how should i convert the harmonic phase constant (in degrees, and i believe this value is local character of the tide, and unchanged with the dates) for the input file (efdc.inp )?
eg:
C18 PERIODIC FORCING (TIDAL) SURF ELEV OR PRESSURE BOUNDARY COND. FORCINGS
…
C18 NPFOR SYMBOL AMPLITUDE PHASE
_______________________________________________________________
(1) how does the model know the original time for simulation? Does ‘Tbegin’ represent ’ the time origin’ for the simulation? how to calculate it ? has it to converted to Julian hours of the specified date and time, or as in Julian hours ‘relative to midnight, January 1 of the simulated year’ ? or it can be set as zero?
(2)does ‘tbegin’ affects the setting of the phase (now in seconds converted by the tidal period)?how to set it ?
The question posted here have tortured me for a long time , i would be greatly apreaciated if anyone could clearify them.
Hi guapanxing,
1) Yes, the starting time for the model simulation is “TBEGIN”. TBEGIN is the time specified by the user on card C8 in EFDC.inp or you can also specify TBEGIN within EFDC Explorer as follows:
Timing/ Linkage --> Model Run Timing --> Time of start
You could specify Tbegin at any time and it doesn’t have to be at the midnight.
2) Tbegin doesn’t affect the setting of the phase. So, using EFDC Explorer you could create a tide level by specifying amplitude, phase and name of the tide as shown in figure below:
