Configuration

The GDAS CMAQ Preprocessor uses YAML configuration files for setup. Here’s a complete reference of all available options.

Basic Configuration

# Input/Output
input_dir: /path/to/input
output_dir: /path/to/output

# Grid Settings
nlat: 180
nlon: 360
lat_border: 1.0

# Processing Options
use_prev_date: false
create_full_files: false
combine_output: true

# GDAS Settings
gdas:
  hours: [0, 6, 12, 18]
  base_url: "https://noaa-gfs-bdp-pds.s3.amazonaws.com"
  file_pattern: "gdas.t{hour:02d}z.sfluxgrbf00.grib2"
  local_pattern: "gdas_{date:%Y%m%d}_{hour:02d}.grib2"

Configuration Options

Input/Output Settings

input_dir

Directory containing GDAS input files

output_dir

Directory where processed files will be written

Grid Settings

nlat

Number of latitude points in output grid

nlon

Number of longitude points in output grid

lat_border

Latitude border in degrees to avoid polar regions

Processing Options

use_prev_date

Whether to use previous date’s data for missing values

create_full_files

Create full resolution output files

combine_output

Combine daily files into a single output file

GDAS Settings

hours

List of hours to process (typically [0, 6, 12, 18])

base_url

Base URL for NOAA’s AWS S3 bucket

file_pattern

Pattern for remote GDAS files

local_pattern

Pattern for local GDAS files

Example Configuration

# Basic example configuration
input_dir: ./data/input
output_dir: ./data/output
nlat: 180
nlon: 360
lat_border: 1.0
use_prev_date: false
create_full_files: false
combine_output: true

gdas:
  hours: [0, 6, 12, 18]
  base_url: "https://noaa-gfs-bdp-pds.s3.amazonaws.com"
  file_pattern: "gdas.t{hour:02d}z.sfluxgrbf00.grib2"
  local_pattern: "gdas_{date:%Y%m%d}_{hour:02d}.grib2"