SLIDE 1
Computational Grid Size: (60 x 60 x 30 x 100 x 30) = 3.24 x 108
Modeling the Dynamics and the Dynamics and Modeling Kinetics of - - PowerPoint PPT Presentation
Modeling the Dynamics and the Dynamics and Modeling Kinetics of - - PowerPoint PPT Presentation
Modeling the Dynamics and the Dynamics and Modeling Kinetics of Gaseous Pollutants and Kinetics of Gaseous Pollutants and Aerosols in the Atmosphere: : Aerosols in the Atmosphere Estimation of the Environmental Estimation of the
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Model Structure
- Atmospheric Thermohydrodynamics
(nonhydrostatic, mesoscale, terrain-following, cloud microphysics, turbulence, heat- and mass-exchange in soil and water)
- Pollutant Diffusion and Transport
(gas- and aqueous phase chemistry, anthropogenic and biogenic emissions, aerosol processing, ion composition of clouds and aerosols, mass-exchange between gas and liquid)
- Homogeneous Nucleation (New-Particle Formation)
(Binary [H2O-H2SO4] and ternary [H2O-H2SO4-NH3])
- Condensation/Evaporation
- Coagulation
- Optimization and Risk Assessment
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Aerosol Formation (Gas-to-Particle Conversion)
SLIDE 5
General Equation for Gas-Aerosol Dynamics
Ci (i = 1, …, N) and ϕk (k = 1, …, M) are the concentrations of gaseous species and aerosols, respectively; N and M are the numbers of gaseous components and aerosol fractions, respectively. The system of equations for the pollution transport and transformation (Aloyan, 2000; Aloyan et al., 2002)
) 3 , 1 ( , = ∂ ∂ ∂ ∂ + + + − − = ∂ ∂ + ∂ ∂ j x C K x P P P P F x C u t C
j i jj j aqu i phot i cond i nucl i gas i j i j i
) 3 , 1 ( , ) (
3
= ∂ ∂ ∂ ∂ + + + + = ∂ ∂ − + ∂ ∂ j x K x P P P F x w u t
j i jj j coag k cond k nucl k aer k j k g j j k
ϕ ϕ δ ϕ
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Regional Model
Equations of Atmospheric Hydrodynamics
SLIDE 7
Pollution Transport
) ( B K y K y x K x u div F t
y x i
ϕ σ ϕ σ ϕ ϕ ϕ ϕ
σ
+ ∂ ∂ ∂ ∂ + ∂ ∂ ∂ ∂ + ∂ ∂ ∂ ∂ + − = ∂ ∂
[ ]
( )
[ ] [ ] [ ]
{ }
H Y Y y X X x y x D T D Dt , , , , , : , , , , ∈ − ∈ − ∈ = × = σ σ
( )
surf c b a z
r r r z K ϕ ϕ ∂ ∂ϕ − + + = 1
. for , for H z t
b i i i i
= = = = ϕ ϕ ϕ ϕ
. if , if
n n
≥ = ∂ ∂ < =
Γ Γ
u n u
b i i b i i
ϕ ϕ ϕ ϕ
Pollution flux in the surface layer Boundary conditions Solution domain Governing equation
SLIDE 8
Photochemistry
The chemical mechanism used in this work is an improved version of that described in Aloyan et al. (1987) and Aloyan et al. (1995). Additional species and chemical reactions were included into the mechanism from the Carbon- Bond Mechanism (CBM-IV) (Gery et al., 1989). The reaction rate constants were taken also from (Anderson 1976; Atkinson and Lloyd, 1984). This approach allows us to describe the intermediate species in more detail, while the computational burden increases only slightly. In total, the resulting hybrid model includes a total of 44 chemical species and 204 chemical reactions. The total list of chemical species is as follows:
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Condensation and Coagulation
∫ ∫
∞ −
− + = ∂ ∂ + ∂ ∂
1 1 1 1
1 1 1
) , ( ~ ) , ( ~ 2 1 ) , ( dg g g K dg g g K t g J v g t
g g g g g g g
ϕ ϕ ϕ ϕ ϕ ϕ
− − + = 1 exp 1 8 / 3 1 ( 4
3 / 1 3 / 1 * 1 3 / 1 3 / 2 2
g g kT l dg g nv d v
T g
λθ απ
The kinetic equation for the change of aerosol particle-mass distribution (Aloyan et al., 1993; Aloyan et al., 1997) where g is the particle mass, J is the nucleation rate, K is the coagulation kernel, vg is the rate of condensation.
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Coagulation Model
= ∂ ∂ t t g C ) , , ( α
− − − − −
∫∫
β β β α β β α
α
dsd ) , s ( C ) , s g ( C ) , s ; , s g ( K 2 1
g 0 0
∫∫
∞ ∞
−
0 0
dsd ) , s ( C ) , s ; , g ( K ) t , , g ( C β β β α α
) , , ( ] ) , ( , ; ) , ( , [ ) , , , ( t s g k t s s t g g K s g K ≡ ≅ β α β α
where g is the total mass of particles, α is the mass of pollutant, K is the coagulation coefficient, C(g, α, t) is the total concentration of particles. The coagulation equation has the form [Golubev and Piskunov, 1999; Aloyan and Piskunov, 2005]
SLIDE 11
∫
=
g
d t g C t g n ) , , ( ) , ( α α
∫
=
g
d t g C t g m ) , , ( ) , ( α α α
C(g, α, t) = c(g, t) δ( g – α) + cc(g, α, t)
= ∂ ∂ t t g n ) , (
∫
− − −
g
ds s n s g n s s g K ) ( ) ( ) , ( 2 1
∫
∞
) ( ) , ( ) ( ds s n s g K g n = ∂ ∂ t t g m ) , (
∫
− − −
g
ds s m s g n s s g K ) ( ) ( ) , ( 2 1
∫
∞
) ( ) , ( ) ( ds s n s g K g m
= ∂ ∂ t t g c ) , (
− − −
∫
g
ds s m s g n s s g K ) ( ) ( ) , ( 2 1
∫
∞
) ( ) , ( ) ( ds s n s g K g c
Main integral characteristics of the particle-size distribution
SLIDE 12
Condensation Model
α − = g g
p 0
) , ( ) , ( ) , ( t g n t g m t g
c c
= α
) ( ) , ( ) , , ( α δ α − − =
po c c
g g t g n t g c
) , ( ) ( ) , ( t g n g g t g m
c po c
− =
( )
[ ]
) ( ) , (
* t
g g t g J c v g t c
g
− = ∂ ∂ + ∂ ∂ δ
( )
= ∂ ∂ + ∂ ∂
c g c
n v g t n
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Binary Nucleation (H2SO4-H2O)
Скорость нуклеации J зависит от трех основных переменных: массовой концентрации кислоты в паровой фазе (С), относительной влажности воздуха (Rh) и температуры (T). Пусть в атмосфере в пересыщенном паре при температуре T и давлении Pv имеется бинарный кластер, состоящий из nw молекулы вещества w и na молекул для a с мольными фракциями xiv (i = w,a). Свободная энергия для образования жидкого зародыша в бинарной смеси имеет вид
σ µ µ A n n G W
a a w w
+ ∆ + ∆ = ∆ =
где ∆G – изменения свободной энергии Гиббса, A – площадь поверхности, σ – поверхностное натяжение, ∆µi = µil(T,Pv,xil) – µiv(T,Pi,xiv), где µil и µiv – химические потенциалы в жидкой и паровой фазах, соответственно.
SLIDE 14
радиус критического кластера определяется из уравнения Кельвина
= ) ( ln ) ( ) ( 2
* , * * *
x kT x x r
free s i free i i
ρ ρ ν σ
работа для формирования критической нуклеации будет
) ( 3 4
* 2 * *
x r w σ π =
общее выражение для скорости нуклеации имеет вид
− − = kT w w z J ) 2 , 1 ( exp ) 2 , 1 (
*
ρ
где ρ(1,2), w(1,2) – численная концентрация и энергия образования дигидрата серной кислоты, соответственно, а z – кинетический коэффициент Зельдовича
SLIDE 15
Ternary Nucleation (H2SO4 – H2O – NH3)
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Gas- and Aqueous-Phase Chemistry Model
[ ] [ ] [ ]
L T k k k C k C w w dt C d
b i H i i aq i i g i g loss i g gen i g
− − − =
, ,
[ ] [ ] [ ]
A b i H i i aq i i g i aq loss i aq gen i aq
N T k k k C k C w w dt C d 1
, ,
− − − =
1 2
3 4 3
−
+ =
i i g i
c r D r k α
is the coefficient of mass-exchange processes kb is the Bolzmann constant, Dg is the diffusion coefficient, αi is the accomodation coefficient, ci is the mean thermal velocity.
− ∆ − = 298 1 1 exp
298 ) 298 ( ) (
T R H K K
r i H i T H
- is Henry’s constant,
- 298
H
r
∆
Is the thermal effect of gas component dissolution at Т = 298 К
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Aqueous-phase chemistry:
- One-way aqueous-phase chemical reactions:
35
- Aqueous-phase photochemical processes:
6
- Reversible chemical reactions (equilibrium):
21 Sulfite oxidation mechanism:
- HSO3
- (aq) + H2O2 + H+
(aq) → SO4 2- + H2O + 2H+,
(1)
- SO2 + O3(aq) → HSO3
- (aq) + O2(aq) + H+
(aq),
(2)
- SO3
2- + O3(aq) → SO4 2- + O2(aq),
(3)
- HSO3
- (aq) + O3(aq) → HSO4
- (aq) + SO3
- (aq).
(4)
These pathways differ essentially in that the final products of the sulfite
- xidation – sulfate ions – are generated directly in reaction (1).
SLIDE 19
HO2, H2O2, O2, OH-, HSO3
- ,
H+, SO4
2-, O2
- , SO3
2-, SO3
- ,
HSO5
- , N2O5, NO3
- , NO3, O3,
SO2, HO2
- , HSO4
- , SO5
- , SO4,
SO5
2-,
S2O8
2-,
NO2, NO, Fe(OH)2+, Fe(OH)2
+, Fe2+,
Fe3+, FeOHSO3H+, FeSO4
+,
NO2
- , HNO2, CO2, H2CO3,
HCO3
- , H2SO4
- .
Ion Composition of Aerosol Particles
SLIDE 20
Ternary Nucleation (H2SO4 – H2O – NH3)
1,00E+00 1,00E+03 1,00E+06 1,00E+09 50 70 90
Rh (%)
J, 1/(cm3.s) T=288K, H2SO4=E8 cm-3 T=254K, H2SO4=E8 cm-3 T=288K, H2SO4=E9 cm-3 T=254K, H2SO4=E9 cm-3
Binary Nucleation (H2SO4 – H2O)
1,00E-10 1,00E-08 1,00E-06 1,00E-04 1,00E-02 1,00E+00 1,00E+02 1,00E+04 1,00E+06 1,00E+08 50 70 90 Rh (%) J, 1/(cm3 s) T=288K, H2SO4=E8 cm-3 T=254K, H2SO4=E8 cm-3 T=288K, H2SO4=E9 cm-3 T=254K, H2SO4=E9 cm-3
Nucleation Rate
SLIDE 21
Radius of Critical Cluster
Ternary Nucleation (H2SO4 – H2O – NH3) Binary Nucleation (H2SO4 – H2O)
0,1 0,2 0,3 0,4 0,5 50 70 90 Rh (%) r_cr (nm) T=288K, H2SO4=E8 cm-3 T=254K, H2SO4=E8 cm-3 T=288K, H2SO4=E9 cm-3 T=254K, H2SO4=E9 cm-3 0,2 0,4 0,6 0,8 1 1,2 50 70 90
Rh (%)
r_cr (nm) T=288K, H2SO4=E8 cm-3 T=254K, H2SO4=E8 cm-3 T=288K, H2SO4=E9 cm-3 T=254K, H2SO4=E9 cm-3
SLIDE 22
1,0E+00 1,0E+01 1,0E+02 1,0E+03 1,0E+04 1,0E+05 1,0E+06 1,0E+07 1,0E+08 1,0E+09 J, cm-3 s-1 20:25 20:45 21:05 21:25 21:45 22:05 22.03.2004 Binary Nucleation Ternary Nucleation 0,2 0,4 0,6 0,8 R_cr, nm 20:25 20:45 21:05 21:25 21:45 22:05 22.03.2004 Binary Nucleation Ternary Nucleation
Nucleation Rate Critical Radius Baikal Area
SLIDE 23
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SLIDE 25
SLIDE 26
FI ELD OBSERVATI ON DATA 2002-04 FI ELD OBSERVATI ON DATA 2002-04
11.03.03 26.05.03 04.08.03 17.10.03 22.12.03 5 10 15 20 5 10 15 20 2 4
mSO4 mSO4 mSO4 mΣ mΣ
mΣ
Иркутск мкг/м
3
Время
Листвянка мкг/м
3
Монды мкг/м
3
Spring Spring-
- summer spike
summer spike
SLIDE 27
PARTI CLE ACI DI TY PARTI CLE ACI DI TY
3x10
- 7
2x10
- 7
1x10
- 7
0.5x10
- 7
1.5x10
- 7
10
- 7
[H
+], моль/м 3
[H2SO4], мкг/м3
(H
+)Σ, моль/м 3
Монды Иркутск Листвянка
(H2SO4), моль/м
3
2 4 6 8 10 12 14
1E-10 1E-9 1E-8 1E-7
[H2SO4]/(H+) ≈ 2 H2SO4(gas) → H2SO4(aq) H2SO4(aq) → 2Haq
+ + SO4(aq) 2-
[H2SO4]/(H+) ≈ 2 H2SO4(gas) → H2SO4(aq) H2SO4(aq) → 2H 2Haq
aq+ + + SO
+ SO4(aq)
4(aq)2 2-
- (H+)Σ = (H+)изм + (H+)CO3 + (H+)NH4
(H+) = 10-pHизмV/103Vgas
SLIDE 28
I RKUTSK 2003-04 I RKUTSK 2003-04
1 2 3 4 0,0 0,5 1,0 1,5
2 3 1
[HCO3
- ], мкг/м
3
[NH4
+], мкг/м 3
No Ammonia No Ammonia: CaCO CaCO3
3 + H
+ H2
2SO
SO4
4 →
→ CaSO CaSO4
4 + H
+ H2
2O + CO
O + CO2
2↑
↑, ,
Mechanism Mechanism: : CaCO CaCO3(s)
3(s) ⇔
⇔ Ca Ca2+
2+ +
+ CO CO3(aq)
3(aq) 2 2-
- CO
CO3(aq)
3(aq) 2 2-
- +
+ H Haq
aq + + ⇔
⇔ HCO HCO3(aq)
3(aq)
- ;
; K K = 2 = 2× ×10 1010
10 l
l mole mole-
- 1
1
HCO HCO3(aq)
3(aq)
- +
+ H Haq
aq + + ⇔
⇔ H H2
2O + CO
O + CO2(aq)
2(aq)
CO CO2(aq)
2(aq) ⇔
⇔ CO CO2(gas)
2(gas)↑
↑
With Atmospheric Ammonia:
NH3(g) ⇔ NH3(aq); H ≈ 60 mole l-1 atm-1 NH3(aq) + Haq
+ ⇔ NH4(aq) +; K = 2×109 l mole-1
With Atmospheric Ammonia With Atmospheric Ammonia:
NH NH3(g)
3(g) ⇔
⇔ NH NH3(aq)
3(aq);
; H H ≈ ≈ 60 mole 60 mole l l-
- 1
1 atm
atm-
- 1
1
NH NH3(aq)
3(aq) +
+ H Haq
aq + + ⇔
⇔ NH NH4(aq)
4(aq) + +;
; K K = 2 = 2× ×10 109
9 l
l mole mole-
- 1
1
Кальциевые частицы Аммиачные частиц
SLIDE 29
MONDY MONDY 2002 2002-
- 04
04
0,0 0,2 0,4 0,6 0,8 1,0 0,0 0,2 0,4 0,6 0,8 1,0
0,0 0,1 0,2 0,0 0,5 1,0
2 1 [HCO3
- ], мкг/м
3
[NH4
+], мкг/м 3
[NH4
+], мкг/м3[NH3], мкг/м
3(NH (NH4(aq)
4(aq) + +)/(NH
)/(NH3(g))
3(g)) =
= H Heff
effRT
RTL L H Heff
eff =
= H HNH3
NH3(1 +
(1 + K K[H [Haq
aq + +]
]) )
Experimental: Experimental: (NH4(aq)
+)/(NH3(g)) ≈ 10
[Haq
+]L = 4×10-12
Within Within AIM AIM ( (Clegg Clegg-
- Wexler
Wexler) ): : L ≈ 7×10-12 и [Haq
+] ≈ 0.5 mole/l
Effect of Ammonia Effect of Ammonia
Кальциевые частицы Аммиачные частиц
SLIDE 30
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SLIDE 40
Comparison between calculated and measured concentrations of H+ after 7 days
SLIDE 41
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SLIDE 44
0,00 0,02 0,04 0,06 0,08 0,10 1 6 11 16 21 26 (6,8) (12,14) (13,18) 0,00 0,02 0,04 0,06 0,08 0,10 1 6 11 16 21 26
(6,8) (12,14) (13,18)
H+, t = 48 h H+, t = 72 h
SLIDE 45
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500 1000 1500 2000 2500
Concentration, cm-3
4 6.3 10 16 20 32
Particle diameter, nm
Irkutsk Measured Calculated
SLIDE 47
500 1000 1500 2000
Concentration, cm-3
4 6.3 10 16 20 32
Particle diameter, nm
Shelekhovo Measured Calculated
SLIDE 48
200 400 600 800 1000 1200
Concentration, cm-3
4 6.3 10 16 20 32
Particle diameter, nm
Bol'shoi Lug Measured Calculated
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200 400 600 800 1000
Concentration, cm- 3
4 6.3 10 16 20 32
Particle diameter, nm
Between BL and Sludyanka Measured Calculated
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200 400 600 800 1000
Concentration, cm-3
4 6.3 10 16 20 32
Particle diameter, nm
Sludyanka Measured Calculated
SLIDE 51
200 400 600 800 1000
Concentration, cm-3
4 6.3 10 16 20 32
Particle diameter, nm
Baykal'sk Measured Calculated
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SLIDE 53
Concentration of H2SO4, z=6850 m, t=10 days
SLIDE 54
Nucleation rate (cm-3 s-1)
SLIDE 55
Critical radius (nm)
SLIDE 56
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Concentration of aerosol particles (r = 0.1 mcm, z = 7100 m, t = 5 days, January 1992) Concentration of aerosol particles (r = 0.01 mcm, z = 7100 m, t = 5 days, January 1992)
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Concentration of aerosol particles (r = 0.1 mcm, z = 7100 m, t = 5 days, June 1992) Concentration of aerosol particles (r = 0.01 mcm, z = 7100 m, t = 5 days, June 1992)
SLIDE 60
Ozone variability in time 0,5 0,8 0,7 0,6 0,74 0,34 0,42 0,63 0,9 0,72 0,2 0,4 0,6 0,8 1 2 4 6 8 10 time, h [O3]/[O3]o I II
( I ) T = 278, [O3] = 1.5×1011, pH = 7, r = 10 µm, δ = 0.1 g⋅m–3 ( II ) T = 298, [O3] = 4.0×1011, pH = 6, r = 50 µm, δ = 0.2 g⋅m–3
SLIDE 61
5,37 3,51 4,02 4,1 4,06 4,07 3,1 1 2 3 4 5 6
O3(-), (M)
1 2 3 4 5 6 7
Fe, Mn, (M)
Sensitivity of ozone concentrations to dissolved metals for different sets of metal concentrations shown in x-axis: (1) Fe = 10-7, Cu = 0; (2) Fe = 10-5, Cu = 10-5; (3) Fe = 10-5, Cu = 10-6; (4) Fe = 10-5, Cu = 10-7; (5) Fe = 10-6, Cu = 106; (6) Fe = 107, Cu = 106; (7) Fe = 10-4, Cu = 105.
SLIDE 62
Adjoint Problem
σ ϕ σ ϕ ϕ ϕ ϕ
σ ∂
∂ ∂ ∂ + ∂ ∂ ∂ ∂ + ∂ ∂ ∂ ∂ + − = ∂ ∂ −
* * * * *
K y K y x K x u div P t
y x i
,
* *
= + + = z r r r z K
c b a z
ϕ ∂ ∂ϕ
. for , for
* *
H z T t = = = = ϕ ϕ
. if , if
n * n *
≥ = ∂ ∂ < =
Γ Γ
u n u ϕ ϕ
Boundary conditions
SLIDE 63
Sensitivity function (winter)
SLIDE 64
Sensitivity function (spring)
SLIDE 65
Sensitivity function (summer)
SLIDE 66
Sensitivity function (fall)
SLIDE 67
Distribution of sensitivity function by selected regions and seasons of the year 10 20 30 40 50 60 70 80 % Winter Spring Summer Fall Northwest Northeast NE China Mongolia
SLIDE 68
Percentage distribution of sensitivity function for July
SLIDE 69
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Hydrodynamic Model for Forest Fires
( )
3 , 2 , 1 j u x t x H dt dP g dt dT x g lw lu z P 1 dt dw x lu lw y p 1 dt dv x lw lv x p 1 dt du
j j j a j j 3 j j 2 j j 1
= = ∂ ∂ + ∂ ∂ ∂ ∂ = − ∂ ∂ + − − + ∂ ∂ − = ∂ ∂ + − + ∂ ∂ − = ∂ ∂ + − + ∂ ∂ − = ρ ρ ρ γ τ ρ τ ρ τ ρ
SLIDE 72
1 1 1
' 1 ; ' ' ; div ) 3 , 1 ( ,
−
+ = − = ′ − = − = ∂ ∂ = ⋅ + = ∂ ∂ = + − + = = T T T T P P R g g R g R x H u T dt dT j x H dt d RT dt dT PR g dt dT dt dT R dt d RT dt dP RT P
a a j j j a
β β ρ ρ γ α γ γ α α α ρ ρ γ ρ ρ ρ r
SLIDE 73
1,0E+00 1,0E+02 1,0E+04 1,0E+06 1,0E+08 1,0E+10 1,0E+12 0,1 0,5 0,8 1,2 1,5 1,8 2,1 2,5 2,8 3,1 3,5 3,8 4,1 4,4 4,8 particle radius, mcm concentration, m-3 Particle Concentration, z=50 m, t=12 h (Fire Zone), Combustion
SLIDE 74
1,0E+00 1,0E+02 1,0E+04 1,0E+06 1,0E+08 1,0E+10 1,0E+12 0,1 0,5 0,8 1,2 1,5 1,8 2,1 2,5 2,8 3,1 3,5 3,8 4,1 4,4 4,8 particle radius, mcm concentration, m-3 Particle Concentration, z=50 m, t=18 h (Fire Zone), Smoldering
SLIDE 75
Concentration of aerosol particles (r = 0.14 mcm, t = 12 h, z = 50 m)
SLIDE 76
Concentration of aerosol particles (r = 3.28 mcm, t = 12 h, z = 50 m)
SLIDE 77
Concentration of aerosol particles (r = 0.14 mcm, t = 12 h, z = 150 m)
SLIDE 78
Concentration of aerosol particles (r =3.28 mcm, t = 12 h, z = 150 m)
SLIDE 79
Concentration of aerosol particles (r = 0.14 mcm, t = 18 h, z = 50 m)
SLIDE 80
Concentration of aerosol particles (r = 0.14 mcm, t = 18 h, z = 150 m)
SLIDE 81
Conclusions
- A new combined multicomponent model for gas-aerosol dynamics in the
Baikal region has been developed, which incorporates atmospheric thermo-hydrodynamics, gas- and aqueous-phase chemistry, nucleation, condensation, and coagulation
- The model allows for numerical simulations of aerosol particle-size
distributions ranging from the molecular level up to 1-3 microns
- The nucleation-mode particle formation in the Baikal area has been
found to be significant
- The calculated and measured values of the integral content of the
aerosol ion composition are well consistent