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2 michaesp 1
      PROGRAM caltra
2
 
3
C     ********************************************************************
4
C     *                                                                  *
5
C     * Calculates trajectories                                          *
6
C     *                                                                  *
7
C     *	Heini Wernli	   first version:	April 1993                   *
8
C     * Michael Sprenger   major upgrade:       2008-2009                *
9
C     *                                                                  *
10
C     ********************************************************************
11
 
12
      implicit none      
13
 
14
c     --------------------------------------------------------------------
15
c     Declaration of parameters
16
c     --------------------------------------------------------------------
17
 
18
c     Maximum number of levels for input files
19
      integer   nlevmax
20
      parameter	(nlevmax=100)
21
 
22
c     Maximum number of input files (dates, length of trajectories)
23
      integer   ndatmax
24
      parameter	(ndatmax=500)
25
 
26
c     Numerical epsilon (for float comparison)
27
      real      eps
28
      parameter (eps=0.001)
29
 
30
c     Distance in m between 2 lat circles 
31
      real	deltay
32
      parameter	(deltay=1.112E5)
33
 
34
c     Number of iterations for iterative Euler scheme
35
      integer   numit
36
      parameter (numit=3)
37
 
38
c     Input and output format for trajectories (see iotra.f)
39
      integer   inpmode
40
      integer   outmode
41
 
42
c     Filename prefix (typically 'P')
43
      character*1 prefix
44
      parameter   (prefix='P')
45
 
46
c     Externals
47
      real       sdis
48
      external   sdis
49
 
50
c     --------------------------------------------------------------------
51
c     Declaration of variables
52
c     --------------------------------------------------------------------
53
 
54
c     Input parameters
55
      integer                                fbflag          ! Flag for forward/backward mode
56
      integer                                numdat          ! Number of input files
57
      character*11                           dat(ndatmax)    ! Dates of input files
58
      real                                   timeinc         ! Time increment between input files
59
      integer                                per             ! Periodicity flag (=0 if none)
60
      integer                                ntra            ! Number of trajectories
61
      character*80                           cdfname         ! Name of output files
62
      real                                   ts              ! Time step
63
      real                                   tst,ten         ! Shift of start and end time relative to first data file
64
      integer                                deltout         ! Output time interval (in minutes)
65
      integer                                jflag           ! Jump flag (if =1 ground-touching trajectories reenter atmosphere)
66
      real                                   wfactor         ! Factor for vertical velocity field
67
      character*80                           strname         ! File with start positions
68
      character*80                           timecheck       ! Either 'yes' or 'no'
69
      character*10		              	     gridflag        ! "ideal" or "real"
70
 
71
c     Trajectories
72
      integer                                ncol            ! Number of columns for insput trajectories
73
      real,allocatable, dimension (:,:,:) :: trainp          ! Input start coordinates (ntra,1,ncol)
74
      real,allocatable, dimension (:,:,:) :: traout          ! Output trajectories (ntra,ntim,4)
75
      integer                                reftime(6)      ! Reference date
76
      character*80                           vars(200)       ! Field names
77
      real,allocatable, dimension (:)     :: xx0,yy0,pp0     ! Position of air parcels
78
      integer,allocatable, dimension (:)  :: leftflag        ! Flag for domain-leaving
79
      real                                   xx1,yy1,pp1     ! Updated position of air parcel
80
      integer                                leftcount       ! Number of domain leaving trajectories
81
      integer                                ntim            ! Number of output time steps
82
 
83
c     Meteorological fields
84
      real,allocatable, dimension (:)     :: spt0,spt1       ! Surface pressure
85
      real,allocatable, dimension (:)     :: uut0,uut1       ! Zonal wind
86
      real,allocatable, dimension (:)     :: vvt0,vvt1       ! Meridional wind
87
      real,allocatable, dimension (:)     :: wwt0,wwt1       ! Vertical wind
88
      real,allocatable, dimension (:)     :: p3t0,p3t1       ! 3d-pressure 
89
 
90
c     Grid description
91
      real                                   pollon,pollat   ! Longitude/latitude of pole
92
      real                                   ak(nlevmax)     ! Vertical layers and levels
93
      real                                   bk(nlevmax) 
94
      real                                   xmin,xmax       ! Zonal grid extension
95
      real                                   ymin,ymax       ! Meridional grid extension
96
      integer                                nx,ny,nz        ! Grid dimensions
97
      real                                   dx,dy           ! Horizontal grid resolution
98
      integer                                hem             ! Flag for hemispheric domain
99
      real                                   mdv             ! Missing data value
100
      real,allocatable, dimension (:,:)   :: mpx,mpy         ! Map scale factor in x,y direction
101
      real,allocatable, dimension (:,:)   :: lat,lon         ! Map scale factor in x,y direction
102
 
103
c     Auxiliary variables                 
104
      real                                   delta,rd
105
      integer	                             itm,iloop,i,j,k,filo,lalo
106
      integer                                ierr,stat
107
      integer                                cdfid,fid
108
      real	                                 tstart,time0,time1,time
109
      real                                   reltpos0,reltpos1
110
      real                                   xind,yind,pind,pp,sp,stagz
111
      character*80                           filename,varname
112
      integer                                reftmp(6)
113
      character                              ch
114
      real                                   frac,tload
115
      integer                                itim
116
      integer                                wstep
117
      character*80                           radunit
118
      real                                   lon1,lat1,lon2,lat2
119
      real                                   scale_max,scale_min
120
 
121
c     --------------------------------------------------------------------
122
c     Start of program, Read parameters
123
c     --------------------------------------------------------------------
124
 
125
c     Write start message
126
      print*,'========================================================='
127
      print*,'              *** START OF PROGRAM CALTRA ***'
128
      print*
129
 
130
c     Open the parameter file
131
      open(9,file='caltra.param')
132
 
133
c     Read flag for forward/backward mode (fbflag)
134
      read(9,*) fbflag
135
 
136
c     Read number of input files (numdat)
137
      read(9,*) numdat
138
      if (numdat.gt.ndatmax) then
139
        print*,' ERROR: too many input files ',numdat,ndatmax
140
        goto 993
141
      endif
142
 
143
c     Read list of input dates (dat, sort depending on forward/backward mode)
144
      if (fbflag.eq.1) then
145
        do itm=1,numdat
146
          read(9,'(a11)') dat(itm)
147
        enddo
148
      else
149
        do itm=numdat,1,-1
150
          read(9,'(a11)') dat(itm)
151
        enddo
152
      endif
153
 
154
c     Read time increment between input files (timeinc)
155
      read(9,*) timeinc
156
 
157
C     Read if data domain is periodic and its periodicity
158
      read(9,*) per
159
 
160
 
161
c     Read the number of trajectories and name of position file
162
      read(9,*) strname
163
      read(9,*) ntra
164
      read(9,*) ncol 
165
      if (ntra.eq.0) goto 991
166
 
167
C     Read the name of the output trajectory file and set the constants file
168
      read(9,*) cdfname
169
 
170
C     Read the timestep for trajectory calculation (convert from minutes to hours)
171
      read(9,*) ts
172
      ts=ts/60.    
173
 
174
C     Read shift of start and end time relative to first data file
175
      read(9,*) tst
176
      read(9,*) ten
177
 
178
C     Read output time interval (in minutes)
179
      read(9,*) deltout
180
 
181
C     Read jumpflag (if =1 ground-touching trajectories reenter the atmosphere)
182
      read(9,*) jflag
183
 
184
C     Read factor for vertical velocity field
185
      read(9,*) wfactor
186
 
187
c     Read the reference time and the time range
188
      read(9,*) reftime(1)                  ! year
189
      read(9,*) reftime(2)                  ! month
190
      read(9,*) reftime(3)                  ! day
191
      read(9,*) reftime(4)                  ! hour
192
      read(9,*) reftime(5)                  ! min
193
      read(9,*) reftime(6)                  ! time range (in min)
194
 
195
c     Read flag for 'no time check'
196
      read(9,*) timecheck
197
 
198
c     Close the input file
199
      close(9)
200
 
201
c     Calculate the number of output time steps
202
      ntim = abs(reftime(6)/deltout) + 1
203
 
204
c     Set the formats of the input and output files
205
      call mode_tra(inpmode,strname)
206
      call mode_tra(outmode,cdfname)
207
      if (outmode.eq.-1) outmode=1
208
 
209
c     Write some status information
210
      print*,'---- INPUT PARAMETERS -----------------------------------'
211
      print* 
212
      print*,'  Forward/Backward       : ',fbflag
213
      print*,'  #input files           : ',numdat
214
      print*,'  First/last input file  : ',trim(dat(1)),' ... ',
215
     >                                     trim(dat(numdat))
216
      print*,'  time increment         : ',timeinc
217
      print*,'  Output file            : ',trim(cdfname)
218
      print*,'  Time step (min)        : ',60.*ts
219
      write(*,'(a27,f7.2,f7.2)') '   Time shift (start,end) : ',tst,ten
220
      print*,'  Output time interval   : ',deltout
221
      print*,'  Jump flag              : ',jflag
222
      print*,'  Vertical wind (scale)  : ',wfactor
223
      print*,'  Trajectory pos file    : ',trim(strname)
224
      print*,'  # of trajectories      : ',ntra
225
      print*,'  # of output timesteps  : ',ntim
226
      if ( inpmode.eq.-1) then
227
         print*,'  Input format           : (x,y,z)-list'
228
      else
229
         print*,'  Input format           : ',inpmode
230
      endif
231
      print*,'  Output format          : ',outmode
232
      print*,'  Periodicity            : ',per
233
      print*,'  Time check             : ',trim(timecheck)
234
      print*
235
 
236
      print*,'---- FIXED NUMERICAL PARAMETERS -------------------------'
237
      print*
238
      print*,'  Number of iterations   : ',numit
239
      print*,'  Filename prefix        : ',prefix
240
      print*,'  Missing data value     : ',mdv
241
      print*
242
 
243
c     --------------------------------------------------------------------
244
c     Read grid parameters, checks and allocate memory
245
c     --------------------------------------------------------------------
246
 
247
c     Read the constant grid parameters (nx,ny,nz,xmin,xmax,ymin,ymax,pollon,pollat)
248
c     The negative <-fid> of the file identifier is used as a flag for parameter retrieval  
249
      filename = prefix//dat(1)
250
      varname  = 'U'
251
      nx       = 1
252
      ny       = 1
253
      nz       = 1
254
      tload    = -tst
255
      call input_open (fid,filename)
256
	  call input_grid_wrf(fid,xmin,xmax,ymin,ymax,dx,dy,nx,ny,nz)
257
      call input_close(fid)
258
 
259
C     Check if the number of levels is too large
260
      if (nz.gt.nlevmax) goto 993
261
 
262
C     Set logical flag for hemispheric mode (not yet supported)
263
      hem = 0
264
 
265
C     Allocate memory for some meteorological arrays
266
      allocate(spt0(nx*ny),stat=stat)
267
      if (stat.ne.0) print*,'*** error allocating array spt0 ***'   ! Surface geopotential height
268
      allocate(spt1(nx*ny),stat=stat)
269
      if (stat.ne.0) print*,'*** error allocating array spt1 ***'
270
      allocate(uut0(nx*ny*nz),stat=stat)
271
      if (stat.ne.0) print*,'*** error allocating array uut0 ***'   ! Zonal wind
272
      allocate(uut1(nx*ny*nz),stat=stat)
273
      if (stat.ne.0) print*,'*** error allocating array uut1 ***'
274
      allocate(vvt0(nx*ny*nz),stat=stat)
275
      if (stat.ne.0) print*,'*** error allocating array vvt0 ***'   ! Meridional wind
276
      allocate(vvt1(nx*ny*nz),stat=stat)
277
      if (stat.ne.0) print*,'*** error allocating array vvt1 ***'
278
      allocate(wwt0(nx*ny*nz),stat=stat)
279
      if (stat.ne.0) print*,'*** error allocating array wwt0 ***'   ! Vertical wind
280
      allocate(wwt1(nx*ny*nz),stat=stat)
281
      if (stat.ne.0) print*,'*** error allocating array wwt1 ***'
282
      allocate(p3t0(nx*ny*nz),stat=stat)
283
      if (stat.ne.0) print*,'*** error allocating array p3t0 ***'   ! geopotential height
284
      allocate(p3t1(nx*ny*nz),stat=stat)
285
      if (stat.ne.0) print*,'*** error allocating array p3t1 ***'
286
      allocate(mpx(nx,ny),stat=stat)
287
      if (stat.ne.0) print*,'*** error allocating array mpx * **'   ! Map scale factor in x
288
      allocate(mpy(nx,ny),stat=stat)
289
      if (stat.ne.0) print*,'*** error allocating array mpy ***'    ! Map scale factor in y
290
      allocate(lon(nx,ny),stat=stat)
291
      if (stat.ne.0) print*,'*** error allocating array lon ***'    ! Grid -> lon
292
      allocate(lat(nx,ny),stat=stat)
293
      if (stat.ne.0) print*,'*** error allocating array lat ***'    ! Gridy -> lat
294
 
295
C     Get memory for trajectory arrays
296
      allocate(trainp(ntra,1,ncol),stat=stat)
297
      if (stat.ne.0) print*,'*** error allocating array trainp   ***' ! Input start coordinates
298
      allocate(traout(ntra,ntim,4),stat=stat)
299
      if (stat.ne.0) print*,'*** error allocating array traout   ***' ! Output trajectories
300
      allocate(xx0(ntra),stat=stat)
301
      if (stat.ne.0) print*,'*** error allocating array xx0      ***' ! X position (longitude)
302
      allocate(yy0(ntra),stat=stat)
303
      if (stat.ne.0) print*,'*** error allocating array yy0      ***' ! Y position (latitude)
304
      allocate(pp0(ntra),stat=stat)
305
      if (stat.ne.0) print*,'*** error allocating array pp0      ***' ! Pressure
306
      allocate(leftflag(ntra),stat=stat)
307
      if (stat.ne.0) print*,'*** error allocating array leftflag ***' ! Leaving-domain flag
308
 
309
c     Write some status information
310
      print*,'---- CONSTANT GRID PARAMETERS ---------------------------'
311
      print*
312
      print*,'  xmin,xmax     : ',xmin,xmax
313
      print*,'  ymin,ymax     : ',ymin,ymax
314
      print*,'  dx,dy         : ',dx,dy
315
      print*,'  nx,ny,nz      : ',nx,ny,nz
316
      print*,'  per, hem      : ',per,hem
317
      print*
318
 
319
c     --------------------------------------------------------------------
320
c     Calculate the map scale factors
321
c     --------------------------------------------------------------------
322
 
323
c     Read lon/lat on the model grid from first data file
324
      filename = prefix//dat(1)
325
      call input_open (fid,filename)
326
      varname='XLONG'
327
      call input_var_wrf(fid,varname,lon,nx,ny,1)
328
      varname='XLAT'
329
      call input_var_wrf(fid,varname,lat,nx,ny,1)
330
      call input_close(fid)
331
 
332
c     Get map scale for interior points
333
      do i=2,nx-1
334
         do j=2,ny-1
335
 
336
c           Map scale in x direction
337
            lon1     = lon(i-1,j)
338
            lat1     = lat(i-1,j)
339
            lon2     = lon(i+1,j)
340
            lat2     = lat(i+1,j)
341
            radunit  = 'km.haversine'
342
            mpx(i,j) = 0.5 * 1000. * sdis(lon1,lat1,lon2,lat2,radunit)
343
 
344
c           Map scale in y direction
345
            lon1     = lon(i,j-1)
346
            lat1     = lat(i,j-1)
347
            lon2     = lon(i,j+1)
348
            lat2     = lat(i,j+1)
349
            radunit  = 'km.haversine'
350
            mpy(i,j) = 0.5 * 1000. * sdis(lon1,lat1,lon2,lat2,radunit)
351
 
352
         enddo
353
      enddo
354
 
355
c     Copy map scale for boundary points
356
      do i=2,nx-1
357
        mpx(i, 1) = mpx(i,   2)
358
        mpx(i,ny) = mpx(i,ny-1)
359
        mpy(i, 1) = mpy(i,   2)
360
        mpy(i,ny) = mpy(i,ny-1)
361
      enddo
362
      do j=2,ny-1
363
        mpx(1, j) = mpx(2,   j)
364
        mpx(nx,j) = mpx(nx-1,j)
365
        mpy(1, j) = mpy(2,   j)
366
        mpy(nx,j) = mpy(nx-1,j)
367
      enddo
368
      mpx(1,1)   = mpx(2,2)
369
      mpy(1,1)   = mpy(2,2)
370
      mpx(nx,1)  = mpx(nx-1,2)
371
      mpy(nx,1)  = mpy(nx-1,2)
372
      mpx(nx,ny) = mpx(nx-1,ny-1)
373
      mpy(nx,ny) = mpy(nx-1,ny-1)
374
      mpx(1,ny)  = mpx(2,ny-1)
375
      mpy(1,ny)  = mpy(2,ny-1)
376
 
377
c	  Write some status information
15 michaesp 378
      print*,'---- MAPPING SCALE FACTORS -----------------------------'
2 michaesp 379
      print*
380
 
381
      scale_max = mpx(1,1)
382
      scale_min = mpx(1,1)
383
      do i=1,nx
384
      	do j=1,ny
385
      	   if ( mpx(i,j).gt.scale_max ) scale_max = mpx(i,j)
386
      	   if ( mpx(i,j).lt.scale_min ) scale_min = mpx(i,j)
387
      	 enddo
388
      enddo
389
      print*,'  map scale x (min,max) : ',scale_min,scale_max
390
      scale_max = mpy(1,1)
391
      scale_min = mpy(1,1)
392
      do i=1,nx
393
      	do j=1,ny
394
      	   if ( mpy(i,j).gt.scale_max ) scale_max = mpy(i,j)
395
      	   if ( mpy(i,j).lt.scale_min ) scale_min = mpy(i,j)
396
      	 enddo
397
      enddo
398
      print*,'  map scale y (min,max) : ',scale_min,scale_max
399
      print*
400
 
401
c     --------------------------------------------------------------------
402
c     Initialize the trajectory calculation
403
c     --------------------------------------------------------------------
404
 
405
c     Read start coordinates from file - Format (x,y,lev)
406
      if (inpmode.eq.-1) then
407
         open(fid,file=strname)
408
          do i=1,ntra
409
             read(fid,*) xx0(i),yy0(i),pp0(i)
410
          enddo
411
         close(fid)
412
 
413
c     Read start coordinates from trajectory file - check consistency of ref time
414
      else
415
         call ropen_tra(cdfid,strname,ntra,1,ncol,reftmp,vars,inpmode)
416
         call read_tra (cdfid,trainp,ntra,1,ncol,inpmode)
417
         do i=1,ntra
418
            time   = trainp(i,1,1)
419
            xx0(i) = trainp(i,1,2) 
420
            yy0(i) = trainp(i,1,3) 
421
            pp0(i) = trainp(i,1,4) 
422
         enddo
423
         call close_tra(cdfid,inpmode)
424
 
425
         if ( ( vars(2).ne.'x').and.(vars(3).ne.'y') ) then
426
            print*,' ERROR: starting positions must be in x/y/z format'
427
            stop
428
         endif
429
 
430
         if ( ( reftime(1).ne.reftmp(1) ).or.
431
     >        ( reftime(2).ne.reftmp(2) ).or.
432
     >        ( reftime(3).ne.reftmp(3) ).or.
433
     >        ( reftime(4).ne.reftmp(4) ).or.
434
     >        ( reftime(5).ne.reftmp(5) ) )
435
     >   then
436
            print*,' WARNING: Inconsistent reference times'
437
            write(*,'(5i8)') (reftime(i),i=1,5)
438
            write(*,'(5i8)') (reftmp (i),i=1,5)
439
            print*,'Enter a key to proceed...'
440
            stop
441
         endif
442
      endif
443
 
444
c     Transform start coordinates from index space to WRF grid
445
      do i=1,ntra
446
         xx0(i) = xmin + ( xx0(i) - 1. ) * dx
447
         yy0(i) = ymin + ( yy0(i) - 1. ) * dy
448
      enddo
449
 
450
c     Set sign of time range
451
      reftime(6) = fbflag * reftime(6)
452
 
453
c     Write some status information
454
      print*,'---- REFERENCE DATE---------- ---------------------------'
455
      print*
456
      print*,' Reference time (year)  :',reftime(1)
457
      print*,'                (month) :',reftime(2)
458
      print*,'                (day)   :',reftime(3)
459
      print*,'                (hour)  :',reftime(4)
460
      print*,'                (min)   :',reftime(5)
461
      print*,' Time range             :',reftime(6),' min'
462
      print*
463
 
464
C     Save starting positions 
465
      itim = 1
466
      do i=1,ntra
467
         traout(i,itim,1) = 0.
468
         traout(i,itim,2) = xx0(i)
469
         traout(i,itim,3) = yy0(i)
470
         traout(i,itim,4) = pp0(i)
471
      enddo
472
 
473
c     Init the flag and the counter for trajectories leaving the domain
474
      leftcount=0
475
      do i=1,ntra
476
         leftflag(i)=0
477
      enddo
478
 
479
C     Convert time shifts <tst,ten> from <hh.mm> into fractional time
480
      call hhmm2frac(tst,frac)
481
      tst = frac
482
      call hhmm2frac(ten,frac)
483
      ten = frac
484
 
485
c     -----------------------------------------------------------------------
486
c     Loop to calculate trajectories
487
c     -----------------------------------------------------------------------
488
 
489
c     Write some status information
490
      print*,'---- TRAJECTORIES ----------- ---------------------------'
491
      print*    
492
 
493
C     Set the time for the first data file (depending on forward/backward mode)
494
      if (fbflag.eq.1) then
495
        tstart = -tst
496
      else
497
        tstart = tst
498
      endif
499
 
500
c     Set the minute counter for output
501
      wstep = 0
502
 
503
c     Read wind fields and vertical grid from first file
504
      filename = prefix//dat(1)
505
 
506
      call frac2hhmm(tstart,tload)
507
 
508
      write(*,'(a16,a20,f7.2)') '  (file,time) : ',
509
     >                       trim(filename),tload
510
 
511
      call input_open (fid,filename)
512
 
513
      varname='U'					! U
514
 	  call input_var_wrf(fid,varname,uut1,nx,ny,nz)
515
 
516
	  varname='V'					! V
517
	  call input_var_wrf(fid,varname,vvt1,nx,ny,nz)
518
 
519
	  varname='W'					! W
520
	  call input_var_wrf(fid,varname,wwt1,nx,ny,nz)
521
 
522
	  varname='geopot'				! geopot.height
523
	  call input_var_wrf(fid,varname,p3t1,nx,ny,nz)
524
 
525
	  varname='geopots'				! geopot.height at surface
526
	  call input_var_wrf(fid,varname,spt1,nx,ny,1)
527
 
528
      call input_close(fid)
529
 
530
c     Loop over all input files (time step is <timeinc>)
531
      do itm=1,numdat-1
532
 
533
c       Calculate actual and next time
534
        time0 = tstart+real(itm-1)*timeinc*fbflag
535
        time1 = time0+timeinc*fbflag
536
 
537
 
538
c       Copy old velocities and pressure fields to new ones       
539
        do i=1,nx*ny*nz
540
           uut0(i)=uut1(i)
541
           vvt0(i)=vvt1(i)
542
           wwt0(i)=wwt1(i)
543
           p3t0(i)=p3t1(i)
544
        enddo
545
        do i=1,nx*ny
546
           spt0(i)=spt1(i)
547
        enddo
548
 
549
c       Read wind fields and surface pressure at next time
550
        filename = prefix//dat(itm+1)
551
 
552
        call frac2hhmm(time1,tload)
553
        write(*,'(a16,a20,f7.2)') '  (file,time) : ',
554
     >                          trim(filename),tload
555
 
556
        call input_open (fid,filename)
557
 
558
  	    varname='U'					! U
559
	    call input_var_wrf(fid,varname,uut1,nx,ny,nz)
560
 
561
	    varname='V'					! V
562
	    call input_var_wrf(fid,varname,vvt1,nx,ny,nz)
563
 
564
	    varname='W'					! W
565
	    call input_var_wrf(fid,varname,wwt1,nx,ny,nz)
566
 
567
	    varname='geopot'				! geopot.height
568
	    call input_var_wrf(fid,varname,p3t1,nx,ny,nz)
569
 
570
	    varname='geopots'				! geopot.height
571
	    call input_var_wrf(fid,varname,spt1,nx,ny,1)
572
 
573
        call input_close(fid)
574
 
575
C       Determine the first and last loop indices
576
        if (numdat.eq.2) then
577
          filo = nint(tst/ts)+1
578
          lalo = nint((timeinc-ten)/ts) 
579
        elseif ( itm.eq.1 ) then
580
          filo = nint(tst/ts)+1
581
          lalo = nint(timeinc/ts)
582
        else if (itm.eq.numdat-1) then
583
          filo = 1
584
          lalo = nint((timeinc-ten)/ts)
585
        else
586
          filo = 1
587
          lalo = nint(timeinc/ts)
588
        endif
589
 
590
c       Split the interval <timeinc> into computational time steps <ts>
591
        do iloop=filo,lalo
592
 
593
C         Calculate relative time position in the interval timeinc (0=beginning, 1=end)
594
          reltpos0 = ((real(iloop)-1.)*ts)/timeinc
595
          reltpos1 = real(iloop)*ts/timeinc
596
 
597
C         Initialize counter for domain leaving trajectories
598
          leftcount=0
599
 
600
c         Timestep for all trajectories
601
          do i=1,ntra
602
 
603
C           Check if trajectory has already left the data domain
604
            if (leftflag(i).ne.1) then	
605
 
606
c             Iterative Euler timestep (x0,y0,p0 -> x1,y1,p1)
607
              call euler(
608
     >               xx1,yy1,pp1,leftflag(i),
609
     >               xx0(i),yy0(i),pp0(i),reltpos0,reltpos1,
610
     >               ts*3600,numit,jflag,mdv,wfactor,fbflag,
611
     >               spt0,spt1,p3t0,p3t1,uut0,uut1,vvt0,vvt1,wwt0,wwt1,
612
     >               xmin,ymin,dx,dy,per,hem,nx,ny,nz,mpx,mpy)
613
 
614
c             Update trajectory position, or increase number of trajectories leaving domain
615
              if (leftflag(i).eq.1) then
616
                leftcount=leftcount+1
617
                if ( leftcount.lt.10 ) then
618
                   print*,'     -> Trajectory ',i,' leaves domain'
619
                elseif ( leftcount.eq.10 ) then
620
                   print*,'     -> N>=10 trajectories leave domain'
621
                endif
622
              else
623
                xx0(i)=xx1      
624
                yy0(i)=yy1
625
                pp0(i)=pp1
626
              endif
627
 
628
c          Trajectory has already left data domain (mark as <mdv>)
629
           else
630
              xx0(i)=mdv
631
              yy0(i)=mdv
632
              pp0(i)=mdv
633
 
634
           endif
635
 
636
          enddo
637
 
638
C         Save positions only every deltout minutes
639
          delta = aint(iloop*60*ts/deltout)-iloop*60*ts/deltout
640
          if (abs(delta).lt.eps) then
641
            time = time0+reltpos1*timeinc*fbflag
642
            itim = itim + 1
643
            do i=1,ntra
644
               call frac2hhmm(time,tload)
645
               traout(i,itim,1) = tload
646
               traout(i,itim,2) = xx0(i)
647
               traout(i,itim,3) = yy0(i) 
648
               traout(i,itim,4) = pp0(i)
649
            enddo
650
          endif
651
 
652
        enddo
653
 
654
      enddo
655
 
656
c     Transform trajectory position from WRF grid do grid index
657
      do i=1,ntra
658
        do j=1,ntim
659
           traout(i,j,2) = ( traout(i,j,2) - xmin ) / dx + 1.
660
           traout(i,j,3) = ( traout(i,j,3) - ymin ) / dy + 1.
661
        enddo
662
      enddo
663
 
664
c     Write trajectory file
665
      vars(1)  ='time'
666
      vars(2)  ='x'
667
      vars(3)  ='y'
668
      vars(4)  ='z'
669
      call wopen_tra(cdfid,cdfname,ntra,ntim,4,reftime,vars,outmode)
670
      call write_tra(cdfid,traout,ntra,ntim,4,outmode)
671
      call close_tra(cdfid,outmode)   
672
 
673
c     Write some status information, and end of program message
674
      print*  
675
      print*,'---- STATUS INFORMATION --------------------------------'
676
      print*
677
      print*,'  #leaving domain    ', leftcount
678
      print*,'  #staying in domain ', ntra-leftcount
679
      print*
680
      print*,'              *** END OF PROGRAM CALTRA ***'
681
      print*,'========================================================='
682
 
683
      stop
684
 
685
c     ------------------------------------------------------------------
686
c     Exception handling
687
c     ------------------------------------------------------------------
688
 
689
 991  write(*,*) '*** ERROR: all start points outside the data domain'
690
      call exit(1)
691
 
692
 992  write(*,*) '*** ERROR: close arrays on files (prog. closear)'
693
      call exit(1)
694
 
695
 993  write(*,*) '*** ERROR: problems with array size'
696
      call exit(1)
697
 
698
      end 
699
 
700
 
701
c     *******************************************************************
702
c     * Time step : either Euler or Runge-Kutta                         *
703
c     *******************************************************************
704
 
705
C     Time-step from (x0,y0,p0) to (x1,y1,p1)
706
C
707
C     (x0,y0,p0) input	coordinates (long,lat,p) for starting point
708
C     (x1,y1,p1) output	coordinates (long,lat,p) for end point
709
C     deltat	 input	timestep in seconds
710
C     numit	 input	number of iterations
711
C     jump	 input  flag (=1 trajectories don't enter the ground)
712
C     left	 output	flag (=1 if trajectory leaves data domain)
713
 
714
c     -------------------------------------------------------------------
715
c     Iterative Euler time step
716
c     -------------------------------------------------------------------
717
 
718
      subroutine euler(x1,y1,p1,left,x0,y0,p0,reltpos0,reltpos1,
719
     >                 deltat,numit,jump,mdv,wfactor,fbflag,
720
     >		           spt0,spt1,p3d0,p3d1,uut0,uut1,vvt0,vvt1,wwt0,wwt1,
721
     >                 xmin,ymin,dx,dy,per,hem,nx,ny,nz,mpx,mpy)
722
 
723
      implicit none
724
 
11 michaesp 725
c     Flag for test mode
726
      integer      test
727
      parameter    (test=0)
728
 
2 michaesp 729
c     Declaration of subroutine parameters
730
      integer      nx,ny,nz
731
      real         x1,y1,p1
732
      integer      left
733
      real	       x0,y0,p0
734
      real         reltpos0,reltpos1
735
      real   	   deltat
736
      integer      numit
737
      integer      jump
738
      real         wfactor
739
      integer      fbflag
740
      real     	   spt0(nx*ny)   ,spt1(nx*ny)
741
      real         uut0(nx*ny*nz),uut1(nx*ny*nz)
742
      real 	       vvt0(nx*ny*nz),vvt1(nx*ny*nz)
743
      real         wwt0(nx*ny*nz),wwt1(nx*ny*nz)
744
      real         p3d0(nx*ny*nz),p3d1(nx*ny*nz)
745
      real         xmin,ymin,dx,dy
746
      integer      per
747
      integer      hem
748
      real         mdv
749
      real         mpx(nx*ny),mpy(nx*ny)
750
 
751
c     Auxiliary variables
752
      real         xmax,ymax
753
      real	       xind,yind,pind
754
 
755
      real	       u0,v0,w0,u1,v1,w1,u,v,w,sp
756
      integer	   icount
757
      character    ch
758
      real         mpsc_x,mpsc_y
759
 
760
c     Externals    
761
      real         int_index4
762
      external     int_index4
763
 
764
c     Reset the flag for domain-leaving
765
      left=0
766
 
767
c     Set the esat-north boundary of the domain
768
      xmax = xmin+real(nx-1)*dx
769
      ymax = ymin+real(ny-1)*dy
770
 
771
C     Interpolate wind fields to starting position (x0,y0,p0)
772
      call get_index4 (xind,yind,pind,x0,y0,p0,reltpos0,
773
     >                 p3d0,p3d1,spt0,spt1,3,
774
     >                 nx,ny,nz,xmin,ymin,dx,dy,mdv)
775
 
776
      u0 = int_index4(uut0,uut1,nx,ny,nz,xind,yind,pind,reltpos0,mdv)
777
      v0 = int_index4(vvt0,vvt1,nx,ny,nz,xind,yind,pind,reltpos0,mdv)
778
      w0 = int_index4(wwt0,wwt1,nx,ny,nz,xind,yind,pind,reltpos0,mdv)
779
 
780
c     Force the near-surface wind to zero
781
      if (pind.lt.1.) w0=w0*pind
782
 
783
C     For first iteration take ending position equal to starting position
784
      x1=x0
785
      y1=y0
786
      p1=p0
787
 
788
C     Iterative calculation of new position
789
      do icount=1,numit
790
 
791
C        Calculate new winds for advection
792
         call get_index4 (xind,yind,pind,x1,y1,p1,reltpos1,
793
     >                    p3d0,p3d1,spt0,spt1,3,
794
     >                    nx,ny,nz,xmin,ymin,dx,dy,mdv)
795
         u1 = int_index4(uut0,uut1,nx,ny,nz,xind,yind,pind,reltpos1,mdv)
796
         v1 = int_index4(vvt0,vvt1,nx,ny,nz,xind,yind,pind,reltpos1,mdv)
797
         w1 = int_index4(wwt0,wwt1,nx,ny,nz,xind,yind,pind,reltpos1,mdv)
798
 
799
c        Force the near-surface wind to zero
800
         if (pind.lt.1.) w1=w1*pind
801
 
802
c        Get the new velocity in between
803
         u=(u0+u1)/2.
804
         v=(v0+v1)/2.
805
         w=(w0+w1)/2.
806
 
807
c        Get the mapping scale factors for this position
808
         mpsc_x = int_index4 (mpx,mpx,nx,ny,1,xind,yind,1.,reltpos1,mdv)
809
         mpsc_y = int_index4 (mpy,mpy,nx,ny,1,xind,yind,1.,reltpos1,mdv)
810
 
811
C        Calculate new positions (adapted for cartesian grid)
812
         x1 = x0 + fbflag * deltat * u * dx/mpsc_x
813
         y1 = y0 + fbflag * deltat * v * dy/mpsc_y
814
         p1 = p0 + fbflag * deltat * w * wfactor
815
 
11 michaesp 816
c        Write the update positions for tests
817
         if ( (icount.eq.3).and.(test.eq.1) ) then
818
            write(*,'(10f10.2)') x0,u,x1-x0,p0,w,p1-p0
819
         endif
820
 
2 michaesp 821
C       Interpolate surface geop.height to actual position
822
        call get_index4 (xind,yind,pind,x1,y1,0.,reltpos1,
823
     >                   p3d0,p3d1,spt0,spt1,3,
824
     >                   nx,ny,nz,xmin,ymin,dx,dy,mdv)
825
        sp = int_index4 (spt0,spt1,nx,ny,1,xind,yind,1.,reltpos1,mdv)
826
 
827
c       Handle trajectories which cross the lower boundary (jump flag)
828
        if ((jump.eq.1).and.(p1.lt.sp)) p1=sp+10.
829
 
830
c       Handle periodioc boundaries for 'ideal' mode
831
        if ( per.eq.1 ) then
832
	        if ( x1.gt.xmax ) x1=x1-xmax
833
	        if ( x1.lt.xmin ) x1=x1+xmax
834
        endif
835
 
836
C       Check if trajectory leaves data domain
837
        if ( (x1.lt.xmin).or.(x1.gt.xmax).or.
838
     >       (y1.lt.ymin).or.(y1.gt.ymax).or.(p1.lt.sp) )   ! geopot : .lt. ; pressure: .gt.
839
     >  then
840
          left=1
841
          print*,x1,y1,p1
842
          print*,xmin,ymin
843
	      print*,xmax,ymax
844
	      print*,sp
845
          goto 100
846
        endif
847
 
848
      enddo
849
 
850
c     Exit point for subroutine
851
 100  continue
852
 
853
      return
854
 
855
      end
856
 
857
 
858
c     ----------------------------------------------------------------------
859
c     Get spherical distance between lat/lon points
860
c     ----------------------------------------------------------------------
861
 
862
      real function sdis(xp,yp,xq,yq,unit)
863
 
864
c     Calculates spherical distance (in km) between two points given
865
c     by their spherical coordinates (xp,yp) and (xq,yq), respectively.
866
 
867
      real,parameter ::       re=6371.229
868
      real,parameter ::       rad2deg=180./3.14159265
869
      real,parameter ::       deg2rad=3.141592654/180.
870
 
871
      real         xp,yp,xq,yq,arg
872
      character*80 unit
873
      real         dlon,dlat,alpha,rlat1,ralt2
874
 
875
      if ( unit.eq.'km' ) then
876
 
15 michaesp 877
         arg=sin(yp*deg2rad)*sin(yq*deg2rad)+
878
     >              cos(yp*deg2rad)*cos(yq*deg2rad)*cos((xp-xq)*deg2rad)
2 michaesp 879
         if (arg.lt.-1.) arg=-1.
880
         if (arg.gt.1.) arg=1.
881
         sdis=re*acos(arg)
882
 
883
      elseif ( unit.eq.'deg' ) then
884
 
885
         dlon = xp-xq
886
         if ( dlon.gt. 180. ) dlon = dlon - 360.
887
         if ( dlon.lt.-180. ) dlon = dlon + 360.
888
         sdis = sqrt( dlon**2 + (yp-yq)**2 )
889
 
890
      elseif ( unit.eq.'km.haversine' ) then
891
 
892
        dlat   =  (yp - yq)*deg2rad
893
        dlon   =  (xp - xq)*deg2rad
894
        rlat1   =  yp*deg2rad
895
        rlat2   =  yq*deg2rad
896
 
897
        alpha  = ( sin(0.5*dlat)**2 ) +
898
     >           ( sin(0.5*dlon)**2 )*cos(rlat1)*cos(rlat2)
899
 
900
        sdis = 4. * re * atan2( sqrt(alpha),1. + sqrt( 1. - alpha ) )
901
 
902
      endif
903
 
904
      end