[MITgcm-support] Anamalous Decrease in Sea Surface Level and SPONGE Layer

[Himansu Pradhan]

Hello MITgcm users,

I have configured MITgcm for my region (174*200*17) to look after
circulation and internal waves. dx = 2.5 km and dy = 2.5km approximatly .
Tides are included  into the  region through momenteum equations to take
note of the thermal/density oscillations. Orlanski OBC were applied at the
boundary to take care for physics/dynamics.
... here starts the PROBLEM ???? their is an ANAMALOUS DECREASE in the Sea
Surface Level with time. ?????
.
 so finding myself NOWHERE i wanted to include SPONGE layer at the BOUNDARY
.------> Is this OK ??? .( need some suggestation/help HERE ).

to proceed with I included :
#define ALLOW_OBCS_SPONGE   : ---> in ..../code/OBCS_OPTIONS.h

and edited "data.obcs" :
# Open-boundaries
 &OBCS_PARM01
 OBCSfixTopo=.FALSE.,
 OB_Jnorth=174*-1,
 OB_Jsouth=174*1,
 OB_Ieast=200*-1,
 OB_Iwest=200*1,
# useOrlanskiN/S/E/S=.FALSE.,
 useOBCSbalance=.FALSE.,
 useOBCSprescribe = .FALSE.,
 useOBCSsponge=.TRUE.,
 &
# Orlanski parameters
 &OBCS_PARM02
 Cmax=0.45,
 cVelTimeScale=1000.,
 &
# Sponge-layer parameters
 &OBCS_PARM03
 Urelaxobcsinner=864000,
 Urelaxobcsbound=43200,
 Vrelaxobcsinner=864000,
 Vrelaxobcsbound=43200,
 spongeThickness=15,
 &

to start with. i had given : " # Sponge-layer parameters ;  &OBCS_PARM03 "
.  values BLINDLY. it didn't HELP. The temperature and Circulation results
were not satisfactory.

I have gone trough the manual , . But need a bit more explanation regarding
the physics of these paramaters.

And supposingly if i want to run MITgcm with this current configuration for
one month, ????? what should be the VALUES (of Sponge-layer parameters) to
START with. ??????

Any Suggestation/Help is highly appreciated.

Thanking all in advance.

Himansu.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mitgcm.org/pipermail/mitgcm-support/attachments/20120920/ff00692e/attachment.htm>