Richard D. Clark
Department of Earth Sciences
Millersville University
Millersville, PA
06 April 2009, 3:30 PM
National Weather Center, Room 1350
120 David L. Boren Blvd.
University of Oklahoma
Norman, OK
Directions to the NWC (.pdf, 60 kb)
Anthropogenic emissions from urban sprawl, traffic, and industrialization along the northeast corridor of the United States are having an increasingly profound effect on urban and regional air quality. Surface air quality over populated areas is an important issue given persuasive data linking high levels of atmospheric oxidants and particulate matter to deleterious human health effects and higher morbidity in at-risk populations.
Predictions of air quality episodes along the Northeast corridor can be confounded by the frequent occurrence of local and regional scale circulations that can influence the magnitude, timing, and spatial extent of air pollution events. While there may be good understanding of the synoptic scale patterns associated with severe air pollution episodes in the mid-Atlantic region, local and regional gradients generated by land-sea discontinuities, topographic features, urban environments, and complicated by a convoluted coastline can give rise to sub-synoptic circulations that are difficult to predict. Forecast skill is often compromised due to the complex scale interactions between the surface layer, boundary layer, and free troposphere. An improved understanding of the influence of local and regional circulations on sources, sinks, transport, mixing, and photochemical transformations controlling the observed abundances of photochemical oxidants and fine particle haze over the mid-Atlantic region is key to developing more reliable pollution forecast capability.
During the summers of 1999, 2001, and 2002 investigators from several institutions and government laboratories conducted an intensive field campaign about 18 km ENE of Philadelphia (40.04o N, 75.00o W). The objectives of this project were to investigate the conditions within the urban polluted environment to find relationships between the meteorological conditions and high O3 concentrations, increased levels of PM2.5, and contributions from local and distant sources. Data were gathered by a number of platforms including Raman Lidar, 915 MHz profiler, multiple tethered balloons, and a suite of surface based criteria and other trace gas analyzers. This presentation will focus on local and regional circulations such as low-level jets and sea breezes that had a profound effect on the air quality and meteorology at the site.
Following on the summer campaign a local study of particulate matter in the wintertime boundary layer was conducted in January-February 2004. These winter investigations support the position that sub-synoptic scale circulations can have a significant influence on the surface and boundary layer variability of trace gas and particle concentrations at a local site. In-situ meteorological observations of select meteorological events and their influence on the trace gas and fine particle concentrations will be presented.
Time permitting this presentation may also include a brief description of several other ongoing research and education initiatives.
Back to NWC Seminar Series and Colloquia