Dry Deposition Methods Based on Turbulence Kinetic Energy: Part 1. Evaluation of Various Resistances and Sensitivity Studies Using a Single-Point Model

Several stability functions are in use to account for turbulence in the atmospheric boundary layer for different stability regimes. These functions are one of the sources for differences among different atmospheric models’ predictions and associated biases. To address this issue with dry deposition, firstly we take advantage of three-dimensional (3-D) aspects of turbulence in estimating resistances by proposing and validating a 3-D turbulence velocity scale that is representative of different stability regimes of atmospheric boundary layer and does not use stability correction functions. Secondly, we hypothesize and prove that 3-D sonic anemometer measured friction velocity, used in several resistances in 0-D and 1-D models, can be effectively replaced by the new turbulence velocity scale multiplied by the von Karman constant. Finally, we (1) evaluate a set of resistance formulations for ozone (O₃), based on the 3-D turbulence velocity scale; and (2) intercompare estimations of such resistances with those obtained using the existing formulations and also evaluate simulated O₃ fluxes using a single-point dry deposition model against long-term observations of O₃ fluxes at the Harvard Forest site. Results indicate that the new resistance formulations work very well in simulating surface latent heat and O₃ fluxes when compared to respective simulations using traditional formulations as well as measurements at decadal time scale. Findings from this research may help to improve the capability of dry deposition schemes for better estimation of dry deposition fluxes and creates opportunities for the development of a community dry deposition model for use in regional/global air quality models.