An Investigation of Non-Gravity Wave Ozone Laminae: Sources and Transport Pathways

It has long been recognized that ozone variability in the upper troposphere and lower stratosphere (UTLS) is often dominated by the appearance of laminated structures. Individual laminae can arise from a wide variety of nonlocal mechanisms and transport processes such as photochemical production/loss, plume advection, stratosphere-troposphere exchange, tropical and monsoon-related deep-convection, gravity waves, differential advection of ozone fields with natural spatial gradients, and more. We have developed methods for identifying and classifying laminae that build on previous analyses of ozone laminae observed in balloon and satellite vertical profiles. While earlier studies established reliable methods for classifying laminae associated with gravity wave activity, there have been relatively fewer quantitative approaches for understanding the sources and transport pathways for all of the other, non-gravity wave (NGW) ozone laminae. Our analysis of the 25-year ozonesonde record from Boulder, Colorado, shows that NGW laminae account for more than 70% of the total number of laminae identified in the UTLS region. We show that these NGW ozone laminae can be effectively characterized in terms of sources and transport pathways by employing complementary diagnostics based on reanalyses, Lagrangian diagnostics, and satellite data.