Offshore China

Over Japan

Slope (> 840 mb) = 51

R2 = 0.76

Slope (> 840 mb) = 22

R2 = 0.45

Suntharalingam et al, 2004

REGIONAL [CO2]:[CO] CORRELATIONS PROVIDE UNIQUE INFORMATION ON SOURCE REGION AND TYPE

*Regional CO:CO2 reflect source mix and variation in FF combustion ratio

*How can we exploit CO:CO2 correlations to improve emission estimates?

A priori bottom-up

Top-down information

CO CO

CO

2

CO

2

Observation vector y

State vector (Emissions x)Consistent CO and CO2 Emissions

Modeling Approach

Inverse model

x = Fluxes of CO and CO2 from Asia (Tg C/yr)

y = TRACE-P CO and CO2 concentration data

x = xa + (KTSy-1K + Sa

-1)-1 KTSy-1(y – Kxa)^

Forward model(GEOS-CHEM)

y = Kxa +

Jacobian describes CTM

0-2 km

Latitude [deg]

CO

[p

pb

]C

O2 [p

pm

]4-6 km

2-4 km

GEOS-CHEM

TRACE-P Data

Remove CO2 bias using 10th

percentile of [CO2]: 4-4.5 ppm

GEOS-CHEM Performance

Sy

*Measurement accuracy *Representation

*Model error (most important)

GEOS-CHEM

Error specification for CO and CO2

Sa

Anthropogenic (c/o Streets) Biomass burning: 50% 30% Chemistry (~CH4): 25% Biosphere: 75%

(measured-GEOS-CHEM) /measured

All latitudes

Alt

itu

de [

km

]

Mean bias

RRE

CO

(y*RRE)2 ~38ppb (CO)

~1.87ppm (CO2)

RRE = total observation error

GEOS-CHEM

2x2.5 cell

TRACE-P

CO

2 e

mis

sio

ns

[Tg

Marc

h 2

001] Biospheric CO2

1~ K

Results consistent with CO inverse

modeling and [CO2]:[CO] analysis

CO

em

issio

ns

[

Tg

yr-

1]

Anthropogenic CO2

CO

2

em

issio

ns

[

Tg

yr-

1]

Anthropogenic COA priori A posteriori

Uncorrelated inversion of CO and CO2 emissions

E = A F

Origin of CO:CO2 Correlations

Activity Rate (Tg fuel yr-1) (amount of fuel

burned)

Emissions (Tg C

yr-1)

Emission Factor (TgC /

Tg fuel)

Colocated Emissions

Atm. Dyn. Processes

Coal-burning cook stoves in Xian, China

cold air

warm air

E.g., frontal system

Compute [CO]:[CO2] correlations from TRACE-P

Sa

Sy

Modeling CO and CO2 emission correlationsECO = (A + AA) (FCO + COFCO)

ECO2 = (A + AA) (FCO2 + CO2FCO2)

N

N

A p

ost

eri

ori

cert

ain

ty r

ela

tive t

o

unco

rrela

ted invers

ion

[%

]

CHINA

China + Taiwan1

0.1

1

Fra

c. F

CO

Frac. A

0 0.5 1-0.5-1

CO:CO2 correlationChina