HR: 09:30h
AN: A51G-06    [Abstracts]
TI: Understanding the Impact of North American Outflow on Tropospheric O$_{3}$ over the North Atlantic Ocean: A Case Study During ICARTT 2004
AU: * Mao, H
EM: hmao@typhoon.sr.unh.edu
AF: Institute for the Study of Earth, Oceans, and Space, Morse Hall, University of New Hampshire, Durham, NH 03824 United States
AU: Talbot, R
EM: robert.talbot@unh.edu
AF: Institute for the Study of Earth, Oceans, and Space, Morse Hall, University of New Hampshire, Durham, NH 03824 United States
AU: Troop, D
EM: don.troop@unh.edu
AF: Institute for the Study of Earth, Oceans, and Space, Morse Hall, University of New Hampshire, Durham, NH 03824 United States
AU: Businger, S
EM: businger@hawaii.edu
AF: Department of Meteorology, University of Hawaii, Honolulu, HI 96822 United States
AU: Johnson, R
EM: randy.johnson@noaa.gov
AF: NOAA Air Resources Laboratory, Field Research Division, Idaho Falls, ID 83402 United States
AB: The objective of this study was to investigate the mechanisms contributing to the temporal and spatial variations of ozone (O$_{3}$) levels in North American continental outflow over the North Atlantic Ocean during a high O$_{3}$ episode on July 17 - 25, 2004. An observational data analysis was carried out for this time period to document variations in O$_{3}$ mixing ratios in urban plumes traveling over the North Atlantic using measurements obtained from the NOAA smart balloon Lagrangian Flight \#2. Flight \#2 started from Long Island, New York and landed near Prince Edward Island, Nova Scotia. This analysis was complemented by model simulations of the distributions of O$_{3}$ and its precursors using an air quality modeling system (i.e. MM5, SMOKE, and CMAQ). The models were rigorously evaluated using the meteorological and chemical measurements from ground and mobile platforms employed in the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) field campaign. The balloon O$_{3}$ measurements exhibited large variations in O$_{3}$ levels in the North American outflow at fairly constant altitudes of 400 - 600 m with the peak value of 195 ppbv observed on the night of July 20. It is hypothesized that local convection, {\it in situ} chemistry and strong detrainment/entrainment could be the primary causes for such large horizontal gradients. Our model results suggest that such enhanced levels of O$_{3}$ can potentially have a great impact on the chemical environments of the remote North Atlantic region.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0343 Planetary atmospheres (5405, 5407, 5409, 5704, 5705, 5707)
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting