ERA5 Data Download Scripts for WRF Initial and Boundary Conditions

This repository contains two scripts, Era_5_singlelevels.ipynb and Era_5_levelpressure.ipynb, designed to download ERA5 reanalysis data from the Copernicus Climate Data Store (CDS). These scripts retrieve single-level and pressure-level data necessary for running the WRF (Weather Research and Forecasting) model as initial and boundary conditions.

Prerequisites

Before running these scripts, ensure you have the following:

Software Requirements

• Python 3.x: Make sure Python is installed on your system. You can download it from python.org.

• cdsapi library: This is the official Python library for accessing the Copernicus Climate Data Store. Install it via pip:

  pip install cdsapi

• Jupyter Notebook: To run the .ipynb files, you need Jupyter Notebook installed. You can install it using:

  pip install notebook

CDS API Key

To use the Copernicus Climate Data Store, you must have an account and set up your API key. Follow these steps:

1. Register for a free account at the Copernicus Climate Data Store.

2. Log in and go to Your API key.

3. Copy the provided API key and configure it on your local machine by adding it to the ~/.cdsapirc file:

   url: https://cds.climate.copernicus.eu/api/v2
   key: <YOUR_UID>:<YOUR_API_KEY>

Script Descriptions

Era_5_singlelevels.ipynb

This script retrieves single-level ERA5 data. It allows the user to specify the year, months, and days of interest, and downloads the selected variables for the specified time range.

• Variables Retrieved:

  • Wind components at 10m (10m_u_component_of_wind, 10m_v_component_of_wind)
  • 2m temperature and dewpoint (2m_temperature, 2m_dewpoint_temperature)
  • Surface and soil parameters, including pressure, temperature, and water content
  • Radiation variables and precipitation

• Output Format: GRIB

• Download Path: /home/juantuf/Descargas/ERADATA/single_levels-ERA5.grib

Era_5_levelpressure.ipynb

This script retrieves ERA5 data on multiple pressure levels. Users can specify the year, months, and days of interest, and download data for a range of meteorological variables on various pressure levels.

• Variables Retrieved:

  • Atmospheric parameters like temperature, humidity, wind components, and cloud properties
  • Geopotential, divergence, vorticity, and other dynamical fields

• Pressure Levels: From 1 hPa to 1000 hPa

• Output Format: GRIB

• Download Path: /home/juantuf/Descargas/ERADATA/pressure_levels-ERA5.grib

Execution Instructions

Clone the Repository:

Clone the repository to your local machine:

git clone <repository_url>
cd <repository_directory>

Run the Jupyter Notebooks:

Open the terminal, navigate to the directory containing the scripts, and start Jupyter Notebook:

jupyter notebook

Open either Era_5_singlelevels.ipynb or Era_5_levelpressure.ipynb in Jupyter and run the cells sequentially. You will be prompted to enter the year, months, and days for which you want to retrieve data.

Check the Downloaded Files:

The downloaded GRIB files will be saved to the specified paths. These files can be used directly as initial and boundary conditions for WRF model simulations.

Troubleshooting

• API Connection Issues: Ensure your CDS API key is correctly configured and you have a stable internet connection.
• Data Download Issues: Check that the specified year, month, and day inputs are valid and that the requested data is available in the CDS.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgements

The scripts use the cdsapi library to interact with the Copernicus Climate Data Store. The ERA5 data is provided by the European Centre for Medium-Range Weather Forecasts (ECMWF).