if (temperature.lt.273.15 .and. temperature.gt.220.15) then
   XNC = 5.0*EXP(0.304*(273.15-max(temperature,238.)))
   Ni = XNC/density
   qi = Ni*1.e-12
   if (height.lt.2500 .or. height.gt.8000) then
      qs = 0.0
   else
      zzref = (height - 5000.) / 1947.2
      qs = -0.0470*zzref**4 + 0.0625*zzref**3 + 0.0242*zzref**2 -0.1657*zzref + 0.2215
      qs = max(0.0, qs*1.e-3)    
   endif
else
   Ni = 0.0
   qi = 0.0
   qs = 0.0
endif