What is the "severity" field in the alerts table, and how can I use it?

When calling the alerts API, I see the following fields:

    "dashboardId": 6,
    "dashboardSlug": "sandbox",
    "dashboardUid": "GzKT10mmk",
    "evalData": null,
    "evalDate": "0001-01-01T00:00:00Z",
    "executionError": "",
    "id": 2,
    "name": "{stats} Test Lambda Alert",
    "newStateDate": "2018-04-06T13:53:15-04:00",
    "panelId": 2,
    "state": "ok",
    "url": "/d/GzKT10mmk/sandbox"

However, when I inspect the DB, there’s a field, severity – it’s unset for all alerts. Can I use this somehow via the API? What’s its designated purpose?

I think I’ve found the purpose of the severity field - I’d still like to know if there’s a way to access / set it via the API though?