Regional and global modeling estimates of policy relevant background ozone over the United States

Emery, Chris; Jung, Jaegun; Downey, Nicole; Johnson, Jeremiah; Jimenez, Michele; Yarwood, Greg; Morris, Ralph

doi:10.1016/j.atmosenv.2011.11.012

Cited by 96 publications

(77 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, several decades of integrations of a global, high-resolution model still require substantial amount of computer time. An alternative could be to use regional models which have been shown in some cases to improve performance in replicating O 3 measurements and trends (Emery et al, 2012;Wilson et al, 2012). The definition of lateral boundary conditions (for both long-range and stratospheric O 3 transport) remains however a key element, in particular to reproduce the lower percentiles of ozone distribution as reported in Hogrefe et al (2011) andEmery (2012).…”

Section: Resultsmentioning

confidence: 99%

“…An alternative could be to use regional models which have been shown in some cases to improve performance in replicating O 3 measurements and trends (Emery et al, 2012;Wilson et al, 2012). The definition of lateral boundary conditions (for both long-range and stratospheric O 3 transport) remains however a key element, in particular to reproduce the lower percentiles of ozone distribution as reported in Hogrefe et al (2011) andEmery (2012). Future global hindcast simulations should therefore seek to employ fully coupled stratospheretroposphere models, higher vertical and horizontal resolution, and to include improved regional emission scenarios in order to simulate accurately ozone trends.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Can a global model reproduce observed trends in summertime surface ozone levels?

Koumoutsaris

Bey

2012

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. Quantifying trends in surface ozone concentrations is critical for assessing pollution control strategies. Here we use observations and results from a global chemical transport model to examine the trends (1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005) in daily maximum 8-h average concentrations in summertime surface ozone at rural sites in Europe and the United States (US). We find a decrease in observed ozone concentrations at the high end of the probability distribution at many of the sites in both regions. The model attributes these trends to a decrease in local anthropogenic ozone precursors, although simulated decreasing trends are overestimated in comparison with observed ones. The low end of observed distribution show small upward trends over Europe and the western US and downward trends in Eastern US. The model cannot reproduce these observed trends, especially over Europe and the western US. In particular, simulated changes between the low and high end of the distributions in these two regions are not significant. Sensitivity simulations indicate that emissions from far away source regions do not affect significantly summer ozone trends at both ends of the distribution in both Europe and US. Possible reasons for discrepancies between observed and simulated trends are discussed.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Can a global model reproduce observed trends in summertime surface ozone levels?

Koumoutsaris

Bey

2012

Atmos. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…The summertime minimum reflects the peak in regional photochemistry, which leads to accumulation of O 3 generated from regional precursors at the same time as it shortens the lifetime of O 3 mixing downward into the photochemically active boundary layer (see e.g., (Fiore et al, 2002) ). At high-altitude WUS sites, models consistently indicate a correlation between NAB levels and total O 3 during spring (Emery et al, 2012;Fiore et al, 2003;Lin et al, 2012a;Lin et al, 2012b;Zhang et al, 2011), implying that enhanced NAB levels play a role in raising total O 3 , including above the NAAQS threshold. While these results are qualitatively consistent across several modeling platforms, the models vary in their quantitative attributions for NAB and its specific sources.…”

Section: Review Of Prior Model Estimates For Nab and Its Componentsmentioning

confidence: 95%

“…In summer, however, the total O 3 distributions in GEOS-Chem are more sensitive to the choice of horizontal resolution, presumably reflecting the larger contributions from local-to-regional photochemical production during this season and the importance of spatially resolving domestic anthropogenic and natural emissions distributions. Emery et al (2012) found that the higher resolution CAMx model generally simulated higher WUS NAB than a coarse resolution version of GEOS-Chem, and better agreement has been noted between CAMx and the higher resolution version of GEOS-Chem (EPA, 2013). Simulation of higher WUS NAB by higher resolution models (Emery et al, 2012;Lin et al, 2012a) likely reflects improved resolution of mesoscale meteorology at higher resolution and the damping of vertical eddy transport at coarser resolution (Wang et al, 2004;Zhang et al, 2011).…”

Section: Seasonal Variabilitymentioning

confidence: 99%

“…Recent work has updated those estimates (Wang et al, 2009;Zhang et al, 2011) and compared them with NAB in regional models using GEOS-Chem boundary conditions (Emery et al, 2012;Mueller and Mallard, 2011) and considered additional years. The first NAB estimates with an independent global model, (GFDL AM3; hereafter AM3; Table 2) were found to episodically reach 60-75 ppb over the Western United States in spring (Lin et al, 2012a).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Estimating North American background ozone in U.S. surface air with two independent global models: Variability, uncertainties, and recommendations

Fiore

Oberman

Lin

et al. 2014

Atmospheric Environment

107

131

View full text Add to dashboard Cite

Accurate estimates for North American background (NAB) ozone (O 3 ) in surface air over the United States are needed for setting and implementing an attainable national O 3 standard. These estimates rely on simulations with atmospheric chemistry-transport models that set North American anthropogenic emissions to zero, and to date have relied heavily on one global model. We examine, for the first time, NAB estimates for spring and summer 2006 with two independent global models (GEOS-Chem and GFDL AM3). where it correlates with observed O 3 . At these sites, a 27-year GFDL AM3 simulation simulates observed O 3 events above 60 ppb and indicates a role for year-to-year variations in NAB O 3 in driving their frequency (contributing 50-60 ppb or more during some events). During summer over the eastern United States (EUS), when photochemical production from regional anthropogenic emissions peaks, NAB is largely uncorrelated with observed values and it is lower than at high-altitude sites (average values of ~20-30 ppb). We identify four processes that contribute substantially to model differences in specific regions and seasons: lightning NO x , biogenic isoprene emissions and chemistry, wildfires, and stratosphere-to-troposphere transport. Differences in model representation of these processes contribute more to uncertainty in NAB estimates than the choice of horizontal resolution within a single model. We propose that future efforts seek to constrain these processes with targeted analysis of multi-model simulations evaluated with observations of O 3 and related species from multiple platforms, and thereby reduce the error on NAB estimates needed for air quality planning.

show abstract

Assessment of source contributions to seasonal vegetative exposure to ozone in the U.S.

et al. 2014

View full text Add to dashboard Cite

[1] W126 is a cumulative ozone exposure index based on sigmoidally weighted daytime ozone concentrations used to evaluate the impacts of ozone on vegetation. We quantify W126 in the U.S. in the absence of North American anthropogenic emissions (North American background or "NAB") using three regional or global chemical transport models for May-July 2010. All models overestimate W126 in the eastern U.S. due to a persistent bias in daytime ozone, while the models are relatively unbiased in California and the Intermountain West. Substantial difference in the magnitude and spatial and temporal variability of the estimates of W126 NAB between models supports the need for a multimodel approach. While the average NAB contribution to daytime ozone in the Intermountain West is 64-78%, the average W126 NAB is only 9-27% of current levels, owing to the weight given to high O 3 concentrations in W126. Based on a three-model mean, NAB explains 30% of the daily variability in the W126 daily index in the Intermountain West. Adjoint sensitivity analysis shows that nationwide W126 is influenced most by NO x emissions from anthropogenic (58% of the total sensitivity) and natural (25%) sources followed by nonmethane volatile organic compounds (10%) and CO (7%). Most of the influence of anthropogenic NO x comes from the U.S. (80%), followed by Canada (9%), Mexico (4%), and China (3%). Thus, long-range transport of pollution has a relatively small impact on W126 in the U.S., and domestic emissions control should be effective for reducing W126 levels.

show abstract

Regional and global modeling estimates of policy relevant background ozone over the United States

Cited by 96 publications

References 22 publications

Can a global model reproduce observed trends in summertime surface ozone levels?

Can a global model reproduce observed trends in summertime surface ozone levels?

Estimating North American background ozone in U.S. surface air with two independent global models: Variability, uncertainties, and recommendations

Assessment of source contributions to seasonal vegetative exposure to ozone in the U.S.

Contact Info

Product

Resources

About