cppdefs.h advection description

[jcwarner]

cppdefs has:

** OPTIONS associated with momentum equations:                               **
**                                                                           **
**   The default horizontal and vertical advection is 4th-order centered.    **
**   Use the splines vertical advection option is shallow, high vertical     **
**   resolution applications.                                                **
**                                                                           **

However, I think the default advection fo rmomentum is still the 3rd order scheme, as stated in previous versions: Select model dynamics for MOMENTUM equations: (The default advection is third-order upstream bias)

Can you modify the comments in cppdefs to be consistent with the code? (This was brought to my attention by Barbara).

[arango]

Yes, the default horizontal advection for both momentum and tracers is 3rd-order upstream bias. However, the default vertical advection for both momentum and tracers is 4th-order centered.