Data Models
The CESM data models perform the basic function of reading external data, modifying that data, and then sending it to the driver via standard CESM coupling interfaces. The driver and other models have no fundamental knowledge of whether another component is fully active or just a data model. In some cases, data models are prognostic and also receive and use some data sent by the driver to the data model. But in most cases, the data models are not running prognostically and have no need to receive any data from the driver.
