Publication Date

Summer 2018

Degree Type


Degree Name

Master of Science (MS)


Meteorology and Climate Science


Sen Chiao


Air Quality, Ozone, Ozone Transport, Potential Vorticity, Stratospheric Intrusion, Surface Pollution

Subject Areas

Meteorology; Atmospheric sciences


Stratospheric intrusions occur above California throughout all seasons. Stratospheric intrusions are known to transport ozone rich stratospheric air into the lower troposphere, influencing surface ozone, especially in the mountainous regions of the western US. These intrusions potentially influence the surface ozone concentrations to be above the health-based national ambient air quality standard. Potential Vorticity is a widely accepted tracer of stratospheric air masses being injected into the troposphere. Stratospheric intrusions during the last few weeks of the California Baseline Ozone Transport Study are identified over Northern California, influencing air masses above Bodega Bay and Sacramento. Utilizing daily ozonesonde data from Bodega Bay CA, a downward progression of increasing ozone from the point of stratospheric air injection to the surface is tracked. Analysis of surface ozone from the Bodega Bay surface ozone monitoring station resembles this. A comparison of surface ozone observations in Bodega Bay and 14 surface sites in Sacramento leads to a better understanding of regional surface ozone variations. The surface ozone data observed at the higher elevation surface sites were correlated with elevated ozone captured by the ozonesondes at similar levels. Stronger correlations are found between higher elevation surface ozone and the elevated ozonesonde data, an indication of regional similarities.