The "Room Air Modeling Type" input field of the Room Air Model Type object dictates what other objects are needed to model air movement within a zone. For cases where "UserDefined" is entered in that input field, then EnergyPlus expects to reference the object you mention (RoomAir:TemperaturePattern:UserDefined). This object then references:

• what zone to model air movement for
• what is the availability schedule that determines when air movement occurs
• what is the "pattern control schedule"

The "pattern control schedule" is really setting what type of air movement patterns occur over the course of the simulation. For example, you could reference a Constant Gradient Temperature Pattern when there's no air movement at night, then change to a Surface Mapping Temperature Pattern if you have radiant ceilings / floors operating during occupied periods. This is done by assigning a unique integer to each temperature pattern you want to model, then use the same unique integer in the "pattern control schedule".

To see this in practice, there is an example file named "UserDefinedRoomAirPatterns.idf" that has multiple instances of user-defined room air temperature patterns. You can also read over assumptions and calculation methods for user-defined room air temperature objects in the Engineering Reference document, if you want to get more into those details.