* rr_diff_tx.F * * Rick Romea * Jan. 24, 2000 * * Computes the zonal diffusive term: A T_xx * Units : oC/s * MOM2 Grid: T * ******************************************************************* SUBROUTINE RR_diff_tx_init(id) IMPLICIT NONE INCLUDE 'ferret_cmn/EF_Util.cmn' INTEGER id CALL ef_set_desc (id, .'Ah d^2T/dx^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 the MOM2 T Grid. ') CALL ef_set_arg_unit (id, ARG2, 'deg-C') 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_tx_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 xU(1024) REAL*8 yT(1024) REAL*8 xT(1024) INTEGER ilat INTEGER ilon CHARACTER *16 ax_name(4) CHARACTER *16 ax_units(4) LOGICAL backward(4) LOGICAL modulo(4) LOGICAL regular(4) REAL dxt, dyt, dxu,xjt REAL cst,diff_fe INCLUDE 'rr_parameters.h' C********************************************************************* C c MOM2 Code: c c DIFF_Tx(i,k,j) = (diff_fe(i,k,j) - diff_fe(i-1,k,j)) * cstdxtr(i,j) c c diff_fe(i,k,j) = ah_cstdxur(i,j) * (t(i+1,k,j,n) - t(i,k,j,n)) c cstdxtr(i,j) = cstr(j) * dxtr(i) c c ah_cstdxur(i,j) = diff_cet(j) * cstr(j) * dxur(i) c c diff_cet(j) = ah*xjt(j) c c ah = constant lateral diffusion coeff for tracers c ah = 2.e7(cm**2/sec) c xjt(j) = 3.166 * dyt(j) * dytr(50) - 2.166 c c dxt = longitudinal width of "t" grid box at the equator (cm) c dxtr = reciprocal of "dxt" c dyt = latitudinal height of "t" grid box (in cm) c dytr = reciprocal of "dyt" c dxu = longitudinal width of "u,v" grid box at the equator (cm) c dxur = reciprocal of "dxu" c c cst = cosine of "t" grid point latitude c cst(j) = cos(phit(j)) c cstr = reciprocal of "cst" c c n = 1 => temperature c n = 2 => salinity c c********************************************************************* dxt(i) = SNGL(xU(i)-xU(i-1))*Longitude_to_cm dyt(j) = SNGL(yU(j)-yU(j-1))*Latitude_to_cm dxu(i) = SNGL(xT(i+1)-xT(i))*Longitude_to_cm cst(i) = cos(SNGL(yT(i))*Degrees_to_radians) xjt(i) = 3.166*dyt(i)/dyt_ref-2.166 diff_fe(i,j,k,l,iLon,iLat) =ah*xjt(iLat) /cst(iLat)/dxu(iLon) . *(arg_2(i+1,j,k,l)-arg_2(i,j,k,l)) 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, X_AXIS, . arg_lo_ss(X_AXIS,ARG1), . arg_hi_ss(X_AXIS,ARG1), xU) 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, X_AXIS, . arg_lo_ss(X_AXIS,ARG2), . arg_hi_ss(X_AXIS,ARG2), xT) CALL ef_get_coordinates (id, ARG2, Y_AXIS, . arg_lo_ss(Y_AXIS,ARG2), . arg_hi_ss(Y_AXIS,ARG2), yT) 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) iLon = 2 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) = . (diff_fe(i2 ,j2,k2,l2,iLon,iLat) . - diff_fe(i2-1,j2,k2,l2,iLon-1,iLat)) . /cst(iLat)/dxt(iLon)*sec_per_month ENDIF iLon = iLon + 1 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