Lamination Frequencies as a Diagnostic for Horizontal Mixing in a 3D Transport Model*

• DOI: 10.1175/1520-0469(2000)057<0247:lfaadf>2.0.co;2
• Publication Date: 2002-07-27T12:09:39Z
• Authors: Clark J. Weaver; Anne R. Douglass; Richard B. Rood

Abstract Ozone simulations are performed in an attempt to simulate laminar events with the frequency observed in balloon ozone sondes. The winds are taken from the Goddard Earth Observing System Data Assimilation System (GEOS DAS); the importance of horizontal and vertical resolution to production of lamina are investigated. A simulation with a high horizontal reolution (grid spacing 1° latitude by 1.25° longitude) and high vertical resolution (∼300 m grid spacing) isentropic model produces lamination frequencies close to the balloon sonde climatology near the polar vortex edge but exhibits too much lamination in the subtropics. This indicates that the GEOS DAS winds contain the information to produce laminar events, although such small-scale features are not manifest in the more commonly used 2° latitude by 2.5° longitude transport model, which uses the hybrid sigma-pressure vertical coordinate. The zonal average ozone tendencies due to horizontal mixing in the lamina-producing models are similar to the ...