wrfaddvar 0.1.0

Add external variables to WRF input files (wrfinput)

wrfaddvar

Add external variables to WRF input files (wrfinput).

Installation

Basic install (bilinear / nearest interpolation only)

pip install wrfaddvar

[!WARNING] Conservative remapping (--method conservative) requires xesmf, which cannot be installed via pip alone — the underlying ESMF Fortran library must come from conda-forge. If you use conservative interpolation without installing these packages, you will see a red error and a yellow hint in the terminal telling you exactly what to run.

Full install with conservative remapping support

conda install -c conda-forge esmf esmpy xesmf
pip install wrfaddvar

[!NOTE] wrfaddahe uses conservative remapping by default (--method conservative). Install the conda packages above if you want to use this command without switching to --method bilinear.

Commands

wrfaddvar — general-purpose

wrfaddvar --varname VARNAME [OPTIONS] SOURCE_FILE WRFINPUT_FILE

Reads VARNAME from SOURCE_FILE, interpolates it to the WRF grid, and writes it into WRFINPUT_FILE.

Supported source formats (auto-detected from extension):

Extension	Format
.nc / .nc4	NetCDF — variable + lat/lon coordinates
.csv	CSV — columns lat, lon, <varname>
.tif / .tiff	GeoTIFF (requires rasterio)

Options

Flag	Default	Description
--varname	(required)	Variable name to write into wrfinput
--source-varname	same as --varname	Variable name inside SOURCE_FILE
--method	bilinear	Interpolation method: bilinear, conservative, or nearest
--output / -o	(in-place)	Write to a new file instead of modifying wrfinput

Examples

# Add AHE from a GeoTIFF (bilinear by default)
wrfaddvar --varname AHE emissions.tif wrfinput.d01

# Add ERA5 2-m temperature (t2m) as T2_OBS, write to a new file
wrfaddvar --varname T2_OBS --source-varname t2m era5.nc wrfinput.d01 -o wrfinput.d01.new

# Nearest-neighbour interpolation from a CSV point dataset
wrfaddvar --varname NDVI --method nearest ndvi_stations.csv wrfinput.d01

---

wrfaddahe — anthropogenic heat emissions shortcut

wrfaddahe [OPTIONS] TIF_FILE WRFINPUT_FILE

Convenience wrapper that reads a GeoTIFF band and writes an AHE variable with WRF-compatible attributes (units = "W m-2", FieldType = 104, etc.). Conservative remapping is used by default, which preserves the spatial integral of the flux field.

wrfaddahe Options

Flag	Default	Description
--band	1	GeoTIFF band number
--varname	AHE	Variable name in wrfinput
--method	conservative	Interpolation method
--output / -o	(in-place)	Write to a new file

wrfaddahe Examples

# Annual mean AHE (conservative remapping)
wrfaddahe ahe_2020.tif wrfinput.d01

# July (band 7), save to a new file
wrfaddahe --band 7 --output wrfinput.d01.ahe monthly_ahe.tif wrfinput.d01

---

Python API

from wrfaddvar import read_geotiff, to_wrf_grid, write_to_wrfinput
import netCDF4 as nc
import numpy as np

src = read_geotiff("ahe_2020.tif", band=1)

with nc.Dataset("wrfinput.d01") as ds:
    wrf_lats = np.array(ds.variables["XLAT"][0])
    wrf_lons = np.array(ds.variables["XLONG"][0])

data_on_wrf = to_wrf_grid(src, wrf_lats, wrf_lons, method="conservative")
write_to_wrfinput("wrfinput.d01", "AHE", data_on_wrf,
                  attrs={"units": "W m-2", "description": "ANTHROPOGENIC HEAT FLUX"})

Publishing

pip install build twine
python -m build
twine upload dist/*