Add ERA5 reference data to a `metamet` object

Reads ERA5 meteorological data and attaches it to a `metamet` object as reference data (`dt_ref`). Converts accumulated precipitation to a rate, renames variables, and ensures temporal alignment between observed and reference data. Optionally restricts date ranges and harmonizes time resolution with the main observations.

Usage

add_era5(
  mm,
  fname_era5 = "data-raw/UK-AMO/dt_era5.csv",
  restrict_ref_to_obs = TRUE,
  restrict_obs_to_ref = FALSE,
  report_end_interval = TRUE,
  first_date = NULL,
  last_date = NULL,
  extra_rows = 2
)

Arguments

mm: A `metamet` object containing observation data and metadata.
fname_era5: Path to a CSV file containing ERA5 data.
restrict_ref_to_obs: Logical. If `TRUE` (default), restricts reference data to the date range of observations.
restrict_obs_to_ref: Logical. If `TRUE`, restricts observations to the date range of the reference data.
report_end_interval: Logical. Should the time be reported at the end (`TRUE`, default) or start (`FALSE`) of the -averaging interval.
first_date: Optional. Earliest date to include (overrides automatic date selection if set).
last_date: Optional. Latest date to include (overrides automatic date selection if set).
extra_rows: Integer. Extra rows to add when time-averaging for padding.

Value

The `metamet` object `mm`, with processed ERA5 data available as `mm$dt_ref`.

Details

- Converts ERA5 precipitation ("tp") from a sum (in mm) to a rate (mm/s). - Renames variables in ERA5 data to match main observations according to `dt_meta`. - Optionally limits ERA5 data to match the observation period, and vice versa. - Ensures reference and observed data tables have matching time resolutions, aggregating or disaggregating if needed. - Warns if dimensions become mismatched.

Examples

# mm <- add_era5(mm)