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Project Status: complete

Title: Particulate monitoring for acid deposition research at Sequoia National Park, California

Principal Investigator / Author(s): Cahill, T. A.

Contractor: Air Quality Group, Crocker Nuclear Laboratory, UC Davis

Contract Number: A4-124-32

Research Program Area: Atmospheric Processes

Topic Areas: Acid Deposition


In support of the acid deposition effects programs at Sequoia National Park, we have made extensive measurements of particulate matter during the summer of 1985. The objectives of this project were: (1) to characterize the particulate composition of fine particles by determining the concentration of all elements from hydrogen through lead; (2) to determine what material is available for wet and dry deposition by measuring particulate concentrations by element with detailed size and time resolution; (3) to determine how particulate concentrations vary with time as the meteorology changes; (4) to determine the extent of transport of particulate pollutants from the San Joaquin Valley by comparing elemental concentrations measured at three elevations with sufficient time resolution to look at transport; and (5) to provide convenient time plots and other visual representations of particulate concentrations to concurrent projects on the effects of wet and dry deposition and to studies dealing with meteorology and gasses. Samples were taken continuously at three elevations (2000 ft, 6400 ft, 10000 ft) in up to nine size ranges. Almost 4000 analyses were done for mass, carbon soot, hydrogen and elemental species up through lead. The data were correlated with local and synoptic meteorology, known elemental source signatures, and wet deposition measurements made in the four major rain events during the summer of 1985. The results show that particulate matter at Sequoia NP is similar to that measured at other, non-urban sites in the Sierra Nevada range and California desert. Particles were carried into the study sites by both local, terrain effect winds coming from the central San Joaquin Valley, and by upper level synoptic flows south and east of Sequoia NP. Rainfall associated with the latter flows contributed most of the wet deposition acidic flux (H, S04, NO3-) in the study period. A large number of individuals and institutions assisted the Air Quality Group, University of California, Davis in the execution of this project, both in the line of official duties, and in many cases, by giving additional voluntary assistance, We warmly thank these persons including amongst others: Staff members of Sacramento office of the California Air Resources Board, Research Division; Lowell Ashbaugh, Kathy Tonnessen, Eric Fujita, Chuck Unger; Sequoia and Kings Canyon National Park, Resource Management' Division; Tom Nichols, Linda Mazzu; Sequoia and Kings Canyon National Park, Research Division; Dave Parsons, Tom Stoblgren, Joann Tribble, Annie Esperanza: Guest Services Inc.; Bob Seeney, Debbie Lawrence; University of California, Santa Barbara; Rick Kattelmann, David Clow; University of South Florida; Bob Braman, Bob Sutton, George Cobb, Steve Hendriks; Land, Air and Water Resources, University of California, Davis; Bob Flocchini, Leonard Myrup.


For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

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