Browsing by Author "Lash, Benjamin"

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    Enhanced representation of soil NO emissions in the Community Multiscale Air Quality (CMAQ) model versionﾠ5.0.2
    (Copernicus Publications, 2016) Rasool, Quazi Z.; Zhang, Rui; Lash, Benjamin; Cohan, Daniel S.; Cooter, Ellen J.; Bash, Jesse O.; Lamsal, Lok N.
    Modeling of soil nitric oxide (NO) emissions is highly uncertain and may misrepresent its spatial and temporal distribution. This study builds upon a recently introduced parameterization to improve the timing and spatial distribution of soil NO emission estimates in the Community Multiscale Air Quality (CMAQ) model. The parameterization considers soil parameters, meteorology, land use, and mineral nitrogen (N) availability to estimate NO emissions. We incorporate daily year-specific fertilizer data from the Environmental Policy Integrated Climate (EPIC) agricultural model to replace the annual generic data of the initial parameterization, and use a 12 km resolution soil biome map over the continental USA. CMAQ modeling for July 2011 shows slight differences in model performance in simulating fine particulate matter and ozone from Interagency Monitoring of Protected Visual Environments (IMPROVE) and Clean Air Status and Trends Network (CASTNET) sites and NO2 columns from Ozone Monitoring Instrument (OMI) satellite retrievals. We also simulate how the change in soil NO emissions scheme affects the expected O3 response to projected emissions reductions.
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    Implementing and Improved Soil NOx Parameterization in the Community Multiscale Air Quality Model: Implications for Air Pollution
    (2014-12-05) Lash, Benjamin; Cohan, Daniel S; Griffin, Robert; Masiello, Caroline
    Soil NO emissions are critical to accurate atmospheric simulations which inform decisions to protect human health. Several studies indicate that the scheme, Yienger and Levy 1995 (YL95), underestimates soil NO emissions by a significant amount. The Berkeley Dalhousie Soil NOx Parameterization (BDSNP) updates soil NO emissions to be more consistent with satellite measurements. This work implements the BDSNP algorithm into CMAQ, adapting it to a 12km grid and comparing the resulting ozone, particulate, and other pollutants with results from the current YL95 algorithm for 2005 satellite data. Results show that summer NO emissions over the US double during the day, and in some places soil NO exceeds industrial sources. A comparison with satellite data, however, does not show strong evidence of the YL underestimation, contrary to other published results.