Change excess ground ice units to unitless

Excess ground ice had been templated in these changes
as mass/area - changing to a volume/volume basis
(and therefore, now unitless).

components/elm/src/data_types/ColumnDataType.F90

@@ -1566,8 +1566,8 @@ subroutine col_ws_init(this, begc, endc, h2osno_input, snow_depth_input, watsat_
  end if
 
  this%excess_ice(begc:endc) = spval
- call hist_addfld1d (fname='EXCESS_ICE', units = 'kg/m2', &
- avgflag='A', long_name='Excess ground ice', &
+ call hist_addfld1d (fname='EXCESS_ICE', units = '1', &
+ avgflag='A', long_name='Excess ground ice (0 to 1)', &
  ptr_col=this%excess_ice, l2g_scale_type='veg') ! <- RPF: should this be natveg?
 
  this%frac_sno(begc:endc) = spval
@@ -1641,7 +1641,7 @@ subroutine col_ws_init(this, begc, endc, h2osno_input, snow_depth_input, watsat_
  this%frac_h2osfc_act(c) = 0._r8
  this%h2orof(c) = 0._r8
  this%frac_h2orof(c) = 0._r8
- this%excess_ice(c) = 500._r8
+ this%excess_ice(c) = 0.5_r8
 
  if (lun_pp%urbpoi(l)) then
  ! From Bonan 1996 (LSM technical note)
@@ -1909,7 +1909,7 @@ subroutine col_ws_restart(this, bounds, ncid, flag, watsat_input)
 
  call restartvar(ncid=ncid, flag=flag, varname='EXCESS_ICE', xtype=ncd_double, &
  dim1name='column', &
- long_name='excess ground ice', units='kg/m2', &
+ long_name='excess ground ice (0 to 1)', units='1', &
  interpinic_flag='interp', readvar=readvar, data=this%excess_ice)
 
  call restartvar(ncid=ncid, flag=flag, varname='frac_sno', xtype=ncd_double, &