Journal article
Impacts of physical parameterization on prediction of ethane concentrations for oil and gas emissions in WRF-Chem
ATMOSPHERIC CHEMISTRY AND PHYSICS, Vol.18(23), pp.16863-16883
2018
DOI: 10.5194/acp-18-16863-2018
Abstract
Recent increases in natural gas (NG) production through hydraulic fracturing have called the climate benefit of switching from coal-fired to natural gas-fired power plants into question. Higher than expected levels of methane, non-methane hydrocarbons (NMHC), and NOx have been observed in areas close to oil and NG operation facilities. Large uncertainties in the oil and NG operation emission inventories reduce the confidence level in the impact assessment of such activities on regional air quality and climate, as well as in the development of effective mitigation policies. In this work, we used ethane as the indicator of oil and NG emissions and explored the sensitivity of ethane to different physical parameterizations and simulation setups in the Weather Research and Forecasting with Chemistry (WRF-Chem) model using the US EPA National Emission Inventory (NEI-2011). We evaluated the impact of the following configurations and parameterizations on predicted ethane concentrations: planetary boundary layer (PBL) parameterizations, daily re-initialization of meteorological variables, meteorological initial and boundary conditions, and horizontal resolution. We assessed the uncertainties around oil and NG emissions using measurements from the FRAPPE and DISCOVER-AQ campaigns over the northern Front Range metropolitan area (NFRMA) in summer 2014. The sensitivity analysis shows up to 57.3% variability in the normalized mean bias of the near-surface modeled ethane across the simulations, which highlights the important role of model configurations on the model performance and ultimately the assessment of emissions. Comparison between airborne measurements and the sensitivity simulations indicates that the model-measurement bias of ethane ranged from -14.9 to -8.2 ppb (NMB ranged from -80.5% to -44 %) in regions close to oil and NG activities. Underprediction of ethane concentration in all sensitivity runs suggests an actual underestimation of the oil and NG emissions in the NEI-2011. An increase of oil and NG emissions in the simulations partially improved the model performance in capturing ethane and lumped alkanes (HC3) concentrations but did not impact the model performance in capturing benzene, toluene, and xylene; this is due to very low emission rates of the latter species from the oil and NG sector in NEI-2011.
Details
- Title: Subtitle
- Impacts of physical parameterization on prediction of ethane concentrations for oil and gas emissions in WRF-Chem
- Creators
- M Abdi-Oskouei - University of IowaG Pfister - NSF National Center for Atmospheric ResearchF Flocke - NSF National Center for Atmospheric ResearchN Sobhani - NSF National Center for Atmospheric ResearchP Saide - University of California, Los AngelesA Fried - Institute of Arctic and Alpine ResearchD Richter - Institute of Arctic and Alpine ResearchP Weibring - Institute of Arctic and Alpine ResearchJ Walega - Institute of Arctic and Alpine ResearchG Carmichael - University of Iowa
- Resource Type
- Journal article
- Publication Details
- ATMOSPHERIC CHEMISTRY AND PHYSICS, Vol.18(23), pp.16863-16883
- DOI
- 10.5194/acp-18-16863-2018
- ISSN
- 1680-7324
- Language
- English
- Date published
- 2018
- Academic Unit
- Civil and Environmental Engineering; Center for Global & Regional Environmental Research; Nursing; Chemical and Biochemical Engineering
- Record Identifier
- 9984231919702771
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