[92fab65] | 1 | ! SPDX-FileCopyrightText: FLEXPART 1998-2019, see flexpart_license.txt |
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| 2 | ! SPDX-License-Identifier: GPL-3.0-or-later |
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[332fbbd] | 3 | |
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[e200b7a] | 4 | subroutine interpol_wind_short(itime,xt,yt,zt) |
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[8a65cb0] | 5 | ! i i i i |
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| 6 | !***************************************************************************** |
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| 7 | ! * |
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| 8 | ! This subroutine interpolates the wind data to current trajectory position.* |
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| 9 | ! * |
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| 10 | ! Author: A. Stohl * |
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| 11 | ! * |
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| 12 | ! 16 December 1997 * |
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| 13 | ! * |
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| 14 | ! Revision March 2005 by AST : all output variables in common block * |
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| 15 | ! * |
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| 16 | !***************************************************************************** |
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| 17 | ! * |
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| 18 | ! Variables: * |
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| 19 | ! u,v,w wind components * |
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| 20 | ! itime [s] current temporal position * |
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| 21 | ! memtime(3) [s] times of the wind fields in memory * |
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| 22 | ! xt,yt,zt coordinates position for which wind data shall be * |
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| 23 | ! calculated * |
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| 24 | ! * |
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| 25 | ! Constants: * |
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| 26 | ! * |
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| 27 | !***************************************************************************** |
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[e200b7a] | 28 | |
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| 29 | use par_mod |
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| 30 | use com_mod |
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| 31 | use interpol_mod |
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| 32 | |
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| 33 | implicit none |
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| 34 | |
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[8a65cb0] | 35 | integer, intent(in) :: itime |
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| 36 | real, intent(in) :: xt,yt,zt |
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[e200b7a] | 37 | |
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| 38 | ! Auxiliary variables needed for interpolation |
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| 39 | real :: dz1,dz2,dz |
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| 40 | real :: u1(2),v1(2),w1(2),uh(2),vh(2),wh(2) |
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| 41 | integer :: i,m,n,indexh,indzh |
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| 42 | |
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| 43 | |
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| 44 | !******************************************** |
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| 45 | ! Multilinear interpolation in time and space |
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| 46 | !******************************************** |
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| 47 | |
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| 48 | ddx=xt-real(ix) |
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| 49 | ddy=yt-real(jy) |
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| 50 | rddx=1.-ddx |
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| 51 | rddy=1.-ddy |
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| 52 | p1=rddx*rddy |
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| 53 | p2=ddx*rddy |
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| 54 | p3=rddx*ddy |
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| 55 | p4=ddx*ddy |
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| 56 | |
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| 57 | ! Calculate variables for time interpolation |
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| 58 | !******************************************* |
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| 59 | |
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| 60 | dt1=real(itime-memtime(1)) |
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| 61 | dt2=real(memtime(2)-itime) |
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| 62 | dtt=1./(dt1+dt2) |
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| 63 | |
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| 64 | ! Determine the level below the current position for u,v |
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| 65 | !******************************************************* |
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| 66 | |
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| 67 | do i=2,nz |
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| 68 | if (height(i).gt.zt) then |
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| 69 | indz=i-1 |
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| 70 | goto 6 |
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| 71 | endif |
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| 72 | end do |
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| 73 | 6 continue |
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| 74 | |
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| 75 | |
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| 76 | ! Vertical distance to the level below and above current position |
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| 77 | !**************************************************************** |
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| 78 | |
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| 79 | dz=1./(height(indz+1)-height(indz)) |
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| 80 | dz1=(zt-height(indz))*dz |
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| 81 | dz2=(height(indz+1)-zt)*dz |
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| 82 | |
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| 83 | |
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| 84 | !********************************************************************** |
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| 85 | ! 1.) Bilinear horizontal interpolation |
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| 86 | ! This has to be done separately for 6 fields (Temporal(2)*Vertical(3)) |
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| 87 | !********************************************************************** |
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| 88 | |
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| 89 | ! Loop over 2 time steps and 2 levels |
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| 90 | !************************************ |
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| 91 | |
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| 92 | do m=1,2 |
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| 93 | indexh=memind(m) |
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| 94 | do n=1,2 |
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| 95 | indzh=indz+n-1 |
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| 96 | |
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| 97 | if (ngrid.lt.0) then |
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| 98 | u1(n)=p1*uupol(ix ,jy ,indzh,indexh) & |
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| 99 | +p2*uupol(ixp,jy ,indzh,indexh) & |
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| 100 | +p3*uupol(ix ,jyp,indzh,indexh) & |
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| 101 | +p4*uupol(ixp,jyp,indzh,indexh) |
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| 102 | v1(n)=p1*vvpol(ix ,jy ,indzh,indexh) & |
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| 103 | +p2*vvpol(ixp,jy ,indzh,indexh) & |
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| 104 | +p3*vvpol(ix ,jyp,indzh,indexh) & |
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| 105 | +p4*vvpol(ixp,jyp,indzh,indexh) |
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| 106 | else |
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| 107 | u1(n)=p1*uu(ix ,jy ,indzh,indexh) & |
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| 108 | +p2*uu(ixp,jy ,indzh,indexh) & |
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| 109 | +p3*uu(ix ,jyp,indzh,indexh) & |
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| 110 | +p4*uu(ixp,jyp,indzh,indexh) |
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| 111 | v1(n)=p1*vv(ix ,jy ,indzh,indexh) & |
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| 112 | +p2*vv(ixp,jy ,indzh,indexh) & |
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| 113 | +p3*vv(ix ,jyp,indzh,indexh) & |
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| 114 | +p4*vv(ixp,jyp,indzh,indexh) |
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| 115 | endif |
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| 116 | w1(n)=p1*ww(ix ,jy ,indzh,indexh) & |
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| 117 | +p2*ww(ixp,jy ,indzh,indexh) & |
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| 118 | +p3*ww(ix ,jyp,indzh,indexh) & |
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| 119 | +p4*ww(ixp,jyp,indzh,indexh) |
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| 120 | end do |
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| 121 | |
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| 122 | |
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| 123 | !********************************** |
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| 124 | ! 2.) Linear vertical interpolation |
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| 125 | !********************************** |
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| 126 | |
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| 127 | uh(m)=dz2*u1(1)+dz1*u1(2) |
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| 128 | vh(m)=dz2*v1(1)+dz1*v1(2) |
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| 129 | wh(m)=dz2*w1(1)+dz1*w1(2) |
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| 130 | end do |
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| 131 | |
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| 132 | |
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| 133 | |
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| 134 | !************************************ |
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| 135 | ! 3.) Temporal interpolation (linear) |
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| 136 | !************************************ |
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| 137 | |
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| 138 | u=(uh(1)*dt2+uh(2)*dt1)*dtt |
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| 139 | v=(vh(1)*dt2+vh(2)*dt1)*dtt |
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| 140 | w=(wh(1)*dt2+wh(2)*dt1)*dtt |
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| 141 | |
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| 142 | end subroutine interpol_wind_short |
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