HR: 1340h
AN: A53C-0916    [Abstracts]
TI: Preliminary Evidence for Ozone Production Within Yosemite Valley
AU: * Dillon, M B
EM: dillon7@llnl.gov
AF: Atmospheric Science Division Lawrence Livermore National Laboratory, P.O. Box 808, L-103, Livermore, CA 94551 United States
AU: Panek, J
EM: jpanek@nature.berkeley.edu
AF: Panek and Associates Consulting, 2311 Webster St., Berkeley, CA 94705 United States
AB: Ozone concentrations within the Yosemite National Park have violated the California human health standard for over a decade. Elevated ozone concentrations have historically been attributed to poor regional air quality and to the long-range transport of ozone and ozone precursors into the park from outside sources. However, there has been increasing concern that local, within Yosemite, pollutant emissions may contribute to Yosemite's air quality issues. During peak tourist season, half a million people visit the Park every month with most people arriving in cars to visit a geographically small feature of the Park, Yosemite Valley. Thus, during peak season on average 6000 cars and 63 buses visit Yosemite Valley daily and campfires burn nightly in up to 472 Valley campsites. In part to address concern over local emission sources, the National Park Service installed several air quality sampling stations within and surrounding Yosemite Valley over the last 4 years. We use the 2000 to 2003 ozone, nitrogen oxide, and meteorological measurements to investigate if local ozone production occurs as air masses are advected over Yosemite Valley pollution sources, predominately located in the eastern Valley. Due to measurement limitations, the amount of ozone produced is difficult to quantify, but on a typical summer day is likely to be at least 5ppb and possibly greater than 20ppb over a 4km transect. This analysis suggests that the air quality in the eastern end of the Yosemite Valley may be worse than previously known and we recommend that more detailed air quality measurements be made in this area. This work was produced at the University of California, Lawrence Livermore National Laboratory (UC LLNL) under contract W-7405-ENG-48 (Contract 48) between the U.S. Department of Energy (DOE) and The Regents of the University of California (University) for the operation of UC LLNL. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, products or process disclosed, or represents that its use would not infringe privately-owned rights. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. (UCRL-ABS-206474)
DE: 0345 Pollution--urban and regional (0305)
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting