AN INVESTIGATION OF THE VERTICAL DISTRIBUTION OF TRACE CONSTITUENTS IN THE TROPOSPHERE WITH A ONE-DIMENSIONAL PHOTOCHEMICAL MODEL AND SIMPLE MODELS OF THE PLANETARY BOUNDARY LAYER

This dissertation describes two separate experiments to improve the vertical transport parameterization of a one-dimensional photochemical model of the troposphere by incorporating models of boundary layer dynamics. The photochemical model is then used to compute tropospheric profiles of selected trace constituents in order to advance our understanding of how vertical transport processes affect the distributions and budgets of trace gases in the troposphere. The first experiment simulated the mid-latitude continental troposphere in summer and contrasted the conventional constant eddy-flux parameterization of tropospheric mixing to a new time- and height-dependent mixing scheme developed from proven models of boundary layer structure and dynamics. The resulting contrast in model-derived profiles suggest that proper parameterization of the diurnal cycle of mixing characteristic of continental areas is important to understanding global trace gas budgets.;The second experiment simulates a remote marine tropical environment. The vertical transport parameterization considered the transport properties of shallow dispersed cumulus characteristic of the divergent trade-wind flow regions. The model-derived vertical profiles of key trace constituents are compared to profiles from the photochemical model with conventional flux parameterizations and to the available measured data. This experiment also demonstrates the value of photochemical models that differentiate the transport properties of distinct tropospheric strata and provides some insight to anomalous observations of ozone and nitric oxide taken during flights in the Pacific trade-wind region in May, 1978.