*IF DEF,W05_1A                                                             WVV0F401.15     
C (c) CROWN COPYRIGHT 1995, METEOROLOGICAL OFFICE, All Rights Reserved.    GTS2F400.15609  
C                                                                          GTS2F400.15610  
C Use, duplication or disclosure of this code is subject to the            GTS2F400.15611  
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C                Meteorological Office                                     GTS2F400.15614  
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C If no contract has been raised with this copy of the code, the use,      GTS2F400.15620  
C duplication or disclosure of it is strictly prohibited.  Permission      GTS2F400.15621  
C to do so must first be obtained in writing from the Head of Numerical    GTS2F400.15622  
C Modelling at the above address.                                          GTS2F400.15623  
C ******************************COPYRIGHT******************************    GTS2F400.15624  
C                                                                          GTS2F400.15625  
                                                                           SBOTTOM.3      

      SUBROUTINE SBOTTOM (F, FL, IJS, IJL, IG,                              1SBOTTOM.4      
*CALL ARGWVAL                                                              SBOTTOM.5      
*CALL ARGWVSH                                                              SBOTTOM.6      
*CALL ARGWVSR                                                              SBOTTOM.7      
     & icode)                                                              SBOTTOM.8      
                                                                           SBOTTOM.9      
*CALL PARWVSH                                                              SBOTTOM.10     
*CALL PARCONS                                                              SBOTTOM.11     
      PARAMETER (CONST = -2.0*0.038/G)                                     SBOTTOM.12     
                                                                           SBOTTOM.13     
*CALL TYPWVSH                                                              SBOTTOM.14     
*CALL TYPWVSR                                                              SBOTTOM.15     
*CALL TYPWVAL                                                              SBOTTOM.16     
                                                                           SBOTTOM.17     
CSHALLOW                                                                   SBOTTOM.18     
C ----------------------------------------------------------------------   SBOTTOM.19     
C                                                                          SBOTTOM.20     
C**** *SBOTTOM* - COMPUTATION OF BOTTOM FRICTION.                          SBOTTOM.21     
C                                                                          SBOTTOM.22     
C     G.J.KOMEN AND Q.D.GAO                                                SBOTTOM.23     
C     OPTIMIZED BY L.F. ZAMBRESKY                                          SBOTTOM.24     
C                                                                          SBOTTOM.25     
C*    PURPOSE.                                                             SBOTTOM.26     
C     --------                                                             SBOTTOM.27     
C                                                                          SBOTTOM.28     
C       COMPUTATION OF BOTTOM FRICTION DISSIPATION                         SBOTTOM.29     
C                                                                          SBOTTOM.30     
C**   INTERFACE.                                                           SBOTTOM.31     
C     ----------                                                           SBOTTOM.32     
C                                                                          SBOTTOM.33     
C       *CALL* *SBOTTOM (F, FL, IJS, IJL, IG)*                             SBOTTOM.34     
C          *F*   - SPECTRUM.                                               SBOTTOM.35     
C          *FL*  - DIAGONAL MATRIX OF FUNCTIONAL DERIVATIVE                SBOTTOM.36     
C          *IJS* - INDEX OF FIRST GRIDPOINT                                SBOTTOM.37     
C          *IJL* - INDEX OF LAST GRIDPOINT                                 SBOTTOM.38     
C          *IG*  - BLOCK NUMBER                                            SBOTTOM.39     
C                                                                          SBOTTOM.40     
C     METHOD.                                                              SBOTTOM.41     
C     -------                                                              SBOTTOM.42     
C                                                                          SBOTTOM.43     
C       SEE REFERENCES.                                                    SBOTTOM.44     
C                                                                          SBOTTOM.45     
C     REFERENCES.                                                          SBOTTOM.46     
C     -----------                                                          SBOTTOM.47     
C                                                                          SBOTTOM.48     
C       HASSELMANN ET AL, D. HYDR. Z SUPPL A12(1973) (JONSWAP)             SBOTTOM.49     
C       BOUWS AND KOMEN, JPO 13(1983)1653-1658                             SBOTTOM.50     
C                                                                          SBOTTOM.51     
C ----------------------------------------------------------------------   SBOTTOM.52     
C                                                                          SBOTTOM.53     
      DIMENSION F(0:NIBLO,NANG,NFRE), FL(0:NIBLO,NANG,NFRE)                SBOTTOM.54     
      DIMENSION SBO(NIBLO)                                                 SBOTTOM.55     
C                                                                          SBOTTOM.56     
C ----------------------------------------------------------------------   SBOTTOM.57     
C                                                                          SBOTTOM.58     
      DO 1050 M=1,NFRE                                                     SBOTTOM.59     
         DO 1010 IJ=IJS,IJL                                                SBOTTOM.60     
            ARG = 2.* DEPTH(IJ,IG)*TFAK(INDEP(IJ),M)                       SBOTTOM.61     
            ARG = MIN(ARG,50.)                                             SBOTTOM.62     
            SBO(IJ) = CONST*TFAK(INDEP(IJ),M)/SINH(ARG)                    SBOTTOM.63     
 1010    CONTINUE                                                          SBOTTOM.64     
                                                                           SBOTTOM.65     
         DO 1040 K=1,NANG                                                  SBOTTOM.66     
            DO 1030 IJ=IJS,IJL                                             SBOTTOM.67     
               SL(IJ,K,M) = SL(IJ,K,M)+SBO(IJ)*F(IJ,K,M)                   SBOTTOM.68     
               FL(IJ,K,M) = FL(IJ,K,M)+SBO(IJ)                             SBOTTOM.69     
 1030      CONTINUE                                                        SBOTTOM.70     
 1040    CONTINUE                                                          SBOTTOM.71     
 1050 CONTINUE                                                             SBOTTOM.72     
                                                                           SBOTTOM.73     
      RETURN                                                               SBOTTOM.74     
      END                                                                  SBOTTOM.75     
*ENDIF                                                                     SBOTTOM.76