CONSTRAINTS OF ASIAN VOC SOURCESCONSTRAINTS OF ASIAN VOC SOURCESFROM GOME HCHO OBSERVATIONSFROM GOME HCHO OBSERVATIONS

Tzung-May Fu, Paul I. Palmer, Dorian S. Abbot, Daniel J. JacobTzung-May Fu, Paul I. Palmer, Dorian S. Abbot, Daniel J. JacobAtmospheric Chemistry Modeling Group, Harvard UniversityAtmospheric Chemistry Modeling Group, Harvard University

Kelly V. Chance and Thomas KurosuKelly V. Chance and Thomas KurosuHarvard/Smithsonian Center for AstrophysicsHarvard/Smithsonian Center for Astrophysics

M.J. Pilling and J. Stanton (U. Leeds); A. Guenther, C. Wiedinmyer (NCAR); M.J. Pilling and J. Stanton (U. Leeds); A. Guenther, C. Wiedinmyer (NCAR); B. Barletta (UC Irvine)B. Barletta (UC Irvine)

OutlineOutline

I. Vegetation representation

- AVHRR LAI

- MEGAN inventory for biogenic VOCs

II. Constraints on East Asian VOC emissions

- GOME information

- TRACEP information

III. Summary

AVHRR Leaf Area Index 1982 – 2000AVHRR Leaf Area Index 1982 – 2000

AVHRR 10 day maximum NDVI

8km monthly LAI

0.5deg monthly LAI

Model grid monthly LAI

Myneni et al. (1997)

Landmap and Climatology T & precip.

NPP

0.5deg monthly LAI

Model grid monthly LAI

+/- 20%

AVHRR Leaf Area Index ValidationAVHRR Leaf Area Index Validation

Buermann et al. (2002)Dust mobilization and dry deposition also sensitive to LAI

AVHRR Leaf Area Index Interannual VariabilityAVHRR Leaf Area Index Interannual Variability

Buermann et al. (2002)

July + August (40-50N)

April + May (40-50N)

Modeling the terrestrial biosphere

April Sep

LA

IPAR – direct and diffuse (GMAO)

AVHRR LAI

Canopy model (Guenther 1995)

Alt

itu

de

Emission

Temperature:

Instantaneous (G95)

15-day history avg

Fixed base emission factors (Guenther 2004)

Emissions

Courtesy Paul Palmer

GEOS3, GEOS4

Model of Emissions of Gas and Aerosols from Model of Emissions of Gas and Aerosols from Nature (MEGAN) INVENTORYNature (MEGAN) INVENTORY

Emission rate = AEF × MEF × DEF × HEF

Alex Guenther and Christine Wiedinmyer (NCAR)

Leaf area

Leaf age

Light

Temperature

Canopy attenuation

T history

World ecoregion map

EF by ecoregion

AVHRR land cover

(plant type fraction)

MEGAN INVENTORYMEGAN INVENTORY

Guenther et al. (manuscript in preparation)

GEIA [Tg C/yr] MEGAN [Tg C/yr]

Isoprene 352.2 367.9

Monoterpenes 147.7 97.6

MBO - 1.16

Acetone (87.76) (87.76)

PRPE (10.07) (10.5)

GEIA [Tg C/yr] MEGAN [Tg C/yr]

Isoprene 12.31 3.99

Monoterpenes 4.59 1.88

(OVOC)* 13 9.1

Not implemented. From Klinger et al. [2002].

Chinese emissions:

Compare to Anthro+BB NMVOC emission = 17.4 Tg/yr

Global emissions:

BVOC EMISSION INVENTORYBVOC EMISSION INVENTORY

MEGAN

• GEOS3, GEOSS• Global isoprene 367.9 Tg C/yr• Latest emission factors• AVHRR land map and lai

• AEF must be computed offline for land use change studies

GEIA

• GEOS1, GEOSS, GEOS3, GEOS4• Global isoprene 352.2 Tg C/yr• Olson (1982) land map

• More flexibility for land use change studies

RELATING HCHO COLUMNS TO VOC EMISSIONRELATING HCHO COLUMNS TO VOC EMISSION

VOCi HCHOh (340 nm), OHoxn.

k ~ 0.5 h-1

Emission Ei

smearing, displacement

In absence of horizontal wind, mass balance for HCHO column HCHO:

i ii

HCHO

y E

k

yield yi

… but wind smears this local relationship between HCHO and Ei depending on the lifetime of the parent VOC with respect to HCHO production:

Local linear relationshipbetween HCHO and E

VOC source Distance downwind

HCHOIsoprene

-pinenepropane

100 km

CourtesyP.I. Palmer (Harvard)

EVALUATING GOME ISOPRENE EMISSION ESTIMATES EVALUATING GOME ISOPRENE EMISSION ESTIMATES vs. PROPHET IN SITU FLUX MEASUREMENTS (2001)vs. PROPHET IN SITU FLUX MEASUREMENTS (2001)

Also shown are local MEGAN isoperene emission inventory values

P.I. Palmer (Harvard), S.N. Pressley and B. Lamb (WSU), A. Guenther and C. Wiedinmyer (NCAR)

GOME HCHO COLUMNS OVER EAST ASIA (1996-2001)GOME HCHO COLUMNS OVER EAST ASIA (1996-2001)

Relationship to VOC emissions far more complex than for N. America. Biomass burning, isoprene, anthropogenic VOCs, direct HCHO emission all contribute; need multivariate regression

APRJAN

FEB

MAR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

GOME HCHO COLUMNS OVER EAST ASIA (1996-2001)GOME HCHO COLUMNS OVER EAST ASIA (1996-2001)

APR

MAY

JUN

JUL

AUG

SEP

NC

CCWC

SC

0% 20% 40% 60% 80% 100%

Changchun

BengbuHefei

BeijingLangfang

QinghuangdaoShijiazhunag

TangshanNanyangXinyang

XuchangZhengzhou

SuizhouJiningJinan

QingdaoZouchengShanghai

TaiyuanWeinan

ChongqingLanzhouGuiyang

YinchuanKunming

HaMiUrumqi

Golmud

AnqingShishouWuhanXiantao

ChangdeChangsha

QiyangShaoyang

ZhangjiajieJi'an

JingdezhenJiujiang

LinchuanNanchang

BeihaiGuilin

HangzhouTaihu

Wenzhou

Ethane

Propane

ALK4

Ethene

PRPE

Benzene

Toluene

Xylene

Isoprene

VOC CONTRIBUTIONS TO HCHO PRODUCTION VOC CONTRIBUTIONS TO HCHO PRODUCTION IN CHINESE CITIES (JAN-FEB 2001)IN CHINESE CITIES (JAN-FEB 2001)

Ethane 0.3 % Benzene 0.4 %

Propane 0.3 % Toluene 2.4 %

ALK4 5.1 % Xylene 20.2 %

Ethene 19 % Isoprene 8.2 %

PRPE 43 %

B. Barletta (UCI), T.-M. Fu (Harvard)

Vehicle-generated xylenes could make a large contribution to HCHO columns

NC

CC

WC

SC

Streets inventory for East AsiaStreets inventory for East Asia

Klimont et al. [2002]

M is c e l la n e o u sW a s te d is p o s a lT ra n s p o r tP a in t u s eS o lv e n t u s eC h e m ic a l in d u s t r yE x t ra c t io n a n d p ro c e s s in gS ta t io n a ry c o m b u s t io n

Eth

an

e

Pro

pa

ne

Bu

tan

es

Oth

er

alk

an

es

Eth

en

e

Pro

pe

ne

Oth

er

alk

en

es

Eth

yne

Be

nz

en

e

To

lue

ne

Oth

er

aro

ma

tic

s

Fo

rma

lde

hyd

e

Oth

er

ald

eh

yde

s

Ke

ton

es

Ha

loca

rbo

ns

Oth

er

sp

ec

ies

Tota

l/1

0

050

010

0015

0020

002

500

NM

VO

C a

nth

rop

og

en

ic e

mis

sio

n, G

g /

ye

ar

GOME r2

0.48

0.47

0.32

Uncertainty

+/- 130%

VOC / CO emission ratio in Chinese citiesVOC / CO emission ratio in Chinese cities

Streets et al. [2001]

Obs. Model

emission

Obs. / Model

emission Ethene NC 1.61e-2 0.66e-2 7.84e-2 0.084 Ethene CC 1.44e-2 0.45e-2 1.17e-2 0.38 Ethene WC 1.39e-2 0.45e-2 0.68e-2 0.66 Ethene SC 1.82e-2 0.51e-2 2.03e-2 0.25

PRPE NC 1.19e-2 0.38e-2 5.79e-2 0.066 PRPE CC 9.88e-3 2.61e-3 8.04e-3 0.32 PRPE WC 9.98e-3 3.00e-3 4.90e-3 0.61 PRPE SC 1.30e-2 0.45e-2 1.45e-2 0.31

XYLE NC 1.41e-3 0.78e-3 6.87e-3 0.11 XYLE CC 1.28e-3 1.99e-3 1.05e-3 1.89 XYLE WC 1.25e-3 1.52e-3 0.62e-3 2.45 XYLE SC 1.16e-3 2.70e-3 1.29e-3 2.09

ISOP NC 0 9.88e-5 0 - ISOP CC 0.16e-4 1.57e-4 0.13e-4 12.07 ISOP WC 6.60e-4 1.58e-4 3.22e-4 0.49 ISOP SC 5.73e-4 2.90e-4 6.45e-4 0.45

Obs data: B. Barletta UC Irvine

Streets ETHE/CO 3x too high

XYLE/CO 2x too low

SimulationSimulation

• GEOS3 2x2.5 2001

• East Asia: Streets inventory [2001] including ETHE, XYLE and direct HCHO emission

• C2H6: Xiao et al. [2004]

• CO correction: Heald et al. [2004]

• NOx correction: Wang et al. [2004b]

• Anthropogenic seasonality (FF+BF): Streets et al. [2003]

• Biomass burning seasonality: Duncan et al. [2003] + Heald et al. [2003]

• MEGAN inventory (AVHRR LAI)

• ETHE, XYLE, MONX chemistry

CC22HH44 chemistry chemistry

Vereecken and Peeters [1999]

Orlando et al. [2003]

Lifetime HCHO Yield per C

OH 6 hours 0.89

O3 6.8 days 0.57

NO3 110 days

Assuming midmorning summer conditions: [OH] = 5 × 106 molecule cm-3, [O3] = 40 ppb, nighttime average [NO3] = 5 × 108 molecules cm-3, and a temperature of 298 K.

AromaticsAromatics

0 1 2 3 4 5 6 7 8 9 100.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

HC

HO

YIE

LD P

ER

C R

EA

CT

ED

days

NOX = 1PPB

NOX = 100 PPTTOLUENE

0.18 per C

J. Stanton and M. Pilling

Bloss et al. [2004]

MCM v3.1

OH = 9.9 h

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 200.00

0.05

0.10

0.15

0.20

0.25

0.30

HC

HO

YIE

LD P

ER

C R

EA

CT

ED

days

NOX = 1 PPB

NOX = 100 PPT

MXYL

0.26 per C

MCM v3.1

OH = 2.4 h

m-xylene

toluene

High HCHO and GLXY yield from aromatic hydrocarbons also observed by Volkamer et al. [2001].

HCHO underestimated in MCM

Xylene removal underestimated in MCM

Measurements show rapid SOA formation

TRACEP: Chinese outflow TRACEP: Chinese outflow [30-60N, 120-150E] z < 2km, [CO] < 400 ppbv[30-60N, 120-150E] z < 2km, [CO] < 400 ppbv

OBS

Model w/ ETHE, XYLE

Model w/o ETHE, XYLEModel only 23% of observation

TRACEP: Chinese outflow TRACEP: Chinese outflow [30-60N, 120-150E] z < 2km, [CO] < 400 ppbv[30-60N, 120-150E] z < 2km, [CO] < 400 ppbv

OBS

Model w/ ETHE, XYLE

Model ETHE/CO 3x too high

HCHO sources independent of ETHE contribute ~50%

Model XYLE/CO 3x too high

Direct HCHO sources from transportation?Direct HCHO sources from transportation?

Kolb et al. [2004]

Streets emission

HCHO / CO2 =

4 x 10-7 – 4 x 10-5 [mole/mole]

Mexico City

2 x 10-4 [mole/mole]Boston

3 x 10-5 [mole/mole]

HC

HO

(p

pb

)

CO2 (ppm)

SUMMARYSUMMARY

• From in-situ measurements:

• Short-lived anthropogenic VOCs such as alkenes and xylenes contributes > 80% to local HCHO production, and > 25% to HCHO VC

• Ethene/CO emission may be overestimated by factors of 3-4 in parts of China

• Xylene/CO emission may be underestimated by factors of 2-2.5

• Preliminary model and TRACEP comparisons agree with in situ measurements

• Possibile direct HCHO source independent of ethene emissions

• In progress: multivariate regression to evaluate relative contribution from different sources

BACKUPBACKUP

1 x 1

2 x 2.5

4 x 5

GOME (launched Apr 1995)

Nadir viewing

Global coverage in 3 days

320 km x 40 km

O3, NO2, HCHO, etc

Jul 1995 to Dec 2003

SCIAMACHY (launched Mar 2002)

Nadir/limb

Global coverage in 3 days

60 km x 30 km

O3, NO2, HCHO, CO, CO2, CH4, etc

A. Richter, IUP U Bremen

OMI (launched Jul 2004)

Nadir viewing

Global coverage in 1 day

24 km x 13 km

O3, NO2, HCHO, etc

1 x 1

2 x 2.5

4 x 5

Monthly mean LAI (AVHRR/MODIS)

MEGAN (isoprene)Canopy model

Leaf areaLeaf age

Temperature historyBase factors

MODEL BIOSPHERE

GEIAMonoterpenes

MBOAcetoneMethanol

GEOS-CHEMGlobal 3D CTM

PAR, T

Emissions

Global 3-D Modeling Overview•Driven by NASA GMAO met data

•2x2.5o resolution/30 vertical levels

•O3-NOx-VOC-aerosol chemistry

INVERTING HCHO COLUMN DATA FOR ISOPRENE EMISSIONINVERTING HCHO COLUMN DATA FOR ISOPRENE EMISSIONGOME slant columns (July 96)

GOME vertical columns (July 96)

Air Mass Factor

EISOPRENE =(1/S)HCHO

GOME isopreneemission inventory

GEOS-CHEMCTM

GOME/OMIsensitivity

HCHO vmrS

igm

a co

ord

inat

e

validationWith HCHOsurface airobservations

with GEIAisoprene emissioninventory

with GOMEisopreneemission inventory

Palmer et al. [2001, 2003]

EISOPRENE

HC

HO

co

lum

n

non- isoprene contribution

Southeast U.S.

slope S

Observed HCHO, ppb

Mo

del

HC

HO

, p

pb

WHAT DRIVES GOME HCHO TEMPORAL VARIABILITY WHAT DRIVES GOME HCHO TEMPORAL VARIABILITY OVER SOUTHEAST U.S. DURING MAY-SEPTEMBER?OVER SOUTHEAST U.S. DURING MAY-SEPTEMBER?

P.I. Palmer (Harvard)

Monthly mean GOME HCHO vs. surface air temperature;MEGAN parameterization shown as fitted curve

GO

ME H

CH

O C

olu

mn

[10

16 m

ole

c

cm

-2]

Southeast US average 32-38N; 265-280W

YEAR-TO-YEAR VARIABILITY OF GOME HCHO OVER SOUTHEAST U.S.YEAR-TO-YEAR VARIABILITY OF GOME HCHO OVER SOUTHEAST U.S.Amplitude and phase are highly reproducible

P. I. Palmer (Harvard)

Biogenic VOC emissions: Biogenic VOC emissions:

a pathway of biosphere – atmosphere interactiona pathway of biosphere – atmosphere interaction

B io s p h e re

A tm o s p h e re

H u m a n a c tiv it ie s

V O C s

O , C H , C O ,o r g a n ic a e ro s o ls

3 4

R a d ia t io n ,Te m p e ra tu re ,P re c ip i ta t io n ,C lo u d c o v e r,C O 2

GHG, aerosols

Changing landuse, hydrology

Fertilization