Transcript CABLE: the Australian community land surface model

CABLE: the Australian
community land surface model
Bernard Pak, Yingping Wang, Eva Kowalczyk
CSIRO Marine and Atmospheric Research
OzFlux08, Adelaide, 4-6 Feb 2008
Australian Community Climate Earth System
Simulator (ACCESS) modelling program
Diagram to right shows
‘scope’
Fundamentally conceived as
a modelling ‘system’ that
meets a variety of needs.
Priority needs are:
•Numerical weather
prediction
•Climate change simulation
capability
Collaboration between key
institutions (Bureau, CSIRO,
Australian Universities,….)
Downscaling
ESM
Model
Evaluation
Data
Assimilation
ACCESS
Supercomputing
Graphics
Visualisation
Software
Engineering
The general structure of CABLE
Interface to the GCM
Canopy
radiation;
sunlit & shaded
visible &
near infra-red,
albedo
soil temp.
SEB & fluxes;
for soil-vegetation
system:
Ef , Hf , Eg , Hg;
evapotranspiration
stomata transp.
& photosynthesis
soil moisture
Carbon
fluxes;
GPP, NPP,NEP
soil respiration
snow
carbon pools; allocation & flow
CASA-CNP
vegetation dynamics/disturbance
Kowalczyk et al., CMAR Research Paper 013, 2006
Vegetation parameters required for CABLE
VEGETATION TYPE
1
2
3
4
5
6
broad-leaf evergreeen trees
broad-leaf deciduous trees
broad-leaf and needle-leaf trees
needle-leaf evergreen trees
needle-leaf deciduous trees
broad-leaf trees with ground cover
/short-vegetation/C4 grass (savanna)
7 perennial grasslands
8 broad-leaf shrubs with grassland
9 broad-leaf shrubs with bare soil
10 tundra
11 bare soil and desert
12 agricultural/c3 grassland
13 ice
A grouping of species that show close
similarities in their response to environmental
control have common properties such as:
- vegetation height
- root distribution
- max carboxylation rate
- leaf dimension and angle, sheltering factor,
- leaf interception capacity
Geographically explicit
data
LAI – leaf area index
fractional cover
C3/C4 - fraction
the model calculates:
z0 – roughness length
α – canopy albedo
Soil parameters required for CABLE
Soil types:
Coarse sand/Loamy sand
Medium clay loam/silty clay loam/silt loam
Fine clay
Coarse-medium sandy loam/loam
Coarse-fine sandy clay
Medium-fine silty clay
Coarse-medium-fine sandy clay loam
Organic peat
Permanent ice
Soil Properties:
- water balance:
wilting point
field capacity
saturation point
hydraulic conductivity at saturation
matric potential at saturation
- heat storage:
albedo,
specific heat, thermal conductivity
density
- soil depth
Post, W., and L. Zobler, 2000
Global Soil Types
Nonlinear parameter estimation
• 19 FLUXNET sites, including all major veg
types in the temperate and subtropical
climate;
• Uniform parameter range ;
• Optimisation was applied to each year’s
measurements separately;
• Each type of obs was weighted by the SD
of measurements over a year.
• Published in Wang et al. (Global Change
Biology, 2001 and 2007)
A temperate evergreen forest, Tumbarumbra,
Australia
-2
Modelled Fe (W m )
Latent heat (Fe)
120
80
40
0
-40
0
5
10
15
20
25
140
120
100
80
60
40
20
0
-20
-20 0 20 40 60 80 100120 140
-2
200
-2
Modelled Fh (W m )
Sensible heat (Fh)
Observed Fe (W m )
100
0
-100
0
5
10
15
20
25
120
100
80
60
40
20
0
-20
-40
-40 -20 0 20 40 60 80 100 120
-2
0
-1
-2
-3
-4
-5
0
Modelled NEE
NEE (Fc)
Observed Fh (W m )
-1
-2
-3
-4
-5
0
5
10
15
Month
20
25
-5
-4
-3
-2
-1
0
Observed NEE (mol m-2 s-1)
Deciduous forest, Walker Branch
Latent heat
2
(W/m )
120
80
40
0
-40
Sensible heat
2
(W/m )
0
10
20
30
40
10
20
30
40
10
20
30
40
200
Fh
100
0
-100
NEE
-2 -1
(mol m s )
0
4
Fnee
0
-4
-8
0
Month
Relative Vcmax: deciduous forests
Deciduous forests
1.2
1.0
0.8
0.6
0.4
0.2
0.0
Leaf
growth
0
2
HE (48N)
HV(42N)
VI (50N)
WB(36N)
WL (46N)
Leaf fall
4
6
Month
8
10
12
Changes to-date
• Major clean-up and rewriting of codes in
FORTRAN90 standard, making it more
modular and more flexible.
• A secured website has been set up for
code distribution, installation help and
exchange of ideas.
• Standard scripts introduced to help
analyzing results.
• Monthly meeting
Future changes
• CASA-CNP: Nitrogen and phosphorus have
been found to impact strongly on climate
predictions. Such nutrient cycles will be
implemented within the current year. It also
necessitates a better phenology module.
• Dynamic vegetation: a UNSW post-doc (Dr. Jiafu
Mao) have just started in January. He will
implement LPJ into CABLE.
• Hydrology: MU and BoM have done some work,
we will have at least one post-doc later this year.
CABLE as the Australian
community land surface model
• Source codes and documentation are
available to all registered users online at
https://teams.csiro.au/sites/cable/default.aspx
(email [email protected] to register)
• We are looking for collaboration to
validate/improve CABLE
The End
Modelling Vcmax and Jmax
af  An
G s  G0 
(C s  )(1  Ds / D0 )
Vc max  vc max f d f T ;
  (1  exp( k n L)) / k n
 Ts , 0.5  To
f d  1  
 T
f T  f (Tleaf )
j max
2
vc max
 s   wp
f  
 fc   wp



(scaling up from leaf of canopy)
2
(leaf age effects)
(Leuning 1997 for C3 species)
(at 25 o C, Leuning 1997)
Parameter ranges
Table 2. Initial values and ranges of optimized model parameters
Parameter
Unit
Initial value
Range
xL
_____
1.0
0.8 – 1.0
xjmax
_____
1.0
0.1-5.0
jmax/vcmax
_____
2.0
Weight=100
xrs
_____
1.0
0.01-50
Topt
o
20
0-50
T
o
20
0-100
C
C
Observed and estimated vcmax per
unit leaf area during growing
season (mol m-2 s-1)
Site
Harvard forest
Estimated
61
observed
56
Tumbarumbra
64
71
Hyytiala
74
64
Hesse
65
70