1. U.S. AIRCRAFT CAMPAIGNS Daniel J. Jacob

2. OBSERVATION PLATFORMS FOR ATMOSPHERIC COMPOSITION SURFACE SITES, SHIPS SONDES, LIDARS AIRCRAFTSATELLITES Horizontal coverage --++ Temporal coverage ++-+ Vertical range -+= (up to ~20 km) = (interferences) Vertical resolution none ++- Chemical detail +-+- Surface fluxes +-++ (by inversion) Cost ++=-

3. AIRCRAFT FLIGHT STRATEGIES Characterization of emissions, surface uptake Process studies: photochemistry plume evolution transport mechanisms Satellite validation Air mass characterization global and regional chemical budgets long-range transport Remote sensing: mapping of surface, atmosphere satellite validation

4. NASA GTE TROPOSPHERIC CHEMISTRY MISSIONS Other important global tropospheric missions: NASA/SONEX (North Atlantic), NSF/TOPSE (Arctic), NSF/ACE (Atlantic, Pacific), NOAA/ITCT-2K2 (E. Pacific)…

5. outbound inbound THE NASA/TRACE-P AIRCRAFT MISSION (Mar—Apr 2001) Characterize Asian chemical outflow and evolution; place top-down constraints on sources Two instrumented aircraft (DC-8 and P-3) operating out of Hong Kong and Yokota AFB (Japan)

6. THE NASA DC-8 “Flying Laboratory”

7. NASA DC-8 – the inside

8. TRACE-P DC-8 PAYLOAD Emphasis: high altitude outflow, large-scale mapping, photochemistry PAN, carbonyls, alcohols aerosols NO, NO 2 OH, HO 2 Actinic fluxes Carbonyls, alcohols O 3 +aerosol DIAL NMHCs, Halocarbons, DMS HCHO CO 2, O 3 Aerosols, SO 2, HNO 3 H 2 O, CO, CH 4, N 2 O H 2 O 2, CH 3 OOH, HCHO

9. TRACE-P P-3 PAYLOAD Emphasis: low altitude outflow, sulfur/aerosols, fluxes to ocean Aerosols H2OH2O NO, NO 2 NMHCs, Halocarbons, DMS SO 2, DMS PAN, PPN Actinic fluxes CO, CH 4 Vertical winds O 3, CO 2 aerosols H 2 SO 4, MSA, OH, HNO 3, HO 2, RO 2

10. TRACE-P INVOLVED THE INTEGRATION OF AIRCRAFT, SATELLITES, MODELS, AND EMISSION INVENTORIES TRACE-P CO DATA (G.W. Sachse) Bottom-up emissions (customized for TRACE-P) Fossil and biofuel Daily biomass burning (satellite fire counts) Chemical Transport Model (CTM) MOPITT CO Inverse analysis validation chemical forecasts top-down constraints OPTIMIZATION OF SOURCES Example: improving constraints on Asian CO sources Streets et al. [2003] Heald et al. [2003a]

11. MOPITT VALIDATION DURING TRACE-P Seven DC-8 vertical profiles (0.15-10 km) coincident with MOPITT overpass Spirals of 20 km diam. matching MOPITT FOV Double spirals to verify stationarity of features One DC-8 transect along orbit track Example (March 20) TRACE-P validation spirals + transect MOPITT underpass

12. MOPITT VALIDATION PROFILES DURING TRACE-P Aircraft Aircraft w/ av. kernels MOPITT (v3,  x = ±100 km) Averaging kernels

13. TRACE-P VALIDATION PROFILES: MOPITT vs. DC-8 CO columns DC-8 w/avKer r 2 > 0.99 DC-8 950-300 hPa r 2 =0.98 CO column, 10 18 molecules cm -2 MOPITT2.25 ± 0.19 DC-8 w/avKer 2.12 ± 0.23 DC-8 950-300 hPa 1.58 ± 0.19 6% positive bias in MOPITT column data Jacob et al. [2003]

14. COMPARATIVE INVERSE ANALYSIS OF ASIAN CO SOURCES USING DAILY MOPITT AND TRACE-P DATA MOPITT and TRACE-P both show underestimate of anthropogenic emissions (40% for China, likely due to under-reporting of industrial coal use) MOPITT and TRACE-P both show overestimate of biomass burning emissions in southeast Asia ;very low values from TRACE-P could reflect transport bias MOPITT has higher information content than TRACE-P because it observes source regions and Indian outflow MOPITT information degrades if data are averaged weekly or monthly Ensemble modeling of MOPITT data indicates 10-40% uncertainty on retrieved sources Heald et al. [2004] CO observations from Spring 2001, GEOS-CHEM CTM as forward model TRACE-P Aircraft COMOPITT CO Columns 4 degrees of freedom 10 degrees of freedom (from validation)

15. ASIAN HALOCARBON EMISSIONS (CH 3 CCl 3, CCl 4, Halon 1211, CFCs) DEDUCED FROM TRACE-P DATA CH 3 CCl 3 CCl 4 TRACE-P PBL halocarbon observations Back-trajectories for top 5% of CH 3 CCl 3 PBL data; Seoul and Shangai are principal sources Halocarbon emissions deduced from relationships with CO Eastern Asian source of CCl 4 deduced from TRACE-P data is 5 times higher than UNEP estimate; other halocarbons are consistent with UNEP Correction to CCl 4 emission implies a 40% increase in total ODP-equivalent emissions from eastern Asia Palmer et al. [2003]

16. TRANSPACIFIC TRANSPORT OF ASIAN CO AND OZONE IN TRACE-P: Feb 26-27, 2001 PLUME MOPITT 500 hPa CO, Feb 26 TRACE-P profiles, Feb 26-27 CO Ozone 1 1 2 2 3 3 4 5 4 5 Heald et al. [2003b] OzoneCO Aircraft track Asian plume

17. NOAA/ITCT-2K2 AIRCRAFT CAMPAIGN IN APRIL-MAY 2002 Monterey, CA High-ozone Asian pollution plumes observed in lower free troposphere but not at surface (Trinidad Head); strong stratospheric influence (Trinidad Head sondes) CO O3O3 PAN HNO 3 May 5 plume at 6 km: High CO and PAN, no O 3 enhancement May 17 subsiding plume at 2.5 km: High CO and O 3, PAN  NO x  HNO 3 Hudman et al. [2004] Observations by D. Parrish, J. Roberts, T. Ryesrson (NOAA/AL)

18. DIURNAL AND CONVECTIVE INFLUENCES ON HO x RADICALS OVER PACIFIC PEM-Tropics B DC-8 flight NW of Tahiti on April 7, 1999 Fly back-and forth “shoelace” pattern for 4 hours Background: 12% RH 80 ppt H 2 O 2 60 ppt CH 3 OOH Conv. influence: 35% RH 80 ppt H 2 O 2 290 ppt CH 3 OOH Observations (W. Brune) Photochemical model Model with k(CH 3 O 2 +HO 2 ) x3 + HO x at sunrise behaves as expected; strong HO x source from photolysis of convected CH 3 OOH; need additional HO x sink to match observations Ravetta et al. [2002]

19. ICARTT: COORDINATED ATMOSPHERIC CHEMISTRY CAMPAIGN OVER EASTERN NORTH AMERICA AND NORTH ATLANTIC IN SUMMER 2004 International, multi-agency (U.S.) collaboration targeted at U.S. regional air quality, pollution outflow, transatlantic transport, aerosol radiative forcing Terra ERS MISR, MODIS, MOPITT ERS-2 GOME Envisat SCIAMACHY Aqua AIRS, MODIS NASA DC-8 UK BAE-143 DLR Falcon NOAA-P3 DOE G-1 NASA Proteus

20. NRT O3O3 HNO 3 CH 2 O CO HIGH FREE TROPOSPHERIC OZONE OVER SE U.S. OBSERVED IN ICARTT July 12 DC-8 flight from St. Louis High ozone appears tropospheric in origin

21. PREDICTED UPPER TROPOSPHERIC OZONE MAXIMUM OVER MIDDLE EAST IN SUMMER: HOW TO TEST? GEOS-CHEM tropospheric ozone column, July 1997 Comparison to MOZAIC observations aboard commercial aircraft, 1995-2000 Jul (red), Jan (blue), model (solid), obs (dotted) Li et al. [2001]

22. FUTURE TROPOSPHERIC CHEMISTRY MISSIONS: INSTRUMENT NEEDS Fast instrumentation for NH 3, bulk aerosol composition including organics Improved precision/accuracy for HO x radical measurements, capability for CH 3 O 2 measurements Improved confidence in measurements of SO 2, bulk aerosol composition, aldehydes, peroxides CO lidar

23. THE FUTURE OF U.S. AIRCRAFT MISSIONS DC-8 to remain an important platform in near future: NASA INTEX-B in spring 2006 Probing the upper troposphere/lower stratosphere using aircraft with 18- 20 km ceilings and tropospheric measurement capability: NSF HIAPER, NASA WB-57 Routine and cheap vertical profiling using small aircraft (e.g., Cessna) Air sampling packages on commercial aircraft (European MOZAIC program has been a big success) Global monitoring using remotely piloted vehicles (RPVs)

24. RPV Capability Development Timeline HALE-ROA Capability Set 14 days @ 60-70K ft 400-lb Payload Autonomous Operations 10-Year Capability Set 100 days @ 75K ft 1000-lb Payload Autonomous Operations Collaborative Engagement Full Capability Set Heavy Lift 100 days @ > 60K ft Autonomous Operations Collaborative Engagement Current SOA: 60K ft @ 14 hrs - 200-lb 100K ft @ 1 hrs - 100-lb Pre-Programmed Required Technologies @ TRL 6 FY09FY14FY19 Current timeline