!********************************************************************** ! Copyright 1998,1999,2000,2001,2002,2005,2007,2008,2009,2010 * ! Andreas Stohl, Petra Seibert, A. Frank, Gerhard Wotawa, * ! Caroline Forster, Sabine Eckhardt, John Burkhart, Harald Sodemann * ! * ! This file is part of FLEXPART. * ! * ! FLEXPART is free software: you can redistribute it and/or modify * ! it under the terms of the GNU General Public License as published by* ! the Free Software Foundation, either version 3 of the License, or * ! (at your option) any later version. * ! * ! FLEXPART is distributed in the hope that it will be useful, * ! but WITHOUT ANY WARRANTY; without even the implied warranty of * ! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * ! GNU General Public License for more details. * ! * ! You should have received a copy of the GNU General Public License * ! along with FLEXPART. If not, see . * !********************************************************************** subroutine part0(dquer,dsigma,density,fract,schmi,cun,vsh) ! i i i o o o o !***************************************************************************** ! * ! Calculation of time independent factors of the dry deposition of * ! particles: * ! Log-Normal-distribution of mass [dM/dlog(dp)], unimodal * ! * ! AUTHOR: Matthias Langer, adapted by Andreas Stohl, 13 November 1993 * ! * ! Literature: * ! [1] Scire/Yamartino/Carmichael/Chang (1989), * ! CALGRID: A Mesoscale Photochemical Grid Model. * ! Vol II: User's Guide. (Report No.A049-1, June, 1989) * ! * !***************************************************************************** ! * ! Variables: * ! alpha help variable * ! cun 'slip-flow' correction after Cunningham * ! d01 [um] upper diameter * ! d02 [um] lower diameter * ! dc [m2/s] coefficient of Brownian diffusion * ! delta distance given in standard deviation units * ! density [kg/m3] density of the particle * ! dmean geometric mean diameter of interval * ! dquer [um] geometric mass mean particle diameter * ! dsigma e.g. dsigma=10 or dsigma=0.1 means that 68% of the mass * ! are between 0.1*dquer and 10*dquer * ! fract(ni) mass fraction of each diameter interval * ! kn Knudsen number * ! ni number of diameter intervals, for which deposition * ! is calculated * ! schmidt Schmidt number * ! schmi schmidt**2/3 * ! vsh [m/s] gravitational settling velocity of the particle * ! x01 normalized upper diameter * ! x02 normalized lower diameter * ! * ! Constants: * ! g [m/s2] Acceleration of gravity * ! kb [J/K] Stefan-Boltzmann constant * ! lam [m] mean free path of air molecules * ! myl [kg/m/s] dynamical viscosity of air * ! nyl [m2/s] kinematic viscosity of air * ! tr reference temperature * ! * ! Function: * ! erf calculates the integral of the Gauss function * ! * !***************************************************************************** use par_mod implicit none real,parameter :: tr=293.15 integer :: i real :: dquer,dsigma,density,xdummy,d01,d02,delta,x01,x02,fract(ni) real :: dmean,alpha,cun,dc,schmidt,schmi(ni),vsh(ni),kn,erf real,parameter :: myl=1.81e-5,nyl=0.15e-4 real,parameter :: lam=6.53e-8,kb=1.38e-23,eps=1.2e-38 ! xdummy constant for all intervals !********************************** xdummy=sqrt(2.)*alog(dsigma) ! particles diameters are split up to ni intervals between ! dquer-3*dsigma and dquer+3*dsigma !********************************************************* delta=6./real(ni) d01=dquer*dsigma**(-3) do i=1,ni d02=d01 d01=dquer*dsigma**(-3.+delta*real(i)) x01=alog(d01/dquer)/xdummy x02=alog(d02/dquer)/xdummy ! Area under Gauss-function is calculated and gives mass fraction of interval !**************************************************************************** fract(i)=0.5*(erf(x01)-erf(x02)) ! Geometric mean diameter of interval in [m] !******************************************* dmean=1.E-6*exp(0.5*alog(d01*d02)) ! Calculation of time independent parameters of each interval !************************************************************ kn=2.*lam/dmean if ((-1.1/kn).le.log10(eps)*log(10.)) then alpha=1.257 else alpha=1.257+0.4*exp(-1.1/kn) endif cun=1.+alpha*kn dc=kb*tr*cun/(3.*pi*myl*dmean) schmidt=nyl/dc schmi(i)=schmidt**(-2./3.) vsh(i)=ga*density*dmean*dmean*cun/(18.*myl) end do end subroutine part0