--- MITgcm/verification/exp4/README	1998/12/08 19:44:29	1.1
+++ MITgcm/verification/exp4/README	2010/04/06 21:04:45	1.6
@@ -1,2 +1,41 @@
-See the file doc/OpenBound.html or doc/OpenBound.txt for information
-on open boundaries
+Example: "Flow over a bump with Open Boundaries and passive tracers"
+====================================================================
+
+default paths are (as used in testreport):
+  set build_dir = ${cwd}/build
+  set exe       = ${cwd}/build
+  set ROOT      = ${cwd}/../../
+
+Configure and compile the code:
+  mkdir ${build_dir}
+  cd ${build_dir}
+  ${ROOT}/tools/genmake2 -mods=${cwd}/code
+  make depend
+  make
+
+To run:
+  mkdir ${exe_dir}
+  cd ${exe_dir}
+  cp ${cwd}/input/* .
+  ${build_dir}/mitgcmuv
+
+There is comparison output in the directory:
+ ..${cwd}/results
+
+Comments:
+The input data is real*8.
+
+This experiment is a channel with topography and four open
+boundaries. Salinity is not dynamically active in this experiment
+(linear equation of state with sBeta=0). Different kinds of open
+boundary values are used: zonal (x-)velocity U is prescribed at all
+open boundaries with values that are read from data files (specified
+in data.obcs); meridional (y-)velocity V is set to zero on all
+boundaries, and temperature to tRef(z), both in obcs_calc.F, this is
+the default behavior; at the western boundary, salinity values are
+used for salinity and one passive tracer in the same way. Salinity is
+set to sLev at all other boundaries, while a (nearly) homogeneous
+v.Neumann condition is applied to the passive tracer (the latter is
+the default in obcs_calc.F), with a relaxation (using pkg rbcs) in
+the Eastern part of the channel. Open boundary parameters are set in
+data.obcs.