[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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[8a65cb0] | 4 | real function photo_O1D(sza) |
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| 5 | |
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| 6 | !***************************************************************************** |
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| 7 | ! * |
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| 8 | ! * |
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| 9 | ! Author: A. Stohl * |
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| 10 | ! * |
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| 11 | ! Nov 2014 * |
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| 12 | ! * |
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| 13 | ! * |
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| 14 | !***************************************************************************** |
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| 15 | ! * |
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| 16 | ! INPUT: * |
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| 17 | ! sza solar zenith angle (degrees) * |
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| 18 | ! * |
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| 19 | ! OUTPUT: * |
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| 20 | ! photo_O1D J(O1D) photoylsis rate * |
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| 21 | ! * |
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| 22 | !***************************************************************************** |
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| 23 | |
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| 24 | implicit none |
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| 25 | |
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| 26 | integer :: iz,ik |
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| 27 | real :: sza |
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| 28 | real :: z1,z2,zg,f1,f2,dummy |
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| 29 | real :: photo_NO2 |
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| 30 | integer, parameter :: nzenith=11 |
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| 31 | real, parameter :: pi=3.1415927 |
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| 32 | real, dimension(nzenith) :: zangle,fact_photo |
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| 33 | |
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| 34 | ! zangle: zenith angles for which fact_photo is tabulated |
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| 35 | ! fact_photo: conversion of photolysis rate of NO2 to photolysis |
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| 36 | ! rate of O3 into O1D as a function of solar zenith angle |
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| 37 | |
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| 38 | zangle=(/0.,10.,20.,30.,40.,50.,60.,70.,78.,86.,90.0001/) |
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| 39 | fact_photo=(/0.4616E-02,0.4478E-02,0.4131E-02,0.3583E-02,0.2867E-02,& |
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| 40 | &0.2081E-02,0.1235E-02,0.5392E-03,0.2200E-03,0.1302E-03,0.0902E-03/) |
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| 41 | |
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| 42 | if (sza.lt.90.) then |
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| 43 | do iz=1,nzenith-1 |
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| 44 | if(sza.ge.zangle(iz)) ik=iz |
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| 45 | end do |
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| 46 | z1=1./cos(zangle(ik)*pi/180.) |
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| 47 | z2=1./cos(zangle(ik+1)*pi/180.) |
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| 48 | zg=1./cos(sza*pi/180.) |
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| 49 | dummy=(zg-z1)/(z2-z1) |
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| 50 | f1=alog(fact_photo(ik)) |
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| 51 | f2=alog(fact_photo(ik+1)) |
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| 52 | photo_NO2=1.45e-2*exp(-0.4/cos(sza*pi/180.)) |
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| 53 | photo_O1D=photo_NO2*exp(f1+(f2-f1)*dummy) |
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| 54 | else |
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| 55 | photo_O1D=0. |
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| 56 | endif |
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| 57 | |
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| 58 | return |
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| 59 | |
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| 60 | end function photo_O1D |
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| 61 | |
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| 62 | |
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