I would like to increase the precipitation efficiency for Grell convection scheme to increase convective precipitation.

Here is what I did in the namelist:

!

! Grell Cumulus scheme control

!

 &grellparam

 shrmin = 0.7,       ! Minimum Shear effect on precip eff.

 shrmax = 1.0,       ! Maximum Shear effect on precip eff.

 edtmin = 0.7,       ! Minimum Precipitation Efficiency

 edtmax = 1.0,       ! Maximum Precipitation Efficiency

 edtmino = 0.7,      ! Minimum Precipitation Efficiency (o var)

 edtmaxo = 1.0,      ! Maximum Precipitation Efficiency (o var)

 edtminx = 0.7,      ! Minimum Precipitation Efficiency (x var)

 edtmaxx = 1.0,      ! Maximum Precipitation Efficiency (x var)

 shrmin_ocn = 0.7,   ! Minimum Shear effect on precip eff. OCEAN points

 shrmax_ocn = 1.0,   ! Maximum Shear effect on precip eff.

 edtmin_ocn = 0.7,   ! Minimum Precipitation Efficiency

 edtmax_ocn = 1.0,   ! Maximum Precipitation Efficiency

 edtmino_ocn = 0.7,  ! Minimum Precipitation Efficiency (o var)

 edtmaxo_ocn = 1.0,  ! Maximum Precipitation Efficiency (o var)

 edtminx_ocn = 0.7,  ! Minimum Precipitation Efficiency (x var)

 edtmaxx_ocn = 1.0,  ! Maximum Precipitation Efficiency (x var)

But it does not work. I got less precipitation. 

Did I change  them in a wrong direction?  How do I adjust this parameter?

Thanks.

- Guangshan