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ITCT 2K2 Field Study (Intercontinental Transport and Chemical Transformation) ITCT 2K2 Introduction Today (briefly): Examine a major Asian emission transport event to demonstrate utility of data set. Is there a temporal trend in springtime tropospheric ozone in the Eastern Pacific? http://www.al.noaa.gov/WWWHD/pubdocs/ITCT/2k2/ David Parrish, NOAA Aeronomy Laboratory & ITCT 2K2 Science Team

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13 Flights of NOAA WP-3D April 22 - May 19 Goal: Characterize chemical composition of the air masses coming ashore, focus on ozone and aerosols. ITCT 2K2 Field Study Spring 2002 West Coast of North America Trinidad Head Ground Site PHOBEA-2 - Jaffe et al. PHOBEA-2 Coordnated with PEACE-B (Japanese aircraft study)

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C. Forster and A. Stohl Technical University of Munich CO tracers FLEXPART Forecast 5/5/2002 125 deg West NOAA WP-3D Flight 5/5/2002 122 - 125 deg West

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NOAA WP-3D Flight 5/5/2002 122 - 125 deg west Up to about 1 ppbv NO y transported with CO NO x, NO y Measurements: T. Ryerson et al.

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NOAA WP-3D Flight 5/5/2002 122 - 125 deg west Most of the HNO 3 has been removed; PAN dominates HNO 3 Measurements: Chemical Ionization Mass Spectrometer A. Neuman et al.

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NOAA WP-3D Flight 5/5/2002 122 - 125 deg west Altitude (km) O 3 elevation is moderate and variable; poor correlation with CO

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NOAA WP-3D Flight 5/5/2002 122 - 125 deg west Altitude (km) CH 3 CN Measurements: Proton Transfer Mass Spectrometer J. de Gouw et al. Largest biomass influence at high altitudes

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NOAA WP-3D Flight 5/5/2002 122 - 125 deg west Altitude (km) Particle Number high at high CO Particle Size Distributions: C. Brock et al.

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Altitude (km) Particle Volume high at lower altitudes

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NOAA WP-3D Flight 5/5/2002 122 - 125 deg west Mineral Aerosol in distinct layers Single Particle Mass Spectrometer Measurements D. Murphy et al.

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Emissions of O 3 precursors from Asia have increased Streets et al. Have O 3 levels in the Eastern Pacific changed? Lets look back in time

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(O 3 2 km over or near continent, 4/20-5/11) O 3 levels in the Eastern Pacific have increased in the last 2 decades Lassen Volcanic National Park 41.6 deg N 1756 m (Mar - May) ITCT 2K2 Jaffe et al. slope = 0.84 ppbv/yr r 2 = 0.52

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O 3 levels in the Eastern Pacific have increased in the last 2 decades

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ITCT 2K2 Field Study (Intercontinental Transport and Chemical Transformation) Introduced ITCT 2K2 Measurements will allow us to characterize chemical and physical properties of gaseous and aerosol species. Substantial evidence for 0.5 ppbv/yr increase of tropospheric O 3 in the Eastern Pacific http://www.al.noaa.gov/WWWHD/pubdocs/ITCT/2k2/ Pronounced episodes of Intercontinental Transport of emissions clearly observed.