\hypertarget{namespacetidal__forcing}{}\section{tidal\+\_\+forcing Module Reference}
\label{namespacetidal__forcing}\index{tidal\_forcing@{tidal\_forcing}}


\subsection{Detailed Description}
Code by Robert Hallberg, August 2005, based on C-\/code by Harper Simmons, February, 2003, in turn based on code by Brian Arbic. 

The main subroutine in this file calculates the total tidal contribution to the geopotential, including self-\/attraction and loading terms and the astronomical contributions. All options are selected with entries in a file that is parsed at run-\/time. Overall tides are enabled with the run-\/time parameter \textquotesingle{}T\+I\+D\+ES=True\textquotesingle{}. Tidal constituents must be individually enabled with lines like \textquotesingle{}T\+I\+D\+E\+\_\+\+M2=True\textquotesingle{}. This file has default values of amplitude, frequency, Love number, and phase at time 0 for the Earth\textquotesingle{}s M2, S2, N2, K2, K1, O1, P1, Q1, MF, and MM tidal constituents, but the frequency, amplitude and phase ant time 0 for each constituent can be changed at run time by setting variables like T\+I\+D\+E\+\_\+\+M2\+\_\+\+F\+R\+EQ, T\+I\+D\+E\+\_\+\+M2\+\_\+\+A\+MP and T\+I\+D\+E\+\_\+\+M2\+\_\+\+P\+H\+A\+S\+E\+\_\+\+T0 (for M2).

In addition, the approach to calculating self-\/attraction and loading is set at run time. The default is to use the scalar approximation, with a coefficient T\+I\+D\+E\+\_\+\+S\+A\+L\+\_\+\+S\+C\+A\+L\+A\+R\+\_\+\+V\+A\+L\+UE that must be set in the run-\/time file (for global runs, 0.\+094 is typical). Alternately, T\+I\+D\+A\+L\+\_\+\+S\+A\+L\+\_\+\+F\+R\+O\+M\+\_\+\+F\+I\+LE can be set to read the S\+AL from a file containing the results of a previous simulation. To iterate the S\+AL to convergence, U\+S\+E\+\_\+\+P\+R\+E\+V\+I\+O\+U\+S\+\_\+\+T\+I\+D\+ES may be useful (for details, see Arbic et al., 2004, D\+SR II). With T\+I\+D\+A\+L\+\_\+\+S\+A\+L\+\_\+\+F\+R\+O\+M\+\_\+\+F\+I\+LE or U\+S\+E\+\_\+\+P\+R\+E\+V\+I\+O\+U\+S\+\_\+\+T\+I\+D\+ES,a list of input files must be provided to describe each constituent\textquotesingle{}s properties from a previous solution.