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Evaluation of a Measurement Model Fusion Approach for Improving Predictions of Wet Deposition from EQUATES
Citation:
Bash, J., S. Benish, K. Foley, C. Hogrefe, AND Keith Appel. Evaluation of a Measurement Model Fusion Approach for Improving Predictions of Wet Deposition from EQUATES. NADP Fall Meeting, Virtual, Virtual, October 27 - 29, 2021.
Impact/Purpose:
Chemical transport models (CTMs), such as the EPA’s Community Multiscale Air Quality (CMAQ) model, simulate the distribution and temporal trends of nitrogen and sulfur deposition. However, model biases and uncertainty in the chemical and physical processes governing deposition, including due to model resolution, can result in errors designating critical load exceedances. Measurement Model Fusion methods are often used to improve deposition estimates, including by the National Atmospheric Deposition Program (NADP) Total Deposition (TDEP) Science Committee. In this presentation, we assess deposition from multiyear simulations from the EPA’s Air QUAlity TimE Series (EQUATES) project employing a consistent modeling framework using CMAQv5.3.2 and the previous timeseries utilizing CMAQv5.0.2. We provide an overview of the measurement model fusion approach previously published by Zhang et al. (2019) that bias-corrects CMAQ wet deposition output using observation-based gridded precipitation data provided by the Parameter-elevation Regressions on Independent Slopes Model (PRISM). The model was evaluated in its ability to reproduce wet deposition of nitrate, ammonium, and sulfate over U.S. climate regions from 2002-2017 using measurements collected by the National Atmospheric Deposition Program (NADP) National Trends Network (NTN).
Description:
Chemical transport models (CTMs), such as the EPA’s Community Multiscale Air Quality (CMAQ) model, simulate the distribution and temporal trends of nitrogen and sulfur deposition. However, model biases and uncertainty in the chemical and physical processes governing deposition, including due to model resolution, can result in errors designating critical load exceedances. Measurement Model Fusion methods are often used to improve deposition estimates, including by the National Atmospheric Deposition Program (NADP) Total Deposition (TDEP) Science Committee. In this presentation, we assess deposition from multiyear simulations from the EPA’s Air QUAlity TimE Series (EQUATES) project employing a consistent modeling framework using CMAQv5.3.2 and the previous timeseries utilizing CMAQv5.0.2. We provide an overview of the measurement model fusion approach previously published by Zhang et al. (2019) that bias-corrects CMAQ wet deposition output using observation-based gridded precipitation data provided by the Parameter-elevation Regressions on Independent Slopes Model (PRISM). The model was evaluated in its ability to reproduce wet deposition of nitrate, ammonium, and sulfate over U.S. climate regions from 2002-2017 using measurements collected by the National Atmospheric Deposition Program (NADP) National Trends Network (NTN). We show that the Measurement Model Fusion technique applied to the EQUATES simulations improves model performance of wet deposition, decreasing the normalized mean bias across the United States by as much as 20-30% annually compared to CMAQv5.3.2. While model performance varies by climate region, particularly in areas with complex terrain and localized precipitation patterns, the Measurement Model Fusion technique applied to the EQUATES simulations may help improve ecological and nutrient assessments. Zhang, Y., Foley, K. M., Schwede, D. B., Bash, J. O., Pinto, J. P., & Dennis, R. L. (2019). A Measurement-Model Fusion Approach for Improved Wet Deposition Maps and Trends. J Geophys Res Atmos, 124(7), 4237-4251. https://www.ncbi.nlm.nih.gov/pubmed/31218153
