HR: 0830h
AN: A51D-0706    [PDF]
TI: Meteorological Controls on Ozone at Two High-Elevation Monitoring Sites in New Hampshire
AU: * Fischer, E V
EM: efischer@gust.sr.unh.edu
AF: Climate Change Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire 39 College Road, Durham, NH 03824 United States
AU: Talbot, R W
EM: robert.talbot@unh.edu
AF: Climate Change Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire 39 College Road, Durham, NH 03824 United States
AU: Moody, J L
EM: moody@virginia.edu
AF: Department of Environmental Sciences, University of Virginia 351 Clark Hall 291 McCormick Road, Charlottesville, VA 22904-4123 United States
AU: Dibb, J E
EM: jack.dibb@unh.edu
AF: Climate Change Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire 39 College Road, Durham, NH 03824 United States
AU: Wake, C P
EM: cameron.wake@unh.edu
AF: Climate Change Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire 39 College Road, Durham, NH 03824 United States
AB: This study is examining the synoptic and regional scale meteorological controls on ozone mixing ratios at two sites in the Atmospheric, Investigation, Regional Modeling, Analysis and Prediction (AIRMAP) network located in New Hampshire, USA. Summertime ozone data is being analyzed from the summit of Mount Washington, the highest peak in the northeastern United States (1910m), and from Castle Springs, a forested site on the southwest flank of the Ossipee Mountains (400m). A five-summer data set (1998-2002) from Mount Washington is being used along with a two-summer data set (2001 and 2002) from Castle Springs in our analysis of extreme ozone at these two sites. Enhanced ozone events, defined as hourly averages above the 90th percentile ($\sim$65 ppbv), and depleted ozone events, defined as hourly averages below the 10th percentile ($\sim$30 ppbv) were identified and are being examined in detail. Due to the high elevation of these two sites and the associated diurnal dynamics, afternoon and nighttime ozone events are being studied separately. Transport analysis is being conducted using HYSPLIT backward trajectories initialized from both sites. We are using coincident meteorological observations and synoptic conditions to understand and interpret both depleted and enhanced ozone events. Trajectory analysis has revealed distinct patterns in transport and air mass history that help explain the variations in ozone extremes. Enhanced ozone events at Mount Washington and Castle Springs are generally associated with descending westerly transport, while depleted ozone events correspond to northerly transport. Our initial analysis of backward trajectories and meteorological conditions suggests an influence of both anthropogenic and stratospheric sources on afternoon and nighttime enhanced ozone events.
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting