*IF DEF,A05_3C CRSFRZ3C.2
C ******************************COPYRIGHT****************************** CRSFRZ3C.3
C (c) CROWN COPYRIGHT 1997, METEOROLOGICAL OFFICE, All Rights Reserved. CRSFRZ3C.4
C CRSFRZ3C.5
C Use, duplication or disclosure of this code is subject to the CRSFRZ3C.6
C restrictions as set forth in the contract. CRSFRZ3C.7
C CRSFRZ3C.8
C Meteorological Office CRSFRZ3C.9
C London Road CRSFRZ3C.10
C BRACKNELL CRSFRZ3C.11
C Berkshire UK CRSFRZ3C.12
C RG12 2SZ CRSFRZ3C.13
C CRSFRZ3C.14
C If no contract has been raised with this copy of the code, the use, CRSFRZ3C.15
C duplication or disclosure of it is strictly prohibited. Permission CRSFRZ3C.16
C to do so must first be obtained in writing from the Head of Numerical CRSFRZ3C.17
C Modelling at the above address. CRSFRZ3C.18
C ******************************COPYRIGHT****************************** CRSFRZ3C.19
C CRSFRZ3C.20
CLL SUBROUTINE CRS_FRZL------------------------------------------ CRSFRZ3C.21
CLL CRSFRZ3C.22
CLL PURPOSE : CHANGE OF PHASE ROUTINE WHERE PRECIPITATION CRSFRZ3C.23
CLL CROSSES A MELTING OR FREEZING LEVEL CRSFRZ3C.24
CLL CRSFRZ3C.25
CLL ADD LATENT HEATING CRSFRZ3C.26
CLL CRSFRZ3C.27
CLL SUITABLE FOR SINGLE COLUMN MODEL USE CRSFRZ3C.28
CLL CRSFRZ3C.29
CLL CODE WRITTEN FOR CRAY Y-MP BY S.BETT AND D.GREGORY AUTUMN 1991 CRSFRZ3C.30
CLL CRSFRZ3C.31
CLL MODEL MODIFICATION HISTORY: CRSFRZ3C.32
CLL VERSION DATE CRSFRZ3C.33
!LL 4.4 17/10/97 New version optimised for T3E. CRSFRZ3C.34
!LL Single PE optimisations D.Salmond CRSFRZ3C.35
!LL 4.5 03/03/98 Insert missing brackets. Julie Gregory. ADR1F405.75
CLL CRSFRZ3C.36
CLL PROGRAMMING STANDARDS : UNIFIED MODEL DOCUMENTATION PAPER NO. 3 CRSFRZ3C.37
CLL VERSION NO. 4 DATED 5/2/92 CRSFRZ3C.38
CLL CRSFRZ3C.39
CLL LOGICAL COMPONENTS COVERED: CRSFRZ3C.40
CLL CRSFRZ3C.41
CLL SYSTEM TASK : P27 CRSFRZ3C.42
CLL CRSFRZ3C.43
CLL DOCUMENTATION : UNIFIED MODEL DOCUMENTATION PAPER 27 CRSFRZ3C.44
CLL CRSFRZ3C.45
CLLEND----------------------------------------------------------------- CRSFRZ3C.46
C CRSFRZ3C.47
C*L ARGUMENTS--------------------------------------------------------- CRSFRZ3C.48
C CRSFRZ3C.49
SUBROUTINE CRS_FRZL (NPNTS,RAIN,SNOW,THDD_KM1,EXKM1, 3CRSFRZ3C.50
& FLX_DD_KM1,BDDWT_KM1) CRSFRZ3C.51
C CRSFRZ3C.52
IMPLICIT NONE CRSFRZ3C.53
C CRSFRZ3C.54
C---------------------------------------------------------------------- CRSFRZ3C.55
C MODEL CONSTANTS CRSFRZ3C.56
C---------------------------------------------------------------------- CRSFRZ3C.57
C CRSFRZ3C.58
*CALL C_LHEAT 
CRSFRZ3C.59
*CALL C_R_CP CRSFRZ3C.60
*CALL C_G CRSFRZ3C.61
*CALL C_0_DG_C CRSFRZ3C.62
C CRSFRZ3C.63
C---------------------------------------------------------------------- CRSFRZ3C.64
C VECTOR LENGTHS AND LOOP COUNTERS CRSFRZ3C.65
C---------------------------------------------------------------------- CRSFRZ3C.66
C CRSFRZ3C.67
INTEGER NPNTS ! IN VECTOR LENGTH CRSFRZ3C.68
C CRSFRZ3C.69
INTEGER I ! LOOP COUNTER CRSFRZ3C.70
C CRSFRZ3C.71
C---------------------------------------------------------------------- CRSFRZ3C.72
C VARIABLES WHICH ARE INPUT CRSFRZ3C.73
C---------------------------------------------------------------------- CRSFRZ3C.74
C CRSFRZ3C.75
LOGICAL BDDWT_KM1(NPNTS) ! IN MASK FOR POINTS WHERE CRSFRZ3C.76
! PRECIPITATION IS LIQUID CRSFRZ3C.77
! IN LAYER K+1 CRSFRZ3C.78
C CRSFRZ3C.79
REAL EXKM1(NPNTS) ! IN EXNER RATIO FOR LAYER K-1 CRSFRZ3C.80
C CRSFRZ3C.81
REAL FLX_DD_KM1(NPNTS) ! IN MASS FLUX OF LAYER K-1 (PA/S) CRSFRZ3C.82
C CRSFRZ3C.83
C---------------------------------------------------------------------- CRSFRZ3C.84
C VARIABLES WHICH ARE INPUT AND OUTPUT CRSFRZ3C.85
C---------------------------------------------------------------------- CRSFRZ3C.86
C CRSFRZ3C.87
REAL RAIN(NPNTS) ! INOUT CRSFRZ3C.88
! IN AMOUNT OF FALLING RAIN CRSFRZ3C.89
! DESCENDING FROM LAYER CRSFRZ3C.90
! K-1 TO K-2 (KG/M**2/S) CRSFRZ3C.91
! OUT UPDATED AMOUNT OF FALLING CRSFRZ3C.92
! RAIN (KG/M**2/S) CRSFRZ3C.93
C CRSFRZ3C.94
REAL SNOW(NPNTS) ! INOUT CRSFRZ3C.95
! IN AMOUNT OF FALLING SNOW CRSFRZ3C.96
! DESCENDING FROM LAYER CRSFRZ3C.97
! K-1 TO K-2 (KG/M**2/S) CRSFRZ3C.98
! OUT UPDATED AMOUNT OF FALLING CRSFRZ3C.99
! SNOW (KG/M**2/S) CRSFRZ3C.100
C CRSFRZ3C.101
REAL THDD_KM1(NPNTS) ! INOUT CRSFRZ3C.102
! IN DOWNDRAUGHT POTENTIAL CRSFRZ3C.103
! TEMPERATURE IN LAYER K-1 (K) CRSFRZ3C.104
! OUT UPDATED DOWNDRAUGHT POTENTIAL CRSFRZ3C.105
! TEMPERATURE IN LAYER K-1 CRSFRZ3C.106
! DUE TO CHANGE OF PHASE (K) CRSFRZ3C.107
C CRSFRZ3C.108
C---------------------------------------------------------------------- CRSFRZ3C.109
C VARIABLES WHICH ARE DEFINED LOCALLY CRSFRZ3C.110
C--------------------------------------------------------------------- CRSFRZ3C.111
C CRSFRZ3C.112
REAL FACTOR ! USED IN THE CALCULATION OF CRSFRZ3C.113
! CHANGE OF PHASE OF FALLING CRSFRZ3C.114
! PRECIPITATION CRSFRZ3C.115
C CRSFRZ3C.116
REAL PRECIP_FRE ! FREEZING PRECIPITATION CRSFRZ3C.117
C CRSFRZ3C.118
REAL PRECIP_MELT ! MELTING PRECIPITATION CRSFRZ3C.119
C CRSFRZ3C.120
CL CRSFRZ3C.121
CL---------------------------------------------------------------------- CRSFRZ3C.122
CL ADD LATENT HEATING WHERE PRECIP CROSSES A MELTING OR FREEZING LEVEL CRSFRZ3C.123
CL CRSFRZ3C.124
CL UM DOCUMENTATION PAPER 27 CRSFRZ3C.125
CL SECTION (11), EQUATION (42) CRSFRZ3C.126
CL---------------------------------------------------------------------- CRSFRZ3C.127
CL CRSFRZ3C.128
DO I=1,NPNTS CRSFRZ3C.129
C CRSFRZ3C.130
IF (.NOT.BDDWT_KM1(I).AND.RAIN(I).GT.0.0.AND.THDD_KM1(I) CRSFRZ3C.131
* *EXKM1(I).LT.TM) THEN CRSFRZ3C.132
C FREEZE CRSFRZ3C.133
FACTOR = (EXKM1(I)*CP*FLX_DD_KM1(I))/(LF*G) ADR1F405.76
PRECIP_FRE = (TM/EXKM1(I)-THDD_KM1(I))* FACTOR CRSFRZ3C.135
PRECIP_FRE = MIN(RAIN(I),PRECIP_FRE) CRSFRZ3C.136
THDD_KM1(I) = THDD_KM1(I)+PRECIP_FRE/FACTOR CRSFRZ3C.137
RAIN(I) = RAIN(I)-PRECIP_FRE CRSFRZ3C.138
SNOW(I) = SNOW(I)+PRECIP_FRE CRSFRZ3C.139
C CRSFRZ3C.140
ELSE IF (BDDWT_KM1(I).AND.SNOW(I).GT.0.0) THEN CRSFRZ3C.141
C MELT CRSFRZ3C.142
FACTOR = (EXKM1(I)*CP*FLX_DD_KM1(I))/(LF*G) ADR1F405.77
PRECIP_MELT = (THDD_KM1(I)-TM/EXKM1(I))*FACTOR CRSFRZ3C.144
PRECIP_MELT = MIN(SNOW(I),PRECIP_MELT) CRSFRZ3C.145
THDD_KM1(I) = THDD_KM1(I)-PRECIP_MELT/FACTOR CRSFRZ3C.146
RAIN(I) = RAIN(I)+PRECIP_MELT CRSFRZ3C.147
SNOW(I) = SNOW(I)-PRECIP_MELT CRSFRZ3C.148
END IF CRSFRZ3C.149
END DO CRSFRZ3C.150
C CRSFRZ3C.151
RETURN CRSFRZ3C.152
END CRSFRZ3C.153
C CRSFRZ3C.154
*ENDIF CRSFRZ3C.155