ERA5: Configuring the CDSAPI

ERA5 is the new dataset replacing the ERA-Interim data provided by our lovely hero: ECMWF. I usually used the ERA-Interim dataset to get the wave data, and now I am trying to use the ERA5. Thus, let’s take some notes on how to access it. (Disclaimer: I know NOTHING about python, so if you know better, please advise me 🙂 )

This is an easy explanation on how to setup the CDSAPI on your machine by using the Anaconda, and testing it to download a sample data. Information on this post is based on: Link.

First, we need to install the Anaconda (I am using the version 3.7) and install the CDSAPI

Once it installed, add the “program” and “Scripts” PATH to the environment variable. Note: I am using Windows 7 pro.

I used Anaconda Prompt as administrator, and then type: conda install cdsapi

Get your API Key

In order to access the ECMWF ERA5 database, we need a user and API key. To do this:

1. create an account at CDS page, and log in.
2. click on your account, and find your API Key (scroll down to the bottom of the page)

Configure the API Key using \.cdsapirc file

open a blank notepad and type:

url: https://cds.climate.copernicus.eu/api/v2
key: <UID>:<API key>

1. save that notepad file to “C:\Users\Username\test.cdsapirc.txt” (I installed the Anaconda in C:\Users\Username\Anaconda3)
2. close, and go to C:\Users\Username\ and rename the file:
3. rename the ” test.cdsapirc.txt” to “.cdsapirc.” (source)
4. done

Test your configuration by downloading a sample file (source).

Prepare a python code as follow and run it.

import cdsapi
 
c = cdsapi.Client()
c.retrieve('reanalysis-era5-pressure-levels', {
        'variable'      : 'temperature',
        'pressure_level': '1000',
        'product_type'  : 'reanalysis',
        'year'          : '2008',
        'month'         : '01',
        'day'           : '01',
        'time'          : '12:00',
        'format'        : 'netcdf' # Supported format: grib and netcdf. Default: grib
    }, 'test.nc')

In this exercise, I used Spider to run it. But if you got the cdsapi installation correct, you can also run it through command prompt, or just double click the file.

Enjoy!