How to Create Data Subscriptions

Data subscriptions provide automatic notifications and updates when new data becomes available. This guide covers two methods for setting up subscriptions: the Earthdata Search web interface and the command-line PO.DAAC Data Subscriber tool. 

Prerequisites

• Create an Earthdata login account if you don't already have one: https://urs.earthdata.nasa.gov/

Earthdata Search

Earthdata Search offers two subscription types: dataset subscriptions and granule subscriptions.

Dataset subscriptions alert you when new datasets matching your search query are added. For an example on how to set up dataset subscriptions, see the ORNL DAAC's tutorial on Github.

Granule subscriptions notify you when new data are added to an existing dataset. To create a granule subscription in Earthdata Search:

1.   Log in to Earthdata Search using https://search.earthdata.nasa.gov and enter your credentials.

2.   Enter your search parameters for the collection. For this example, we'll search for ATL03 data available in Earthdata Cloud (the cloud-hosted version of the dataset). Select the matching collection.

3.   Enter your granule subscription filters. In this example, we want notifications when new granules or data files are added within our area of interest—a bounding box over the northern Colorado Front Range—for new data arriving in 2025 (after January 1, 2025).

4.   Click the Subscriptions button at the bottom of the search results.

5.   Add a subscription name that best fits your subscription filters. Click the Create Subscription button to finalize the subscription.

6.   After creating the subscription, you'll receive email notifications whenever new data matching your specified criteria becomes available in Earthdata Search. 

To manage your active subscriptions, click your username in the upper right corner of the Earthdata Search page and select "Subscriptions" from the dropdown menu. In the Subscriptions page, you'll find separate sections for granule and collection subscriptions, where you can edit or cancel them.

Data Subscriber

PO.DAAC's Data Subscriber is a Python-based tool that continuously downloads data. While originally built for the PO.DAAC archive, it can request data from other DAACs, including NSIDC DAAC. The tool works best for users familiar with command-line applications, as it can be run repeatedly to fetch only new data.

To start using the Data Subscriber tool, ensure you have Data Subscriber installed and a .netrc file set up for authentication. For installation and dependency information, see the installation section and Step 2 on .netrc file in the Data Subscriber Github page: https://github.com/podaac/data-subscriber/blob/main/README.md

To use the Data Subscriber for NSIDC DAAC data:

1.   Open a command line and make sure you are in an environment where the Data Subscriber is installed. Here is the usage syntax:

$> usage: PO.DAAC data subscriber [-h] -c COLLECTION -d OUTPUTDIRECTORY [-f] [-sd STARTDATE] [-ed ENDDATE] [-b BBOX] [-dc] [-dydoy] [-dymd] [-dy] [--offset OFFSET] [-m MINUTES]
                               [-e EXTENSIONS] [--process PROCESS_CMD] [--version] [--verbose] [-p PROVIDER] [--dry-run]

...

2.   Enter subscription parameters. For example, to download and subscribe to the cloud copy of the latest version of the ATL03 dataset, from 2024-05-10T22:32:22Z to 2024-05-10T22:39:25Z:

• Use the collection flag (-c) to set the collection: ATL03
• Use the provider flag (-p) to set the provider: NSIDC_CPRD
• Use the start date flag (-sd) to set the start date: 2024-05-10T22:32:22Z
• Use the end date flag (-ed) to set the end date: 2024-05-10T22:39:25Z
• The directory flag (-d) creates a folder at your current location. On first run, you'll receive a message confirming the directory creation. In this example, a folder called ATL03_05102024 is created.

podaac-data-subscriber -c ATL03 -d ATL03_05102024 -p NSIDC_CPRD -sd 2024-05-10T22:32:22Z -ed 2024-05-10T22:39:25Z

3.   Run the command. The tool will display:

• Number of files matching your criteria
• Download progress for each file, including status and HTTPS path
• Total files downloaded
• Any failed or skipped downloads (files are skipped if they already exist in your directory)

More examples:

• Let's recreate the same subscription we set up in the Earthdata Search section above—requesting the latest Earthdata Cloud version of ATL03 data for the northern Colorado Front Range, starting from January 1, 2025. In this example, the -b flag is used to set the bounding box:

  podaac-data-subscriber -c ATL03 -d ATL03_2025 -p NSIDC_CPRD -sd 2025-01-01T00:00:00Z -b="-105.5,40,-105,41"

• The --subset flag enables granule subsetting, which downloads only the data within your specified region. Without this flag, the tool checks file metadata for intersection with your region but downloads entire files—even when they contain data outside your area of interest. The --subset flag works through the NASA Harmony API, though it only functions for collections with subsetting enabled. Otherwise, the data downloads normally. This example script spatially subsets ATL03 Earthdata Cloud data (which supports spatial subsetting) for data files from January 01, 2025 to February 01, 2025 over the Northern Colorado Front Range:

  podaac-data-subscriber -c ATL03 -d ATL03_2025 -p NSIDC_CPRD -sd 2025-01-01T00:00:00Z -ed 2025-02-01T00:00:00Z -b="-105.5,40,-105,41" --subset

Final Thoughts

This guide covered two methods for creating data subscriptions:

• Earthdata Search - A web interface for email notifications about new data
• Data Subscriber - A command-line tool for automated downloads

Regularly review your subscription settings and adjust filters to ensure you receive the most relevant data for your research.

If you have any questions or need assistance, please contact NSIDC User Services at nsidc@nsidc.org.