wrf_load: Load WRF model run data

In MazamaScience/AirFireWRF: Utilities for working with WRF atmospheric model data

Description

Loads WRF model run data as a raster package RasterBrick. If the specified data does not exist on the user's machine, then it will try to be downloaded from the AirFire database.

On 2020-09-03, available model identifiers include the following:

• PNW-1.33km

• PNW-4km

Some useful variables provided by WRF:

• XLONG - Longitude (degrees East)

• XLAT - Latitude (degrees North)

• XLONG_U - Longitude (degrees East)

• XLAT_U - Latitude (degrees North)

• XLONG_V - Longitude (degrees East)

• XLAT_V - Latitude (degrees North)

• U - Wind X component (m/s)

• V - Wind Y component (m/s)

• W - Wind Z component (m/s)

• U10 - Wind X component at 10 meters (m/s)

• V10 - Wind Y component at 10 meters (m/s)

• ZNU - eta values on half (mass) levels

• ZNW - eta values on full (w) levels

• LU_INDEX - Land use category

• Q2 - QV at 2 M (kg)

• T - Perturbation potential temperature theta-t0 (K)

• T2 - Temperature at 2 meters (K)

• TH2 - Potential temperature at 2 meters (K)

• HGT - Terrain height (m)

• RAINNC - Accumulated total grid scale precipitation (mm)

• CFRACT - Total cloud fraction

• PBLH - Planetary boundary layer height (m)

Usage

wrf_load(
  modelName = NULL,
  modelRun = NULL,
  modelRunHour = NULL,
  baseUrl = "http://m2.airfire.org",
  localPath = NULL,
  varNames = NULL,
  res = NULL,
  xlim = NULL,
  ylim = NULL,
  verbose = TRUE
)

Arguments

modelName	Model identifier.
modelRun	Model initialization timestamp as "YYYYMMDDHH".
modelRunHour	Hour forecasted from initial time, i.e. 7.
baseUrl	Base URL for WRF output.
localPath	Absolute path to a NetCDF file not found in 'WRFDataDir'.
varNames	WRF variable(s) to load. If NULL, the following subset specified by AirFire will be loaded: XLONG, XLAT, XLONG_U, XLAT_U, XLONG_V, XLAT_V, U, V, U10, V10, ZNU, ZNW, LU_INDEX, Q2, T, T2, TH2, HGT, RAINNC, CFRACT, and PBLH.
res	Resolution of raster in degrees.
xlim	A vector of coordinate longitude bounds.
ylim	A vector of coordinate latitude bounds.
verbose	Logical to display messages.

Value

A raster package RasterBrick object.

Examples

library(AirFireWRF)
setWRFDataDir("~/Data/WRF")

raster <- wrf_load(
  modelName = "PNW-4km",
  modelRun = "2020082612",
  modelRunHour = 9,
  varNames = c("HGT", "TSK", "U10", "V10"),
  res = 0.1,
  xlim = c(-125, -116),
  ylim = c(45, 50)
)

print(raster)

MazamaScience/AirFireWRF documentation built on Nov. 11, 2020, 3:32 a.m.