*IF DEF,A05_3B,OR,DEF,A05_3C                                               AJX1F405.168    
C (c) CROWN COPYRIGHT 1995, METEOROLOGICAL OFFICE, All Rights Reserved.    GTS2F400.14691  
C                                                                          GTS2F400.14692  
C Use, duplication or disclosure of this code is subject to the            GTS2F400.14693  
C restrictions as set forth in the contract.                               GTS2F400.14694  
C                                                                          GTS2F400.14695  
C                Meteorological Office                                     GTS2F400.14696  
C                London Road                                               GTS2F400.14697  
C                BRACKNELL                                                 GTS2F400.14698  
C                Berkshire UK                                              GTS2F400.14699  
C                RG12 2SZ                                                  GTS2F400.14700  
C                                                                          GTS2F400.14701  
C If no contract has been raised with this copy of the code, the use,      GTS2F400.14702  
C duplication or disclosure of it is strictly prohibited.  Permission      GTS2F400.14703  
C to do so must first be obtained in writing from the Head of Numerical    GTS2F400.14704  
C Modelling at the above address.                                          GTS2F400.14705  
C ******************************COPYRIGHT******************************    GTS2F400.14706  
C                                                                          GTS2F400.14707  
CLL  SUBROUTINE DD_ENV-------------------------------------------------    DDENV3A.3      
CLL                                                                        DDENV3A.4      
CLL  PURPOSE : CALCULATE THE EFFECT OF THE DOWNDRAUGHT                     DDENV3A.5      
CLL            ON THE LARGE_SCALE ATMOSPHERE                               DDENV3A.6      
CLL                                                                        DDENV3A.7      
CLL  SUITABLE FOR SINGLE COLUMN MODEL USE                                  DDENV3A.8      
CLL                                                                        DDENV3A.9      
CLL                                                                        DDENV3A.10     
CLL  MODEL            MODIFICATION HISTORY FROM MODEL VERSION 3.0:         DDENV3A.11     
CLL VERSION  DATE                                                          DDENV3A.12     
CLL   4.0   5/5/95    new deck added for vesrion 3A of convection          DDENV3A.13     
CLL                   scheme. Includes tracers and momentum in the         DDENV3A.14     
CLL                   downdraught.                                         DDENV3A.15     
CLL                   Pete Inness.                                         DDENV3A.16     
CLL                                                                        DDENV3A.17     
CLL  PROGRAMMING STANDARDS : UNIFIED MODEL DOCUMENTATION PAPER NO. 3       DDENV3A.18     
CLL  VERSION NO. 4  DATED 5/2/92                                           DDENV3A.19     
CLL                                                                        DDENV3A.20     
CLL  LOGICAL COMPONENTS COVERED:                                           DDENV3A.21     
CLL                                                                        DDENV3A.22     
CLL  SYSTEM TASK : P27                                                     DDENV3A.23     
CLL                                                                        DDENV3A.24     
CLL  DOCUMENTATION : UNIFIED MODEL DOCUMENTATION PAPER P27                 DDENV3A.25     
CLL                                                                        DDENV3A.26     
CLLEND-----------------------------------------------------------------    DDENV3A.27     
C                                                                          DDENV3A.28     
C*L  ARGUMENTS---------------------------------------------------------    DDENV3A.29     
C                                                                          DDENV3A.30     

      SUBROUTINE DD_ENV (NPNTS,NP_FULL,THDD_K,THDD_KM1,QDD_K,QDD_KM1,       3DDENV3A.31     
     *                   THE_K,THE_KM1,QE_K,QE_KM1,DTHBYDT_K,              DDENV3A.32     
     *                   DTHBYDT_KM1,DQBYDT_K,DQBYDT_KM1,FLX_DD_K,         DDENV3A.33     
     *                   FLX_DD_KM1,DELPK,DELPKM1,DELTD,DELQD,AMDETK,      DDENV3A.34     
     *                   EKM14,B_DD_END,BDD_START,BDD_ON,L_MOM,UDD_K,      DDENV3A.35     
     *                   VDD_K,UDD_KM1,VDD_KM1,UE_K,VE_K,UE_KM1,VE_KM1,    DDENV3A.36     
     *                   DUBYDT_K,DUBYDT_KM1,DVBYDT_K,DVBYDT_KM1,DELUD,    DDENV3A.37     
     *                   DELVD,EFLUX_U_DD,EFLUX_V_DD,                      DDENV3A.38     
     *                   L_TRACER,NTRA,TRADD_K,TRADD_KM1,TRAE_K,           DDENV3A.39     
     *                   TRAE_KM1,DTRABYDT_K,DTRABYDT_KM1,DELTRAD)         DDENV3A.40     
C                                                                          DDENV3A.41     
      IMPLICIT NONE                                                        DDENV3A.42     
C                                                                          DDENV3A.43     
C-----------------------------------------------------------------------   DDENV3A.44     
C VECTOR LENGTHS AND LOOP COUNTERS                                         DDENV3A.45     
C-----------------------------------------------------------------------   DDENV3A.46     
C                                                                          DDENV3A.47     
      INTEGER NPNTS                 ! IN VECTOR LENGTH                     DDENV3A.48     
C                                                                          DDENV3A.49     
      INTEGER NP_FULL               ! IN FULL VECTOR LENGTH                DDENV3A.50     
C                                                                          DDENV3A.51     
      INTEGER I,KTRA                ! LOOP COUNTERS                        DDENV3A.52     
C                                                                          DDENV3A.53     
      INTEGER NTRA                  ! IN NUMBER OF TRACERS                 DDENV3A.54     
C                                                                          DDENV3A.55     
C-----------------------------------------------------------------------   DDENV3A.56     
C VARIABLES WHICH ARE INPUT                                                DDENV3A.57     
C-----------------------------------------------------------------------   DDENV3A.58     
C                                                                          DDENV3A.59     
      REAL THDD_K(NPNTS)            ! IN DOWNDRAUGHT POTENTIAL             DDENV3A.60     
                                    !    TEMPERATURE IN LAYER K (K)        DDENV3A.61     
C                                                                          DDENV3A.62     
      REAL THDD_KM1(NPNTS)          ! IN DOWNDRAUGHT POTENTIAL             DDENV3A.63     
                                    !    TEMPERATURE IN LAYER K-1 (K)      DDENV3A.64     
C                                                                          DDENV3A.65     
      REAL QDD_K(NPNTS)             ! IN DOWNDRAUGHT MIXING RATIO          DDENV3A.66     
                                    !    AT LAYER K (KG/KG)                DDENV3A.67     
C                                                                          DDENV3A.68     
      REAL QDD_KM1(NPNTS)           ! IN DOWNDRAUGHT MIXING RATIO          DDENV3A.69     
                                    !    AT LAYER K-1 (KG/KG)              DDENV3A.70     
C                                                                          DDENV3A.71     
      REAL UDD_K(NPNTS)             ! IN DOWNDRAUGHT U IN LAYER            DDENV3A.72     
                                    !    K (M/S)                           DDENV3A.73     
C                                                                          DDENV3A.74     
      REAL UDD_KM1(NPNTS)           ! IN DOWNDRAUGHT U IN LAYER            DDENV3A.75     
                                    !     K-1 (M/S)                        DDENV3A.76     
C                                                                          DDENV3A.77     
      REAL VDD_K(NPNTS)             ! IN DOWNDRAUGHT V IN LAYER            DDENV3A.78     
                                    !    K (M/S)                           DDENV3A.79     
C                                                                          DDENV3A.80     
      REAL VDD_KM1(NPNTS)           ! IN DOWNDRAUGHT V IN LAYER            DDENV3A.81     
                                    !     K-1 (M/S)                        DDENV3A.82     
C                                                                          DDENV3A.83     
      REAL TRADD_K(NP_FULL,NTRA)    ! IN DOWNDRAUGHT TRACER CONTENT        DDENV3A.84     
                                    !    IN LAYER K (KG/KG)                DDENV3A.85     
C                                                                          DDENV3A.86     
      REAL TRADD_KM1(NPNTS,NTRA)    ! IN DOWNDRAUGHT TRACER CONTENT        DDENV3A.87     
                                    !    AT LAYER K-1 (KG/KG)              DDENV3A.88     
C                                                                          DDENV3A.89     
      REAL THE_K(NPNTS)             ! IN POTENTIAL TEMPERATURE OF          DDENV3A.90     
                                    !    ENVIRONMENT IN LAYER K (K)        DDENV3A.91     
C                                                                          DDENV3A.92     
      REAL THE_KM1(NPNTS)           ! IN POTENTIAL TEMPERATURE OF          DDENV3A.93     
                                    !    ENVIRONMENT IN LAYER K-1 (K)      DDENV3A.94     
C                                                                          DDENV3A.95     
      REAL QE_K(NPNTS)              ! IN MIXING RATIO AT LAYER K (KG/KG)   DDENV3A.96     
C                                                                          DDENV3A.97     
      REAL QE_KM1(NPNTS)            ! IN MIXING RATIO AT LAYER K-1         DDENV3A.98     
                                    !    (KG/KG)                           DDENV3A.99     
C                                                                          DDENV3A.100    
      REAL UE_K(NPNTS)              ! IN U AT LAYER K (M/S)                DDENV3A.101    
C                                                                          DDENV3A.102    
      REAL UE_KM1(NPNTS)            ! IN U AT LAYER K-1 (M/S)              DDENV3A.103    
C                                                                          DDENV3A.104    
      REAL VE_K(NPNTS)              ! IN V AT LAYER K (M/S)                DDENV3A.105    
C                                                                          DDENV3A.106    
      REAL VE_KM1(NPNTS)            ! IN V AT LAYER K-1 (M/S)              DDENV3A.107    
C                                                                          DDENV3A.108    
      REAL TRAE_K(NP_FULL,NTRA)     ! IN TRACER CONTENT OF                 DDENV3A.109    
                                    !    ENVIRONMENT IN LAYER K (KG/KG)    DDENV3A.110    
C                                                                          DDENV3A.111    
      REAL TRAE_KM1(NP_FULL,NTRA)   ! IN TRACER CONTENT OF ENVIRONMENT     DDENV3A.112    
                                    !    IN LAYER K-1 (KG/KG)              DDENV3A.113    
C                                                                          DDENV3A.114    
      REAL FLX_DD_K(NPNTS)          ! IN MASS FLUX IN LAYER K (PA/S)       DDENV3A.115    
C                                                                          DDENV3A.116    
      REAL FLX_DD_KM1(NPNTS)        ! IN MASS FLUX IN LAYER K-1 (PA/S)     DDENV3A.117    
C                                                                          DDENV3A.118    
      REAL DELPK(NPNTS)             ! IN DIFFERENCE IN PRESSURE ACROSS     DDENV3A.119    
                                    !    LAYER K (PA)                      DDENV3A.120    
C                                                                          DDENV3A.121    
      REAL DELPKM1(NPNTS)           ! IN DIFFERENCE IN PRESSURE ACROSS     DDENV3A.122    
                                    !    LAYER K-1 (PA)                    DDENV3A.123    
C                                                                          DDENV3A.124    
      REAL DELTD(NPNTS)             ! IN COOLING NECESSARY TO ACHIEVE      DDENV3A.125    
                                    !    SATURATION (K)                    DDENV3A.126    
C                                                                          DDENV3A.127    
      REAL DELQD(NPNTS)             ! IN MOISTENING NECESSARY TO ACHIEVE   DDENV3A.128    
                                    !    SATURATION (KG/KG)                DDENV3A.129    
C                                                                          DDENV3A.130    
      REAL DELUD(NPNTS)             ! IN CHANGE TO ENVIRONMENT U DUE TO    DDENV3A.131    
                                    !    DOWNDRAUGHT FORMATION (M/S)       DDENV3A.132    
C                                                                          DDENV3A.133    
      REAL DELVD(NPNTS)             ! IN CHANGE TO ENVIRONMENT V DUE TO    DDENV3A.134    
                                    !    DOWNDRAUGHT FORMATION (M/S)       DDENV3A.135    
C                                                                          DDENV3A.136    
      REAL DELTRAD(NP_FULL,NTRA)    ! IN DEPLETION OF ENVIRONMENT TRACER   DDENV3A.137    
                                    !    DUE TO DOWNDRAUGHT FORMATION      DDENV3A.138    
C                                                                          DDENV3A.139    
      REAL AMDETK(NPNTS)            ! IN MIXING DETRAINMENT AT LEVEL K     DDENV3A.140    
                                    !    MULTIPLIED BY APPROPRIATE LAYER   DDENV3A.141    
                                    !    THICKNESS                         DDENV3A.142    
C                                                                          DDENV3A.143    
      REAL EKM14(NPNTS)             ! IN EXNER RATIO AT LAYER K-1/4        DDENV3A.144    
C                                                                          DDENV3A.145    
      LOGICAL B_DD_END(NPNTS)       ! IN MASK FOR THOSE POINTS WHERE       DDENV3A.146    
                                    !    DOWNDRAUGHT IS TERMINATING        DDENV3A.147    
C                                                                          DDENV3A.148    
      LOGICAL BDD_START(NPNTS)      ! IN MASK FOR THOSE POINTS WHERE       DDENV3A.149    
                                    !    DOWNDRAUGHT IS STARTING           DDENV3A.150    
C                                                                          DDENV3A.151    
      LOGICAL BDD_ON(NPNTS)         ! IN MASK FOR THOSE POINTS WHERE       DDENV3A.152    
                                    !    DOWNDRAUGHT IS ON                 DDENV3A.153    
C                                                                          DDENV3A.154    
      LOGICAL L_TRACER              ! IN SWITCH FOR INCLUSION OF TRACERS   DDENV3A.155    
C                                                                          DDENV3A.156    
      LOGICAL L_MOM                 ! IN SWITCH FOR INCLUSION OF           DDENV3A.157    
                                    !    MOMENTUM TRANSPORTS               DDENV3A.158    
C                                                                          DDENV3A.159    
C-----------------------------------------------------------------------   DDENV3A.160    
C VARIABLES WHICH ARE INPUT AND OUTPUT                                     DDENV3A.161    
C-----------------------------------------------------------------------   DDENV3A.162    
C                                                                          DDENV3A.163    
      REAL DTHBYDT_K(NPNTS)         ! INOUT                                DDENV3A.164    
                                    ! IN  INCREMENT TO POTENTIAL           DDENV3A.165    
                                    !     TEMPERATURE IN LAYER K (K/S)     DDENV3A.166    
                                    ! OUT UPDATED INCREMENT TO POTENTIAL   DDENV3A.167    
                                    !     TEMPERATURE IN LAYER K (K/S)     DDENV3A.168    
C                                                                          DDENV3A.169    
      REAL DTHBYDT_KM1(NPNTS)       ! INOUT                                DDENV3A.170    
                                    ! IN  INCREMENT TO POTENTIAL           DDENV3A.171    
                                    !     TEMPERATURE AT LAYER K-1 (K/S)   DDENV3A.172    
                                    ! OUT UPDATED INCREMENT TO POTENTIAL   DDENV3A.173    
                                    !     TEMPERATURE AT LAYER K-1 (K/S)   DDENV3A.174    
C                                                                          DDENV3A.175    
      REAL DQBYDT_K(NPNTS)          ! INOUT                                DDENV3A.176    
                                    ! IN  INCREMENT TO MIXING RATIO        DDENV3A.177    
                                    !     AT LAYER K (KG/KG/S)             DDENV3A.178    
                                    ! OUT UPDATED INCREMENT TO MIXING      DDENV3A.179    
                                    !     RATIO AT LAYER K (KG/KG/S)       DDENV3A.180    
C                                                                          DDENV3A.181    
      REAL DQBYDT_KM1(NPNTS)        ! INOUT                                DDENV3A.182    
                                    ! IN  INCREMENT TO MIXING RATIO AT     DDENV3A.183    
                                    !     LAYER K-1 (KG/KG/S)              DDENV3A.184    
                                    ! OUT UPDATED INCREMENT TO MIXING      DDENV3A.185    
                                    !     RATIO AT LAYER K-1 (KG/KG/S)     DDENV3A.186    
C                                                                          DDENV3A.187    
      REAL DUBYDT_K(NPNTS)          ! INOUT                                DDENV3A.188    
                                    ! IN  INCREMENT TO U AT LAYER K        DDENV3A.189    
                                    !     (M/S**2)                         DDENV3A.190    
                                    ! OUT UPDATED INCREMENT TO U           DDENV3A.191    
                                    !     AT LAYER K (M/S**2)              DDENV3A.192    
C                                                                          DDENV3A.193    
      REAL DUBYDT_KM1(NPNTS)        ! INOUT                                DDENV3A.194    
                                    ! IN  INCREMENT TO U AT LAYER K-1      DDENV3A.195    
                                    !     (M/S**2)                         DDENV3A.196    
                                    ! OUT UPDATED INCREMENT TO U           DDENV3A.197    
                                    !     AT LAYER K-1 (M/S**2)            DDENV3A.198    
C                                                                          DDENV3A.199    
      REAL DVBYDT_K(NPNTS)          ! INOUT                                DDENV3A.200    
                                    ! IN  INCREMENT TO V AT LAYER K        DDENV3A.201    
                                    !     (M/S**2)                         DDENV3A.202    
                                    ! OUT UPDATED INCREMENT TO V           DDENV3A.203    
                                    !     AT LAYER K (M/S**2)              DDENV3A.204    
C                                                                          DDENV3A.205    
      REAL DVBYDT_KM1(NPNTS)        ! INOUT                                DDENV3A.206    
                                    ! IN  INCREMENT TO V AT LAYER K-1      DDENV3A.207    
                                    !     (M/S**2)                         DDENV3A.208    
                                    ! OUT UPDATED INCREMENT TO V           DDENV3A.209    
                                    !     AT LAYER K-1 (M/S**2)            DDENV3A.210    
C                                                                          DDENV3A.211    
      REAL DTRABYDT_K(NP_FULL,NTRA) ! INOUT                                DDENV3A.212    
                                    ! IN  INCREMENT TO TRACER CONTENT      DDENV3A.213    
                                    !     IN LAYER K (KG/KG/S)             DDENV3A.214    
                                    ! OUT UPDATED INCREMENT TO TRACER      DDENV3A.215    
                                    !     CONTENT IN LAYER K (KG/KG/S)     DDENV3A.216    
C                                                                          DDENV3A.217    
      REAL DTRABYDT_KM1(NP_FULL,    ! INOUT                                DDENV3A.218    
     *                  NTRA)       ! IN  INCREMENT TO TRACER CONTENT      DDENV3A.219    
                                    !     AT LAYER K-1 (KG/KG/S)           DDENV3A.220    
                                    ! OUT UPDATED INCREMENT TO TRACER      DDENV3A.221    
                                    !     CONTENT AT LAYER K-1             DDENV3A.222    
                                    !     (KG/KG/S)                        DDENV3A.223    
C                                                                          DDENV3A.224    
      REAL EFLUX_U_DD(NPNTS),       ! INOUT                                DDENV3A.225    
     *     EFLUX_V_DD(NPNTS)        ! IN  EDDY FLUX OF MOMENTUM DUE TO     DDENV3A.226    
                                    !     DD AT TOP OF LAYER               DDENV3A.227    
                                    ! OUT EDDY FLUX OF MOMENTUM DUE TO     DDENV3A.228    
                                    !     DD AT BOTTOM OF LAYER            DDENV3A.229    
C                                                                          DDENV3A.230    
C-----------------------------------------------------------------------   DDENV3A.231    
C VARIABLES WHICH ARE DEFINED LOCALLY                                      DDENV3A.232    
C-----------------------------------------------------------------------   DDENV3A.233    
C                                                                          DDENV3A.234    
      REAL TEMPRY                   ! USED IN CALCULATIONS OF THE          DDENV3A.235    
                                    ! EFFECT ON THE ENVIRONMENT            DDENV3A.236    
C                                                                          DDENV3A.237    
      REAL FLX_U_KM0P5,             ! EDDY FLUX OF U AND V AT              DDENV3A.238    
     *     FLX_V_KM0P5              ! BOTTOM OF LAYER                      DDENV3A.239    
C                                                                          DDENV3A.240    
C-----------------------------------------------------------------------   DDENV3A.241    
C CALCULATE THE EFFECT ON THE ENVIRONMENT IN LAYER K                       DDENV3A.242    
C-----------------------------------------------------------------------   DDENV3A.243    
C                                                                          DDENV3A.244    
      DO I=1,NPNTS                                                         DDENV3A.245    
       IF (BDD_ON(I)) THEN                                                 DDENV3A.246    
C                                                                          DDENV3A.247    
C-----------------------------------------------------------------------   DDENV3A.248    
C SUBTRACT ENERGY USED TO FORM DOWNDRAUGHT                                 DDENV3A.249    
C-----------------------------------------------------------------------   DDENV3A.250    
C                                                                          DDENV3A.251    
       TEMPRY = FLX_DD_K(I)/DELPK(I)                                       DDENV3A.252    
       IF (BDD_START(I)) THEN                                              DDENV3A.253    
         DTHBYDT_K(I) = DTHBYDT_K(I)-TEMPRY*DELTD(I)                       DDENV3A.254    
         DQBYDT_K(I) = DQBYDT_K(I)-TEMPRY*DELQD(I)                         DDENV3A.255    
       END IF                                                              DDENV3A.256    
C                                                                          DDENV3A.257    
C-----------------------------------------------------------------------   DDENV3A.258    
C EFFECT OF CONVECTION AND DOWNDRAUGHT UPON POTENTIAL TEMPERATURE OF       DDENV3A.259    
C LAYER K                                                                  DDENV3A.260    
C-----------------------------------------------------------------------   DDENV3A.261    
C                                                                          DDENV3A.262    
       DTHBYDT_K(I) = DTHBYDT_K(I) + TEMPRY * (                            DDENV3A.263    
     *                                                                     DDENV3A.264    
     *          (1.0+EKM14(I)) * (1.0-AMDETK(I)) *      ! COMPENSATING     DDENV3A.265    
     *           (THE_KM1(I)-THE_K(I))                  ! SUBSIDENCE       DDENV3A.266    
     *        +                                                            DDENV3A.267    
     *          AMDETK(I)* (THDD_K(I)-THE_K(I))         ! MIXING           DDENV3A.268    
     *        )                                         ! DETRAINMENT      DDENV3A.269    
C                                                                          DDENV3A.270    
C-----------------------------------------------------------------------   DDENV3A.271    
C EFFECT OF CONVECTION AND DOWNDRAUGHT UPON MIXING RATIO OF                DDENV3A.272    
C LAYER K                                                                  DDENV3A.273    
C-----------------------------------------------------------------------   DDENV3A.274    
C                                                                          DDENV3A.275    
       DQBYDT_K(I) = DQBYDT_K(I) + TEMPRY * (                              DDENV3A.276    
     *                                                                     DDENV3A.277    
     *      (1.0+EKM14(I)) * (1.0-AMDETK(I)) *       ! COMPENSATING        DDENV3A.278    
     *      (QE_KM1(I)-QE_K(I))                      ! SUBSIDENCE          DDENV3A.279    
     *    +                                                                DDENV3A.280    
     *      AMDETK(I)* (QDD_K(I)-QE_K(I))            ! MIXING              DDENV3A.281    
     *    )                                          ! DETRAINMENT         DDENV3A.282    
C                                                                          DDENV3A.283    
C                                                                          DDENV3A.284    
C-----------------------------------------------------------------------   DDENV3A.285    
C TERMINAL DETRAINMENT AND SUBSIDENCE IN TERMINAL LAYER                    DDENV3A.286    
C-----------------------------------------------------------------------   DDENV3A.287    
C                                                                          DDENV3A.288    
         IF (B_DD_END(I)) THEN                                             DDENV3A.289    
           TEMPRY = FLX_DD_KM1(I)/DELPKM1(I)                               DDENV3A.290    
           DTHBYDT_KM1(I) = DTHBYDT_KM1(I)+TEMPRY*                         DDENV3A.291    
     *                      (THDD_KM1(I)-THE_KM1(I))                       DDENV3A.292    
           DQBYDT_KM1(I) = DQBYDT_KM1(I)+TEMPRY*(QDD_KM1(I)-QE_KM1(I))     DDENV3A.293    
C                                                                          DDENV3A.294    
         END IF                                                            DDENV3A.295    
C                                                                          DDENV3A.296    
       END IF                                                              DDENV3A.297    
      END DO                                                               DDENV3A.298    
C                                                                          DDENV3A.299    
C-----------------------------------------------------------------------   DDENV3A.300    
C EFFECT OF CONVECTION AND DOWNDRAUGHT UPON MOMENTUM OF                    DDENV3A.301    
C LAYER K                                                                  DDENV3A.302    
C-----------------------------------------------------------------------   DDENV3A.303    
C                                                                          DDENV3A.304    
      IF(L_MOM)THEN                                                        DDENV3A.305    
C                                                                          DDENV3A.306    
      DO I=1,NPNTS                                                         DDENV3A.307    
      IF(BDD_ON(I))THEN                                                    DDENV3A.308    
       TEMPRY = FLX_DD_K(I)/DELPK(I)                                       DDENV3A.309    
       IF(BDD_START(I))THEN                                                DDENV3A.310    
         DUBYDT_K(I) = DUBYDT_K(I)-TEMPRY*DELUD(I)                         DDENV3A.311    
         DVBYDT_K(I) = DVBYDT_K(I)-TEMPRY*DELVD(I)                         DDENV3A.312    
       END IF                                                              DDENV3A.313    
C                                                                          DDENV3A.314    
C----------------------------------------------------------------------    DDENV3A.315    
C CALCULATE MOMENTUM FLUX AT BOTTOM OF LAYER                               DDENV3A.316    
C----------------------------------------------------------------------    DDENV3A.317    
C                                                                          DDENV3A.318    
       FLX_U_KM0P5 = FLX_DD_K(I) * (1.0-AMDETK(I)) * (1.0+EKM14(I)) *      DDENV3A.319    
     *               (UDD_K(I) - UE_KM1(I))                                DDENV3A.320    
       FLX_V_KM0P5 = FLX_DD_K(I) * (1.0-AMDETK(I)) * (1.0+EKM14(I)) *      DDENV3A.321    
     *               (VDD_K(I) - VE_KM1(I))                                DDENV3A.322    
C                                                                          DDENV3A.323    
C---------------------------------------------------------------------     DDENV3A.324    
C CALCULATE INCREMENT TO LAYER K                                           DDENV3A.325    
C---------------------------------------------------------------------     DDENV3A.326    
C                                                                          DDENV3A.327    
       IF (BDD_START(I)) THEN                                              DDENV3A.328    
C                                                                          DDENV3A.329    
        DUBYDT_K(I) = DUBYDT_K(I) - FLX_U_KM0P5/DELPK(I)                   DDENV3A.330    
        DVBYDT_K(I) = DVBYDT_K(I) - FLX_V_KM0P5/DELPK(I)                   DDENV3A.331    
C                                                                          DDENV3A.332    
C STORE FLUX READY FOR UPDATING NEXT LAYER                                 DDENV3A.333    
C                                                                          DDENV3A.334    
        EFLUX_U_DD(I) = FLX_U_KM0P5                                        DDENV3A.335    
        EFLUX_V_DD(I) = FLX_V_KM0P5                                        DDENV3A.336    
C                                                                          DDENV3A.337    
       ELSE                                                                DDENV3A.338    
C                                                                          DDENV3A.339    
        DUBYDT_K(I) = DUBYDT_K(I) + ((EFLUX_U_DD(I) - FLX_U_KM0P5)/        DDENV3A.340    
     *                                                    DELPK(I))        DDENV3A.341    
        DVBYDT_K(I) = DVBYDT_K(I) + ((EFLUX_V_DD(I) - FLX_V_KM0P5)/        DDENV3A.342    
     *                                                    DELPK(I))        DDENV3A.343    
C                                                                          DDENV3A.344    
C STORE FLUX READY FOR UPDATING NEXT LAYER                                 DDENV3A.345    
C                                                                          DDENV3A.346    
        EFLUX_U_DD(I) = FLX_U_KM0P5                                        DDENV3A.347    
        EFLUX_V_DD(I) = FLX_V_KM0P5                                        DDENV3A.348    
C                                                                          DDENV3A.349    
       END IF                                                              DDENV3A.350    
C                                                                          DDENV3A.351    
CL--------------------------------------------------------------------     DDENV3A.352    
CL TERMINAL DETRAINMENT OF MOMENTUM                                        DDENV3A.353    
CL-------------------------------------------------------------------      DDENV3A.354    
C                                                                          DDENV3A.355    
        IF(B_DD_END(I))THEN                                                DDENV3A.356    
           DUBYDT_KM1(I) = FLX_U_KM0P5/DELPKM1(I)                          DDENV3A.357    
           DVBYDT_KM1(I) = FLX_V_KM0P5/DELPKM1(I)                          DDENV3A.358    
C                                                                          DDENV3A.359    
C ZERO FLUX AT BOTTOM OF LAYER                                             DDENV3A.360    
C                                                                          DDENV3A.361    
           EFLUX_U_DD(I) = 0.0                                             DDENV3A.362    
           EFLUX_V_DD(I) = 0.0                                             DDENV3A.363    
        END IF                                                             DDENV3A.364    
      END IF                                                               DDENV3A.365    
      END DO                                                               DDENV3A.366    
C                                                                          DDENV3A.367    
      END IF                                                               DDENV3A.368    
C                                                                          DDENV3A.369    
C-----------------------------------------------------------------------   DDENV3A.370    
C EFFECT OF CONVECTION AND DOWNDRAUGHT UPON TRACER CONTENT OF              DDENV3A.371    
C LAYER K                                                                  DDENV3A.372    
C-----------------------------------------------------------------------   DDENV3A.373    
C                                                                          DDENV3A.374    
      IF(L_TRACER)THEN                                                     DDENV3A.375    
C                                                                          DDENV3A.376    
      DO KTRA=1,NTRA                                                       DDENV3A.377    
       DO I=1,NPNTS                                                        DDENV3A.378    
        IF(BDD_ON(I))THEN                                                  DDENV3A.379    
C                                                                          DDENV3A.380    
        TEMPRY = FLX_DD_K(I)/DELPK(I)                                      DDENV3A.381    
        IF(BDD_START(I))THEN                                               DDENV3A.382    
        DTRABYDT_K(I,KTRA) = DTRABYDT_K(I,KTRA)-TEMPRY*DELTRAD(I,KTRA)     DDENV3A.383    
        END IF                                                             DDENV3A.384    
        DTRABYDT_K(I,KTRA) = DTRABYDT_K(I,KTRA) + TEMPRY * (               DDENV3A.385    
     *                                                                     DDENV3A.386    
     *   (1.0+EKM14(I)) * (1.0-AMDETK(I)) *             ! COMPENSATING     DDENV3A.387    
     *   (TRAE_KM1(I,KTRA)-TRAE_K(I,KTRA))              ! SUBSIDENCE       DDENV3A.388    
     *        +                                                            DDENV3A.389    
     *   AMDETK(I)* (TRADD_K(I,KTRA)-TRAE_K(I,KTRA))    ! MIXING           DDENV3A.390    
     *        )                                         ! DETRAINMENT      DDENV3A.391    
C                                                                          DDENV3A.392    
C-----------------------------------------------------------------------   DDENV3A.393    
C TERMINAL DETRAINMENT OF TRACER                                           DDENV3A.394    
C-----------------------------------------------------------------------   DDENV3A.395    
C                                                                          DDENV3A.396    
           IF(B_DD_END(I))THEN                                             DDENV3A.397    
             TEMPRY = FLX_DD_KM1(I)/DELPKM1(I)                             DDENV3A.398    
             DTRABYDT_KM1(I,KTRA)=DTRABYDT_KM1(I,KTRA)+TEMPRY*             DDENV3A.399    
     *                            (TRADD_KM1(I,KTRA)-TRAE_KM1(I,KTRA))     DDENV3A.400    
           END IF                                                          DDENV3A.401    
C                                                                          DDENV3A.402    
        END IF                                                             DDENV3A.403    
       END DO                                                              DDENV3A.404    
      END DO                                                               DDENV3A.405    
C                                                                          DDENV3A.406    
      END IF                                                               DDENV3A.407    
C                                                                          DDENV3A.408    
      RETURN                                                               DDENV3A.409    
      END                                                                  DDENV3A.410    
C                                                                          DDENV3A.411    
*ENDIF                                                                     DDENV3A.412