Description of Program:
Objectives:
The objectives are to investigate the urban polluted environment to find the relationships among conditions leading to high ozone concentrations and increased levels of fine particles, determine the contributions from local and distant sources, examine the role of that meteorological properties play in the build-up and distribution of pollutant concentrations over urban- and regional-scales and interpret these results within the context of past measurement programs to extend the knowledge gained to other applicable locations and atmospheric conditions. This investigation will report findings and observe guidelines adopted by the NARSTO-NE program and expect that the proposed effort will materially contribute to the overall NARSTO objectives.
Approach:
The latest developments in remote sensing techniques and in situ measuring instruments will be brought to bear on the problem of understanding the urban polluted atmosphere with extended (6 to 8 week periods during two summer seasons) and intensive measurements during summer exceedances in the ozone and fine particle concentrations in Philadelphia, PA. The local and distant sources of pollutants will be considered by installing instrumented sites in the urban area, making aircraft measurements to determine the upwind and downwind distribution, and using the network of PAMS and other ground sites in the Northeast region. The measurements will be made through two summer seasons and supporting data will be obtained during a brief sensor verification campaign and a brief winter measurement period.
Expected Results:
The extended summer measurement periods should provide a critical data base on the vertical and horizontal distribution of the ozone and fine particle concentrations together with the meteorological conditions to allow interpretation of the contributions from local and distant sources to the urban pollution exceedances of ozone and PM10 as well as the new PM2.5 standards. The contributions to surface based layers from entrainment and redistribution from reservoirs in the boundary layer and the lower free troposphere will be examined. The first instrument performance campaign will provide an input to our quality assurance of the final data product. The brief winter campaign will use the suite of sensors used during the summer intensive study to provide an opportunity for comparisons with the summer results, but under conditions of a vastly different photochemical production rate. |
