diff --git a/myconstants.py b/myconstants.py
new file mode 100644
index 0000000..1d24a24
--- /dev/null
+++ b/myconstants.py
@@ -0,0 +1,5 @@
+rho0    = 1027.0      # reference density     [kg m**-3] 
+grav    = 9.81        # gravity               [m s**-2]
+r_earth = 6.4e06      # earth radis           [m]
+gbuo    = -grav/rho0  #
+