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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
 
17 michaesp 42
c     Missing data value
43
      real      mdv
44
      parameter (mdv = -999. )
45
 
2 michaesp 46
c     Filename prefix (typically 'P')
47
      character*1 prefix
48
      parameter   (prefix='P')
49
 
50
c     Externals
51
      real       sdis
52
      external   sdis
53
 
54
c     --------------------------------------------------------------------
55
c     Declaration of variables
56
c     --------------------------------------------------------------------
57
 
58
c     Input parameters
59
      integer                                fbflag          ! Flag for forward/backward mode
60
      integer                                numdat          ! Number of input files
61
      character*11                           dat(ndatmax)    ! Dates of input files
62
      real                                   timeinc         ! Time increment between input files
63
      integer                                per             ! Periodicity flag (=0 if none)
64
      integer                                ntra            ! Number of trajectories
65
      character*80                           cdfname         ! Name of output files
66
      real                                   ts              ! Time step
67
      real                                   tst,ten         ! Shift of start and end time relative to first data file
68
      integer                                deltout         ! Output time interval (in minutes)
69
      integer                                jflag           ! Jump flag (if =1 ground-touching trajectories reenter atmosphere)
70
      real                                   wfactor         ! Factor for vertical velocity field
71
      character*80                           strname         ! File with start positions
72
      character*80                           timecheck       ! Either 'yes' or 'no'
73
      character*10		              	     gridflag        ! "ideal" or "real"
21 michaesp 74
      real                                   aglconst        ! constant level above ground  
75
      real                                   isen            ! isentropic level
76
      character*80                           vertmode        ! Vertical mode (kinematic,aglconst)
2 michaesp 77
 
78
c     Trajectories
79
      integer                                ncol            ! Number of columns for insput trajectories
80
      real,allocatable, dimension (:,:,:) :: trainp          ! Input start coordinates (ntra,1,ncol)
81
      real,allocatable, dimension (:,:,:) :: traout          ! Output trajectories (ntra,ntim,4)
82
      integer                                reftime(6)      ! Reference date
83
      character*80                           vars(200)       ! Field names
84
      real,allocatable, dimension (:)     :: xx0,yy0,pp0     ! Position of air parcels
85
      integer,allocatable, dimension (:)  :: leftflag        ! Flag for domain-leaving
86
      real                                   xx1,yy1,pp1     ! Updated position of air parcel
87
      integer                                leftcount       ! Number of domain leaving trajectories
88
      integer                                ntim            ! Number of output time steps
89
 
90
c     Meteorological fields
91
      real,allocatable, dimension (:)     :: spt0,spt1       ! Surface pressure
92
      real,allocatable, dimension (:)     :: uut0,uut1       ! Zonal wind
93
      real,allocatable, dimension (:)     :: vvt0,vvt1       ! Meridional wind
94
      real,allocatable, dimension (:)     :: wwt0,wwt1       ! Vertical wind
95
      real,allocatable, dimension (:)     :: p3t0,p3t1       ! 3d-pressure 
21 michaesp 96
      real,allocatable, dimension (:)     :: tht0,tht1       ! potential temperature
97
      real,allocatable, dimension (:)     :: sth0,sth1       ! surface potential temperature 
2 michaesp 98
 
99
c     Grid description
100
      real                                   pollon,pollat   ! Longitude/latitude of pole
101
      real                                   ak(nlevmax)     ! Vertical layers and levels
102
      real                                   bk(nlevmax) 
103
      real                                   xmin,xmax       ! Zonal grid extension
104
      real                                   ymin,ymax       ! Meridional grid extension
105
      integer                                nx,ny,nz        ! Grid dimensions
106
      real                                   dx,dy           ! Horizontal grid resolution
107
      integer                                hem             ! Flag for hemispheric domain
108
      real,allocatable, dimension (:,:)   :: mpx,mpy         ! Map scale factor in x,y direction
109
      real,allocatable, dimension (:,:)   :: lat,lon         ! Map scale factor in x,y direction
110
 
111
c     Auxiliary variables                 
112
      real                                   delta,rd
113
      integer	                             itm,iloop,i,j,k,filo,lalo
114
      integer                                ierr,stat
115
      integer                                cdfid,fid
116
      real	                                 tstart,time0,time1,time
117
      real                                   reltpos0,reltpos1
118
      real                                   xind,yind,pind,pp,sp,stagz
119
      character*80                           filename,varname
120
      integer                                reftmp(6)
121
      character                              ch
122
      real                                   frac,tload
123
      integer                                itim
124
      integer                                wstep
125
      character*80                           radunit
126
      real                                   lon1,lat1,lon2,lat2
127
      real                                   scale_max,scale_min
128
 
21 michaesp 129
c     Externals
130
      real         int_index4
131
      external     int_index4
132
 
2 michaesp 133
c     --------------------------------------------------------------------
134
c     Start of program, Read parameters
135
c     --------------------------------------------------------------------
136
 
137
c     Write start message
138
      print*,'========================================================='
139
      print*,'              *** START OF PROGRAM CALTRA ***'
140
      print*
141
 
142
c     Open the parameter file
143
      open(9,file='caltra.param')
144
 
145
c     Read flag for forward/backward mode (fbflag)
146
      read(9,*) fbflag
147
 
148
c     Read number of input files (numdat)
149
      read(9,*) numdat
150
      if (numdat.gt.ndatmax) then
151
        print*,' ERROR: too many input files ',numdat,ndatmax
152
        goto 993
153
      endif
154
 
155
c     Read list of input dates (dat, sort depending on forward/backward mode)
156
      if (fbflag.eq.1) then
157
        do itm=1,numdat
158
          read(9,'(a11)') dat(itm)
159
        enddo
160
      else
161
        do itm=numdat,1,-1
162
          read(9,'(a11)') dat(itm)
163
        enddo
164
      endif
165
 
166
c     Read time increment between input files (timeinc)
167
      read(9,*) timeinc
168
 
169
C     Read if data domain is periodic and its periodicity
170
      read(9,*) per
171
 
172
 
173
c     Read the number of trajectories and name of position file
174
      read(9,*) strname
175
      read(9,*) ntra
176
      read(9,*) ncol 
177
      if (ntra.eq.0) goto 991
178
 
179
C     Read the name of the output trajectory file and set the constants file
180
      read(9,*) cdfname
181
 
182
C     Read the timestep for trajectory calculation (convert from minutes to hours)
183
      read(9,*) ts
184
      ts=ts/60.    
185
 
186
C     Read shift of start and end time relative to first data file
187
      read(9,*) tst
188
      read(9,*) ten
189
 
190
C     Read output time interval (in minutes)
191
      read(9,*) deltout
192
 
193
C     Read jumpflag (if =1 ground-touching trajectories reenter the atmosphere)
194
      read(9,*) jflag
195
 
196
C     Read factor for vertical velocity field
197
      read(9,*) wfactor
198
 
199
c     Read the reference time and the time range
200
      read(9,*) reftime(1)                  ! year
201
      read(9,*) reftime(2)                  ! month
202
      read(9,*) reftime(3)                  ! day
203
      read(9,*) reftime(4)                  ! hour
204
      read(9,*) reftime(5)                  ! min
205
      read(9,*) reftime(6)                  ! time range (in min)
206
 
207
c     Read flag for 'no time check'
208
      read(9,*) timecheck
21 michaesp 209
 
210
c     Read flag for trajectories at constant level above ground
211
      read(9,*) aglconst      
212
 
213
c     Read flag for trajectories at constant isentropic level
214
      read(9,*) isen      
2 michaesp 215
 
216
c     Close the input file
217
      close(9)
218
 
21 michaesp 219
c     Set the vertical mode of the trajectory calculation
220
      vertmode = 'kinematic'
221
      if ( aglconst.gt.0. ) then
222
         vertmode = 'aglconst'
223
      endif
224
      if ( isen.gt.0. ) then
225
         vertmode = 'isen'
226
      endif
227
 
2 michaesp 228
c     Calculate the number of output time steps
229
      ntim = abs(reftime(6)/deltout) + 1
230
 
231
c     Set the formats of the input and output files
232
      call mode_tra(inpmode,strname)
233
      call mode_tra(outmode,cdfname)
234
      if (outmode.eq.-1) outmode=1
235
 
236
c     Write some status information
237
      print*,'---- INPUT PARAMETERS -----------------------------------'
238
      print* 
239
      print*,'  Forward/Backward       : ',fbflag
240
      print*,'  #input files           : ',numdat
241
      print*,'  First/last input file  : ',trim(dat(1)),' ... ',
242
     >                                     trim(dat(numdat))
243
      print*,'  time increment         : ',timeinc
244
      print*,'  Output file            : ',trim(cdfname)
245
      print*,'  Time step (min)        : ',60.*ts
246
      write(*,'(a27,f7.2,f7.2)') '   Time shift (start,end) : ',tst,ten
247
      print*,'  Output time interval   : ',deltout
248
      print*,'  Jump flag              : ',jflag
249
      print*,'  Vertical wind (scale)  : ',wfactor
250
      print*,'  Trajectory pos file    : ',trim(strname)
251
      print*,'  # of trajectories      : ',ntra
252
      print*,'  # of output timesteps  : ',ntim
253
      if ( inpmode.eq.-1) then
254
         print*,'  Input format           : (x,y,z)-list'
255
      else
256
         print*,'  Input format           : ',inpmode
257
      endif
258
      print*,'  Output format          : ',outmode
259
      print*,'  Periodicity            : ',per
260
      print*,'  Time check             : ',trim(timecheck)
21 michaesp 261
      if ( vertmode.eq.'aglconst' ) then
262
         print*,'  Z = const AGL          : ',aglconst
263
      endif
264
      if ( vertmode.eq.'isen' ) then
265
         print*,'  isentropic             : ',isen
266
      endif
267
 
2 michaesp 268
      print*
269
 
270
      print*,'---- FIXED NUMERICAL PARAMETERS -------------------------'
271
      print*
272
      print*,'  Number of iterations   : ',numit
273
      print*,'  Filename prefix        : ',prefix
274
      print*,'  Missing data value     : ',mdv
275
      print*
276
 
277
c     --------------------------------------------------------------------
278
c     Read grid parameters, checks and allocate memory
279
c     --------------------------------------------------------------------
280
 
281
c     Read the constant grid parameters (nx,ny,nz,xmin,xmax,ymin,ymax,pollon,pollat)
282
c     The negative <-fid> of the file identifier is used as a flag for parameter retrieval  
283
      filename = prefix//dat(1)
284
      varname  = 'U'
285
      nx       = 1
286
      ny       = 1
287
      nz       = 1
288
      tload    = -tst
289
      call input_open (fid,filename)
290
	  call input_grid_wrf(fid,xmin,xmax,ymin,ymax,dx,dy,nx,ny,nz)
291
      call input_close(fid)
292
 
293
C     Check if the number of levels is too large
294
      if (nz.gt.nlevmax) goto 993
295
 
296
C     Set logical flag for hemispheric mode (not yet supported)
297
      hem = 0
298
 
299
C     Allocate memory for some meteorological arrays
300
      allocate(spt0(nx*ny),stat=stat)
301
      if (stat.ne.0) print*,'*** error allocating array spt0 ***'   ! Surface geopotential height
302
      allocate(spt1(nx*ny),stat=stat)
303
      if (stat.ne.0) print*,'*** error allocating array spt1 ***'
304
      allocate(uut0(nx*ny*nz),stat=stat)
305
      if (stat.ne.0) print*,'*** error allocating array uut0 ***'   ! Zonal wind
306
      allocate(uut1(nx*ny*nz),stat=stat)
307
      if (stat.ne.0) print*,'*** error allocating array uut1 ***'
308
      allocate(vvt0(nx*ny*nz),stat=stat)
309
      if (stat.ne.0) print*,'*** error allocating array vvt0 ***'   ! Meridional wind
310
      allocate(vvt1(nx*ny*nz),stat=stat)
311
      if (stat.ne.0) print*,'*** error allocating array vvt1 ***'
312
      allocate(wwt0(nx*ny*nz),stat=stat)
313
      if (stat.ne.0) print*,'*** error allocating array wwt0 ***'   ! Vertical wind
314
      allocate(wwt1(nx*ny*nz),stat=stat)
315
      if (stat.ne.0) print*,'*** error allocating array wwt1 ***'
316
      allocate(p3t0(nx*ny*nz),stat=stat)
317
      if (stat.ne.0) print*,'*** error allocating array p3t0 ***'   ! geopotential height
318
      allocate(p3t1(nx*ny*nz),stat=stat)
319
      if (stat.ne.0) print*,'*** error allocating array p3t1 ***'
320
      allocate(mpx(nx,ny),stat=stat)
321
      if (stat.ne.0) print*,'*** error allocating array mpx * **'   ! Map scale factor in x
322
      allocate(mpy(nx,ny),stat=stat)
323
      if (stat.ne.0) print*,'*** error allocating array mpy ***'    ! Map scale factor in y
324
      allocate(lon(nx,ny),stat=stat)
325
      if (stat.ne.0) print*,'*** error allocating array lon ***'    ! Grid -> lon
326
      allocate(lat(nx,ny),stat=stat)
327
      if (stat.ne.0) print*,'*** error allocating array lat ***'    ! Gridy -> lat
328
 
329
C     Get memory for trajectory arrays
330
      allocate(trainp(ntra,1,ncol),stat=stat)
331
      if (stat.ne.0) print*,'*** error allocating array trainp   ***' ! Input start coordinates
332
      allocate(traout(ntra,ntim,4),stat=stat)
333
      if (stat.ne.0) print*,'*** error allocating array traout   ***' ! Output trajectories
334
      allocate(xx0(ntra),stat=stat)
335
      if (stat.ne.0) print*,'*** error allocating array xx0      ***' ! X position (longitude)
336
      allocate(yy0(ntra),stat=stat)
337
      if (stat.ne.0) print*,'*** error allocating array yy0      ***' ! Y position (latitude)
338
      allocate(pp0(ntra),stat=stat)
339
      if (stat.ne.0) print*,'*** error allocating array pp0      ***' ! Pressure
340
      allocate(leftflag(ntra),stat=stat)
341
      if (stat.ne.0) print*,'*** error allocating array leftflag ***' ! Leaving-domain flag
342
 
21 michaesp 343
c     Get memory for potential temperature (isentropic trajectories)
344
      if ( vertmode.eq.'isen' ) then
345
          allocate(tht0(nx*ny*nz),stat=stat)
346
          if (stat.ne.0) print*,'*** error allocating array tht0 ***'
347
          allocate(tht1(nx*ny*nz),stat=stat)
348
          if (stat.ne.0) print*,'*** error allocating array tht1 ***'
349
          allocate(sth0(nx*ny),stat=stat)
350
          if (stat.ne.0) print*,'*** error allocating array sth0 ***'
351
          allocate(sth1(nx*ny),stat=stat)
352
          if (stat.ne.0) print*,'*** error allocating array sth1 ***'
353
      endif
354
 
2 michaesp 355
c     Write some status information
356
      print*,'---- CONSTANT GRID PARAMETERS ---------------------------'
357
      print*
358
      print*,'  xmin,xmax     : ',xmin,xmax
359
      print*,'  ymin,ymax     : ',ymin,ymax
360
      print*,'  dx,dy         : ',dx,dy
361
      print*,'  nx,ny,nz      : ',nx,ny,nz
362
      print*,'  per, hem      : ',per,hem
363
      print*
364
 
365
c     --------------------------------------------------------------------
366
c     Calculate the map scale factors
367
c     --------------------------------------------------------------------
368
 
369
c     Read lon/lat on the model grid from first data file
370
      filename = prefix//dat(1)
371
      call input_open (fid,filename)
372
      varname='XLONG'
373
      call input_var_wrf(fid,varname,lon,nx,ny,1)
374
      varname='XLAT'
375
      call input_var_wrf(fid,varname,lat,nx,ny,1)
376
      call input_close(fid)
377
 
378
c     Get map scale for interior points
379
      do i=2,nx-1
380
         do j=2,ny-1
381
 
382
c           Map scale in x direction
383
            lon1     = lon(i-1,j)
384
            lat1     = lat(i-1,j)
385
            lon2     = lon(i+1,j)
386
            lat2     = lat(i+1,j)
387
            radunit  = 'km.haversine'
388
            mpx(i,j) = 0.5 * 1000. * sdis(lon1,lat1,lon2,lat2,radunit)
389
 
390
c           Map scale in y direction
391
            lon1     = lon(i,j-1)
392
            lat1     = lat(i,j-1)
393
            lon2     = lon(i,j+1)
394
            lat2     = lat(i,j+1)
395
            radunit  = 'km.haversine'
396
            mpy(i,j) = 0.5 * 1000. * sdis(lon1,lat1,lon2,lat2,radunit)
397
 
398
         enddo
399
      enddo
400
 
401
c     Copy map scale for boundary points
402
      do i=2,nx-1
403
        mpx(i, 1) = mpx(i,   2)
404
        mpx(i,ny) = mpx(i,ny-1)
405
        mpy(i, 1) = mpy(i,   2)
406
        mpy(i,ny) = mpy(i,ny-1)
407
      enddo
408
      do j=2,ny-1
409
        mpx(1, j) = mpx(2,   j)
410
        mpx(nx,j) = mpx(nx-1,j)
411
        mpy(1, j) = mpy(2,   j)
412
        mpy(nx,j) = mpy(nx-1,j)
413
      enddo
414
      mpx(1,1)   = mpx(2,2)
415
      mpy(1,1)   = mpy(2,2)
416
      mpx(nx,1)  = mpx(nx-1,2)
417
      mpy(nx,1)  = mpy(nx-1,2)
418
      mpx(nx,ny) = mpx(nx-1,ny-1)
419
      mpy(nx,ny) = mpy(nx-1,ny-1)
420
      mpx(1,ny)  = mpx(2,ny-1)
421
      mpy(1,ny)  = mpy(2,ny-1)
422
 
423
c	  Write some status information
15 michaesp 424
      print*,'---- MAPPING SCALE FACTORS -----------------------------'
2 michaesp 425
      print*
426
 
427
      scale_max = mpx(1,1)
428
      scale_min = mpx(1,1)
429
      do i=1,nx
430
      	do j=1,ny
431
      	   if ( mpx(i,j).gt.scale_max ) scale_max = mpx(i,j)
432
      	   if ( mpx(i,j).lt.scale_min ) scale_min = mpx(i,j)
433
      	 enddo
434
      enddo
435
      print*,'  map scale x (min,max) : ',scale_min,scale_max
436
      scale_max = mpy(1,1)
437
      scale_min = mpy(1,1)
438
      do i=1,nx
439
      	do j=1,ny
440
      	   if ( mpy(i,j).gt.scale_max ) scale_max = mpy(i,j)
441
      	   if ( mpy(i,j).lt.scale_min ) scale_min = mpy(i,j)
442
      	 enddo
443
      enddo
444
      print*,'  map scale y (min,max) : ',scale_min,scale_max
445
      print*
446
 
447
c     --------------------------------------------------------------------
448
c     Initialize the trajectory calculation
449
c     --------------------------------------------------------------------
450
 
451
c     Read start coordinates from file - Format (x,y,lev)
452
      if (inpmode.eq.-1) then
453
         open(fid,file=strname)
454
          do i=1,ntra
455
             read(fid,*) xx0(i),yy0(i),pp0(i)
456
          enddo
457
         close(fid)
458
 
459
c     Read start coordinates from trajectory file - check consistency of ref time
460
      else
461
         call ropen_tra(cdfid,strname,ntra,1,ncol,reftmp,vars,inpmode)
462
         call read_tra (cdfid,trainp,ntra,1,ncol,inpmode)
463
         do i=1,ntra
464
            time   = trainp(i,1,1)
465
            xx0(i) = trainp(i,1,2) 
466
            yy0(i) = trainp(i,1,3) 
467
            pp0(i) = trainp(i,1,4) 
468
         enddo
469
         call close_tra(cdfid,inpmode)
470
 
471
         if ( ( vars(2).ne.'x').and.(vars(3).ne.'y') ) then
472
            print*,' ERROR: starting positions must be in x/y/z format'
473
            stop
474
         endif
475
 
476
         if ( ( reftime(1).ne.reftmp(1) ).or.
477
     >        ( reftime(2).ne.reftmp(2) ).or.
478
     >        ( reftime(3).ne.reftmp(3) ).or.
479
     >        ( reftime(4).ne.reftmp(4) ).or.
480
     >        ( reftime(5).ne.reftmp(5) ) )
481
     >   then
482
            print*,' WARNING: Inconsistent reference times'
483
            write(*,'(5i8)') (reftime(i),i=1,5)
484
            write(*,'(5i8)') (reftmp (i),i=1,5)
21 michaesp 485
            print*,' Enter a key to proceed...'
2 michaesp 486
            stop
487
         endif
488
      endif
489
 
490
c     Transform start coordinates from index space to WRF grid
491
      do i=1,ntra
492
         xx0(i) = xmin + ( xx0(i) - 1. ) * dx
493
         yy0(i) = ymin + ( yy0(i) - 1. ) * dy
494
      enddo
495
 
496
c     Set sign of time range
497
      reftime(6) = fbflag * reftime(6)
498
 
499
c     Write some status information
500
      print*,'---- REFERENCE DATE---------- ---------------------------'
501
      print*
502
      print*,' Reference time (year)  :',reftime(1)
503
      print*,'                (month) :',reftime(2)
504
      print*,'                (day)   :',reftime(3)
505
      print*,'                (hour)  :',reftime(4)
506
      print*,'                (min)   :',reftime(5)
507
      print*,' Time range             :',reftime(6),' min'
508
      print*
509
 
21 michaesp 510
C     Save starting positions - vertical position will be corrected below for <aglconst> and <isen>
2 michaesp 511
      itim = 1
512
      do i=1,ntra
513
         traout(i,itim,1) = 0.
514
         traout(i,itim,2) = xx0(i)
515
         traout(i,itim,3) = yy0(i)
516
         traout(i,itim,4) = pp0(i)
517
      enddo
518
 
519
c     Init the flag and the counter for trajectories leaving the domain
520
      leftcount=0
521
      do i=1,ntra
522
         leftflag(i)=0
523
      enddo
524
 
525
C     Convert time shifts <tst,ten> from <hh.mm> into fractional time
526
      call hhmm2frac(tst,frac)
527
      tst = frac
528
      call hhmm2frac(ten,frac)
529
      ten = frac
530
 
21 michaesp 531
c     Adjust the starting heights in mode <aglconst>
532
      if ( vertmode.eq.'aglconst' ) then
533
        filename = prefix//dat(1)
534
        call input_open (fid,filename)
535
	      varname='geopot'				! geopot.height
536
	      call input_var_wrf(fid,varname,p3t0,nx,ny,nz)
537
	      varname='geopots'				! geopot.height at surface
538
	      call input_var_wrf(fid,varname,spt0,nx,ny,1)
539
        call input_close(fid)
540
        filename = prefix//dat(2)
541
        call input_open (fid,filename)
542
	      varname='geopot'				! geopot.height
543
	      call input_var_wrf(fid,varname,p3t1,nx,ny,nz)
544
	      varname='geopots'				! geopot.height at surface
545
	      call input_var_wrf(fid,varname,spt1,nx,ny,1)
546
        call input_close(fid)
547
        do i=1,ntra
548
           call get_index4 (xind,yind,pind,xx0(i),yy0(i),0.,reltpos0,
549
     >                      p3t0,p3t1,spt0,spt1,3,
550
     >                      nx,ny,nz,xmin,ymin,dx,dy,mdv)
551
           sp = int_index4 (spt0,spt1,nx,ny,1,xind,yind,1.,reltpos0,mdv)
552
           traout(i,1,4) = sp + aglconst
553
        enddo
554
      endif
555
 
556
c     Adjust the starting heights in mode <isen>
557
      if ( vertmode.eq.'isen' ) then
558
        filename = prefix//dat(1)
559
        call input_open (fid,filename)
560
	      varname='geopot'				! geopot.height
561
	      call input_var_wrf(fid,varname,p3t0,nx,ny,nz)
562
	      varname='geopots'				! geopot.height at surface
563
	      call input_var_wrf(fid,varname,spt0,nx,ny,1)
564
          varname='TH'					! TH
565
          call input_var_wrf(fid,varname,tht0,nx,ny,nz)
566
          do i=1,nx*ny 
567
              sth0(i) = tht0(i)
568
          enddo
569
        call input_close(fid)
570
        filename = prefix//dat(2)
571
        call input_open (fid,filename)
572
	      varname='geopot'				! geopot.height
573
	      call input_var_wrf(fid,varname,p3t1,nx,ny,nz)
574
	      varname='geopots'				! geopot.height at surface
575
	      call input_var_wrf(fid,varname,spt1,nx,ny,1)
576
          varname='TH'					! TH
577
          call input_var_wrf(fid,varname,tht1,nx,ny,nz)
578
          do i=1,nx*ny 
579
              sth1(i) = tht1(i)
580
          enddo
581
        call input_close(fid)
582
        do i=1,ntra
583
 
584
          call get_index4 (xind,yind,pind,xx0(i),yy0(i),isen,reltpos0,
585
     >                    tht0,tht1,sth0,sth1,1,
586
     >                    nx,ny,nz,xmin,ymin,dx,dy,mdv)
587
          traout(i,1,4) = int_index4 
588
     >          (p3t0,p3t1,nx,ny,nz,xind,yind,pind,reltpos0,mdv)
589
        enddo
590
      endif
591
 
2 michaesp 592
c     -----------------------------------------------------------------------
593
c     Loop to calculate trajectories
594
c     -----------------------------------------------------------------------
595
 
596
c     Write some status information
597
      print*,'---- TRAJECTORIES ----------- ---------------------------'
598
      print*    
599
 
600
C     Set the time for the first data file (depending on forward/backward mode)
601
      if (fbflag.eq.1) then
602
        tstart = -tst
603
      else
604
        tstart = tst
605
      endif
606
 
607
c     Set the minute counter for output
608
      wstep = 0
609
 
610
c     Read wind fields and vertical grid from first file
611
      filename = prefix//dat(1)
612
 
613
      call frac2hhmm(tstart,tload)
614
 
615
      write(*,'(a16,a20,f7.2)') '  (file,time) : ',
616
     >                       trim(filename),tload
617
 
618
      call input_open (fid,filename)
619
 
620
      varname='U'					! U
621
 	  call input_var_wrf(fid,varname,uut1,nx,ny,nz)
622
 
623
	  varname='V'					! V
624
	  call input_var_wrf(fid,varname,vvt1,nx,ny,nz)
625
 
626
	  varname='W'					! W
627
	  call input_var_wrf(fid,varname,wwt1,nx,ny,nz)
628
 
629
	  varname='geopot'				! geopot.height
630
	  call input_var_wrf(fid,varname,p3t1,nx,ny,nz)
631
 
632
	  varname='geopots'				! geopot.height at surface
633
	  call input_var_wrf(fid,varname,spt1,nx,ny,1)
634
 
21 michaesp 635
      if (vertmode.eq.'isen') then
636
           varname='TH'					! TH
637
 	       call input_var_wrf(fid,varname,tht1,nx,ny,nz)
638
           do i=1,nx*ny 
639
              sth1(i) = tht1(i)
640
           enddo
641
      endif
642
 
2 michaesp 643
      call input_close(fid)
644
 
645
c     Loop over all input files (time step is <timeinc>)
646
      do itm=1,numdat-1
647
 
648
c       Calculate actual and next time
649
        time0 = tstart+real(itm-1)*timeinc*fbflag
650
        time1 = time0+timeinc*fbflag
651
 
652
c       Copy old velocities and pressure fields to new ones       
653
        do i=1,nx*ny*nz
654
           uut0(i)=uut1(i)
655
           vvt0(i)=vvt1(i)
656
           wwt0(i)=wwt1(i)
657
           p3t0(i)=p3t1(i)
658
        enddo
659
        do i=1,nx*ny
660
           spt0(i)=spt1(i)
661
        enddo
662
 
21 michaesp 663
c       Copy potential temperature
664
        if ( vertmode.eq.'isen' ) then
665
           do i=1,nx*ny*nz
666
              tht0(i)=tht1(i)
667
           enddo
668
           do i=1,nx*ny
669
             sth0(i)=sth1(i)
670
           enddo
671
        endif
672
 
2 michaesp 673
c       Read wind fields and surface pressure at next time
674
        filename = prefix//dat(itm+1)
675
 
676
        call frac2hhmm(time1,tload)
677
        write(*,'(a16,a20,f7.2)') '  (file,time) : ',
678
     >                          trim(filename),tload
679
 
680
        call input_open (fid,filename)
681
 
682
  	    varname='U'					! U
683
	    call input_var_wrf(fid,varname,uut1,nx,ny,nz)
684
 
685
	    varname='V'					! V
686
	    call input_var_wrf(fid,varname,vvt1,nx,ny,nz)
687
 
688
	    varname='W'					! W
689
	    call input_var_wrf(fid,varname,wwt1,nx,ny,nz)
690
 
691
	    varname='geopot'				! geopot.height
692
	    call input_var_wrf(fid,varname,p3t1,nx,ny,nz)
693
 
694
	    varname='geopots'				! geopot.height
695
	    call input_var_wrf(fid,varname,spt1,nx,ny,1)
21 michaesp 696
 
697
        if (vertmode.eq.'isen') then
698
           varname='TH'					! TH
699
 	       call input_var_wrf(fid,varname,tht1,nx,ny,nz)
700
           do i=1,nx*ny 
701
              sth1(i) = tht1(i)
702
           enddo
703
        endif
704
 
2 michaesp 705
        call input_close(fid)
706
 
707
C       Determine the first and last loop indices
708
        if (numdat.eq.2) then
709
          filo = nint(tst/ts)+1
710
          lalo = nint((timeinc-ten)/ts) 
711
        elseif ( itm.eq.1 ) then
712
          filo = nint(tst/ts)+1
713
          lalo = nint(timeinc/ts)
714
        else if (itm.eq.numdat-1) then
715
          filo = 1
716
          lalo = nint((timeinc-ten)/ts)
717
        else
718
          filo = 1
719
          lalo = nint(timeinc/ts)
720
        endif
721
 
722
c       Split the interval <timeinc> into computational time steps <ts>
723
        do iloop=filo,lalo
724
 
725
C         Calculate relative time position in the interval timeinc (0=beginning, 1=end)
726
          reltpos0 = ((real(iloop)-1.)*ts)/timeinc
727
          reltpos1 = real(iloop)*ts/timeinc
728
 
729
C         Initialize counter for domain leaving trajectories
730
          leftcount=0
731
 
732
c         Timestep for all trajectories
21 michaesp 733
          do i=1,ntra                
2 michaesp 734
 
735
C           Check if trajectory has already left the data domain
736
            if (leftflag(i).ne.1) then	
737
 
738
c             Iterative Euler timestep (x0,y0,p0 -> x1,y1,p1)
21 michaesp 739
              if ( vertmode.eq.'kinematic' ) then
740
                 call euler_kinematic(
2 michaesp 741
     >               xx1,yy1,pp1,leftflag(i),
742
     >               xx0(i),yy0(i),pp0(i),reltpos0,reltpos1,
743
     >               ts*3600,numit,jflag,mdv,wfactor,fbflag,
744
     >               spt0,spt1,p3t0,p3t1,uut0,uut1,vvt0,vvt1,wwt0,wwt1,
745
     >               xmin,ymin,dx,dy,per,hem,nx,ny,nz,mpx,mpy)
21 michaesp 746
              elseif ( vertmode.eq.'aglconst' ) then
747
                 call euler_aglconst(
748
     >               xx1,yy1,pp1,leftflag(i),
749
     >               xx0(i),yy0(i),pp0(i),reltpos0,reltpos1,
750
     >               ts*3600,numit,jflag,mdv,wfactor,fbflag,
751
     >               spt0,spt1,p3t0,p3t1,uut0,uut1,vvt0,vvt1,
752
     >               xmin,ymin,dx,dy,per,hem,nx,ny,nz,mpx,mpy,aglconst)
753
              elseif ( vertmode.eq.'isen' ) then
754
                 call euler_isen(
755
     >               xx1,yy1,pp1,leftflag(i),
756
     >               xx0(i),yy0(i),pp0(i),reltpos0,reltpos1,
757
     >               ts*3600,numit,jflag,mdv,wfactor,fbflag,
758
     >               spt0,spt1,p3t0,p3t1,uut0,uut1,vvt0,vvt1,
759
     >               tht0,tht1,sth0,sth1,
760
     >               xmin,ymin,dx,dy,per,hem,nx,ny,nz,mpx,mpy,isen)
761
 
762
              endif
2 michaesp 763
 
764
c             Update trajectory position, or increase number of trajectories leaving domain
765
              if (leftflag(i).eq.1) then
766
                leftcount=leftcount+1
767
                if ( leftcount.lt.10 ) then
768
                   print*,'     -> Trajectory ',i,' leaves domain'
769
                elseif ( leftcount.eq.10 ) then
770
                   print*,'     -> N>=10 trajectories leave domain'
771
                endif
772
              else
773
                xx0(i)=xx1      
774
                yy0(i)=yy1
775
                pp0(i)=pp1
776
              endif
777
 
778
c          Trajectory has already left data domain (mark as <mdv>)
779
           else
780
              xx0(i)=mdv
781
              yy0(i)=mdv
782
              pp0(i)=mdv
783
 
784
           endif
785
 
786
          enddo
787
 
788
C         Save positions only every deltout minutes
789
          delta = aint(iloop*60*ts/deltout)-iloop*60*ts/deltout
790
          if (abs(delta).lt.eps) then
791
            time = time0+reltpos1*timeinc*fbflag
792
            itim = itim + 1
793
            do i=1,ntra
794
               call frac2hhmm(time,tload)
795
               traout(i,itim,1) = tload
796
               traout(i,itim,2) = xx0(i)
797
               traout(i,itim,3) = yy0(i) 
798
               traout(i,itim,4) = pp0(i)
799
            enddo
800
          endif
801
 
802
        enddo
803
 
804
      enddo
805
 
806
c     Transform trajectory position from WRF grid do grid index
807
      do i=1,ntra
808
        do j=1,ntim
19 michaesp 809
           if ( abs(traout(i,j,2)-mdv).gt.eps ) then
810
              traout(i,j,2) = ( traout(i,j,2) - xmin ) / dx + 1.
811
           else
812
              traout(i,j,2) = mdv
813
           endif
814
           if ( abs(traout(i,j,3)-mdv).gt.eps ) then
815
              traout(i,j,3) = ( traout(i,j,3) - ymin ) / dy + 1.
816
           else
817
              traout(i,j,3) = mdv
818
           endif
2 michaesp 819
        enddo
820
      enddo
821
 
822
c     Write trajectory file
823
      vars(1)  ='time'
824
      vars(2)  ='x'
825
      vars(3)  ='y'
826
      vars(4)  ='z'
827
      call wopen_tra(cdfid,cdfname,ntra,ntim,4,reftime,vars,outmode)
828
      call write_tra(cdfid,traout,ntra,ntim,4,outmode)
829
      call close_tra(cdfid,outmode)   
830
 
831
c     Write some status information, and end of program message
832
      print*  
833
      print*,'---- STATUS INFORMATION --------------------------------'
834
      print*
835
      print*,'  #leaving domain    ', leftcount
836
      print*,'  #staying in domain ', ntra-leftcount
837
      print*
838
      print*,'              *** END OF PROGRAM CALTRA ***'
839
      print*,'========================================================='
840
 
841
      stop
842
 
843
c     ------------------------------------------------------------------
844
c     Exception handling
845
c     ------------------------------------------------------------------
846
 
847
 991  write(*,*) '*** ERROR: all start points outside the data domain'
848
      call exit(1)
849
 
850
 992  write(*,*) '*** ERROR: close arrays on files (prog. closear)'
851
      call exit(1)
852
 
853
 993  write(*,*) '*** ERROR: problems with array size'
854
      call exit(1)
855
 
856
      end 
857
 
858
 
859
c     *******************************************************************
860
c     * Time step : either Euler or Runge-Kutta                         *
861
c     *******************************************************************
862
 
863
C     Time-step from (x0,y0,p0) to (x1,y1,p1)
864
C
865
C     (x0,y0,p0) input	coordinates (long,lat,p) for starting point
866
C     (x1,y1,p1) output	coordinates (long,lat,p) for end point
867
C     deltat	 input	timestep in seconds
868
C     numit	 input	number of iterations
869
C     jump	 input  flag (=1 trajectories don't enter the ground)
870
C     left	 output	flag (=1 if trajectory leaves data domain)
871
 
872
c     -------------------------------------------------------------------
21 michaesp 873
c     Iterative Euler time step - kinematic trajectory
2 michaesp 874
c     -------------------------------------------------------------------
875
 
21 michaesp 876
      subroutine euler_kinematic
877
     >          (x1,y1,p1,left,x0,y0,p0,reltpos0,reltpos1,
878
     >           deltat,numit,jump,mdv,wfactor,fbflag,
879
     >		     spt0,spt1,p3d0,p3d1,uut0,uut1,vvt0,vvt1,wwt0,wwt1,
880
     >           xmin,ymin,dx,dy,per,hem,nx,ny,nz,mpx,mpy)
2 michaesp 881
 
882
      implicit none
883
 
11 michaesp 884
c     Flag for test mode
885
      integer      test
886
      parameter    (test=0)
887
 
2 michaesp 888
c     Declaration of subroutine parameters
889
      integer      nx,ny,nz
890
      real         x1,y1,p1
891
      integer      left
892
      real	       x0,y0,p0
893
      real         reltpos0,reltpos1
894
      real   	   deltat
895
      integer      numit
896
      integer      jump
897
      real         wfactor
898
      integer      fbflag
899
      real     	   spt0(nx*ny)   ,spt1(nx*ny)
900
      real         uut0(nx*ny*nz),uut1(nx*ny*nz)
901
      real 	       vvt0(nx*ny*nz),vvt1(nx*ny*nz)
902
      real         wwt0(nx*ny*nz),wwt1(nx*ny*nz)
903
      real         p3d0(nx*ny*nz),p3d1(nx*ny*nz)
904
      real         xmin,ymin,dx,dy
905
      integer      per
906
      integer      hem
907
      real         mdv
908
      real         mpx(nx*ny),mpy(nx*ny)
909
 
910
c     Auxiliary variables
911
      real         xmax,ymax
912
      real	       xind,yind,pind
913
 
914
      real	       u0,v0,w0,u1,v1,w1,u,v,w,sp
915
      integer	   icount
916
      character    ch
917
      real         mpsc_x,mpsc_y
918
 
919
c     Externals    
920
      real         int_index4
921
      external     int_index4
922
 
923
c     Reset the flag for domain-leaving
924
      left=0
925
 
926
c     Set the esat-north boundary of the domain
927
      xmax = xmin+real(nx-1)*dx
928
      ymax = ymin+real(ny-1)*dy
929
 
930
C     Interpolate wind fields to starting position (x0,y0,p0)
931
      call get_index4 (xind,yind,pind,x0,y0,p0,reltpos0,
932
     >                 p3d0,p3d1,spt0,spt1,3,
933
     >                 nx,ny,nz,xmin,ymin,dx,dy,mdv)
934
 
935
      u0 = int_index4(uut0,uut1,nx,ny,nz,xind,yind,pind,reltpos0,mdv)
936
      v0 = int_index4(vvt0,vvt1,nx,ny,nz,xind,yind,pind,reltpos0,mdv)
937
      w0 = int_index4(wwt0,wwt1,nx,ny,nz,xind,yind,pind,reltpos0,mdv)
938
 
939
c     Force the near-surface wind to zero
940
      if (pind.lt.1.) w0=w0*pind
941
 
942
C     For first iteration take ending position equal to starting position
943
      x1=x0
944
      y1=y0
945
      p1=p0
946
 
947
C     Iterative calculation of new position
948
      do icount=1,numit
949
 
950
C        Calculate new winds for advection
951
         call get_index4 (xind,yind,pind,x1,y1,p1,reltpos1,
952
     >                    p3d0,p3d1,spt0,spt1,3,
953
     >                    nx,ny,nz,xmin,ymin,dx,dy,mdv)
954
         u1 = int_index4(uut0,uut1,nx,ny,nz,xind,yind,pind,reltpos1,mdv)
955
         v1 = int_index4(vvt0,vvt1,nx,ny,nz,xind,yind,pind,reltpos1,mdv)
956
         w1 = int_index4(wwt0,wwt1,nx,ny,nz,xind,yind,pind,reltpos1,mdv)
957
 
958
c        Force the near-surface wind to zero
959
         if (pind.lt.1.) w1=w1*pind
960
 
961
c        Get the new velocity in between
962
         u=(u0+u1)/2.
963
         v=(v0+v1)/2.
964
         w=(w0+w1)/2.
965
 
966
c        Get the mapping scale factors for this position
967
         mpsc_x = int_index4 (mpx,mpx,nx,ny,1,xind,yind,1.,reltpos1,mdv)
968
         mpsc_y = int_index4 (mpy,mpy,nx,ny,1,xind,yind,1.,reltpos1,mdv)
969
 
970
C        Calculate new positions (adapted for cartesian grid)
971
         x1 = x0 + fbflag * deltat * u * dx/mpsc_x
972
         y1 = y0 + fbflag * deltat * v * dy/mpsc_y
973
         p1 = p0 + fbflag * deltat * w * wfactor
974
 
11 michaesp 975
c        Write the update positions for tests
976
         if ( (icount.eq.3).and.(test.eq.1) ) then
977
            write(*,'(10f10.2)') x0,u,x1-x0,p0,w,p1-p0
978
         endif
979
 
2 michaesp 980
C       Interpolate surface geop.height to actual position
981
        call get_index4 (xind,yind,pind,x1,y1,0.,reltpos1,
982
     >                   p3d0,p3d1,spt0,spt1,3,
983
     >                   nx,ny,nz,xmin,ymin,dx,dy,mdv)
984
        sp = int_index4 (spt0,spt1,nx,ny,1,xind,yind,1.,reltpos1,mdv)
985
 
986
c       Handle trajectories which cross the lower boundary (jump flag)
987
        if ((jump.eq.1).and.(p1.lt.sp)) p1=sp+10.
988
 
989
c       Handle periodioc boundaries for 'ideal' mode
990
        if ( per.eq.1 ) then
991
	        if ( x1.gt.xmax ) x1=x1-xmax
992
	        if ( x1.lt.xmin ) x1=x1+xmax
993
        endif
994
 
995
C       Check if trajectory leaves data domain
996
        if ( (x1.lt.xmin).or.(x1.gt.xmax).or.
997
     >       (y1.lt.ymin).or.(y1.gt.ymax).or.(p1.lt.sp) )   ! geopot : .lt. ; pressure: .gt.
998
     >  then
999
          left=1
1000
          print*,x1,y1,p1
1001
          print*,xmin,ymin
1002
	      print*,xmax,ymax
1003
	      print*,sp
1004
          goto 100
1005
        endif
1006
 
1007
      enddo
1008
 
1009
c     Exit point for subroutine
1010
 100  continue
1011
 
1012
      return
1013
 
1014
      end
1015
 
21 michaesp 1016
c     -------------------------------------------------------------------
1017
c     Iterative Euler time step - constant level above ground
1018
c     -------------------------------------------------------------------
2 michaesp 1019
 
21 michaesp 1020
      subroutine euler_aglconst
1021
     >          (x1,y1,p1,left,x0,y0,p0,reltpos0,reltpos1,
1022
     >           deltat,numit,jump,mdv,wfactor,fbflag,
1023
     >		     spt0,spt1,p3d0,p3d1,uut0,uut1,vvt0,vvt1,
1024
     >           xmin,ymin,dx,dy,per,hem,nx,ny,nz,mpx,mpy,aglconst)
1025
 
1026
      implicit none
1027
 
1028
c     Flag for test mode
1029
      integer      test
1030
      parameter    (test=0)
1031
 
1032
c     Declaration of subroutine parameters
1033
      integer      nx,ny,nz
1034
      real         x1,y1,p1
1035
      integer      left
1036
      real	       x0,y0,p0
1037
      real         reltpos0,reltpos1
1038
      real   	   deltat
1039
      integer      numit
1040
      integer      jump
1041
      real         wfactor
1042
      integer      fbflag
1043
      real     	   spt0(nx*ny)   ,spt1(nx*ny)
1044
      real         uut0(nx*ny*nz),uut1(nx*ny*nz)
1045
      real 	       vvt0(nx*ny*nz),vvt1(nx*ny*nz)
1046
      real         p3d0(nx*ny*nz),p3d1(nx*ny*nz)
1047
      real         xmin,ymin,dx,dy
1048
      integer      per
1049
      integer      hem
1050
      real         mdv
1051
      real         mpx(nx*ny),mpy(nx*ny)
1052
      real         aglconst
1053
 
1054
c     Auxiliary variables
1055
      real         xmax,ymax
1056
      real	       xind,yind,pind
1057
 
1058
      real	       u0,v0,u1,v1,u,v,w,sp
1059
      integer	   icount
1060
      character    ch
1061
      real         mpsc_x,mpsc_y
1062
 
1063
c     Externals    
1064
      real         int_index4
1065
      external     int_index4
1066
 
1067
c     Reset the flag for domain-leaving
1068
      left=0
1069
 
1070
c     Set the esat-north boundary of the domain
1071
      xmax = xmin+real(nx-1)*dx
1072
      ymax = ymin+real(ny-1)*dy
1073
 
1074
C     Set parcel height to aglconst above topography
1075
      call get_index4 (xind,yind,pind,x1,y1,0.,reltpos0,
1076
     >                 p3d0,p3d1,spt0,spt1,3,
1077
     >                 nx,ny,nz,xmin,ymin,dx,dy,mdv)
1078
      sp = int_index4 (spt0,spt1,nx,ny,1,xind,yind,1.,reltpos0,mdv)
1079
      p0 = sp + aglconst
1080
 
1081
C     Interpolate wind fields to starting position (x0,y0,p0)
1082
      call get_index4 (xind,yind,pind,x0,y0,p0,reltpos0,
1083
     >                 p3d0,p3d1,spt0,spt1,3,
1084
     >                 nx,ny,nz,xmin,ymin,dx,dy,mdv)
1085
      u0 = int_index4(uut0,uut1,nx,ny,nz,xind,yind,pind,reltpos0,mdv)
1086
      v0 = int_index4(vvt0,vvt1,nx,ny,nz,xind,yind,pind,reltpos0,mdv)
1087
 
1088
C     For first iteration take ending position equal to starting position
1089
      x1 = x0
1090
      y1 = y0
1091
      p1 = p0
1092
 
1093
C     Iterative calculation of new position
1094
      do icount=1,numit
1095
 
1096
C        Calculate new winds for advection
1097
         call get_index4 (xind,yind,pind,x1,y1,p1,reltpos1,
1098
     >                    p3d0,p3d1,spt0,spt1,3,
1099
     >                    nx,ny,nz,xmin,ymin,dx,dy,mdv)
1100
         u1 = int_index4(uut0,uut1,nx,ny,nz,xind,yind,pind,reltpos1,mdv)
1101
         v1 = int_index4(vvt0,vvt1,nx,ny,nz,xind,yind,pind,reltpos1,mdv)
1102
 
1103
c        Get the new velocity in between
1104
         u=(u0+u1)/2.
1105
         v=(v0+v1)/2.
1106
 
1107
c        Get the mapping scale factors for this position
1108
         mpsc_x = int_index4 (mpx,mpx,nx,ny,1,xind,yind,1.,reltpos1,mdv)
1109
         mpsc_y = int_index4 (mpy,mpy,nx,ny,1,xind,yind,1.,reltpos1,mdv)
1110
 
1111
C        Calculate new positions (adapted for cartesian grid)
1112
         x1 = x0 + fbflag * deltat * u * dx/mpsc_x
1113
         y1 = y0 + fbflag * deltat * v * dy/mpsc_y
1114
 
1115
c        Write the update positions for tests
1116
         if ( (icount.eq.3).and.(test.eq.1) ) then
1117
            write(*,'(10f10.2)') x0,u,x1-x0,p0,w,p1-p0
1118
         endif
1119
 
1120
C       Set trajectory height to aglconst above topography
1121
        call get_index4 (xind,yind,pind,x1,y1,0.,reltpos1,
1122
     >                   p3d0,p3d1,spt0,spt1,3,
1123
     >                   nx,ny,nz,xmin,ymin,dx,dy,mdv)
1124
        sp = int_index4 (spt0,spt1,nx,ny,1,xind,yind,1.,reltpos1,mdv)
1125
        p1 = sp + aglconst
1126
 
1127
c       Handle trajectories which cross the lower boundary (jump flag)
1128
        if ((jump.eq.1).and.(p1.lt.sp)) then
1129
            print*,'jump'
1130
            p1=sp+10.
1131
        endif
1132
 
1133
c       Handle periodioc boundaries for 'ideal' mode
1134
        if ( per.eq.1 ) then
1135
	        if ( x1.gt.xmax ) x1=x1-xmax
1136
	        if ( x1.lt.xmin ) x1=x1+xmax
1137
        endif
1138
 
1139
C       Check if trajectory leaves data domain
1140
        if ( (x1.lt.xmin).or.(x1.gt.xmax).or.
1141
     >       (y1.lt.ymin).or.(y1.gt.ymax).or.(p1.lt.sp) )   ! geopot : .lt. ; pressure: .gt.
1142
     >  then
1143
          left=1
1144
          goto 100
1145
        endif
1146
 
1147
      enddo
1148
 
1149
c     Exit point for subroutine
1150
 100  continue
1151
 
1152
      return
1153
 
1154
      end
1155
 
1156
c     -------------------------------------------------------------------
1157
c     Iterative Euler time step - isentropic
1158
c     -------------------------------------------------------------------
1159
 
1160
      subroutine euler_isen
1161
     >          (x1,y1,p1,left,x0,y0,p0,reltpos0,reltpos1,
1162
     >           deltat,numit,jump,mdv,wfactor,fbflag,
1163
     >		     spt0,spt1,p3d0,p3d1,uut0,uut1,vvt0,vvt1,
1164
     >           tht0,tht1,sth0,sth1,
1165
     >           xmin,ymin,dx,dy,per,hem,nx,ny,nz,mpx,mpy,isen)
1166
 
1167
      implicit none
1168
 
1169
c     Flag for test mode
1170
      integer      test
1171
      parameter    (test=0)
1172
 
1173
c     Declaration of subroutine parameters
1174
      integer      nx,ny,nz
1175
      real         x1,y1,p1
1176
      integer      left
1177
      real	       x0,y0,p0
1178
      real         reltpos0,reltpos1
1179
      real   	   deltat
1180
      integer      numit
1181
      integer      jump
1182
      real         wfactor
1183
      integer      fbflag
1184
      real     	   spt0(nx*ny)   ,spt1(nx*ny)
1185
      real         uut0(nx*ny*nz),uut1(nx*ny*nz)
1186
      real 	       vvt0(nx*ny*nz),vvt1(nx*ny*nz)
1187
      real         tht0(nx*ny*nz),tht1(nx*ny*nz),sth0(nx*ny),sth1(nx*ny)
1188
      real         p3d0(nx*ny*nz),p3d1(nx*ny*nz)
1189
      real         xmin,ymin,dx,dy
1190
      integer      per
1191
      integer      hem
1192
      real         mdv
1193
      real         mpx(nx*ny),mpy(nx*ny)
1194
      real         isen
1195
 
1196
c     Auxiliary variables
1197
      real         xmax,ymax
1198
      real	       xind,yind,pind
1199
 
1200
      real	       u0,v0,u1,v1,u,v,w,sp
1201
      integer	   icount
1202
      character    ch
1203
      real         mpsc_x,mpsc_y
1204
 
1205
c     Externals    
1206
      real         int_index4
1207
      external     int_index4
1208
 
1209
c     Reset the flag for domain-leaving
1210
      left=0
1211
 
1212
c     Set the esat-north boundary of the domain
1213
      xmax = xmin+real(nx-1)*dx
1214
      ymax = ymin+real(ny-1)*dy
1215
 
1216
C     Interpolate wind fields to starting position (x0,y0,p0)
1217
      call get_index4 (xind,yind,pind,x0,y0,p0,reltpos0,
1218
     >                 p3d0,p3d1,spt0,spt1,3,
1219
     >                 nx,ny,nz,xmin,ymin,dx,dy,mdv)
1220
      u0 = int_index4(uut0,uut1,nx,ny,nz,xind,yind,pind,reltpos0,mdv)
1221
      v0 = int_index4(vvt0,vvt1,nx,ny,nz,xind,yind,pind,reltpos0,mdv)
1222
 
1223
C     For first iteration take ending position equal to starting position
1224
      x1 = x0
1225
      y1 = y0
1226
      p1 = p0
1227
 
1228
C     Iterative calculation of new position
1229
      do icount=1,numit
1230
 
1231
C        Calculate new winds for advection
1232
         call get_index4 (xind,yind,pind,x1,y1,p1,reltpos1,
1233
     >                    p3d0,p3d1,spt0,spt1,3,
1234
     >                    nx,ny,nz,xmin,ymin,dx,dy,mdv)
1235
         u1 = int_index4(uut0,uut1,nx,ny,nz,xind,yind,pind,reltpos1,mdv)
1236
         v1 = int_index4(vvt0,vvt1,nx,ny,nz,xind,yind,pind,reltpos1,mdv)
1237
 
1238
c        Get the new velocity in between
1239
         u=(u0+u1)/2.
1240
         v=(v0+v1)/2.
1241
 
1242
c        Get the mapping scale factors for this position
1243
         mpsc_x = int_index4 (mpx,mpx,nx,ny,1,xind,yind,1.,reltpos1,mdv)
1244
         mpsc_y = int_index4 (mpy,mpy,nx,ny,1,xind,yind,1.,reltpos1,mdv)
1245
 
1246
C        Calculate new positions (adapted for cartesian grid)
1247
         x1 = x0 + fbflag * deltat * u * dx/mpsc_x
1248
         y1 = y0 + fbflag * deltat * v * dy/mpsc_y
1249
 
1250
c        Write the update positions for tests
1251
         if ( (icount.eq.3).and.(test.eq.1) ) then
1252
            write(*,'(10f10.2)') x0,u,x1-x0,p0,w,p1-p0
1253
         endif
1254
 
1255
c        Set trajectory height to isentropic level         
1256
         call get_index4 (xind,yind,pind,x1,y1,isen,reltpos1,
1257
     >                    tht0,tht1,sth0,sth1,1,
1258
     >                    nx,ny,nz,xmin,ymin,dx,dy,mdv)
1259
         p1 = int_index4 
1260
     >          (p3d0,p3d1,nx,ny,nz,xind,yind,pind,reltpos1,mdv)
1261
 
1262
C       Interpolate surface geop.height to actual position
1263
        call get_index4 (xind,yind,pind,x1,y1,0.,reltpos1,
1264
     >                   p3d0,p3d1,spt0,spt1,3,
1265
     >                   nx,ny,nz,xmin,ymin,dx,dy,mdv)
1266
        sp = int_index4 (spt0,spt1,nx,ny,1,xind,yind,1.,reltpos1,mdv)
1267
 
1268
c       Handle trajectories which cross the lower boundary (jump flag)
1269
        if ((jump.eq.1).and.(p1.lt.sp)) then
1270
            print*,'jump'
1271
            p1=sp+10.
1272
        endif
1273
 
1274
c       Handle periodioc boundaries for 'ideal' mode
1275
        if ( per.eq.1 ) then
1276
	        if ( x1.gt.xmax ) x1=x1-xmax
1277
	        if ( x1.lt.xmin ) x1=x1+xmax
1278
        endif
1279
 
1280
C       Check if trajectory leaves data domain
1281
        if ( (x1.lt.xmin).or.(x1.gt.xmax).or.
1282
     >       (y1.lt.ymin).or.(y1.gt.ymax).or.(p1.lt.sp) )   ! geopot : .lt. ; pressure: .gt.
1283
     >  then
1284
          left=1
1285
          goto 100
1286
        endif
1287
 
1288
      enddo
1289
 
1290
c     Exit point for subroutine
1291
 100  continue
1292
 
1293
      return
1294
 
1295
      end
1296
 
2 michaesp 1297
c     ----------------------------------------------------------------------
1298
c     Get spherical distance between lat/lon points
1299
c     ----------------------------------------------------------------------
1300
 
1301
      real function sdis(xp,yp,xq,yq,unit)
1302
 
1303
c     Calculates spherical distance (in km) between two points given
1304
c     by their spherical coordinates (xp,yp) and (xq,yq), respectively.
1305
 
1306
      real,parameter ::       re=6371.229
1307
      real,parameter ::       rad2deg=180./3.14159265
1308
      real,parameter ::       deg2rad=3.141592654/180.
1309
 
1310
      real         xp,yp,xq,yq,arg
1311
      character*80 unit
1312
      real         dlon,dlat,alpha,rlat1,ralt2
1313
 
1314
      if ( unit.eq.'km' ) then
1315
 
15 michaesp 1316
         arg=sin(yp*deg2rad)*sin(yq*deg2rad)+
1317
     >              cos(yp*deg2rad)*cos(yq*deg2rad)*cos((xp-xq)*deg2rad)
2 michaesp 1318
         if (arg.lt.-1.) arg=-1.
1319
         if (arg.gt.1.) arg=1.
1320
         sdis=re*acos(arg)
1321
 
1322
      elseif ( unit.eq.'deg' ) then
1323
 
1324
         dlon = xp-xq
1325
         if ( dlon.gt. 180. ) dlon = dlon - 360.
1326
         if ( dlon.lt.-180. ) dlon = dlon + 360.
1327
         sdis = sqrt( dlon**2 + (yp-yq)**2 )
1328
 
1329
      elseif ( unit.eq.'km.haversine' ) then
1330
 
1331
        dlat   =  (yp - yq)*deg2rad
1332
        dlon   =  (xp - xq)*deg2rad
1333
        rlat1   =  yp*deg2rad
1334
        rlat2   =  yq*deg2rad
1335
 
1336
        alpha  = ( sin(0.5*dlat)**2 ) +
1337
     >           ( sin(0.5*dlon)**2 )*cos(rlat1)*cos(rlat2)
1338
 
1339
        sdis = 4. * re * atan2( sqrt(alpha),1. + sqrt( 1. - alpha ) )
1340
 
1341
      endif
1342
 
1343
      end