Simulations of winter ozone in the Upper Green River basin, Wyoming, using WRF-Chem

<p>In the Upper Green River basin (UGRB) of Wyoming and the Uintah Basin of Utah, strong wintertime ozone (O<span class="inline-formula"><sub>3</sub></span>) formation episodes leading to O<span class="inline-formula"><sub>3</sub>&l...

Full description

Bibliographic Details
Main Authors: S. Ghimire, Z. J. Lebo, S. Murphy, S. Rahimi, T. Tran
Format: Article
Language:English
Published: Copernicus Publications 2023-08-01
Series:Atmospheric Chemistry and Physics
Online Access:https://acp.copernicus.org/articles/23/9413/2023/acp-23-9413-2023.pdf
_version_ 1797737208965234688
author S. Ghimire
Z. J. Lebo
S. Murphy
S. Rahimi
T. Tran
author_facet S. Ghimire
Z. J. Lebo
S. Murphy
S. Rahimi
T. Tran
author_sort S. Ghimire
collection DOAJ
description <p>In the Upper Green River basin (UGRB) of Wyoming and the Uintah Basin of Utah, strong wintertime ozone (O<span class="inline-formula"><sub>3</sub></span>) formation episodes leading to O<span class="inline-formula"><sub>3</sub></span> mixing ratios occasionally exceeding 70 parts per billion (ppb) have been observed over the last 2 decades. Wintertime O<span class="inline-formula"><sub>3</sub></span> events in the UGRB were first observed in 2005 and since then have continued to be observed intermittently when meteorological conditions are favorable, despite significant efforts to reduce emissions from oil and natural gas extraction and production. While O<span class="inline-formula"><sub>3</sub></span> formation has been successfully simulated using observed volatile organic compound (VOC) and nitrogen oxide (NO<span class="inline-formula"><sub><i>x</i></sub></span>) mixing ratios, successful simulation of these wintertime episodes using emission inventories in a 3-D photochemical model has remained elusive. An accurate 3-D photochemical model driven by an emission inventory is critical to understanding the spatial extent of high-O<span class="inline-formula"><sub>3</sub></span> events and which emission sources have the most impact on O<span class="inline-formula"><sub>3</sub></span> formation. In the winter of 2016/17 (December 2016–March 2017) several high-O<span class="inline-formula"><sub>3</sub></span> events were observed with 1 h mixing ratios exceeding 70 ppb. This study uses the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) to simulate one of the high-O<span class="inline-formula"><sub>3</sub></span> events observed in the UGRB during March 2017. The WRF-Chem simulations were carried out using the 2014 edition of the Environmental Protection Agency National Emissions Inventory (EPA NEI2014v2), which, unlike previous versions, includes estimates of emissions from non-point oil and gas production sources. Simulations were carried out with two different chemical mechanisms: the Model for Ozone and Related Chemical Tracers (MOZART) and the Regional Atmospheric Chemistry Mechanism (RACM), and the results were compared with data from seven weather and air quality monitoring stations in the UGRB operated by the Wyoming Department of Environmental Quality (WYDEQ). The simulated meteorology compared favorably to observations with regard to temperature inversions, surface temperature, and wind speeds. Notably, because of snow cover present in the basin, the photolysis surface albedo had to be modified to predict O<span class="inline-formula"><sub>3</sub></span> in excess of 70 ppb, although the models were relatively insensitive to the exact photolysis albedo if it was over 0.65. O<span class="inline-formula"><sub>3</sub></span> precursors, i.e., NO<span class="inline-formula"><sub><i>x</i></sub></span> and VOCs, are predicted similarly in simulations with both chemical mechanisms, but simulated VOC mixing ratios are a factor of 6 or more lower than the observations, while NO<span class="inline-formula"><sub><i>x</i></sub></span> is also underpredicted but to a lesser degree. Sensitivity simulations revealed that increasing NO<span class="inline-formula"><sub><i>x</i></sub></span> and VOC emissions to match observations produced slightly more O<span class="inline-formula"><sub>3</sub></span> compared to baseline simulations, but an additional sensitivity simulation with doubled NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions resulted in a considerable increase in O<span class="inline-formula"><sub>3</sub></span> formation. These results suggest that O<span class="inline-formula"><sub>3</sub></span> formation in the basin is most sensitive to NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions.</p>
first_indexed 2024-03-12T13:25:10Z
format Article
id doaj.art-41ef93583f90423382137e468d07809d
institution Directory Open Access Journal
issn 1680-7316
1680-7324
language English
last_indexed 2024-03-12T13:25:10Z
publishDate 2023-08-01
publisher Copernicus Publications
record_format Article
series Atmospheric Chemistry and Physics
spelling doaj.art-41ef93583f90423382137e468d07809d2023-08-25T08:11:09ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242023-08-01239413943810.5194/acp-23-9413-2023Simulations of winter ozone in the Upper Green River basin, Wyoming, using WRF-ChemS. Ghimire0Z. J. Lebo1S. Murphy2S. Rahimi3T. Tran4Department of Atmospheric Science, University of Wyoming, Laramie, Wyoming, United StatesSchool of Meteorology, University of Oklahoma, Norman, Oklahoma, United StatesDepartment of Atmospheric Science, University of Wyoming, Laramie, Wyoming, United StatesInstitute of the Environment and Sustainability, University of California, Los Angeles, Los Angeles, California, United StatesRamboll, Novato, California, United States<p>In the Upper Green River basin (UGRB) of Wyoming and the Uintah Basin of Utah, strong wintertime ozone (O<span class="inline-formula"><sub>3</sub></span>) formation episodes leading to O<span class="inline-formula"><sub>3</sub></span> mixing ratios occasionally exceeding 70 parts per billion (ppb) have been observed over the last 2 decades. Wintertime O<span class="inline-formula"><sub>3</sub></span> events in the UGRB were first observed in 2005 and since then have continued to be observed intermittently when meteorological conditions are favorable, despite significant efforts to reduce emissions from oil and natural gas extraction and production. While O<span class="inline-formula"><sub>3</sub></span> formation has been successfully simulated using observed volatile organic compound (VOC) and nitrogen oxide (NO<span class="inline-formula"><sub><i>x</i></sub></span>) mixing ratios, successful simulation of these wintertime episodes using emission inventories in a 3-D photochemical model has remained elusive. An accurate 3-D photochemical model driven by an emission inventory is critical to understanding the spatial extent of high-O<span class="inline-formula"><sub>3</sub></span> events and which emission sources have the most impact on O<span class="inline-formula"><sub>3</sub></span> formation. In the winter of 2016/17 (December 2016–March 2017) several high-O<span class="inline-formula"><sub>3</sub></span> events were observed with 1 h mixing ratios exceeding 70 ppb. This study uses the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) to simulate one of the high-O<span class="inline-formula"><sub>3</sub></span> events observed in the UGRB during March 2017. The WRF-Chem simulations were carried out using the 2014 edition of the Environmental Protection Agency National Emissions Inventory (EPA NEI2014v2), which, unlike previous versions, includes estimates of emissions from non-point oil and gas production sources. Simulations were carried out with two different chemical mechanisms: the Model for Ozone and Related Chemical Tracers (MOZART) and the Regional Atmospheric Chemistry Mechanism (RACM), and the results were compared with data from seven weather and air quality monitoring stations in the UGRB operated by the Wyoming Department of Environmental Quality (WYDEQ). The simulated meteorology compared favorably to observations with regard to temperature inversions, surface temperature, and wind speeds. Notably, because of snow cover present in the basin, the photolysis surface albedo had to be modified to predict O<span class="inline-formula"><sub>3</sub></span> in excess of 70 ppb, although the models were relatively insensitive to the exact photolysis albedo if it was over 0.65. O<span class="inline-formula"><sub>3</sub></span> precursors, i.e., NO<span class="inline-formula"><sub><i>x</i></sub></span> and VOCs, are predicted similarly in simulations with both chemical mechanisms, but simulated VOC mixing ratios are a factor of 6 or more lower than the observations, while NO<span class="inline-formula"><sub><i>x</i></sub></span> is also underpredicted but to a lesser degree. Sensitivity simulations revealed that increasing NO<span class="inline-formula"><sub><i>x</i></sub></span> and VOC emissions to match observations produced slightly more O<span class="inline-formula"><sub>3</sub></span> compared to baseline simulations, but an additional sensitivity simulation with doubled NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions resulted in a considerable increase in O<span class="inline-formula"><sub>3</sub></span> formation. These results suggest that O<span class="inline-formula"><sub>3</sub></span> formation in the basin is most sensitive to NO<span class="inline-formula"><sub><i>x</i></sub></span> emissions.</p>https://acp.copernicus.org/articles/23/9413/2023/acp-23-9413-2023.pdf
spellingShingle S. Ghimire
Z. J. Lebo
S. Murphy
S. Rahimi
T. Tran
Simulations of winter ozone in the Upper Green River basin, Wyoming, using WRF-Chem
Atmospheric Chemistry and Physics
title Simulations of winter ozone in the Upper Green River basin, Wyoming, using WRF-Chem
title_full Simulations of winter ozone in the Upper Green River basin, Wyoming, using WRF-Chem
title_fullStr Simulations of winter ozone in the Upper Green River basin, Wyoming, using WRF-Chem
title_full_unstemmed Simulations of winter ozone in the Upper Green River basin, Wyoming, using WRF-Chem
title_short Simulations of winter ozone in the Upper Green River basin, Wyoming, using WRF-Chem
title_sort simulations of winter ozone in the upper green river basin wyoming using wrf chem
url https://acp.copernicus.org/articles/23/9413/2023/acp-23-9413-2023.pdf
work_keys_str_mv AT sghimire simulationsofwinterozoneintheuppergreenriverbasinwyomingusingwrfchem
AT zjlebo simulationsofwinterozoneintheuppergreenriverbasinwyomingusingwrfchem
AT smurphy simulationsofwinterozoneintheuppergreenriverbasinwyomingusingwrfchem
AT srahimi simulationsofwinterozoneintheuppergreenriverbasinwyomingusingwrfchem
AT ttran simulationsofwinterozoneintheuppergreenriverbasinwyomingusingwrfchem