gri-tropo-data 0.2.2

ERA5 data pipeline for generating tropospheric refractivity datasets

Tropo Data (Troposphere Data Processing)

ERA5 data download and processing tools for generating tropospheric refractivity datasets used by gri-tropo. Requires Python 3.12+.

Overview

This package provides scripts for:

• Downloading ERA5 reanalysis data from the Copernicus Climate Data Store (CDS)
• Processing surface data to calculate surface refractivity (n_sur)
• Processing pressure-level data to calculate reference heights (ref_ht)

The output NPZ files are consumed by the gri-tropo library for tropospheric correction calculations.

Installation

# Clone and setup
git clone https://gitlab.com/geosol-foss/python/gri-tropo-data.git
cd gri-tropo-data
. .init_venv.sh

# Activate environment
source .venv/bin/activate

Usage

1. Download ERA5 Data

Download ERA5 surface and pressure-level data for a specific date:

python -m gri_tropo_data.download_era5 2025 03 15

Output:

• ./data/era5_raw/era5_surface_2025_03_15.nc - Surface meteorological data
• ./data/era5_raw/era5_pressure_2025_03_15.nc - Pressure-level data

Note: Requires CDS API credentials. Register at the Copernicus Climate Data Store and configure your ~/.cdsapirc file with your UID and API key. See setup instructions in the script header.

2. Process Surface Refractivity Data

Process all unprocessed ERA5 surface data to generate n_sur files:

python -m gri_tropo_data.update_nsur

Output:

• ./data/n_sur/n_sur_2025_03_15.npz - Surface refractivity data

3. Process Reference Height Data

Process all unprocessed ERA5 pressure-level data to generate ref_ht files:

python -m gri_tropo_data.update_refht

Output:

• ./data/ref_ht/ref_ht_2025_03_15.npz - Reference height data

Data Formats

Downloaded ERA5 Data

Surface Data (Single-Level):

• Variables: 2m temperature, surface pressure, 2m dewpoint temperature
• Temporal resolution: Hourly (24 snapshots per day)
• Spatial resolution: 1 x 1 degree global grid

Pressure-Level Data:

• Variables: Temperature, geopotential, specific humidity
• Pressure levels: 1000, 925, 850, 700, 500, 300 hPa
• Temporal resolution: Hourly (24 snapshots per day)
• Spatial resolution: 1 x 1 degree global grid

Processed NPZ Files

n_sur files - Shape: (181, 360, 24) for (latitude, longitude, hour)

• Surface refractivity in N-units
• Hourly data for a single day

ref_ht files - Shape: (181, 360) for (latitude, longitude)

• Reference height in meters (scale height of exponential refractivity decay)
• Daily average data

Indexing scheme:

• Latitudes: indices 0-90 for 0 to 90 degrees N, indices 91-180 for -90 to -1 degrees S
• Longitudes: indices 0-359 for 0 to 359 degrees E
• Hours (n_sur only): indices 0-23 for UTC hours

See detailed format documentation for more information.

Configuration

All scripts default to ./data/ for input/output but can be configured by modifying the paths in the scripts.

Other Projects

Current list of other GRI FOSS Projects we are building and maintaining.

License

MIT License. See LICENSE for details.