Transcript PPT

Physical and Biogeochemical
Coupled Modelling
Presented by Christel PINAZO
Mediterranean University
Oceanographic Center of Marseille
Physical & Biogeochemical Oceanographic Laboratory
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
LECTURE SCHEDULE
• Introduction
Why use Coupled Models ?
Historical considerations
• Different types of Coupled Models
 Box models
 Fine grid Models (1D, 2D and 3D)
• Different ways of Coupling Models
 « Off-line » Coupling
 « On-line » Coupling
• Examples
LECTURE SCHEDULE
• Introduction
Why use Coupled Models ?
Historical considerations
• Different types of Coupled Models
 Box models
 Fine grid Models (1D, 2D and 3D)
• Different ways of Coupling Models
 « Off-line » Coupling
 « On-line » Coupling
• Examples
INTRODUCTION
WHY
USE
PHYSICAL AND BIOGEOCHEMICAL
COUPLED MODELS
TO STUDY
ECOSYSTEM FUNCTIONING?
INTRODUCTION > WHY?
COUPLING TYPES
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
INTRODUCTION
A BIOGEOCHEMICAL MODEL
TO DESCRIBE
ECOSYSTEM FUNCTIONING
INTRODUCTION > WHY?
COUPLING TYPES
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
IRRADIANCE
BIOGEOCHEMICAL
GEOCHEMICAL MODEL
Atmospheric inputs
River Inputs
Phytoplankton
T°
Grazing
Bacteria
Exudation
Uptake
Zooplankton
Grazing
Mineralisation
Nutrients
POM DOM
Uptake
Faeces
Grazing
Schematic
Marine
Ecosystem
Benthic
Fluxes
Erosion
Sediment
INTRODUCTION
A PHYSICAL MODEL
TO DESCRIBE
ECOSYSTEM FORCING CONDITIONS
INTRODUCTION > WHY?
COUPLING TYPES
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
IRRADIANCE
PHYSICAL MODEL
Atmospheric inputs
River Inputs
Waves
WIND
Tide
Currents
Phytoplankton
Bacteria
T°
Zooplankton
Nutrients
POM DOM
Schematic
Marine
Ecosystem
Benthic
Fluxes
Erosion
Sediment
INTRODUCTION
A PHYSICAL AND BIOGEOCHEMICAL
COUPLED MODEL
IS NEEDED
TO DESCRIBE
BOTH
ECOSYSTEM FUNCTIONING
AND FORCING CONDITIONS
INTRODUCTION > WHY?
COUPLING TYPES
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
LECTURE SCHEDULE
• Introduction
Why use Coupled Models ?
Historical considerations
• Different types of Coupled Models
 Box models
 Fine grid Models (1D, 2D and 3D)
• Different ways of Coupling Models
 « Off-line » Coupling
 « On-line » Coupling
• Examples
INTRODUCTION
Physical and Biogeochemical
Coupled Modelling
is a Recent Scientific Discipline
Developed since the 1990’s
INTRODUCTION > HISTORY
COUPLING TYPES
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
INTRODUCTION
BECAUSE
1
Biogeochemical Modelling
was
Developed since the 1940’s with
Riley’s (1946) and Steele’s (1962) Models
INTRODUCTION > HISTORY
COUPLING TYPES
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
PHYTOPLANKTON MODELS
Riley’s Model (1946)
Photosynthesis
Respiration
Grazing
Phytoplankton Carbon
Concentration
From Tett & Wilson (2000)
Steele’s Model (1962)
Phytoplankton
Carbon
Concentration
INTRODUCTION > HISTORY
Photosynthesis depending on light limitation
COUPLING TYPES
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
N-P-Z-D MODELS
Nutrient-Phytoplankton-Zooplankton-Detritus
Fasham’s Model (1990)
DON
Phytoplankton
Nitrate
Ammonium
Bacteria
INTRODUCTION > HISTORY
Zooplankton
COUPLING TYPES
Detritus
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
INTRODUCTION
&
BECAUSE
2
Hydrodynamical Modelling
was
Developed since the 1970’s with
the development of computers
and computing resources
INTRODUCTION > HISTORY
COUPLING TYPES
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
INTRODUCTION
POM was created by
Blumberg in late 1970’s
Blumberg & Yamada (1974)
Blumberg & Mellor (1980)
INTRODUCTION
THUS
3
First coupled Models appeared in the 1980’s
Cloern & Cheng (1981) 1DH (Phytopk)
Klein & Coste (1984) 1DV (Nutrients)
Klein & Steele (1985) 1DV (N-P)
INTRODUCTION > HISTORY
COUPLING TYPES
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
INTRODUCTION
First 3D coupled Models
appeared in the 1990’s
Sarmiento et al. (1993) (Fasham’s model)
Buckley and O’Kane (1993) (GHER model)
Skogen et al. (1995) (NORWECOM model)
Six and Maier-Reimer (1996) (HAMOCC model)
Pinazo et al. (1996) (ECO3M model)
INTRODUCTION > HISTORY
COUPLING TYPES
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
LECTURE SCHEDULE
• Introduction
Why use Coupled Models ?
Historical considerations
• Different types of Coupled Models
 Box models
 Fine grid Models (1D, 2D and 3D)
• Different ways of Coupling Models
 « Off-line » Coupling
 « On-line » Coupling
• Examples
COUPLING OR FORCING?
THAT IS THE QUESTION!
FORCING
Hydrodynamic
Model
Ecological
Model
NO
FEED BACK
FORCING
INTRODUCTION
COUPLING TYPES
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
LECTURE SCHEDULE
• Introduction
Why use Coupled Models ?
Historical considerations
• Different types of Coupled Models
 Box models
 Fine grid Models (1D, 2D and 3D)
• Different ways of Coupling Models
 « Off-line » Coupling
 « On-line » Coupling
• Examples
COUPLING TYPES
THE STUDY SITE COULD BE
SPATIALLY DESCRIBED BY BOXES
INTRODUCTION
COUPLING TYPES >BOX
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
BOX MODEL
VERTICALLY HOMOGENEOUS
h
z=0

u
Velocity = v v
w
z
y
O
z=-h
x
INTRODUCTION
SEDIMENT
COUPLING TYPES >BOX
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
CONSERVATION LAWS
TO CALCULATE ADVECTION
OF BIOGEOCHEMICAL SUBSTANCES :
- FLUID MASS CONSERVATION = CONTINUITY EQUATION
- SUBSTANCE MASS CONSERVATION
INTRODUCTION
COUPLING TYPES >BOX
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
CONSERVATION LAWS
FLUID MASS CONSERVATION = CONTINUITY EQUATION
In case of
incompressible fluids
  0 Density is constant
INTRODUCTION
u
v
w


 0
x
y
z
COUPLING TYPES >BOX
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
BOX MODEL
h
z=0
Along Ox axis
uin
uout
x  xout  xin
z
y
O
z=-h
x
INTRODUCTION
SEDIMENT
COUPLING TYPES >BOX
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
BOX MODEL
h
z=0
Along Ox axis
uin
uout
u uout  uin

x
x
x  xout  xin
z
y
O
z=-h
x
INTRODUCTION
SEDIMENT
COUPLING TYPES >BOX
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
CONSERVATION LAWS
FLUID MASS CONSERVATION = CONTINUITY EQUATION
In case of
incompressible fluids
  0 is constant
u v w


0
x y z
Boundary conditions along Oz axis:
h
0
w t

z
z
wbottom  0
h
wsurface 
t
z  h  (h)  D
INTRODUCTION
COUPLING TYPES >BOX
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
CONSERVATION LAWS
FLUID MASS CONSERVATION = CONTINUITY EQUATION
In case of
incompressible fluids
  0 is constant
INTRODUCTION
h
u
v
D
D
0
t
x
y
COUPLING TYPES >BOX
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
CONSERVATION LAWS
SUBSTANCE MASS CONSERVATION = STATE EQUATION
C is the concentration of the substance
INTRODUCTION
COUPLING TYPES >BOX
C
?
t
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
BOX MODEL
h
z=0
C M out  M in

x
Vol
Along Ox axis
z
Min  Cin .uin .y.z
z
M out  Cout .uout .y.z
y
y
O
x  xout  xin
z=-h
x
INTRODUCTION
SEDIMENT
COUPLING TYPES >BOX
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
CONSERVATION LAWS
SUBSTANCE MASS CONSERVATION = STATE EQUATION
C is the concentration of the substance
C  Cout .uout  Cin .uin  .y.z  Cout .vout  Cin .vin  .x.z  Cout .wout  Cin .win  .x.y



0
t
Vol
Vol
Vol
with
Vol  x.y.z
And at the surface
at the bottom
M out  0
Min  Cin .wsettling .x.y
Cu   Cv  C.wsettling

C



t
x
y
z
INTRODUCTION
COUPLING TYPES >BOX
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
BOX MODEL
If C is the concentration of a biologic substance,
C is not conservative
Cu   Cv  C.wsettling

C



 Trend
t
x
y
z
INTRODUCTION
COUPLING TYPES >BOX
COUPLING WAYS
Concentration
Trend term=
Sources – Sinks
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas
COUPLING TYPES
BOX MODEL
ADVANTAGES:
-SHORT COMPUTATIONAL TIME
-VERY LONG SIMULATION OF YEARS OR DECADES
DISADVANTAGES:
-MAINLY ADVECTIVE TRANSPORT: Paul Tett TRIED TO ADD VERTICAL EDDY
DIFFUSIVITY THROUGH 3 VERTICAL LAYERS
-ROUGH SPATIAL DESCRIPTION
-NUMERICAL HORIZONTAL DIFFUSIVITY
INTRODUCTION
COUPLING TYPES >BOX
COUPLING WAYS
EXAMPLES
Regional Advanced School on Physical and Mathematical Tools for the study of Marine Processes of Coastal Areas