c  $Header: /usr/people/flittner/radtran/tomrad/pv2.2/src/RCS/set_p11_z11_spline.f,v 2.22 2000/08/30 16:38:09 flittner Exp $
        subroutine set_p11_z11_splines()
c
c*****perform a spline fit to log(p) and z
c
        include 'parameter.inc'
        include 'atm_11.cmn'
        include 'input.cmn'
        include 'switches.cmn'
c local
        integer mode
        real*8 y21,y2n,const
c
        if(lv7tab)then
          mode=0
          y21=1.0d30
          y2n=1.0d30
          call spline(z11,plginv,n_p_lay,y21,y2n,cz,mode)
          call spline(plginv,z11,n_p_lay,y21,y2n,cp,mode)
        else
          mode=0
          y21=1.0d30
          y2n=1.0d30
          call spline(z11,plginv,n_p_lay,y21,y2n,cz,mode)
c
          mode=0
          const=1.0/(-34.163)
cc use upper 2 average temperatures to compute the boundary value for the
cc spline fit at the top of the atmosphere in hopes that it will cause 
cc the fit to behave better.
c          y2n=1.5*(z11(n_p_lay)-z11(n_p_lay-1))/const/(plginv(n_p_lay)-plginv(n_p_lay-1))/
c     &((1.0+0.5*(z11(n_p_lay)+z11(n_p_lay-1))/r)**2)-
c     &0.5*(z11(n_p_lay-1)-z11(n_p_lay-2))/const/(plginv(n_p_lay-1)-plginv(n_p_lay-2))/
c     &((1.0+0.5*(z11(n_p_lay-1)+z11(n_p_lay-2))/r)**2)
c          y2n=y2n*const
          y2n=1.0d30
cc use the surface temperature from the us76 std atmo
c          y21=288.15*const
          y21=tmpsfc*const
          call spline(plginv,z11,n_p_lay,y21,y2n,cp,mode)
        endif
        end