[MITgcm-support] orlanski open boundary conditions

[Martin Losch]

Hi,

is there any experience on how well the open boudary conditions with 
orlanski radiation  are working? I would like to study the 
relaxation/spin-down of a solitary geostrophic eddy and from my initial 
adjustment I get all sorts of odd processes near the open boundaries 
(only "north" and "east"). I had hoped that the gravity waves would be 
more or less radiated out of the domain, which they mostly do, but 
there are strong vertical velocities near the open boundaries and 
eventually, the (linear free) sea-surface height is affected (its mean 
goes down by meters) and the solution diverges (explodes).

Any experience with this? Any ideas?

Martin

PS. this is my data.obcs
  &OBCS_PARM01
  OB_Jnorth=100*-1,
  OB_Jsouth=100*1,
  OB_Ieast=100*-1,
  OB_Iwest=100*1,
  useOrlanskiNorth=.TRUE.,
  useOrlanskiSouth=.TRUE.,
  useOrlanskiEast =.TRUE.,
  useOrlanskiWest =.TRUE.,
  &

  &OBCS_PARM02
  cmax=0.45D0,
  cvelTimeScale=500.D0,
  &