! (C) Copyright 2000- ECMWF. ! (C) Copyright 2000- Meteo-France. ! ! This software is licensed under the terms of the Apache Licence Version 2.0 ! which can be obtained at http://www.apache.org/licenses/LICENSE-2.0. ! In applying this licence, ECMWF does not waive the privileges and immunities ! granted to it by virtue of its status as an intergovernmental organisation ! nor does it submit to any jurisdiction. ! MODULE SPNSDE_MOD CONTAINS SUBROUTINE SPNSDE(KM,KF_SCALARS,PEPSNM,PF,PNSD) USE PARKIND1 ,ONLY : JPIM ,JPRB USE TPM_DIM ,ONLY : R USE TPM_FIELDS ,ONLY : F !**** *SPNSDE* - Compute North-South derivative in spectral space ! Purpose. ! -------- ! In Laplace space compute the the North-south derivative !** Interface. ! ---------- ! CALL SPNSDE(...) ! Explicit arguments : ! -------------------- ! KM -zonal wavenumber (input-c) ! PEPSNM - REPSNM for wavenumber KM (input-c) ! PF (NLEI1,2*KF_SCALARS) - input field (input) ! PNSD(NLEI1,2*KF_SCALARS) - N-S derivative (output) ! Organisation within NLEI1: ! NLEI1 = NSMAX+4+mod(NSMAX+4+1,2) ! overdimensioning ! 1 : n=NSMAX+2 ! 2 : n=NSMAX+1 ! 3 : n=NSMAX ! . : ! . : ! NSMAX+3 : n=0 ! NSMAX+4 : n=-1 ! Implicit arguments : YOMLAP ! -------------------- ! Method. ! ------- ! Externals. None. ! ---------- ! Reference. ! ---------- ! ECMWF Research Department documentation of the IFS ! Temperton, 1991, MWR 119 p1303 ! Author. ! ------- ! Mats Hamrud and Philippe Courtier *ECMWF* ! Modifications. ! -------------- ! Original : 00-02-01 From SPNSDE in IFS CY22R1 ! ------------------------------------------------------------------ IMPLICIT NONE INTEGER(KIND=JPIM), INTENT(IN) :: KM INTEGER(KIND=JPIM), INTENT(IN) :: KF_SCALARS REAL(KIND=JPRB), INTENT(IN) :: PEPSNM(0:R%NTMAX+2) REAL(KIND=JPRB), INTENT(IN) :: PF(:,:) REAL(KIND=JPRB), INTENT(OUT) :: PNSD(:,:) ! LOCAL INTEGER SCALARS INTEGER(KIND=JPIM) :: IJ, ISKIP, J, JN,JI,ISMAX REAL(KIND=JPRB) :: ZEPSNM(-1:R%NSMAX+4) REAL(KIND=JPRB) :: ZN(-1:R%NTMAX+4) ! ------------------------------------------------------------------ !* 1. COMPUTE NORTH SOUTH DERIVATIVE. ! ------------------------------- !* 1.1 COMPUTE ISMAX = R%NSMAX DO JN=KM-1,ISMAX+2 IJ = ISMAX+3-JN ZN(IJ) = F%RN(JN) IF( JN >= 0 ) ZEPSNM(IJ) = PEPSNM(JN) ENDDO ZN(0) = F%RN(ISMAX+3) IF(KM == 0) THEN ISKIP = 2 ELSE ISKIP = 1 ENDIF DO J=1,2*KF_SCALARS,ISKIP DO JI=2,ISMAX+3-KM PNSD(JI,J) = -ZN(JI+1)*ZEPSNM(JI)*PF(JI+1,J)+& &ZN(JI-2)*ZEPSNM(JI-1)*PF(JI-1,J) ENDDO ENDDO ! ------------------------------------------------------------------ END SUBROUTINE SPNSDE END MODULE SPNSDE_MOD