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Download Daily NASA POWER (MERRA-2) Data for a Named Point

Source: R/dl_daily_nasa.R
smn_dl_daily_nasa.Rd

Downloads daily NASA POWER variables for a specific point (lat/lon) and tags the result with a user-defined station (node) name so you can join/trace later.

Usage

smn_dl_daily_nasa(
  station,
  lat,
  lon,
  altitude = NA_real_,
  start_date = "1984-01-01",
  end_date = Sys.Date(),
  vars = c("T2M_MAX", "T2M_MIN", "RH2M", "PRECTOTCORR", "EVLAND"),
  community = "AG",
  retries = 5,
  sleep_sec = 3,
  output_format = c("all", "reduce")
)

Arguments

station

Character. A label or node name to tag the time series (e.g., "Toluca_Node").

lat

Numeric. Latitude in decimal degrees (WGS84).

lon

Numeric. Longitude in decimal degrees (WGS84).

altitude

Numeric (optional). Altitude of the point (m a.s.l.). Default NA_real_.

start_date

Start date (YYYY-MM-DD). If earlier than 1984-01-01, it is automatically adjusted to 1984-01-01 (POWER coverage).

end_date

End date (YYYY-MM-DD). Default Sys.Date().

vars

Character vector of POWER parameter short names. Defaults to a compact set: c("T2M_MAX","T2M_MIN","RH2M","PRECTOTCORR","EVLAND").

community

POWER community. Default "AG". (Common alternatives: "SSE", "RE")

retries

Integer. Max GET retries on failure (default 5).

sleep_sec

Numeric. Seconds to sleep between retries (default 3).

output_format

Either "all" (default) or "reduce". The "reduce" option keeps only station, latitude, longitude, altitude, date and the requested variables.

Value

A data.frame ordered by date with columns: station, latitude, longitude, altitude, date, <requested POWER variables>. POWER missing values -999 are returned as NA.

Examples

if (FALSE) { # \dontrun{
nasa_df <- smn_dl_daily_nasa(
  station = "Toluca_Node",
  lat = 19.289, lon = -99.657, altitude = 2670,
  start_date = "2020-01-01", end_date = "2020-12-31",
  vars = c("T2M_MAX","T2M_MIN","PRECTOTCORR"),
  output_format = "reduce"
)
} # }