The Influence of Meteorology on the Air Quality in the San Luis Obispo County-Southwestern San Joaquin Valley Region for 36 August 1990

Abstract The large volume of data measured during the 1990 summer San Joaquin Valley Air Quality Study/Atmospheric Utility Signatures, Predictions, and Experiments (SJVAQS/AUSPEX) provides a unique opportunity to examine the influence of meteorology on air quality for a variety of regions in central California. This paper provides a qualitative analysis of surface and upper-level meteorological and air quality data measured during 3–6 August 1990 in San Luis Obispo County (SLOC) and the southwestern side of the San Joaquin Valley (SJV). During this 4-day period, daytime and nighttime atmospheric mechanisms helped to transport ozone into layers aloft over the SJV. Air flowing out of the SJV in the afternoon transported elevated layers of ozone into SLOC. The daily onshore flow from the west opposed this outflow of air from the SJV. The onshore flow prevented the transported ozone from the SJV from reaching the surface and allowed some ventilation into the southwestern side of the SJV. However, on 5 August ...