What is synda?

Synda is a command line tool to search and download files from the Earth System Grid Federation (ESGF) archive. Synda is a useful tool if you need to download Climate Model Intercomparison Project Phase 6 (CMIP6) data in particular.

We'll describe the steps to install and use synda on Mahuika or Maui_ancil.

How to install synda

1. Load Anaconda3

module load Anaconda3

2. Create a conda environment and activate the environment

conda create -n syndaenv

Activate your new environment in a separate window (otherwise you will get a conda init error),

conda activate syndaenv

3. Install synda

conda install -c IPSL synda

4. Configure synda

Set the ST_HOME environment variable and populate $ST_HOME, for instance

export ST_HOME=/nesi/nobackup/<YOUR PROJECT>/synda_home synda -h

Note: you may want to add the above "export ST_HOME=<...>" somewhere near the bottom of your ~/.bashrc file.

To search and download climate model data you will in addition need to create an account on one or more of the ESGF nodes, e.g. This will require you to provide a user name (USER_NAME) and a password - you will receive an openID in return. Copy your openID string as you will need later.

To store your ESGF credentials, type

synda check-env

Pate in the openID you received when creating your ESGF account. If you created an account on then your openID will be (USER_NAME is the user name you chose when creating the account):

openID url:


Find all the datasets for ocean surface temperature ("tos") available at a monthly frequency

synda search CMIP6 variable=tos realm=ocean frequency=mon

This will return many potential datasets. Choose one of the datasets. Next we want to find out how big the dataset is

synda stat

which returns

New files size: 161.2 MB

To download the data, type

synda get

The datasets (NetCDF files) will be downloaded locally in your directory.

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