* rr_diff_ty.F * * Rick Romea * Jan. 24, 2000 * * Computes the meridional diffusive term: A T_yy * Units : oC/s * MOM2 Grid: T * ******************************************************************* SUBROUTINE RR_diff_ty_init(id) IMPLICIT NONE INCLUDE 'ferret_cmn/EF_Util.cmn' INTEGER id CALL ef_set_desc (id, .'Ah(d^2T/dy^2) diffusive term (oC/s);MOM2 T Grid') CALL ef_set_num_args (id, 2) CALL ef_set_axis_inheritance (id, IMPLIED_BY_ARGS, . IMPLIED_BY_ARGS, . IMPLIED_BY_ARGS, . IMPLIED_BY_ARGS) CALL ef_set_piecemeal_ok (id, NO, NO, NO, NO) CALL ef_set_arg_name (id, ARG1, 'U') CALL ef_set_arg_desc (id, ARG1, . 'Zonal velocity, required to access the MOM2 U Grid. ') CALL ef_set_arg_unit (id, ARG1, 'cm/sec') CALL ef_set_arg_type (id, ARG1, FLOAT_ARG) CALL ef_set_axis_influence (id, ARG1, YES, YES, YES, YES) CALL ef_set_axis_extend (id, ARG1, X_AXIS,-1,+1) CALL ef_set_axis_extend (id, ARG1, Y_AXIS,-1,+1) CALL ef_set_arg_name (id, ARG2, 'TEMP') CALL ef_set_arg_desc (id, ARG2, . 'Potential temperature, on MOM2 T Grid.') CALL ef_set_arg_unit (id, ARG2, '(oC') CALL ef_set_arg_type (id, ARG2, FLOAT_ARG) CALL ef_set_axis_influence (id, ARG2, NO, NO,YES,YES) CALL ef_set_axis_extend (id, ARG2, X_AXIS,-1,+1) CALL ef_set_axis_extend (id, ARG2, Y_AXIS,-1,+1) END SUBROUTINE RR_diff_ty_compute(id, arg_1, arg_2, result) IMPLICIT NONE INCLUDE 'ferret_cmn/EF_Util.cmn' INCLUDE 'ferret_cmn/EF_mem_subsc.cmn' INTEGER id REAL bad_flag(EF_MAX_ARGS) REAL bad_flag_result REAL arg_1 (mem1lox:mem1hix, mem1loy:mem1hiy, . mem1loz:mem1hiz, mem1lot:mem1hit) REAL arg_2 (mem2lox:mem2hix, mem2loy:mem2hiy, . mem2loz:mem2hiz, mem2lot:mem2hit) REAL result (memreslox:memreshix,memresloy:memreshiy, . memresloz:memreshiz,memreslot:memreshit) INTEGER res_lo_ss (4) INTEGER res_hi_ss (4) INTEGER res_incr (4) INTEGER arg_lo_ss (4,EF_MAX_ARGS) INTEGER arg_hi_ss (4,EF_MAX_ARGS) INTEGER arg_incr (4,EF_MAX_ARGS) INTEGER i, j, k, l INTEGER i2, j2, k2, l2 REAL*8 yU(1024) REAL*8 yT(1024) INTEGER ilat CHARACTER *16 ax_name(4) CHARACTER *16 ax_units(4) LOGICAL backward(4) LOGICAL modulo(4) LOGICAL regular(4) REAL dyt,dyu,xjt REAL cst,csu,diff_cnt,ahc_south,ahc_north . INCLUDE 'rr_parameters.h' C********************************************************************* c MOM2 Code: c DIFF_Ty(i,k,j) = ahc_north(j)*(t(i,k,j+1,n) - t(i,k,j, n)) c & - ahc_south(j)*(t(i,k,j ,n) - t(i,k,j-1,n)) c ahc_north(j) = diff_cnt(j)*csu(j)*dyur(j) c & *cstr(j)*dytr(j) c ahc_south(j) = diff_cnt(j)*csu(j-1)*dyur(j-1) c & *cstr(j)*dytr(j) c diff_cnt(j) = ah*xjt(j) c xjt(j) = 3.166*dyt(j)*dytr(50)-2.166 c dyt = latitudinal height of "t" grid box (in cm) c dytr = reciprocal of "dyt" c dyu = latitudinal height of "u,v" grid box (cm) c dyur = reciprocal of "dyu" c c ah = constant lateral diffusion coeff for tracers(cm**2/sec) c ah = 2.e7 c csu = cosine of "u,v" grid point latitude c csu(j) = cos(phiu(j)) c cst = cosine of "t" grid point latitude c cst(j) = cos(phit(j)) c cstr = reciprocal of "cst" c n = 1 => temperature c n = 2 => salinity c********************************************************************* ! Statement functions dyt(iLat) = SNGL(yU(iLat)-yU(iLat-1))*Latitude_to_cm dyu(iLat) = SNGL(yT(iLat+1)-yT(iLat))*Latitude_to_cm xjt(iLat) = 3.166*dyt(iLat)/dyt_ref-2.166 diff_cnt(iLat) = ah*xjt(iLat) cst(iLat) = cos(SNGL(yT(iLat))*Degrees_to_radians) csu(iLat) = cos(SNGL(yU(iLat))*Degrees_to_radians) ahc_south(iLat) = diff_cnt(iLat)*csu(iLat-1) . /cst(iLat)/dyu(iLat)/dyt(iLat) ahc_north(iLat) = diff_cnt(iLat)*csu(iLat) . /cst(iLat)/dyu(iLat)/dyt(iLat) ! Get axis data CALL ef_get_res_subscripts (id, res_lo_ss, res_hi_ss, res_incr) CALL ef_get_arg_subscripts (id, arg_lo_ss, arg_hi_ss, arg_incr) CALL ef_get_bad_flags (id, bad_flag, bad_flag_result) CALL ef_get_coordinates (id, ARG1, Y_AXIS, . arg_lo_ss(Y_AXIS,ARG1), . arg_hi_ss(Y_AXIS,ARG1), yU) CALL ef_get_coordinates (id, ARG2, Y_AXIS, . arg_lo_ss(Y_AXIS,ARG2), . arg_hi_ss(Y_AXIS,ARG2), yT) ! Check axis units: bail out if not lat and lon. CALL ef_get_axis_info (id, ARG1, ax_name, ax_units, . backward, modulo, regular) IF ( ax_units(1) .NE. 'deg' .AND. . ax_units(1) .NE. 'degrees_E' .AND. . ax_units(1) .NE. 'longitude' .AND. . ax_units(1) .NE. 'Longitude' .AND. . ax_units(1) .NE. 'LONGITUDE' ) THEN WRITE (6,*)'Longitude axis units =', ax_units(1) !CALL ef_bail_out(id,'Longitude axis must be in degrees') ENDIF IF ( ax_units(2) .NE. 'deg' .AND. . ax_units(2) .NE. 'degrees_N' .AND. . ax_units(2) .NE. 'latitude' .AND. . ax_units(2) .NE. 'Latitude' .AND. . ax_units(2) .NE. 'LATITUDE' ) THEN WRITE (6,*)'Latitude axis units =', ax_units(2) !CALL ef_bail_out(id,'Latitude axis must be in degrees') ENDIF l2 = arg_lo_ss(T_AXIS,ARG2) DO l = res_lo_ss(T_AXIS), res_hi_ss(T_AXIS) k2 = arg_lo_ss(Z_AXIS,ARG2) DO k = res_lo_ss(Z_AXIS), res_hi_ss(Z_AXIS) ilat = 2 j2 = arg_lo_ss(Y_AXIS,ARG2) + 1 DO j = res_lo_ss(Y_AXIS), res_hi_ss(Y_AXIS) i2 = arg_lo_ss(X_AXIS,ARG2) + 1 DO i = res_lo_ss(X_AXIS), res_hi_ss(X_AXIS) IF (arg_2(i2, j2, k2,l2) .EQ. bad_flag(ARG2) .OR. . arg_2(i2+1,j2, k2,l2) .EQ. bad_flag(ARG2) .OR. . arg_2(i2-1,j2, k2,l2) .EQ. bad_flag(ARG2) .OR. . arg_2(i2, j2+1,k2,l2) .EQ. bad_flag(ARG2) .OR. . arg_2(i2+1,j2+1,k2,l2) .EQ. bad_flag(ARG2) .OR. . arg_2(i2-1,j2+1,k2,l2) .EQ. bad_flag(ARG2) .OR. . arg_2(i2, j2-1,k2,l2) .EQ. bad_flag(ARG2) .OR. . arg_2(i2+1,j2-1,k2,l2) .EQ. bad_flag(ARG2) .OR. . arg_2(i2-1,j2-1,k2,l2) .EQ. bad_flag(ARG2) )THEN result(i,j,k,l) = bad_flag_result ELSE result(i,j,k,l) = ( . ahc_north(iLat)* . ( arg_2(i2,j2+1,k2,l2) . - arg_2(i2,j2 ,k2,l2)) . - ahc_south(iLat)* . ( arg_2(i2,j2 ,k2,l2) . - arg_2(i2,j2-1,k2,l2)) . )*sec_per_month ENDIF i2 = i2 + arg_incr(X_AXIS,ARG2) ENDDO iLat = iLat + 1 j2 = j2 + arg_incr(Y_AXIS,ARG2) ENDDO k2 = k2 + arg_incr(Z_AXIS,ARG2) ENDDO l2 = l2 + arg_incr(T_AXIS,ARG2) ENDDO END