INTERCONTINENTAL TRANSPORT EXPERIMENT NORTH AMERICA (INTEX-NA)

To quantify the North American import and export of (1) atmospheric oxidants and their precursors, (2) aerosols and their precursors, (3) long-lived greenhouse gasesTo relate this import/export to surface sources/sinks and to continental boundary layer chemistry

OBJECTIVES:TWO PHASES:Summer 2004:active photochemistry, biosphereaerosol radiative forcingcarbon uptakeSpring 2006:maximum Asian inflowcontrast with summerTWO AIRCRAFT: NASA DC-8 and P-3Revised white paper, Nov 2001 (H.B. Singh, D.J. Jacob, L. Pfister)

INTEGRATION OF AIRCRAFT OBSERVATIONS WITH SATELLITE DATA AND MODEL INFORMATIONIS CRITICAL TO THE OBJECTIVES OF INTEX-NA3-D CHEMICAL TRACER MODELSU.S IMPORT/EXPORTSATELLITE OBSERVATIONSGlobal and continuous but few species, low resolutionAIRCRAFT OBSERVATIONSHigh resolution, targeted flightsprovide snapshots with optimized informationSURFACE OBSERVATIONShigh resolution but spatially limitedSource/sinkinventoriesAssimilated meteorological dataChemical and aerosolprocesses

TRACE-P EXECUTIONEmissionsFossil fuelBiomass burningBiosphere, dustLong-range transport fromEurope, N. America, AfricaASIAPACIFICP-3Satellite datain near-real time:MOPITTTOMSSEAWIFSAVHRRLISDC-83D chemical model forecasts: - ECHAM - GEOS-CHEM - Iowa/Kyushu - Meso-NH -LaRC/U. WisconsinFLIGHTPLANNINGBoundary layerchemical/aerosolprocessingASIANOUTFLOWStratosphericintrusionsPACIFIC

TRACE-P DC-8 PAYLOADEmphasis:high altitude outflow,large-scale mapping,photochemistryPAN, carbonyls, alcohols, cyanidesaerosolsNO, NO2OH, HO2ActinicfluxesCarbonyls, alcoholsO3+aerosolDIALNMHCs,Halocarbons,DMSHCHOCO2, O3Aerosols, SO2, HNO3H2O, CO, CH4,N2OH2O2, CH3OOH, HCHO

TRACE-P P-3 PAYLOADEmphasis:low altitude outflow,sulfur/aerosols,fluxes to oceanAerosolsH2ONO, NO2NMHCs,Halocarbons,DMSSO2, DMSPAN, PPNActinic fluxesCO, CH4Vertical windsO3, CO2aerosolsH2SO4, MSA,OH, HNO3,HO2, RO2

INTEX-NA HAS LINKAGES WITH A NUMBER OF ATMOSPHERIC PROGRAMSIn situNorth American Carbon Program (2002-)NOAA Northeast U.S. Study (2004)European UT/LS program (-2005)Asian APARE program (ongoing)SatellitesTerra [MOPITT] (1999-)Envisat [SCIAMACHY, MIPAS] (2002-)NMP/GIFTS (2003-)Aura [TES, OMI, HRDLS, TES] (2004-)ESSP/OCO (2004-)ModelingEPA OAQPS/ORD climate change/air quality initiative (2001-2010)

INTEX-NA FLIGHT TYPESN American outflow to Atlantic (DC-8, P-3)Follow TRACE-P modelN American inflow from Pacific (DC-8)Curtains parallel to coastTranscontinental flights (DC-8)Curtains to define transcontinental gradients, inflow/outflow pathwaysContinental boundary layer mapping (P-3)Relate gradients to sources, processingContinental boundary layer free troposphere exchange (P-3, DC-8)Determine outflow mechanisms, fluxesSatellite validation (DC-8)Expand on TRACE-P model

SATELLITE VALIDATION DURING TRACE-P (MOPITT) MOPITT validation spirals in TRACE-PMOPITT validation transect (following orbit track) MOPITT orbit track was an important factor in day-to-day flight planning;~50% of flights had good opportunities for validationorbit track, timing, clouds had to be consistent with science goals large orbit swath, similarity of pixel w/ DC-8 spiral radius was an advantage Large range of vertical structures were sampledthis is easily achieved in a GTE-type mission Unavoidable time mismatch between satellite and aircraft was shown to be a non-issue- tropospheric structures are persistent on scales < 1 hour

MOPITT validation:40N, 132W0226 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)

DC-8 CO data(Sachse)MOPITT validation18N, 175W0227 at 2245Z; spiral at time of satellite overpass. Scattered cumulus deck with tops at 6Kft, otherwise clear sky. Layer at 2-4 km is aged Asian pollution subsiding around high pressure over W Pacific

DC-8 CO data(Sachse) MOPITT validation at 20N, 123E

0317 at 0240Z; double spiral at timeof satellite overpass, in clear sky. Tropical air in FT, river of pollution(cf. PEMTB) in lower troposphere

SATELLITE VALIDATION DURING INTEX-NA WILL BE MORE COMPLEX AND REQUIRE MORE HOURS6-8 under-flights/Phase( 3-4 hrs) More satellite instruments with different fields of view, limb+nadir sounding

Two spirals along orbit track joined by high-altitude transect may provide the right model INTEX-NA should be part of a satellite validation strategy but it cant do it all

Tropopause

100 km

D. Example satellite under-flight pattern for the DC-8

DRRLBGBRAZWLDC-8P-3BHINOOzonesonde sitesINTEX NOMINAL FLIGHT TRACKS FOR PHASE A (SUMMER)

DRSTRLBGBRAZWLDC-8P3-BHI`

WHY DOES INTEX-NA NEED TO GO IN 2004?To maintain the momentum of GTE,a key program in tropospheric chemistry researchWho says we need a mission every three years?This interval (2001-2004) is already longer than it has ever been for GTE. Such a delay is justified to exploit the richness of the TRACE-P data set and to set aside time for instrument development and intercomparison, but a longer delay would break GTE momentum.What about the money?INTEX per se is not the issue deployment is a small fraction of the cost of the NASA tropospheric chemistry program, and deployment in the U.S. will be relatively inexpensive.What about Aura validation needs?They can be addressed in INTEX-NA (B). INTEX-NA (A) will meet other satellite validation needs. What about linkages with other aircraft programs?NOAA/Northeast will take place in 2004. Timelines of other programs are not well defined at this stage and will depend in part on INTEX timing

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