HR: 15:10h
AN: A53D-07    [Abstracts]
TI: Ozone Production in the Boston Urban Area and Transport Downwind: Computation from Lidar Measurements and Comparison with Air Quality Forecast Models
AU: * Hardesty, R M
EM: Michael.Hardesty@noaa.gov
AF: NOAA Environmental Technology Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: Senff, C J
A53D-07 AF: NOAA Environmental Technology Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: Senff, C J
A53D-07 AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, CB 216, Boulder, CO 80309 United States
AU: Alvarez, R J
A53D-07 AF: NOAA Environmental Technology Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: Sandberg, S P
A53D-07 AF: NOAA Environmental Technology Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: McKeen, S A
A53D-07 AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, CB 216, Boulder, CO 80309 United States
AU: McKeen, S A
A53D-07 AF: NOAA Aeronomy Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: Wilczak, J M
A53D-07 AF: NOAA Environmental Technology Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: Djalalova, I V
A53D-07 AF: NOAA Environmental Technology Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: Djalalova, I V
A53D-07 AF: Science and Technology Corporation, 10 Basil Sawyer Drive, Hampton, VA 23666 United States
AU: White, A B
A53D-07 AF: NOAA Environmental Technology Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: White, A B
A53D-07 AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, CB 216, Boulder, CO 80309 United States
AB: An important element in understanding and successfully forecasting local air quality events is accurate characterization of production of pollutants in urban regions and advection to areas downwind. During the 2004 New England Air Quality Study (NEAQS), which was conducted within the framework of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) field experiment, NOAA deployed its airborne ozone and aerosol lidar to characterize the 3-dimensional structure of ozone and aerosol fields in the New England region. We have used the data set gathered with the lidar to compute ozone production in the Boston urban plume and to investigate transport and mixing processes for several days of the study. One of the few high ozone events in northern New England during the summer of 2004 occurred on July 30, when ozone levels exceeded 100 ppbv on Appledore Island just east of Portsmouth, NH. On this day, trajectories computed from wind profiler data showed that the New York plume was transported directly over Boston and then north-northeastwards along the New Hampshire and Maine coasts. By flying across the plume upstream and downwind of Boston and computing the horizontal ozone flux within the plume, we were able to estimate that the ozone flux downwind of Boston increased by 36 percent, concentrating the pollutants and likely playing a role in the high ozone observed. We also examined transport on August 3, when a shallow plume of high ozone was observed near Bar Harbor, ME. Trajectories indicated that this was a piece of the previous day's Boston plume, which was likely transported overnight across the Gulf of Maine in a very shallow layer. Later in the day, another plume was observed further south near Portland, ME. Trajectories showed that this was the Boston plume emitted on the morning of August 3, which followed a different transport path due to changes in the wind field over the period. On August 9, we mapped out the Boston urban plume against a clean background and characterized ozone production within the plume and its transport downwind over the Cape Cod area. A noticeable plume was observed although ozone levels did not exceed 70 ppb in the plume. Due to vertical wind shear and limited vertical coupling in the stable atmosphere over the ocean, the plume was sheared apart as it traveled downwind. Such measurements of pollutant distribution and plume structure as observed with the lidar during NEAQS 2004 provide an ideal data set for comparison with air quality model predictions. The complex meteorology in coastal New England, in particular the land-ocean transition, the stable marine layer over the Gulf of Maine, and the land-sea breeze circulation, strongly affect pollutant distribution and represent a challenge for air quality models. Comparison of model predictions with the lidar observations will help elucidate how well these processes are represented in the models. We will present model predictions of plume structure, ozone distribution and ozone production in the Boston urban plume for several cases using the high-resolution CMAQ-ETA and WRF-Chem models and compare them to the lidar observations.
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005