Project at a Glance
Title: Los Angeles to San Diego three dimensional ozone transport study
Principal Investigator / Author(s): Kauper, Erwin K
Contractor: Metro Monitoring Services
Contract Number: A6-090-30
Research Program Area: Atmospheric Processes
The three dimensional distributions of ozone concentrations and meteorological parameters were measured during a ten-day period which included an entire Santa Ana (North-easterly) wind episode in the South Coast Air Basin. The ozone concentrations and wind and temperature structure were measured by an instrumented light aircraft and network of wind and ozone monitors in the coastal area between Los Angeles and San Diego, including the offshore islands.
Air masses with high ozone concentrations in the lower 200 feet were commonly found over the ocean south of Los Angeles during Santa Ana wind conditions; during "marine layer" conditions, the high ozone concentrations were observed at or above the base of the characteristic subsidence inversion existing between Los Angeles and San Diego.
Concurrent surface and upper air wind measurements made at intervals throughout the days and nights provide data from which streamline airflow maps were prepared for the levels associated with high ozone concentrations. Airmass trajectories constructed from these streamline maps indicate that the measured high ozone concentrations at the surface and aloft over coastal San Diego most likely originated from precursor emissions in the Los Angeles - Orange County area. The relationship between ozone aloft, precursor origin and measured ozone at the surface in eastern San Diego County is less well established.
For questions regarding research reports, contact: Heather Choi at (916) 322-3893
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