GEOS-CHEM GLOBAL 3-D MODEL OF TROPOSPHERIC CHEMISTRY

• Assimilated NASA/DAO meteorological observations for 1988-2001

• 1ox1o to 4ox5o horizontal resolution, 20-48 vertical layers

• Applied to simulations of O3, aerosols, precursors, other species in different regions of the world

• 120 chemical species to describe tropospheric O3-NOx-hydrocarbon chemistry; aerosol effects on chemistry, radiation

MODEL ANALYSIS OF TRANSATLANTIC TRANSPORT OF OZONE AND PRECURSORS: 1993-1997

[Li et al., 2001]

MODEL EVALUATION WITH 1997 OZONESONDES

Bermuda,April

Keflavik,August

Sable Island,September

observations

model

MODEL EVALUATION WITH NARE 1997 AIRCRAFT DATA (NORTHWEST ATLANTIC)

Sep.13:cleanday

Sep.16:U.S.outflow

observations model

CO O3 NOy NO

MODEL EVALUATION WITH ACSOE 1997AIRCRAFT DATA (NORTHEAST ATLANTIC)

Clean day

Europeanoutflowday

CO O3

ORIGIN OF OZONE AT BERMUDA IN SPRING:production over U.S. is dominant source

ENHANCEMENTS OF SURFACE OZONE IN NORTH AMERICA AND EUROPE DUE TO ANTHROPOGENIC

EMISSIONS IN THE OTHER CONTINENT

N.American influenceon Europe

European influenceon N. America

GEOS-CHEM model results, July 1997

FUTURE RESEARCH NEEDS BETTER COUPLING OF 3-D MODELS AND OBSERVATIONS

3-D CHEMICAL TRANSPORT

MODELS

INTERCONTINENTAL TRANSPORT INTERCONTINENTAL TRANSPORT OF POLLUTIONOF POLLUTION

SATELLITE OBSERVATIONSGlobal and continuous but few species, low resolution

AIRCRAFT OBSERVATIONSHigh resolution, targeted flights

provide critical snapshots for model testing

SURFACE OBSERVATIONShigh resolution but spatially limited

Source/sinkinventories

Assimilated meteorological

data

Chemical and aerosolprocesses

TROPOSPHERIC NO2 FROM GOME (July 1996):mapping of NOx emissions [Martin et al., 2001]

Scattering AMF using local shape factors from the GEOS-CHEM model andaccounting for local cloud information (fraction, top, optical depth)

GEOS-CHEM global3-D model with GEIAinventory for NOx (scaled to 1996)

FORMALDEHYDE COLUMNS FROM GOME (July 1996):mapping of isoprene emissions [Palmer et al., 2001]

MOPITT validationduring TRACE-P:40N, 132W

0226 at 2005Z; double spiralbracketing in time the MOPITToverpass. Solid stratus deckwith tops at 3.5Kft, otherwiseclear sky. Layer at 4-7 km is agedAsian pollution.

DC-8 CO data(Sachse)

0 50 100 150 200 250 300CO (ppbv)

0

5000

10000

15000

20000

25000

30000

35000

AscentDescent

MOPITTobservationsof CO

CONVERGENCE OF SCALES FOR AIR QUALITY AND CLIMATE RESEARCH

AIR QUALITY RESEARCH

urban regional continental intercontinental global

CLIMATE RESEARCH

Let’s take advantage of synergistic opportunities!

• Quantify the export of radiatively and chemically

important trace gases and aerosols from North

America

• Relate these exports to surface sources and sinks

and to continental boundary layer chemistry

INTERCONTINENTAL TRANSPORT EXPERIMENT – NORTH AMERICA (INTEX-NA)

NASA/GTE two-aircraft mission for summer 2004based in Maine, California, Wisconsin

OBJECTIVES:

Coordinated with • North American Carbon Cycle (NACC)• NOAA regional pollution study in New England• European research programs (transatlantic transport)

INTEX MISSION DESIGN

P-3

DC-8

Outflow

PACIFIC ATLANTICNORTH AMERICA

Emissions/Deposition

Inflow

3-D chemical models:forecasts/analyses

DC-8

Satellite datafor gases/aerosols(near real-time)

Surfacesites