1subroutine grayline(nyear,month,nday,uth,mygrid,nduration,isun) 2 3 character*6 mygrid 4 real LST 5 real lat,lon 6 7 call grid2deg(MyGrid,elon,lat) 8 lon=-elon 9 10 uth0=uth-0.5*nduration/60.0 11 uth1=uth+0.5*nduration/60.0 12 13 call sun(nyear,month,nday,uth0,lon,lat,RASun,DecSun,LST, & 14 AzSun,ElSun0,mjd,day) 15 call sun(nyear,month,nday,uth1,lon,lat,RASun,DecSun,LST, & 16 AzSun,ElSun1,mjd,day) 17 18 elchk=-0.8333 19 isun=-1 20 if(elsun0.lt.elchk .and. elsun1.ge.elchk) then 21 isun=0 22 else if(elsun0.gt.elchk .and. elsun1.le.elchk) then 23 isun=2 24 else if(elsun1.gt.elchk) then 25 isun=1 26 else 27 isun=3 28 endif 29 30 return 31end subroutine grayline 32 33