| 1 | subroutine re_initialize_particle(zp,ust,wst,h,sigmaw,wp,nrand,ol) |
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| 2 | ! i i i i i io io i |
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| 3 | !=============== CBL skewed vertical profiles and formulation of LHH 1996 with profile of w3 from lHB 2000 ====== |
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| 4 | !=============== LHH formulation has been modified to account for variable density profiles and backward in time or forward in time simulations ====== |
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| 5 | !=============== this routine re-initiaalize particle velocity if a numerical instability in the cbl scheme generated a NaN value ====== |
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| 6 | !=============== the particle velocity is extracted from the updraft and downdraft distribution as required ====== |
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| 7 | !=============== the re-initialization si not perfect see e.g. Cassiani et al(2015) BLM ====== |
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| 8 | !====================================================================================================================================================== |
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| 9 | !====================================================================================================================================================== |
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| 10 | use par_mod, only:pi |
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| 11 | use com_mod, only:ldirect,rannumb |
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| 12 | |
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| 13 | implicit none |
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| 14 | |
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| 15 | |
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| 16 | real :: usurad2,usurad2p,C0,costluar4,eps |
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| 17 | parameter (usurad2=0.7071067812,usurad2p=0.3989422804,C0=2,costluar4=0.66667,eps=0.000001) |
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| 18 | |
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| 19 | integer idum,nrand |
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| 20 | real :: wp,zp,ust,wst,h,dens,ddens,sigmaw,dsigmawdz,tlw,dcas,dcas1 !,ran3,gasdev |
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| 21 | real :: w3,w2 |
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| 22 | real :: z, & |
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| 23 | skew, & |
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| 24 | skew2, & |
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| 25 | radw2, & |
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| 26 | fluarw,fluarw2, & |
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| 27 | rluarw, & |
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| 28 | xluarw, & |
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| 29 | aluarw, & |
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| 30 | bluarw, & |
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| 31 | sigmawa, & |
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| 32 | sigmawb, & |
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| 33 | ath, & |
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| 34 | bth, & |
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| 35 | wb,wa |
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| 36 | real timedir |
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| 37 | real ol,transition |
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| 38 | |
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| 39 | !--------------------------------------------------------------------------- |
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| 40 | !timedir direction of time forward (1) or backward(-1) |
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| 41 | nrand=nrand+1 |
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| 42 | dcas1=rannumb(nrand) |
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| 43 | timedir=ldirect |
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| 44 | z=zp/h |
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| 45 | transition=1. |
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| 46 | |
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| 47 | if (-h/ol.lt.15) transition=((sin((((-h/ol)+10.)/10.)*pi)))/2.+0.5 |
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| 48 | |
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| 49 | w2=sigmaw*sigmaw |
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| 50 | w3=(((1.2*z*((1.-z)**(3./2.)))+eps)*wst**3)*transition |
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| 51 | skew=w3/(w2**1.5) |
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| 52 | skew2=skew*skew |
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| 53 | radw2=sqrt(w2) !sigmaw |
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| 54 | |
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| 55 | fluarw=costluar4*skew**0.333333333333333 |
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| 56 | fluarw2=fluarw*fluarw |
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| 57 | rluarw=(1.+fluarw2)**3.*skew2/((3.+fluarw2)**2.*fluarw2) !-> r |
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| 58 | xluarw=rluarw**0.5 !(1.+fluarw2)**1.5*skew/((3.+fluarw2)*fluarw) !----> r^1/2 |
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| 59 | |
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| 60 | aluarw=0.5*(1.-xluarw/(4.+rluarw)**0.5) |
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| 61 | bluarw=1.-aluarw |
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| 62 | |
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| 63 | sigmawa=radw2*(bluarw/(aluarw*(1.+fluarw2)))**0.5 |
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| 64 | sigmawb=radw2*(aluarw/(bluarw*(1.+fluarw2)))**0.5 |
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| 65 | |
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| 66 | wa=(fluarw*sigmawa) |
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| 67 | wb=(fluarw*sigmawb) |
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| 68 | |
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| 69 | |
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| 70 | |
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| 71 | if ((sign(1.,wp)*timedir).gt.0) then !updraft |
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| 72 | 100 wp=(dcas1*sigmawa+wa) |
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| 73 | if (wp.lt.0) then |
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| 74 | nrand=nrand+1 |
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| 75 | dcas1=rannumb(nrand) |
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| 76 | goto 100 |
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| 77 | end if |
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| 78 | wp=wp*timedir |
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| 79 | else if ((sign(1.,wp)*timedir).lt.0) then !downdraft |
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| 80 | 101 wp=(dcas1*sigmawb-wb) |
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| 81 | if (wp.gt.0) then |
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| 82 | nrand=nrand+1 |
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| 83 | dcas1=rannumb(nrand) |
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| 84 | goto 101 |
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| 85 | end if |
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| 86 | wp=wp*timedir |
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| 87 | end if |
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| 88 | |
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| 89 | return |
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| 90 | end subroutine re_initialize_particle |
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