Prabir K. Patra, Shamil Maksyutov, A. Ito

and TransCom-3 modellers

Jena; 13 May 2003

An evaluation of an ecosystem model for studying CO2 seasonal cycle

TransCom-3 (Level-1) related activities

at FRSGC

Goals…To configure optimal observation system

– Measurement network optimisation (surface)

– Estimate benefits of satellite data in inversion

– Evaluate of their relative performance

Tools

Inverse Modelling

Least squares fitting of observed data and model simulations

Matrix multiplication and SVD

TransCom-3 setup for 11 land and 11 ocean regions

HiRes setup for 42 land and 11 ocean regions

Forward Modelling

16 global transport models of TransCom-3

Advection, PBL, Convection etc. are treated differently

ECMWF, NCEP, GCM meteorological fields

Simulation of monthly-mean source/basis functions

Network Optimization

Patra and Maksyutov, GRL, 29, 28 May 2002 CD=RSD2

Incremental Optimization of Surface Network (Case 1)

O basic[] Model Ensemble

Average uncertainty for TransCom-3 models

Total Source Covar C = CS; Average Unc = C/ No. of Region

Signal gradients at optimal stations

Model Dependent Uncertainty Reduction

1:UCB 2:UCI 3:UCI:s 4:UCI:b 5:JMA 6:MATCH:b 7:MATCH:c 8:MATCH:l 9:NIES:FRSGC10:NIRE-CTM11:RPN:SEF12:SKIHI13:TM214:TM315:CSU

Patra et al., Tellus, 55B(2), 2003

Signal gradients within NH regions

Occultation based satellite measurements (Case 2)

CD =

RS

D2 +In

st. Err. 2

Regional flux

uncertainty at several satellite

data precision

Satellite vs Surface data inversion

(inst err=0)

Ecosystem production

distribution: a justification for high resolution inverse model

The fossil fuel emission do not have seasonality.Oceanic sources and sinks are weaker compared to the land and less heterogeneous.

HiRes Inverse Model(42 Land and 11 Ocean Regions)

0 0

0

0

( )( ) ( )*2.0*

( )S S

S newC new C old

S old

Inverse Model Intercomparison

Optimal Networks:TransCom-3 vs HiRes

Comparison of average flux uncertainty

C_D=RSD^2

Satellite vs Surface Observations

TransCom-3 HiRes setup

C_D=RSD^2 + P^2

Multimodel Inversion of SOFIS data

Three model groups: 1. High, Low and Intermediate signal in the “global” middle-upper troposphere

High C_Ds compared to the signal – flat flux unc. with precision

Multimodel Inversion (no RSDs)

Is the use of RSDs (derived from NIES model only) in satellite data inversion justified?

Com

pari

son

s fo

r diff

ere

nt

lati

tude b

elt

s

Flux uncertainty reduction with surface network extension depends on vertical profiles near the surface

Diving the Tracom-3 region into four smaller regions do seem to pose a severe aggregation problem

The use to different ATM simulations effect the pseudo-satellite inversion results

Conclusions

An evaluation of an ecosystem model for studying CO2 seasonal cycle

Tests with an Ecosystem Model Outputs

Optimisation of SimCYCLE model parameters:

– 1. Q10 for respiration change with temperature

– 2. Leaf-level Photosynthetic Capacity (PC)

Both parameters were changed by -20%, -10%,

-5%, -3%, -1%, +1%, +3%, +5%, +10%, and +20%

SimCYCLE: SIMulation model of the Carbon cYCle in Land Ecosystem (Ito and Oikawa, Eco. Mod., 2002)

Flowchart of SimCYCLE model

Source: A

. Ito

Light-photosynthesis relationship with different maximum rate

Source: A

. Ito

Temperature-respiration relationship with different Q10

Source: A

. Ito

Procedure Monthly-mean SimCYCLE outputs are

transported using NIES/FRSGC model Signals are sampled at 8 background stations in

NH high latitude:• Alert, Greenland 82.45 297.48 210. • Zeppelin St., Norway 78.90 11.88 474. • Mould Bay, Canada 76.25 240.65 58. • Barrow, Alaska 71.32 203.40 11. • Atlantic Ocean, Norway 66.00 2.00 7. • Storhofdi, Iceland 63.25 339.85 100. • Baltic Sea, Poland 55.50 16.67 7. • Cold Bay, Alaska 55.20 197.28 25. • Mace Head 53.33 350.10 26. • Shemya Island, Alaska 52.72 174.10 40.

The simulations are then fitted to the Observed seasonal cycles of CO2

Fitting at Alert

Q10 is not so sensitive

Best fit at PSR=-10%

(Bad)Fitting

at Baltic Sea

Best fit at PSR=-10%

(Good)Fitting

at Mace Head

Good fit atPSR=-5%

Summary

Recommended:5 to 10% Q10 &-5 to -10% PSR

Thanks for your attention

TransCom-3 Modellers:

D. Baker (NCAR), P. Bousquet (LSCE), L. Bruhwiler (CMDL), Y-H. Chen (MIT), P. Ciais (LSCE), A. S. Denning (CSU), S. Fan (PU), I. Y. Fung (UCB), M. Gloor (MPI), K. R. Gurney (CSU), M. Heimann (MPI), K. Higuchi (MSC), J. John (UCB),R. M.Law (CSIRO), T. Maki (JMA), P. Peylin (LSCE), M. Prather (UCI), B. Pak (UCI), P. J. Rayner (CSIRO), J. L. Sarmiento (PU), S. Taguchi (NIAIST), T. Takahashi (LDEO),

C-W. Yuen (MSC)