*IF DEF,OCEAN BIOMIX.2
C *****************************COPYRIGHT****************************** BIOMIX.3
C (c) CROWN COPYRIGHT 1997, METEOROLOGICAL OFFICE, All Rights Reserved. BIOMIX.4
C BIOMIX.5
C Use, duplication or disclosure of this code is subject to the BIOMIX.6
C restrictions as set forth in the contract. BIOMIX.7
C BIOMIX.8
C Meteorological Office BIOMIX.9
C London Road BIOMIX.10
C BRACKNELL BIOMIX.11
C Berkshire UK BIOMIX.12
C RG12 2SZ BIOMIX.13
C BIOMIX.14
C If no contract has been raised with this copy of the code, the use, BIOMIX.15
C duplication or disclosure of it is strictly prohibited. Permission BIOMIX.16
C to do so must first be obtained in writing from the Head of Numerical BIOMIX.17
C Modelling at the above address. BIOMIX.18
C ******************************COPYRIGHT****************************** BIOMIX.19
!+ Mixes biology tracers in the ocean mixed layer BIOMIX.20
! Subroutine Interface: BIOMIX.21
SUBROUTINE BIOMIX (TA, IMT, KM, NT, DZ, ZDZ, RZ, 1BIOMIX.22
& FM, KMT, MLD_MIX) BIOMIX.23
IMPLICIT NONE BIOMIX.24
! Description: BIOMIX.25
! Mixes the biology variables in the fully mixed part BIOMIX.26
! of the mixed layer, as defined by mixed layer depth BIOMIX.27
! 'MLD_MIX' BIOMIX.28
! Required for minimising timestep dependence of long BIOMIX.29
! timestep (eg 12,24 hour) biology runs. BIOMIX.30
! BIOMIX.31
! Current Code Owner: Richard Wood BIOMIX.32
! BIOMIX.33
! History: BIOMIX.34
! Version Date Comment BIOMIX.35
! ======= ==== ======= BIOMIX.36
! UM4.4 9.97 Original code. (Jonathan Palmer) BIOMIX.37
! BIOMIX.38
! Code description: BIOMIX.39
! FORTRAN 77 + common extensions also in fortran 90. BIOMIX.40
! This code is written to UM programming standards version 6 BIOMIX.41
! BIOMIX.42
! Global variables (*CALLed common blocks etc.) BIOMIX.43
*CALL CNTLOCN 
BIOMIX.44
*CALL OARRYSIZ BIOMIX.45
! Subroutine arguments BIOMIX.46
! Scalar arguments with intent(in): BIOMIX.47
INTEGER IMT ! IN Number of points in first dimension BIOMIX.48
! of arrays BIOMIX.49
INTEGER KM ! IN Number of points in vertical BIOMIX.50
INTEGER NT ! IN Number of tracers BIOMIX.51
INTEGER KMT(IMT) ! IN Number of gridpoints in each column BIOMIX.52
BIOMIX.53
! Array arguments with intent(in): BIOMIX.54
REAL DZ(KM) ! IN model layer thicknesses BIOMIX.55
REAL ZDZ(KM) ! IN depth of base of layers BIOMIX.56
REAL RZ(KM) ! IN layer thicknesses scaled by 1/RAT(K) BIOMIX.57
REAL FM(IMT,KM) ! IN Land/ea mask: 1.0=sea BIOMIX.58
REAL MLD_MIX(IMT) ! IN Instantaneous mixed layer depth from BIOMIX.59
! previous call to MIXLAY in this timestep. BIOMIX.60
! Note:MLD_MIX is in metres, DZ etc are in cm. BIOMIX.61
BIOMIX.62
! Array arguments with intent(InOut): BIOMIX.63
REAL TA (IMT, KM, NT) ! IN/OUT Tracer values BIOMIX.64
BIOMIX.65
! Local parameters: BIOMIX.66
INTEGER firstbiotracer ! index into TA of first tracer to mix BIOMIX.67
INTEGER lastbiotracer ! index into TA of last tracer to mix BIOMIX.68
PARAMETER (firstbiotracer=3) BIOMIX.69
PARAMETER (lastbiotracer=8) BIOMIX.70
BIOMIX.71
! Local scalars: BIOMIX.72
INTEGER i ! zonal index for loops BIOMIX.73
INTEGER k ! vertical index for loops BIOMIX.74
INTEGER m ! tracer number in loops BIOMIX.75
REAL column_sum ! Tracer integrated over fully mixed column BIOMIX.76
REAL column_mean ! Tracer meaned over column BIOMIX.77
BIOMIX.78
!- End of header BIOMIX.79
BIOMIX.80
! Loop over mixing tracers (m) and along row (i), averaging BIOMIX.81
! each tracer over the mixed layer depth (MLD_MIX). BIOMIX.82
BIOMIX.83
DO m=firstbiotracer,lastbiotracer BIOMIX.84
DO i=1,IMT BIOMIX.85
column_sum=0.0 BIOMIX.86
k=1 BIOMIX.87
DO WHILE ( (ZDZ(k).LE.MLD_MIX(i)*100.0).AND. BIOMIX.88
& ((k.LE.KMT(i)).AND.(FM(i,k).GT. 0.0)) ) BIOMIX.89
column_sum=column_sum + TA(i,k,m)*DZ(k)*FM(i,k) BIOMIX.90
k=k+1 BIOMIX.91
ENDDO BIOMIX.92
IF (k.GT.1) THEN BIOMIX.93
column_mean=column_sum/ZDZ(k-1) BIOMIX.94
k=1 BIOMIX.95
DO WHILE ( (ZDZ(k).LE.MLD_MIX(i)*100.0).AND. BIOMIX.96
& ((k.LE.KMT(i)).AND.(FM(i,k).GT. 0.0)) ) BIOMIX.97
TA(i,k,m)=column_mean BIOMIX.98
k=k+1 BIOMIX.99
ENDDO BIOMIX.100
ENDIF BIOMIX.101
ENDDO BIOMIX.102
ENDDO BIOMIX.103
BIOMIX.104
RETURN BIOMIX.105
END BIOMIX.106
*ENDIF BIOMIX.107