1. An Overview of the TRACE-P Experiment

2. NASA/GTE MISSIONS, 1983-2001

3. TRAnsport and Chemical Evolution over the Pacific (TRACE-P) A two-aircraft GTE mission over the western Pacific in February-April 2001 MISSION OBJECTIVES to determine the chemical composition of the Asian outflow over the western Pacific in spring in order to understand and quantify the export of chemically and radiatively important gases and aerosols, and their precursors, from the Asian continent. to determine the chemical evolution of the Asian outflow over the western Pacific in spring and to understand the ensemble of processes that control this evolution.

4. WHY TRACE-P? Energy use in eastern Asia is expected to grow by 5% yr -1 until at least 2015: global implications for greenhouse gases, aerosols, OH, air quality –We need to observe the time-dependent impact on atmospheric composition. Little is known of the emissions, export, and chemical aging of pollution from eastern Asia –Features of Asian outflow include active photochemistry (low latitudes), heterogeneous chemistry (dust, sulfur), complex aerosol microphysics, stratospheric and European/American pollution influences, seasonal biomass burning. Need to build on previous knowledge acquired in PEM missions –PEM missions were exploratory; focus of TRACE-P is on quantifying Asian outflow in relation to emissions and fluxes.

5. CHINESE EMISSIONS ARE GROWING – OR ARE THEY ?? Latest report from China to Energy Information Administration claims a decrease of emissions after 1997! Verification of emission estimates through atmospheric observations is critical for development of international environmental policy

6. QUANTIFYING CHEMICAL EXPORT FLUXES FROM LARGE GEOPOLITICAL SOURCE REGIONS 3-D CHEMICAL TRACER MODELS EXPORT FLUXES SATELLITE OBSERVATIONS Global and continuous but few species, low resolution AIRCRAFT OBSERVATIONS High resolution, targeted flights but limited in time; critical snapshots for model testing SURFACE OBSERVATIONS high resolution but spatially limited Source/sink inventories Assimilated meteorological data Chemical and aerosol processes

7. TRACE-P EXECUTION Emissions -Fossil fuel -Biomass burning -Biosphere, dust Long-range transport from Europe, N. America, Africa ASIA PACIFIC P-3 Satellite data in near-real time: MOPITT TOMS SEAWIFS AVHRR LIS DC-8 3D chemical model forecasts: - ECHAM - GEOS-CHEM - Iowa/Kyushu - Meso-NH -LaRC/U. Wisconsin FLIGHT PLANNING Boundary layer chemical/aerosol processing ASIAN OUTFLOW Stratospheric intrusions PACIFIC

8. INTEGRATION OF SATELLITE DATA AND CTMs INTO TRACE-P PLANNING AND EXECUTION PRE-MISSION EMISSION INVENTORY DEVELOPMENT: provide the best a priori information for mission planning. PRE-MISSION WORKSHOP (coordinated with ACE-Asia): use analyses of satellite data, 3D CTMs for spring 1994 and 2000 to identify major outflow patterns and develop menu of flights. SUPPORT DURING MISSION EXECUTION: use near-real- time satellite data and CTM forecasts (in addition to meteorological forecasts) for day-to-day flight planning

9. CO Emissions (Fossil & Biofuel) Source: D. Streets, Argonne National Lab EMISSION INVENTORIES PREPARED FOR TRACE-P PERIOD PROVIDED A PRIORI INFORMATION FOR CHEMICAL FORECASTS

10. March 4 March 7 March 13 Near-real-time AVHRR fire count data were critical for TRACE-P flight planning Source: G.R. Carmichael, U. Iowa

11. TOMS observations of absorbing aerosols (March 8, 2001) Biomass burning plume Biomass burning Dust plume K.E. Pickering A.M. Thompson NASA/GSFC

12. K.E. Pickering, U. Maryland; A.M. Thompson, NASA/GSFC TOMS aerosol forecast for March 10

13. TRACE-P DC-8 PAYLOAD Emphasis: high altitude, large-scale mapping, photochemistry

14. TRACE-P P-3 PAYLOAD Emphasis: low altitude, sulfur/aerosols, fluxes to ocean

15. INTERCOMPARISON FLIGHTS BETWEEN THE NASA DC-8 AND P-3B Sampling runs were conducted on 3 occasions (Guam, Japan, and Hawaii) resulting in a total of 2.5 hours of proximity flight. Level flight legs were conducted at altitudes of 500, 1000, 10000, and 18000 and 19000 feet Soundings were conducted between 500-10000 and 1000-18000 feet

17. TRACE-P COORDINATION WITH ACE-ASIA Two joint Asian outflow chemical characterization flights between the TRACE-P P-3 and the ACE-Asia C-130 out of Japan including a Terra underpass on each flight. One DIAL overpass of the ACE-Asia Twin Otter by the TRACE-P DC-8 during a column radiation closure experiment over the Sea of Japan

18. MOPITT near-real time data for CO columns and validation experiments during TRACE-P Source: J.C. Gille, NCAR MOPITT validation spirals MOPITT validation transect (following orbit track)

19. MOPITT validation: 40N, 132W 0226 at 2005Z; double spiral bracketing in time the MOPITT overpass. Solid stratus deck with tops at 3.5Kft, otherwise clear sky. Layer at 4-7 km is aged Asian pollution.

20. MOPITT Validation Profiles during TRACE-P Courtesy: Louisa Emmons (NCAR) BLACK=AIRCRAFT RED=AIRCRAFTxAVG KERNELS BLUE=MOPITT V2 Retrieval: ~20% bias V3 Retrieval: Better agreement V3 Changes: Calibration Recovered data (40%) Clouds from MODIS New a priori

21. NASA Aircraft Flight Tracks During the TRACE-P Mission

22. Flight Tracks Along the Asian Pacific Rim During the TRACE-P Mission

23. Frontal outflow of biomass burning plumes E of Hong Kong P-3 Hong Kong local 2, March 9 (two days later) Observed CO (G.W. Sachse, NASA/LaRC ) Observed aerosol potassium (R. Weber, Georgia Tech) Biomass burning CO and total CO forecast (G.R. Carmichael & I. Uno-U. Iowa/Kyushu) P-3

24. CO and C 2 Cl 4 Distributions Measured in TRACE-P (G.W. Sachse, NASA/LaRC) (D. Blake, UC-Irvine)

25. Forecast vs. observed CO: DC-8 Hong Kong local 1, March 7 Observed (G.W. Sachse, NASA/LaRC) GEOS-CHEM forecast (D.J. Jacob, Harvard)

26. Mixing of biomass burning pollution with industrial pollution in FRONTAL OUTFLOW, TRACE-P DC-8 flight #7 (March 7, 2001)

27. Warm Conveyor Belt Transport of Asian Emissions Biomass Burning CO Anthropogenic CO H. Liu, HarvardR. Pierce, NASA Langley

28. Q1: Are our present estimates of Asian CO sources consistent with concentrations of CO measured during TRACE-P? (Use forward model approach: GEOS-CHEM model) Inverse model P3B, DC8 observations CO Emissions Q2: To what extent can TRACE-P aircraft observations of CO constrain specific Asian sources of CO? (Use inverse model approach: optimal estimation model) Forward model (Assume linear processes) (P. Palmer, Harvard)

29. Forward Model: GEOS-CHEM A priori emissions Global CO emissions (FF, BF, BB) from J. Logan + TRACE-P specific Asian emissions (FF, BF) from D. Streets. Uncertainties assumed 50% (anth), 25% (chem) GEOS-CHEMObservations 1943 FF+BF BB 0 – 2 km2 - 4 km

30. A posteriori emissions – % Change GEOS-CHEMObservations Inverse Model Results FF+BF BB 0 – 2 km2 - 4 km FF+BF results are robust; BB results are tentative

31. Fourteen day overlap. Average TRACE-P sampling about 20 days later than PEM-West B Temporal and Latitudinal Sampling Overlap >25°N <25°N

32. N. Blake, UC-Irvine

36. Ozone in the troposphere at four locations in the western Pacific Tsukuba (36N)Kagoshima (32N) Naha (26N)Hong Kong (23 N) S. Oltmans, NOAA CMDL

37. PRELIMINARY CONCLUSIONS FROM TRACE-P Cold fronts are the major mechanism for outflow from Asia to the Pacific in spring. Biomass burning is a major component of Asian outflow in spring. Current estimates of anthropogenic emissions in East Asia appear to be too low. Comparison with PEM-West B (1994) suggests that emissions are not significantly higher during TRACE-P (2001).