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Project at a Glance

Project Status: complete

Report Published October 1991:

Title: Analysis of the 1987 Southern California air quality study (SCAQS) sulfur hexafluoride atmospheric tracer data.

Principal Investigator / Author(s): Shair, Frederick H

Contractor: California Institute of Technology

Contract Number: A932-051

Research Program Area: Atmospheric Processes

Topic Areas: Acid Deposition, Field Studies, Modeling, Transport


Eight sets of atmospheric tracer experiment data obtained during the 1987 Southern California Air Quality Study (SCAQS) are analyzed by mass balance and qualitative agreement with surface winds gathered during the same period. The sulfur hexafluoride tracer releases done near downtown Los Angeles reveal aspects of the complexity of the atmospheric emission transport from this location. The total material release of sulfur hexafluoride can be accounted for by mass balancing. The mass balances are used to examine the residence time of the tracer in the basin. The residence time for the sulfur hexafluoride tracer released from Vernon CA is 10 hours in the summer, and exceeds 24 hours for the fall. The primary exit route of the sulfur hexafluoride tracer during the summer releases was the San Fernando Valley to the northwest of downtown.

The surface-level diagnostic wind model (D WM) was made operational on a PC. A mechanism for accepting the output from the DWM into WIND, the Caltech PC-based wind field interpretation tool was devised. A detailed manual describing the operation of WIND, and the PC version of WIND2D was developed, and provided to the CARB under separate cover.


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

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