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##

Updating the forcing values

Forcing values are updated based on the value of `*_interp_inc`
*and* whether the value of the forcing term depends explicitly on
the ocean state, as detailed below.

Wind stress (`ws`) and atmospheric pressure (`ap`)
forcing currently do not depend explicitly on the ocean state so
the forcing terms in the equations are updated depending on the
value of `[ws,ap]_interp_freq`. For example, with
`ws_data_type` = 'monthly-calendar',
`ws_interp_type` = 'linear', and

`ws_interp_freq` = 24., the code will linearly interpolate
monthly wind stress values at the beginning of each day and will
use this interpolated value for one model day.

Potential temperature and salinity forcing typically
do explicitly depend on the ocean state (for example, restoring
to climatology depends on the difference between the
climatological value and the current model value) so the
forcing terms in the equations are evaluated every timestep.
However, just like with the wind stress and atmospheric pressure,
the value of the data used in calculating the forcing
terms depends on the value of `*_interp_freq`.
For example, with
`pt_interior_data_type` = 'monthly-calendar',
`pt_interior_interp_type` = 'linear',
`pt_interior_interp_freq` = 48., and
`pt_interior_formulation` = 'restoring',
the code will linearly interpolate monthly potential temperature
values at the beginning of each 2-day interval and will use this
interpolated value for two model days when calculating the forcing.
Again, the actual forcing term is evaluated every timestep, but the
value that is being restored to stays constant over the 2 day period.

** Next:** Forcing modules
** Up:** Forcing options (ocean-only mode)
** Previous:** Forcing units
** Contents**
2010-01-14