the effect of future climate change on aerosols: biogenic...

The Effect of Future ClimateChange on Aerosols:

Biogenic SOA and Inorganics

GCAP Phase 2 Science Team Meeting

October 12, 2007

Havala O. T. Pye1, Hong Liao2, John Seinfeld1,

Shiliang Wu3, Loretta Mickley3, Daniel Jacob3,

Athanasios Nenes4

1California Institute of Technology, 2Chinese Academy of Sciences,3Harvard University, 4Georgia Institute of Technology

How Will Changing Climate and EmissionsAffect Aerosols?

Gas Phase Chemistry

(T)

Inorganic Aerosols

(NH4+, NO3

-, SO42-,

seasalt, mineral dust)

Organic Aerosols (BC,

POA, SOA)

Lightning NOX

(T, cloud top height, etc.)

Seasalt (u) SO4

2-

Other Natural andAnthropogenicemissions:

NOX, SO2, NH3 …

Natural emissions:

DMS

Soil NOX

Biogenic HCs

(u, T, precip., …)BC

POA

SOA eqlb

partitioning

(T)

Inorganic

equilibrium

(T, RH)

Dry

deposition

(stability)

Wet

deposition

(precip.,…)

transport

SO42-

production

(clouds,…)

Outline

• Findings from the GISS GCMTropospheric Unified Simulation[Liao et al.]

• Comparison of GEOS-Chempredictions to observations

• The influence of climate onbiogenic SOA

• Implementation ofISORROPIAII for inorganicaerosols

Cli

ma

te (

GIS

S G

CM

II’

)

Gas-phase Tropospheric Chemistry

O3-NOx-CO-CH4-NMHC

Tropospheric Clouds

Tropospheric Aerosols

Temperature

Wind, etc.

Temperature

Wind, etc.

Gas-phase species for

aerosol formationHeterogeneous

chemistryAlteration of

actinic flux

Anthropogenic Natural

Anthropogenic Biogenic Stratospheric input

Flux of gaseous

species to clouds

Cloud processing

Aerosol Thermodynamics

BC/POA/SOAMineral dust

InorganicAerosol

Thermodynamics

Tropospheric Unified Simulation

[modified Liao et al., JGR 2003,2004]

CO2 Emissions

(Year 2000 and 2100)

Numbers in parentheses are percentage changes compared with

the simulation with year 2000 climate and year 2000 emissions.

Effects of Climate Change and Changes in Emissionson Global Burdens (Tg) of Ozone and Aerosols

15.20 (-16.3%)

4.39 (-19.3%)

0.38 (+8.6%)

1.17 (-9.3%)

0.20 (-13.0%)

0.28 (-47.2%)

1.84 (-14.0%)

307 (-12.0%)

Climate Change

(2000-2100)

18.17

5.44

0.35

1.29

0.23

0.53

2.14

349

Present Day Climate

and Emissions

15.20 (-16.3%)Mineral dust

4.39 (-19.3%)Sea salt

0.54 (+54.3%)SOA

2.72 (+110.9%)POA

0.48 (+108.7%)BC

1.49 (+181.1%)

1.79 (-16.4%)

521 (+49.3%)O3

Climate and

Emission Changes

Species

2

4SO

3NO

[Liao et al., JGR 2006]

GEOS-Chem with GISS GCMMeteorology:Predictions

Compared to Observations

Sulfate Aerosol Predictions and Observations

GEOS-Chem IMPROVE

-0.49 μg/m3US

-0.90 μg/m3Eastern US

-0.33 μg/m3Western US

Mean bias* in 1.37 x [SO42-]

[Liao et al., 2007]

*

Carbonaceous Aerosol Predictions andObservations

[Liao et al., 2007]

Annual B

C

IMPROVEGEOS-Chem

JJA

OA

-0.004 μg/m3US

+0.09 μg/m3Eastern US


Mean bias in BC

-0.56 μg/m3US



Mean bias in OA

R = 0.67

R = 0.72, 0.64, 0.41, 0.46

PM2.5 Predictions and Observations

GEOS-Chem IMPROVE

-0.87 μg/m3US



Mean bias in PM2.5

[Liao et al., 2007]

Biogenic SOAand Climate Change

Climate Change and Biogenic SOA

Objective: Determine the effect of climate change on SOA

Approach for examining the effect of climate change on SOA:

GEOS-Chem (v.7-04-05)

full chemistry simulation



GISS GCM III meteorology

(1999-2001)


(2049-2051

AIB GHG driven climate)

Compare

predicted SOA

concentrations

(Anthropogenic emissions held constant)

SOA is represented using a

two (or one) product model:

Parameters obtained from laboratory experiments: i , K

OM,i

SOA Model

HC + Ox 1G1 + 2G2

A1 A2

Oi

i

iOM

MG

AK

][

][, =

=O

i

O

OiOMiOM

TTR

H

T

TTKTK

11exp)()( ,,

+=i

iOAPOAM ][][

[Chung and Seinfeld, 2002; Pankow, 1994]

SOA Precursors

(I) ALPH: -pinene, -pinene, sabinene, careen, terpenoid ketones(II) LIMO: limonene

(III) TERP: -terpinene, -terpinene, terpinolene(IV) ALCO: myrcene, terpenoid alcohols, ocimene

(V) SESQ: sesquiterpenes

(VI) ISOP: isoprene

Parent VOC categories treated by GEOS-Chem

Biogenic Emission Scheme

Emissions are potentially influenced by climate through temperatureand changes in light received at the surface

Monoterpenes (I-IV):

No light dependence

ORVOC (I, IV, V):

CL independent of climate

change

No T dependence

Isoprene (VI):

CL depends on column cloud

cover

E = EO CT CL

[Guenther et al., 1995]

Predicted Present Day SOA Concentrations

DJF MAM

JJA SON

Predicted Present Day SOA Concentrations:The U. S.

DJF MAM

JJA SON

The Effect of Temperature onBiogenic Emissions

Isoprene emissions increase 24%

Monoterpene emissions increase 20%

24%629505IsopreneISOP

0%1515ORVOCSESQ

5%4240Monoterpenes, ORVOCALCO

20%54MonoterpenesTERP

20%4034MonoterpenesLIMO

18%131111Monoterpenes, ORVOCALPH

Tg/yrTg/yr

PercentChange

FuturePresent

DayContributing EmissionsSOA Precursor

Category

Changes in SOA Surface Concentrations

• SOA concentrations increase near source regions

• Decreases in SOA are related to strong increases in precipitation

Changes in SOA as a Function of Altitude

• Warming at high altitude shifts the SOA equilibrium towards the gas phase

The Effect of Climate Change onSOA Global Burdens

Climate change does not significantly affect the global SOA burden

The burden decreases if biogenic emissions do not increase(SOA from sesquiterpenes)

319160.45future

317140.44present

(Tg/yr)(Tg/yr)(Tg/yr)(Tg)

dry

deposition

net

productionwet depositionburden

0.231.170.950.016future

0.231.210.980.020present

(Tg/yr)(Tg/yr)(Tg/yr)(Tg)

dry

deposition

net

productionwet depositionburden

Conclusions

• Higher temperatures in the future result in higherbiogenic emissions

• In general, surface SOA concentrations are elevatedin the future

• Concentrations of SOA in the upper troposphere aretypically lower in the future

• Despite changes in concentrations, the SOA globalburden remains constant with 2000—2050 climatechange

ISORROPIAII forInorganic Aerosols

Inorganic Aerosols

DMS gas

phase

chemistry

SO2 Chemistry

SO42-

Aerosol Phase in Thermodynamic Equilibrium

DMS emission

SO4 emission

SO2 emission

NH4+

water

NH3

NH3 emission

NO3-

HNO3

Na+ Cl-

Ca2+

Mg2+K+

NOX

chemistry

NOX emission

Seasalt

emission

Nitrate Aerosol Predictions

CASTNET

GEOS-Chem with ISORROPIAII GEOS-Chem with ISORROPIA1.3

CA

ST

NE

T fig

ure

sourc

e: U

S E

PA

Seasonal Nitrate ConcentrationsGEOS-Chem with ISORROPIAII GEOS-Chem with ISORROPIA1.3

JAN

APR

JULY

OCT

Seasonal NIT Comparison to Observations

DJF MAM JJA SON

Units: ug/m3

Annual

Predictions

CASTNET IMPROVE

Ammonium Aerosol Predictions

CASTNET

GEOS-Chem with ISORROPIAII GEOS-Chem with ISORROPIA1.3

CA

ST

NE

T fig

ure

sourc

e: U

S E

PA

Seasonal Ammonium ConcentrationsGEOS-Chem with ISORROPIAII GEOS-Chem with ISORROPIA1.3

JAN

APR

JULY

OCT

Seasonal NH4+ Comparison to Observations

DJF MAM JJA SON

Units: ug/m3

Annual

Predictions

Climate Change and Inorganic Aerosols(preliminary)

Objective: Determine the effect of climate change (T, RH,precipitation, etc.) on inorganic aerosols

Approach for examining the effect of climate change:



with ISORROPIAII



with ISORROPIAII


(2000)


(2050

AIB GHG driven climate)

Compare

predicted

concentrations

(Anthropogenic emissions held constant)

Changes in Natural Emissions

4.0%5574.55359.8Seasalt (Tg)

2.0%16.115.7DMS (Tg S)

16.0%10.59.0lightning NOX (Tg N)

7.0%7.06.5soil NOX (Tg N)

ChangeFuturePresent DaySpecies

47.9

66.0

1.4

58.6

NOX

SO2

SO4

NH3

Year 2000 Emissions

(all sources)

Tg N

Tg S

Tg S

Tg N

Changes in Sulfate

• No significant change in sulfate global burden (~0.85 Tg)

• MAM, JJA, SON surface concentration changes reflect changes in precipitation

• Jan concentration changes suggest an influence other than precipitation

MAMJan

JJA SON

Changes in Nitrate Concentrations

• Jan surface concentrations follow Temperature change trend (higher T=lower NIT)

• Precipitation plays a more minor role in controlling NIT concentrations

• ISORROPIA II predicts minor (<~0.08 μg/m3) evaporation of Nitrate (RPMARES does not

show the same trend) at higher altitudes (10-15 km)

MAMJan

JJA SON

Changes in Ammonium Concentrations

• Change in Ammonium concentrations follow changes in SO4 and NIT

• SO4 more strongly influences ammonium than nitrate in JJA and SON

MAMJan

JJA SON

Conclusions

• GHG driven climate change alone can cause significant changesin aerosol concentrations

• For biogenic SOA, temperature is the most important parameteris determining how concentrations will change with climate

• ISORROPIAII should provide a good representation of NH4+ and

NO3- in GEOS-Chem

• For inorganic aerosols, temperature and precipitation influencesurface concentrations across the United States

• Finalize ISORROPIAII

• Examine the effect of changes in anthropogenic emissions onaerosols

• Include SOA from aromatics in the climate change simulations

Future Work

Acknowledgements This material is based upon work supported under a

National Science Foundation Graduate ResearchFellowship. Support from EPA is also appreciated.

References:

• Chung, S. H. and J. H. Seinfeld (2002), Global distribution and climateforcing of carbonaceous aerosols, J. Geophys. Res., 107, D19, 4407.

• Guenther, A., et al. (1995), A global model of natural volatile organiccompound emissions, J. Geophys. Res., 100, D5, 8873-8892.

• Pankow, J. F. (1994), An absorption model of gas/particle partitioning oforganic compounds in the atmosphere, Atmos. Environ., 28, 185-188.

• Wu, S., L. J. Mickley, D. J. Jacob, D. Rind, and D. G. Streets (2007), Effectof 2000-2050 global change on ozone air quality in the United States, inpreparation .

• Liao, H., et al. (2006), Role of climate change in global predictions of futuretropospheric ozone and aerosols, J. Geophys. Res., 111(D12).

• Liao, H., et al. (2007), Biogenic secondary organic aerosol over the UnitedStates: Comparison of climatological simulations with observations, J.Geophys. Res., 112(D6).

• Fountoukis, C., and A. Nenes (2007), ISORROPIA II: a computationallyefficient thermodynamic equilibrium model for K+-Ca2+-Mg2+-NH4+-Na+-SO42--NO3--Cl--H2O aerosols, Atmos. Chem. Phys. Discuss., 7.

ISORROPIAII

ISORROPIA

V.II

RH

T

Deliquescence

behavior (metastable

vs. stable)

Total (NH3 + NH4+)

Total (HNO3 + NIT)

Total SO42-

Na and Cl from

Seasalt

K, Mg, Ca from

Seasalt/dust

NH3

NH4+

HNO3

NIT

(SO42-)

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