subroutine deg2grid(dlong0,dlat,grid) real dlong !West longitude (deg) real dlat !Latitude (deg) character grid*6 dlong=dlong0 if(dlong.lt.-180.0) dlong=dlong+360.0 if(dlong.gt.180.0) dlong=dlong-360.0 ! Convert to units of 5 min of longitude, working east from 180 deg. nlong=60.0*(180.0-dlong)/5.0 n1=nlong/240 !20-degree field n2=(nlong-240*n1)/24 !2 degree square n3=nlong-240*n1-24*n2 !5 minute subsquare grid(1:1)=char(ichar('A')+n1) grid(3:3)=char(ichar('0')+n2) grid(5:5)=char(ichar('a')+n3) ! Convert to units of 2.5 min of latitude, working north from -90 deg. nlat=60.0*(dlat+90)/2.5 n1=nlat/240 !10-degree field n2=(nlat-240*n1)/24 !1 degree square n3=nlat-240*n1-24*n2 !2.5 minuts subsquare grid(2:2)=char(ichar('A')+n1) grid(4:4)=char(ichar('0')+n2) grid(6:6)=char(ichar('a')+n3) return end subroutine deg2grid