c
      parameter(imx=73,kmx=25,jmx=36,nflds=16)
      parameter(imxp1=imx+1, nwlat=1+imxp1*kmx*nflds)
      parameter(zp1=-7.,dzp=0.5)
c
      common/tgcmrd/ frd(nwlat),gcmwt(nflds),gcmn2(imxp1,kmx),
     +  gcmzp(kmx)
      dimension f(imxp1,kmx,nflds)
      equivalence(frd(2),f)
      common /tigcmix/ ixt,ixu,ixv,ixo2,ixo1,ixn4s,ixno,ixop,ixn2d,
     +                 ixti,ixte,ixne,ixo2p,ixw,ixz,ixpot
      dimension ixgcm(nflds)
      equivalence(ixgcm,ixt)