TESTING GLOBAL MODELS OF INTERCONTINENTAL POLLUTION TRANSPORT USING AIRCRAFT AND SATELLITE OBSERVATIONS Daniel J. Jacob with Mathew J. Evans, T. Duncan Fairlie, Rynda C. Hudman, Colette L. Heald, Qinbin Li, Randall V. Martin, Paul I. Palmer, Rokjin J. Park, Yaping Xiao

INTERCONTINENTAL TRANSPORT, HEMISPHERIC POLLUTION Tropopause HEMISPHERIC POLLUTION BACKGROUND Mixing Free troposphere “Direct” intercontinental transport PBL boundary layer advection WCB subsidence Asia N. America Europe

Present-day ozone background at northern midlatitudes HEMISPHERIC OZONE POLLUTION: IMPLICATIONS OF ENHANCED BACKGROUND FOR MEETING AIR QUALITY STANDARDS (AQS) Europe AQS (8-h avg.) Europe AQS (seasonal) U.S. AQS (8-h avg.) U.S. AQS (1-h avg.) 0 20 40 60 80 100 120 ppbv Preindustrial ozone background Present-day ozone background at northern midlatitudes

FOR OZONE, HEMISPHERIC ENHANCEMENT OF BACKGROUND IS A GREATER ISSUE THAN INTERCONTINENTAL TRANSPORT EVENTS Model vs. observed stats, 1993-1997 Ozone at Mace Head (Ireland), Mar-Aug 1997 Observed [Simmonds] GEOS-CHEM model N.America pollution events in model Li et al. [2002]

Asian dust in western U.S. Asian dust in southeastern U.S. …FOR AEROSOLS IT IS PROBABLY THE OPPOSITE Dust observations from U.S. IMPROVE network April 16, 2001 Asian dust in western U.S. April 22, 2001 Asian dust in southeastern U.S. 0 2 4 6 8 mg m-3 Glen Canyon, AZ April 16, 2001: Asian dust! Clear day

TRANSPACIFIC TRANSPORT OF ASIAN DUST PLUMES GEOS-CHEM Longitude cross-section at 40N, 16 April, 2001 LONGITUDE ALTITUDE (km) 100E 150E 150W 100W Source region (inner Asia) Subsidence over western U.S. Asian plumes over Pacific 10 5 ASIA UNITED STATES T.D. Fairlie, Harvard

CONTRIBUTION OF ASIAN SOURCES TO CARBONACEOUS AEROSOLS IN NORTH AMERICA IS NEGLIGIBLE Annual means, GEOS-CHEM simulation (1998) Standard (OC+EC) Asian sources only Model simulation of 1998 observations from U.S. IMPROVE network OC EC model R.J. Park, Harvard observations observations

TRACE-P AIRCRAFT MISSION (March-April 2001) CO observations from G.W. Sachse Daily CO biomass burning emissions from AVHRR (C.L. Heald, Harvard) CO fossil and biofuel emissions (D.R. Streets, ANL)

USING TRACE-P DATA TO CONSTRAIN ASIAN CO EMISSIONS Bottom-up (a priori): Asian anthropogenic emissions from D.R. Streets Daily biomass burning emissions from AVHRR (C.L. Heald, Harvard) Other sources from J.A. Logan TRACE-P observations GEOS-CHEM with a priori emissions Inverse model analysis indicates that Chinese anthropogenic emissions are 30% too low (P.I. Palmer, Harvard)

NOy:CO RELATIONSHIP IN ASIAN OUTFLOW IN TRACE-P: Quantifying anthropogenic and biomass burning NOx emissions Conclusion: bottom-up Asian NOx emission is correct within 50% Fossil Biomass > 30oN Fossil fuel dominates < 30oN Biomass burning dominates M.J. Evans, Harvard

NOy SPECIATION IN ASIAN OUTFLOW DURING TRACE-P M. J. Evans, Harvard NOx/NOy PAN/NOy (HNO3 + NO3-)/NOy Observed Model

GEOS-CHEM vs. observed CH4: a priori Asian CH4 source too high by 25% TESTING a priori ASIAN METHANE SOURCE ESTIMATES WITH TRACE-P CORRELATIONS FOR CH4-C2H6-CO Y. Xiao, Harvard GEOS-CHEM vs. observed CH4: a priori Asian CH4 source too high by 25% GEOS-CHEM vs. observed C2H6/CH4: Coal mining CH4source likely too high

TRANSPACIFIC TRANSPORT OF ASIAN CO AND OZONE IN TRACE-P: Feb 26-27, 2001 PLUME MOPITT 500 hPa CO, Feb 26 2 1 3 2 3 4 5 CO Ozone 4 5 TRACE-P profiles, Feb 26-27 C.L. Heald, Harvard

MODEL ANALYSIS OF TRACE-P TRANSPACIFIC POLLUTION PLUME (GEOS-CHEM CO SIMULATION) Feb 23, 0 GMT: warm conveyor belt lifts CO over China 6-8 km Feb 26, 0 GMT: Plume encounters blocking H over central Pacific, splits 6-8 km Feb 26, 12 GMT: N branch of plume transported to N America, sampled by TRACE-P 6-8 km Feb 27, 21 GMT: S branch of plume transported to tropics to die, sampled by TRACE-P 3-4 km C.L. Heald, Harvard

OZONE:CO RELATIONSHIPS IN TRANSPACIFIC POLLUTION PLUMES Data from MOPITT underpass profiles TRACE-P aircraft GEOS-CHEM High ozone production efficiency in low-latitude Asian plume, but U.S.-bound plume has little ozone production N plume (40 N) S plume (18 N) C.L. Heald, Harvard

SURFACE OZONE ENHANCEMENT FROM ASIAN EMISSIONS DURING TRACE-P PERIOD (GEOS-CHEM) Anthropogenic Biomass burning The Asian anthropogenic source contributes significantly to surface ozone in the western U.S. (mean 2-4 ppbv), while the influence from Asian biomass burning source emissions is negligible. M.J. Evans, Harvard

Surface data at Trinidad Head, Apr-May 2002 ASIAN POLLUTION ENHANCEMENTS OF OZONE AND CO AT CALIFORNIA COASTAL SITE DURING ITCT-2K2 Surface data at Trinidad Head, Apr-May 2002 Apr 17 May 17 Observations (A.H. Goldstein) GEOS-CHEM Asian pollution enhancement in GEOS-CHEM Ozone CO R.C.Hudman, Harvard Maximum observed ozone correlates with Asian influence in model

GEOS-CHEM Tropospheric NO2 GOME Tropospheric NO2 GEOS-CHEM Tropospheric NO2 r = 0.75 bias=5% DJF MAM JJA R.V. Martin, Harvard SON 1015 molecules cm-2

CAN WE USE SATELLITES FOR GLOBAL MAPPING OF EMISSIONS CAN WE USE SATELLITES FOR GLOBAL MAPPING OF EMISSIONS? NO2 TROPOSPHERIC COLUMNS FROM GOME R.V. Martin, Harvard GOME NO2 GEOS-CHEM JUN 96 JUL 96 AUG 96 r = 0.79 bias = -19% 1015 molec cm-2

TAKING THE LEAP: GLOBAL NOx EMISSIONS FROM GOME ENOx, GOME = ENOx, GEOS-CHEM (WNO2, GOME/WNO2, GEOS-CHEM) Tg N yr-1 36.6 37.3 R.V. Martin, Harvard

INTERCONTINENTAL TRANSPORT EXPERIMENT – NORTH AMERICA (INTEX) A NASA Global Tropospheric Chemistry Program aircraft mission OBJECTIVES: (1) To quantify the outflow of climatically important trace gases and aerosols (CIGAs) from North America to the Atlantic, and relate this outflow to our understanding of North American sources and sinks; (2) To understand the chemical evolution of the North American outflow over the Atlantic, and assess the implications for global influence and intercontinental transport of pollution; (3) To quantify the transpacific transport of Asian pollution to North America.and its implications for surface air quality. TWO AIRCRAFT: NASA DC-8 and P-3B TWO PHASES: A (Jun-Jul 2004) and B (Mar-Apr 2006)