NCEPLIBS-ip  5.0.0
sptrunsv.f
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1 C> @file
2 C> @brief Spectrally interpolate vectors to polar stereo.
3 C>
4 C> 96-02-29 | Iredell | Initial.
5 C> 1998-12-15 | Iredell | Openmp directives inserted.
6 C>
7 C> @author Iredell @date 96-02-29
8 
9 C> This subprogram spectrally truncates vector fields
10 C> on a global cylindrical grid, returning the fields
11 C> to specific pairs of polar stereographic scalar fields.
12 C>
13 C> The wave-space can be either triangular or rhomboidal.
14 C>
15 C> The grid-space can be either an equally-spaced grid
16 C> (with or without pole points) or a gaussian grid.
17 C>
18 C> The grid fields may have general indexing.
19 C>
20 C> The transforms are all multiprocessed.
21 C>
22 C> Transform several fields at a time to improve vectorization.
23 C>
24 C> Subprogram can be called from a multiprocessing environment.
25 C>
26 C> Minimum grid dimensions for unaliased transforms to spectral:
27 C> Dimension |Linear |Quadratic
28 C> ----------------------- |--------- |-------------
29 C> IMAX |2*MAXWV+2 |3*MAXWV/2*2+2
30 C> JMAX (IDRT=4,IROMB=0) |1*MAXWV+1 |3*MAXWV/2+1
31 C> JMAX (IDRT=4,IROMB=1) |2*MAXWV+1 |5*MAXWV/2+1
32 C> JMAX (IDRT=0,IROMB=0) |2*MAXWV+3 |3*MAXWV/2*2+3
33 C> JMAX (IDRT=0,IROMB=1) |4*MAXWV+3 |5*MAXWV/2*2+3
34 C> JMAX (IDRT=256,IROMB=0) |2*MAXWV+1 |3*MAXWV/2*2+1
35 C> JMAX (IDRT=256,IROMB=1) |4*MAXWV+1 |5*MAXWV/2*2+1
36 C>
37 C> @param IROMB integer spectral domain shape
38 C> (0 for triangular, 1 for rhomboidal)
39 C> @param MAXWV integer spectral truncation
40 C> @param IDRTI integer input grid identifier
41 C> - IDRTI=4 for Gaussian grid
42 C> - IDRTI=0 for equally-spaced grid including poles
43 C> - IDRTI=256 for equally-spaced grid excluding poles
44 C> @param IMAXI integer even number of input longitudes.
45 C> @param JMAXI integer number of input latitudes.
46 C> @param KMAX integer number of fields to transform.
47 C> @param NPS integer odd order of the polar stereographic grids
48 C> @param IPRIME integer input longitude index for the prime meridian.
49 C> (defaults to 1 if IPRIME=0)
50 C> (output longitude index for prime meridian assumed 1.)
51 C> @param ISKIPI integer skip number between input longitudes
52 C> (defaults to 1 if ISKIPI=0)
53 C> @param JSKIPI integer skip number between input latitudes from south
54 C> (defaults to -IMAXI if JSKIPI=0)
55 C> @param KSKIPI integer skip number between input grid fields
56 C> (defaults to IMAXI*JMAXI if KSKIPI=0)
57 C> @param KGSKIP integer skip number between grid fields
58 C> (defaults to NPS*NPS if KGSKIP=0)
59 C> @param NISKIP integer skip number between grid i-points
60 C> (defaults to 1 if NISKIP=0)
61 C> @param NJSKIP integer skip number between grid j-points
62 C> (defaults to NPS if NJSKIP=0)
63 C> @param JCPU integer number of cpus over which to multiprocess
64 C> (defaults to environment NCPUS if JCPU=0)
65 C> @param TRUE real latitude at which ps grid is true (usually 60.)
66 C> @param XMESH real grid length at true latitude (m)
67 C> @param ORIENT real longitude at bottom of Northern PS grid
68 C> (Southern PS grid will have opposite orientation.)
69 C> @param GRIDUI real input grid u-winds
70 C> @param GRIDVI real input grid v-winds
71 C> @param LUV logical flag whether to return winds
72 C> @param LDZ logical flag whether to return divergence and vorticity
73 C> @param LPS logical flag whether to return potential and streamfcn
74 C> @param UN real northern ps u-winds if luv
75 C> @param VN real northern ps v-winds if luv
76 C> @param US real southern ps u-winds if luv
77 C> @param VS real southern ps v-winds if luv
78 C> @param DN real northern divergences if ldz
79 C> @param ZN real northern vorticities if ldz
80 C> @param DS real southern divergences if ldz
81 C> @param ZS real southern vorticities if ldz
82 C> @param PN real northern potentials if lps
83 C> @param SN real northern streamfcns if lps
84 C> @param PS real southern potentials if lps
85 C> @param SS real southern streamfcns if lps
86 C>
87 C> @author Iredell @date 96-02-29
88  SUBROUTINE sptrunsv(IROMB,MAXWV,IDRTI,IMAXI,JMAXI,KMAX,NPS,
89  & IPRIME,ISKIPI,JSKIPI,KSKIPI,KGSKIP,
90  & NISKIP,NJSKIP,JCPU,TRUE,XMESH,ORIENT,
91  & GRIDUI,GRIDVI,
92  & LUV,UN,VN,US,VS,LDZ,DN,ZN,DS,ZS,
93  & LPS,PN,SN,PS,SS)
94  LOGICAL LUV,LDZ,LPS
95  REAL GRIDUI(*),GRIDVI(*)
96  REAL UN(*),VN(*),US(*),VS(*),DN(*),ZN(*),DS(*),ZS(*)
97  REAL PN(*),SN(*),PS(*),SS(*)
98  REAL EPS((MAXWV+1)*((IROMB+1)*MAXWV+2)/2),EPSTOP(MAXWV+1)
99  REAL ENN1((MAXWV+1)*((IROMB+1)*MAXWV+2)/2)
100  REAL ELONN1((MAXWV+1)*((IROMB+1)*MAXWV+2)/2)
101  REAL EON((MAXWV+1)*((IROMB+1)*MAXWV+2)/2),EONTOP(MAXWV+1)
102  REAL WD((MAXWV+1)*((IROMB+1)*MAXWV+2)/2*2+1,KMAX)
103  REAL WZ((MAXWV+1)*((IROMB+1)*MAXWV+2)/2*2+1,KMAX)
104 
105 C TRANSFORM INPUT GRID TO WAVE
106  jc=jcpu
107  IF(jc.EQ.0) jc=ncpus()
108  mx=(maxwv+1)*((iromb+1)*maxwv+2)/2
109  mdim=2*mx+1
110  jn=-jskipi
111  IF(jn.EQ.0) jn=imaxi
112  js=-jn
113  inp=(jmaxi-1)*max(0,-jn)+1
114  isp=(jmaxi-1)*max(0,-js)+1
115  CALL sptranv(iromb,maxwv,idrti,imaxi,jmaxi,kmax,
116  & iprime,iskipi,jn,js,mdim,kskipi,0,0,jc,
117  & wd,wz,
118  & gridui(inp),gridui(isp),gridvi(inp),gridvi(isp),-1)
119 
120 C TRANSFORM WAVE TO OUTPUT WINDS
121  IF(luv) THEN
122  CALL sptgpsv(iromb,maxwv,kmax,nps,mdim,kgskip,niskip,njskip,
123  & true,xmesh,orient,wd,wz,un,vn,us,vs)
124  ENDIF
125 
126 C TRANSFORM WAVE TO OUTPUT DIVERGENCE AND VORTICITY
127  IF(ldz) THEN
128  CALL sptgps(iromb,maxwv,kmax,nps,mdim,kgskip,niskip,njskip,
129  & true,xmesh,orient,wd,dn,ds)
130  CALL sptgps(iromb,maxwv,kmax,nps,mdim,kgskip,niskip,njskip,
131  & true,xmesh,orient,wz,zn,zs)
132  ENDIF
133 
134 C TRANSFORM WAVE TO OUTPUT POTENTIAL AND STREAMFUNCTION
135  IF(lps) THEN
136  CALL spwget(iromb,maxwv,eps,epstop,enn1,elonn1,eon,eontop)
137 C$OMP PARALLEL DO
138  DO k=1,kmax
139  CALL splaplac(iromb,maxwv,enn1,wd(1,k),wd(1,k),-1)
140  CALL splaplac(iromb,maxwv,enn1,wz(1,k),wz(1,k),-1)
141  wd(1:2,k)=0.
142  wz(1:2,k)=0.
143  ENDDO
144  CALL sptgps(iromb,maxwv,kmax,nps,mdim,kgskip,niskip,njskip,
145  & true,xmesh,orient,wd,pn,ps)
146  CALL sptgps(iromb,maxwv,kmax,nps,mdim,kgskip,niskip,njskip,
147  & true,xmesh,orient,wz,sn,ss)
148  ENDIF
149  END
ncpus
function ncpus()
Set number of CPUs - the number of processors over which to parallelize.
Definition: ncpus.F:24
splaplac
subroutine splaplac(I, M, ENN1, Q, QD2, IDIR)
Computes the laplacian or the inverse laplacian of a scalar field in spectral space.
Definition: splaplac.f:25
sptgps
subroutine sptgps(IROMB, MAXWV, KMAX, NPS, KWSKIP, KGSKIP, NISKIP, NJSKIP, TRUE, XMESH, ORIENT, WAVE, GN, GS)
This subprogram performs a spherical transform from spectral coefficients of scalar quantities to sca...
Definition: sptgps.f:81
sptgpsv
subroutine sptgpsv(IROMB, MAXWV, KMAX, NPS, KWSKIP, KGSKIP, NISKIP, NJSKIP, TRUE, XMESH, ORIENT, WAVED, WAVEZ, UN, VN, US, VS)
This subprogram performs a spherical transform from spectral coefficients of divergences and curls to...
Definition: sptgpsv.f:83
sptranv
subroutine sptranv(IROMB, MAXWV, IDRT, IMAX, JMAX, KMAX, IPRIME, ISKIP, JNSKIP, JSSKIP, KWSKIP, KGSKIP, JBEG, JEND, JCPU, WAVED, WAVEZ, GRIDUN, GRIDUS, GRIDVN, GRIDVS, IDIR)
This subprogram performs a spherical transform between spectral coefficients of divergences and curls...
Definition: sptranv.f:91
sptrunsv
subroutine sptrunsv(IROMB, MAXWV, IDRTI, IMAXI, JMAXI, KMAX, NPS, IPRIME, ISKIPI, JSKIPI, KSKIPI, KGSKIP, NISKIP, NJSKIP, JCPU, TRUE, XMESH, ORIENT, GRIDUI, GRIDVI, LUV, UN, VN, US, VS, LDZ, DN, ZN, DS, ZS, LPS, PN, SN, PS, SS)
This subprogram spectrally truncates vector fields on a global cylindrical grid, returning the fields...
Definition: sptrunsv.f:94
spwget
subroutine spwget(IROMB, MAXWV, EPS, EPSTOP, ENN1, ELONN1, EON, EONTOP)
This subprogram gets wave-space constants.
Definition: spwget.f:18