Tidal effection with analytical expression

[susonic]

Hi all,
I want to use tidal effect using analytical expression in my domain. Since my domain is too small to use large scale data such as TPXO6. So, I think it's better to use the ana_fsobc.h to make tadal effect. Hence I put this

m2=0.757_r8
s2=0.337_r8
k1=0.245_r8
o1=0.177_r8
ttime=time(ng)+162.0_r8*3600.0_r8
m2t=2.0_r8*pi*ttime/(12.42_r8*3600.0_r8)
s2t=2.0_r8*pi*ttime/(12.00_r8*3600.0_r8)
k1t=2.0_r8*pi*ttime/(23.93_r8*3600.0_r8)
o1t=2.0_r8*pi*ttime/(25.82_r8*3600.0_r8)
IF (WESTERN_EDGE) THEN
DO j=JstrR,JendR
BOUNDARY(ng)%zeta_west(j)=m2*sin(m2t+274.6*pi/180.0)+ &
& s2*sin(s2t+294.4*pi/180.0)+ &
& k1*sin(k1t+201.3*pi/180.0)+ &
& o1*sin(o1t+177.6*pi/180.0)
END DO
END IF
IF (EASTERN_EDGE) THEN
DO j=JstrR,JendR
BOUNDARY(ng)%zeta_east(j)=m2*sin(m2t+274.6*pi/180.0)+ &
& s2*sin(s2t+294.4*pi/180.0)+ &
& k1*sin(k1t+201.3*pi/180.0)+ &
& o1*sin(o1t+177.6*pi/180.0)
IF (SOUTHERN_EDGE) THEN
DO i=IstrR,IendR
BOUNDARY(ng)%zeta_east(i)=m2*sin(m2t+274.6*pi/180.0)+ &
& s2*sin(s2t+294.4*pi/180.0)+ &
& k1*sin(k1t+201.3*pi/180.0)+ &
& o1*sin(o1t+177.6*pi/180.0)

END DO
END IF

#define NORTHERN_WALL
#define EAST_M2FLATHER
#define EAST_FSCHAPMAN
#define EAST_M3CLAMPED
#define EAST_TCLAMPED
#define SOUTH_M2FLATHER
#define SOUTH_FSCHAPMAN
#define SOUTH_M3CLAMPED
#define SOUTH_TCLAMPED
#define WEST_M2FLATHER
#define WEST_FSCHAPMAN
#define WEST_M3CLAMPED
#define WEST_TCLAMPED
#define ANA_M2OBC
#define ANA_FSOBC

I have 3 open boundary except north.when I run the model I get weird zeta vlaue in my result.
What seems be the problem?
Any tips would be great for me.
Best,
-Peter

[wilkin]

I think you would find it much easier to build your "analytical" tidal forcing conditions into an external tides forcing netcdf file, and then give this as an input in ocean.in in the same way that most users apply the TPXO and ADCIRC (and other) tidal model forcings.

[johnluick]

I agree with Wilkin, but if you insist on trying this (i.e. you don't care about accurately reproducing the tides, just want some tidal dispersion) just drive one boundary the way the kelvin test case does. Your tides are in phase all around the boundary! You are driving it like an eskimo blanket toss. Note that in the kelvin test case the tidal velocities (out of phase with sea levels) are also specified. But in the end, you'll never know how realistic your results are.

[susonic]

Thank you so much for your reply, Mr.Wilkin and Mr.Johnluick.
And yes I will try to make a netcdf file to force the tide.
Before that I wanted to use the analytical method(I drove just one boundary-thanks to Johnluick)
and it works!

Now I will try to make a netcdf file. And I have a question.
How can I make a netcdf file with only analyzed value such as M2,S2,K1,O1?
Maybe it might be a really basic question but for your information, I'm an undergraduate
student, so any tips would be really appreciated for me.

Thank you.
Regards,

-Peter