Simulations and analysis of mesoscale to turbulence scale process models to facilitate observational process deployments in the Equatorial Pacific Cold Tongue

Due to the far-reaching societal impacts, developing models and observing systems that enable reliable forecasts of the tropical Pacific Ocean in general and the Equatorial Cold Tongue (ECT) in particular are a high priority. However, global numerical models used for this purpose have significant deficiencies. Several of these deficiencies may result from poorly-constrained parameterizations in the ocean model and/or coarse grid resolution (usually 10-100 km in the horizontal and 10 m in the vertical). For example, upwelling and vertical mixing are two processes that are crucial components of the heat budget of the ECT, but these processes have traditionally been difficult to observe and depend significantly on physics that occurs at scales much smaller than a typical model grid cell. In addition, previous studies have demonstrated that these processes are sensitive to model resolution and parameterization scheme.
This proposal is to support a team of modelers and observationalists in conducting process-oriented numerical experiments designed to reveal how small-scale (< 500 km, subannual) processes contribute to upwelling, mixing and thereby the heat budget of the ECT. The ECT is a “pacemaker” of global climate, and therefore obtaining improved forecasts and observations of the ECT is a high priority for NOAA. The proposed work contributes to this broader objective, and more specifically aids the scientific community and the broader public by addressing the goals of this competition: ● New state-of-the-art high-resolution simulations of the ECT will be shared with the scientific community, which will facilitate scientific discovery via future analysis. ● By quantifying the contribution of different small-scale processes in the models to upwelling and vertical heat fluxes, the proposed work will clarify the benefits associated with observing various processes and scales, so that observational process studies can focus on the spatial and temporal scales and processes that are most important. ● By identifying aspects of regional model solutions of the ECT that are most biased in their representation of vertical mixing and accompanying heat fluxes, the results of the proposed work will be used to help design a sampling plan for observational process studies that will constrain later parameterization and model development efforts and more efficiently improve model solutions and forecasts. ● By conducting observing system simulation experiments, the proposed effort will identify optimal observational tools for future process studies. ● By supporting the career development of early career scientists (Whitt, Bachman, and a to-be-named postdoc), the proposal supports the development of a globally-competitive STEM workforce.