SLIDE 1
Incorporation of Tritium Transport Processes into - - PowerPoint PPT Presentation
Incorporation of Tritium Transport Processes into - - PowerPoint PPT Presentation
1/18 S ystem for P rediction of E nvironmental E mergency D ose I nformation M ulti-model P ackage Incorporation of Tritium Transport Processes into Atmosphere-soil-vegetation Model: SOLVEG ~OBT dynamics in plants using the SOLVEG code after an
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Diffusion Fog water Water vapor Phase change Latent heat Temperature Wind, Turbulence CO2 concentration Surface exchange: Momentum, Heat, Water, CO2 Rain CO2 assimilation, Transpiration Heat exchange, Evaporation/condensation Absorption, Emission Temperature, water Heat/water budget Drip Interception Photosynthesis Short wave Long wave Scattering Surface water Advection & Diffusion Surface budget: Heat, Water, CO2 Uptake: Water & CO2 Water vapor Liquid water Phase change Latent heat Temperature CO2 conc. Root/soil respiration
Soil Vegetation Atmosphere
Physical processes are calculated at each layer of vertical multi-layer model Bold: main var., Underlined: processes, Red: heat/rad., Blue: water, Green: CO2
Land surface model SOLVEG2 Physical processes
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SLIDE 4
Atmosphere
Diffusion:
Soil
Heat: Liquid water: Water vapor:
Vegetation
Heat budget: Leaf water: Water flux:
Radiation
Short wave: Downward and upward transfer (Next slide) Direct (visible + near-infrared) + Diffuse (visible + near-infrared) Long wave: Downward and upward transfer
φ
∂ ∂φ ∂ ∂ ∂ ∂φ F z K z t
z
+ = z T C E C C H z T K z t T
s s s w w s s b s T s
∂ ∂ ρ ρ ∂ ∂ ∂ ∂ ∂ ∂ − + = ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ + + − =
b t w w w
E E z E t ∂ ∂ ρ ∂ η ∂ 1
[ ]
ρ ∂ ∂ η ∂ ∂ ∂ η η ∂
b s w a w s w ws
E z q f D z t q + = − ) ( ) (
p c c c
H lE H R + + =
d cap d d
P E E E dt dw − + − =
int
( )
col pr d r
E E P E a dz dP − + − =
int b b
lE H − =
f a
w e e q v u , , , , , , λ θ φ =
s d c
E E E + =
Transpiration Evaporation/ condensation Boundary condition Source term Net radiation
Land surface model SOLVEG2 Basic equations (1): heat, water, momentum
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SLIDE 5
Radiation scheme (coefficients based on Verstraete 1987, 1988)
Short: (direct) (diffuse) (visible) (near-IR) Long wave:
( )
,
↓ ↓
′ + ′ + =
d w w rd d
S A a aF dz dS
( ) [ ]
( )
, 1
↓ ↑ ↓ ↓
− ′ + − ′ + ′ + − =
d df rd s w sb rs s w w sf rs s
S f aF S A f aF S A a f aF dz dS
( ) [ ]
( )
. 1
↓ ↓ ↑ ↑
+ ′ + + ′ + ′ + − − =
d db rd s w sb rs s w w sf rs s
S f aF S A f aF S A a f aF dz dS
( )
[ ] ( ),
1
4 4 a l l c c sb sf rs
T L w k T L f L f aF dz dL σ σ ε − + − − − =
↓ ↑ ↓ ↓
( )
[ ] ( ).
1
4 4 a l l c c sb sf rs
T L w k T L f L f aF dz dL σ σ ε − − − − − − =
↑ ↓ ↑ ↑
Scattering Leaf projection cf.: Frd Scattering cf.: fdf (forward), fdb (backward) Depend on solar angle and leaf surface angle Forward scattering cf.: fsf Back scattering cf.: fsb └Depend on leaf surface angle┘ Leaf projection cf.: Frs Depend on leaf area density
Land surface model SOLVEG2 Basic equations (2): radiation
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Stomatal resistance (Jarvis scheme): BATS (Dickinson et al. 1993) rs,min ⇒ measured parameter fr, fs, fm, ft : Functions of PAR, soil water, humidity, temperature CO2 assimilation (An): Farquhar et al. (1980) wc, we, ws, Rd : Depend on PAR, leaf CO2 conc., temperature Stomatal resistance (rs): Collatz et al. (1991, 1992) m (constant), b (minimum conductance) ⇒ measured parameter cs CO2 partial pressure at leaf surface es/esat(Tv) Relative humidity at leaf surface pa Atmospheric pressure
( )
d s e c n
R w w w A − = , , min
( )
b p T e e c A m g r
a v sat s s n s s
+ = = 1
1 1 1 min , − − −
=
t m s r s s
f f f f r r Land surface model SOLVEG2 Basic equations (3): CO2, stomata resistance 2 options
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SLIDE 7
Soil CO2 conservation: Simunek and Suarez (1993) Volume: Diffusion: Advection: ⇒ Treatment of CO2 in gas and aqueous phase together by Henry’s Law: cw = KHRTca ca CO2 conc. in soil air ηw Volumetric water content Et
*
Root uptake (transpiration) S CO2 source term (＝ soil: Ss ＋ root: Sr)
S RTc K E c E z z c D z c V t
a H t a E a E a E
+ − ∂ ∂ − ∂ ∂ ∂ ∂ = ∂ ∂
* *
( )
,
w H w ws E
RT K V η η η + − =
( )
,
w w H a w ws E
D RT K D D η η η + − = ,
* * * w H a E
RTE K E E + =
( ) ( ) ( ) ( ) ( )
t f c f T f f z f S S
s a s s w s s s s
η =
( ) ( ) ( ) ( ) ( )
t f c f T f f z f S S
r a r r w r r r r
η = Land surface model SOLVEG2 Basic equations (4): soil CO2
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SLIDE 8
- 2 0 0
2 0 0 4 0 0 6 0 0 9 7 1 2 7 1 5 7 1 8 7 2 1 7 2 4 7 2 7 7 3 0 7 J u lia n d a y s (L S T ) LH (W m
- 2)
- 4 0
- 2 0
2 0 9 7 1 2 7 1 5 7 1 8 7 2 1 7 2 4 7 2 7 7 3 0 7 J u lia n d a y s (L S T ) FC (μmol m
- 2 s
- 1)
APR MAY JUN JUL AUG SEP OCT NOV Observation ○: daily mean ◇: daily max ＋: daily min Calculation ―: daily mean ―: daily max ―: daily min Upward positive
Latent heat (water vapor) flux CO2 flux Good performance for water and CO2 exchanges at grassland (AmeriFlux data) Diurnal variation and seasonal change are well reproduced. It can be applied for detailed simulation of 3H and 14C transport.
Land surface model SOLVEG2 Water and CO2 fluxes at grassland
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Land surface model SOLVEG2 Incorporation of HTO transport processes
Concept
Process based HTO transport model to simulate dynamic behavior
- f HTO in air-soil-plant system
Explicit calculation of HTO transport in a similar way as water and
vapor transport
Model development
Step 1: transport in the atmosphere and bare soil (no decay)
- In-soil transport by Yamazawa (2001) applied for BIOMASS
Theme 3-F (rise of HTO from contaminated groundwater)
- Atmospheric transport for HTO vapor (1-D diffusion eq.)
- Test calculation using met. data of AmeriFlux (previous slide)
Step 2: inclusion of plant uptake processes Step 3: OBT formation and translocation
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external input: precipitation stomata Fog water Diffusion equation Precipitation Conservation equation
- f vertical flux
Water vapor in air Diffusion equation Ground surface water budget eq. Water vapor in soil Diffusion eq. Liquid water in soil Transport equation Leaf surface water Water budget eq. accretion accretion condensation evaporation interception drip evaporation/ condensation transpi- ration evaporation/ condensation evaporation/ condensation evaporation/ condensation drip run-off uptake by root
Land surface model SOLVEG2 Incorporation of HTO transport processes Water and vapor exchange processes Step 1
HTO transport process Calculate HTO conc. for each variable of water
Step 2
New variable: Plant water Water budget eq.
(root uptake - transpiration)
Step 3
OBT formation and translocation 10/18
SLIDE 11
Soil HTO transport: Yamazawa (2001) applied for BIOMASS theme 3 Liquid phase: Gas phase: Surface B.C.: χw, χsa , χr HTO conc. in soil water (Bq/m3-water), soil air and air (Bq/m3-air) ηw, ηsw Volumetric soil water content and saturated value (m3/m3) ρw Density of soil water (kg/m3) Ew Vertical liquid water flux (kg/m2/s) DTw, Dta Effective diffusivities of HTO in water and HTO vapor in air (m2/s) fsa(ηw) Tortuosity for diffusion in soil air eb HTO conc. in soil air (Bq/m3-air) cE0, |ur| Bulk transfer coefficient for evaporation, wind speed (m/s)
b w Tw w w w w w
e z D z E z t − ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ∂ ∂ ∂ ∂ + ∂ ∂ − = ∂ ∂ χ χ ρ χ η 1 Land surface model SOLVEG2 In-soil HTO transport processes
( )
[ ]
( )
b sa w sa Ta sa w ws
e z f D z t + ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ ∂ ∂ ∂ ∂ = − ∂ ∂ χ η χ η η
+: evaporation
- : Condensation
( ) ( )
r sa r E b z sa w sa Ta
c e z f D χ χ χ η − = + ∂ ∂ −
=
u
Atmosphere- land exchange
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SLIDE 12
HTO budget: Stomata uptake: Root uptake: OBT formation: (proportional to CO2 assimilation rate) OBT decomposition: (proportional to respiration rate)
χv , χa HTO conc. in leaf water (Bq/m3-water) and air (Bq/m3-air) ηv Leaf water content in unit leaf area (m3/m2) ra , rs Resistances (s/m) of leaf boundary layer and stomata qsat(Tc) Saturated specific humidity (kg/kg) at leaf temperature (Tc) ρa, ρw Density of air and water (kg/m3) Er Root uptake rate of HTO (Bq/m3/s) froot(zs,z) Distribution function of root uptake water mw , mglu Weight of 1 mol water and glucose (kg/mol) Ag , Rd Gross CO2 assimilation rate and respiration rate (mol-CO2/m2/s) Sint OBT amount in intermediate pool (Bq/kg)
res phot root stom v v
E E E E t + − + = ∂ ∂ χ η
Land surface model SOLVEG2 HTO budget in leaf
( )
⎭ ⎬ ⎫ ⎩ ⎨ ⎧ − + =
v w a c sat a s a stom
T q r r E χ ρ ρ χ 1
( ) ( )
s s root z s r root
dz z z f z E E
btm
,
∫
=
g w w v phot
A m E ρ χ =
d glu res
R m S E 6 1
int
=
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Carbohydrate formation and translocation processes based on experimental result (Fondy & Geiger 1982) Land surface model SOLVEG2 OBT formation and translocation
Daytime Nighttime 0.19EAn 0.48EAn 0.26EAn 1.00EAn starch 0.46EAn 1.00ERd 4.58ERd 5.23ERd 7.07ERd intermediates intermediates sucrose sucrose starch structural structural
Translocation Translocation CO2 assimilation rate An Respiration rate Rd OBT formation: EAn OBT decomposition: ERd
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SLIDE 14
Land surface model SOLVEG2 Test calculation
[Calculation setting] Experiment: HTO exposure to blooming vine at Cadarache (Guenot and Belot 1984) Comparison with measurement of TWFT concentration and OBT amount in leaf
Chamber HTO generator 0.1 0.3 0.5 0.7 1.0 Crown 5.0 8.0 1.5 3.0 1500 m3 h-1 12.0 Vertical coordinate (m) Meteorological data Atmosphere Vinyl film Input data –2.0 Stem –1.0 –0.50 –0.10 –0.05 –0.02 –0.20 Blower Soil Rooting zone
Experiment
HTO exposure from 09 to 13 LST
Calculation
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SLIDE 15
TFWT concentration Cal. & Obs.
Local time on 1 Jul. 1982 TFWT conc. 2000 4000 Come to equilibrium several hours after start/end of exposure (3) TFWT conc. (1) Air HTO conc. (input) (2) HTO flux (Bq m-3) 600 1x106
- 600
1x103 1x100 (Bq m-2 s-1) (MBq m-3) HTO conc. HTO flux TFWT conc.: Cal. / Obs. 9–13 h period 1.3 (n = 8) 0.5 (n = 30) 13–120 h period
Stomatal conductance: almost constant
Exposure start: Exposure end: Air→Leaf Leaf→Air
Exposure
(1) (2) (3)
1000 3000 105 Bq m-3 101 Bq m-3 z = 0.6 m z = 0.6 m
8 10 12 14 16 18 20 Obs
- Cal. z = 0.6 m
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SLIDE 16
12 24 36 48 60 72 84 96 108 120 Obs z = 0.85 m z = 0.6 m z = 0.4 m
OBT amount in leaf Cal. & Obs.
Time from 1982 7/1 0:00 (h)
OBT amount 0.5 1.0 (MBq kg-1) OBT Inventory 5 (MBq m-2) 10 15 Intermediate Structural starch sucrose OBT : Cal. / Obs. 9–13 h period 0.6 (n = 8) 1.4 (n = 30) 13–120 h period (1) OBT inventory in each pool（MBq m-2） (2) OBT amount（MBq kg-1）
Exposure
day night
top middle low
day night
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SLIDE 17
Total OBT fixed during exposure 1% 2% 2% t = 48 h t = 120 h t = 24 h Residual 35% 28% 63% 42% 57% Respired 70% Translocated 15% OBT fixed to structural carbohydrates
Fate of OBT generated in leaf
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SLIDE 18
Land surface model SOLVEG2 Summary
Incorporation of HTO transport into SOLVEG
Process based HTO transport model to simulate dynamic behavior
- f HTO in air-soil-plant system