c
c Grid sizes:
c
c nfhist = 34: tn,un,vn,o2,ox,n4s,noz,co,co2,h2o,h2,hox,o+,ch4,o21d,
c              no2,no,o3,o1,oh,ho2,h,n2d,ti,te,ne,o2+,w,z,epot,
c              ui,vi,wi,n2
c nftot = nfhist
c
      parameter(jmx=36,imx=73,nfhist=34,glat1=-87.5,glon1=-180.,
     +  dlat=5.,dlon=5.,dzp=0.5,spval=1.e36,zp1times=-17.,zp1tigcm=-7.,
     +  ispval=9999,rminlog=1.e-20,nftot=nfhist)
      character*8 flab(nftot)
      character*56 unixdir,mssdir
      pointer(pgcmzp,gcmzp(1))
c
      common/gcm/ gcmlat(jmx),gcmlon(imx),pgcmzp,kmx,ifields(nftot),
     +  nflds,flab,logint(nftot),unixdir,mssdir,ionvel,ifget(nfhist),
     +  nfget,pdipdec
c
c History input:
c
      parameter(mxvols=10,mxtms=241)
      character*24 histvol(mxvols)
      logical istimes,isdyn,issech
      common/input/ histvol,iden,mtimes(3,mxtms),ntms,ut(mxtms),
     +  nhvols,luhist,ivol,lumag,istimes,isdyn,ludipdec
      common/ixgcm/
     +  ixt     ,ixu     ,ixv     ,ixo2    ,ixox    ,ixn4s   ,
     +  ixnoz   ,ixco    ,ixco2   ,ixh2o   ,ixh2    ,ixhox   ,
     +  ixop    ,ixch4   ,ixo21d  ,ixno2   ,ixno    ,ixo3    ,
     +  ixo1    ,ixoh    ,ixho2   ,ixh     ,ixn2d   ,ixti    ,
     +  ixte    ,ixne    ,ixo2p   ,ixw     ,ixz     ,ixpot   ,
     +  ixn2    ,ixui    ,ixvi    ,ixwi
c
c Tgcm header:
c
      common /tgcmhdr/ iter,nday,nhr,nmin,label(40),
     +  date(2),output(3,20),start(3),stp(6),hist(6),sav(3),step,
     +  mag(4),difhor,iuivi,sdtide(10),ipower,aurora,dispos,data(3),
     +  source(3),sourct(3),dtide(2),dum(8),rdate,naur,hp,cp,byimf,
     +  aurp(60),rmodnum,colfac,f107d,f107a,modelhts
      integer start,stp,hist,step,sourct,sav,date,difhor,aurora,dispos
      real mag
      character*8 data,source,label,output,rdate