"sf"/"terra".. Should the function return with geometry? Default is FALSE, options with geometry are "sf" or "terra". The coordinate reference system of the sf or SpatVector is that of from.

...

Placeholders

Value

a data.frame or SpatVector object. When .by_time is provided, rows are aggregated using calc_summarize_by().

See also

calculate_geos(), process_merra2()

Author

Mitchell Manware

Examples

## NOTE: Example is wrapped in `\dontrun{}` as function requires a large
##       amount of data which is not included in the package.
if (FALSE) { # \dontrun{
loc <- data.frame(id = "001", lon = -78.90, lat = 35.97)
calculate_merra2(
  from = merra2, # derived from process_merra2() example
  locs = loc,
  locs_id = "id",
  radius = 0,
  fun = "mean",
  geom = FALSE
)
} # }