SPDZ2UV

The SPDZ2UV routine computes the wind components from divergence
            and vorticity in spectral space.
            Subprogram SPEPS should be called already.
            If l is the zonal wavenumber, n is the total wavenumber,
            eps(l,n)=sqrt((n**2-l**2)/(4*n**2-1)) and a is earth radius,
            then the zonal wind component u is computed as
              U(L,N)=-I*L/(N*(N+1))*A*D(L,N)
                     +EPS(L,N+1)/(N+1)*A*Z(L,N+1)-EPS(L,N)/N*A*Z(L,N-1)

            and the meridional wind component v is computed as
              V(L,N)=-I*L/(N*(N+1))*A*Z(L,N)
                     -EPS(L,N+1)/(N+1)*A*D(L,N+1)+EPS(L,N)/N*A*D(L,N-1)

            Where d is divergence and z is vorticity.
            u and v are weighted by the cosine of latitude.
            extra terms are computed over top of the spectral domain.
            advantage is taken of the fact that eps(l,l)=0
            in order to vectorize over the entire spectral domain.

USAGE:    CALL SPDZ2UV(I,M,ENN1,ELONN1,EON,EONTOP,D,Z,U,V,UTOP,VTOP)

   Input argument list:
      I        - INTEGER SPECTRAL DOMAIN SHAPE
                 (0 FOR TRIANGULAR, 1 FOR RHOMBOIDAL)
      M        - INTEGER SPECTRAL TRUNCATION
      ENN1     - REAL ((M+1)*((I+1)*M+2)/2) N*(N+1)/A**2
      ELONN1   - REAL ((M+1)*((I+1)*M+2)/2) L/(N*(N+1))*A
      EON      - REAL ((M+1)*((I+1)*M+2)/2) EPSILON/N*A
      EONTOP   - REAL (M+1) EPSILON/N*A OVER TOP
      D        - REAL ((M+1)*((I+1)*M+2)) DIVERGENCE
      Z        - REAL ((M+1)*((I+1)*M+2)) VORTICITY
 
   Output argument list:
      U        - REAL ((M+1)*((I+1)*M+2)) ZONAL WIND (TIMES COSLAT)
      V        - REAL ((M+1)*((I+1)*M+2)) MERID WIND (TIMES COSLAT)
      UTOP     - REAL (2*(M+1)) ZONAL WIND (TIMES COSLAT) OVER TOP
      VTOP     - REAL (2*(M+1)) MERID WIND (TIMES COSLAT) OVER TOP

 
SPLIB.tar Library contains routines to be be used for a variety of spectral transform functions. (Fortran90)
Date posted: 2/23/2007