Ozone production rates as a function of NOxabundances and HOxproduction rates in the Nashville urban plume

2002 ◽  
Vol 107 (D12) ◽  
Author(s):  
J. A. Thornton
Keyword(s):  
Ozone Production ◽  
Production Rates ◽  
Urban Plume

scholarly journals Observations of the temperature dependent response of ozone to NO<sub>x</sub> reductions in the Sacramento, CA urban plume

2011 ◽  
Vol 11 (14) ◽  
pp. 6945-6960 ◽  
Author(s):  
B. W. LaFranchi ◽  
A. H. Goldstein ◽  
R. C. Cohen
Keyword(s):  
Ozone Production ◽  
Metropolitan Region ◽  
Temperature Dependent ◽  
Strongly Coupled ◽  
Detailed Chemistry ◽  
Mixing Ratios ◽  
Current Trends ◽  
Biogenic Voc ◽  
Steady State Model ◽  
Urban Plume

Abstract. Observations of NOx in the Sacramento, CA region show that mixing ratios decreased by 30 % between 2001 and 2008. Here we use an observation-based method to quantify net ozone (O3) production rates in the outflow from the Sacramento metropolitan region and examine the O3 decrease resulting from reductions in NOx emissions. This observational method does not rely on assumptions about detailed chemistry of ozone production, rather it is an independent means to verify and test these assumptions. We use an instantaneous steady-state model as well as a detailed 1-D plume model to aid in interpretation of the ozone production inferred from observations. In agreement with the models, the observations show that early in the plume, the NOx dependence for Ox (Ox = O3 + NO2) production is strongly coupled with temperature, suggesting that temperature-dependent biogenic VOC emissions and other temperature-related effects can drive Ox production between NOx-limited and NOx-suppressed regimes. As a result, NOx reductions were found to be most effective at higher temperatures over the 7 year period. We show that violations of the California 1-h O3 standard (90 ppb) in the region have been decreasing linearly with decreases in NOx (at a given temperature) and predict that reductions of NOx concentrations (and presumably emissions) by an additional 30 % (relative to 2007 levels) will eliminate violations of the state 1 h standard in the region. If current trends continue, a 30 % decrease in NOx is expected by 2012, and an end to violations of the 1 h standard in the Sacramento region appears to be imminent.

scholarly journals Diagnosis of Photochemical Ozone Production Rates and Limiting Factors in Continental Outflow Air Masses Reaching Fukue Island, Japan: Ozone-Control Implications

2016 ◽  
Vol 16 (2) ◽  
pp. 430-441 ◽  
Author(s):  
Yugo Kanaya ◽  
Hiroshi Tanimoto ◽  
Yoko Yokouchi ◽  
Fumikazu Taketani Fumikazu Taketani ◽  
Yuichi Komazaki ◽  
...  
Keyword(s):  
Ozone Production ◽  
Limiting Factors ◽  
Production Rates ◽  
Air Masses ◽  
Ozone Control ◽  
Photochemical Ozone ◽  
Continental Outflow

scholarly journals A quantitative analysis of grid-related systematic errors in oxidising capacity and ozone production rates in chemistry transport models

2004 ◽  
Vol 4 (7) ◽  
pp. 1781-1795 ◽  
Author(s):  
J. G. Esler ◽  
G. J. Roelofs ◽  
M. O. Köhler ◽  
F. M. O'Connor
Keyword(s):  
High Resolution ◽  
Spatial Scales ◽  
Systematic Errors ◽  
Ozone Production ◽  
Systematic Effect ◽  
Model Errors ◽  
Low Resolution ◽  
Production Rates ◽  
Transport Models ◽  
The Difference

Abstract. Limited resolution in chemistry transport models (CTMs) is necessarily associated with systematic errors in the calculated chemistry, due to the artificial mixing of species on the scale of the model grid (grid-averaging). Here, the errors in calculated hydroxyl radical (OH) concentrations and ozone production rates 3 are investigated quantitatively using both direct observations and model results. Photochemical steady-state models of radical chemistry are exploited in each case to examine the effect on both OH and 3 of averaging relatively long-lived precursor species, such as O3, NOx, CO, H2O, etc. over different spatial scales. Changes in modelled 3 are estimated, independently of other model errors, by calculating the systematic effect of spatial averaging on the ozone production efficiency 1, defined as the ratio of ozone molecules produced per NOx molecule destroyed. Firstly, an investigation of in-flight measurements suggests that, at least in the northern midlatitude upper-troposphere/lower stratosphere, averaging precursor species on the scale of a T42 grid (2.75° x 2.75°) leads to a 15-20% increase in OH concentrations and a 5-10% increase in 1. Secondly, results from CTM model experiments are compared at different horizontal resolutions. Low resolution experiments are found to have significantly higher [OH] and 3 compared with high resolution experiments. The extent to which these differences may be explained by the systematic error in the model chemistry associated with grid size is estimated by degrading the high resolution data onto a low resolution grid and then recalculating 1 and [OH]. The change in calculated 1 is found to be significant and can account for much of the difference in 3 between the high and low resolution experiments. The calculated change in [OH] is less than the difference in [OH] found between the experiments, although the shortfall is likely to be due to the indirect effect of the change in modelled NOx, which is not accounted for in the calculation. It is argued that systematic errors caused by limited resolution need to be considered when evaluating the relative impacts of different pollutant sources on tropospheric ozone.

scholarly journals Direct measurement of ozone production rates in Houston in 2009 and comparison with two estimation methods

2011 ◽  
Vol 11 (10) ◽  
pp. 27521-27546
Author(s):  
M. Cazorla ◽  
W. H. Brune ◽  
X. Ren ◽  
B. Lefer
Keyword(s):  
Nitric Oxide ◽  
Box Model ◽  
Ozone Production ◽  
Estimation Methods ◽  
Production Rates ◽  
Quality Models ◽  
State Measurement ◽  
Similar Dependence ◽  
Penn State ◽  
Similar Peak

Abstract. Ozone production rates, P(O3), were measured directly using the Penn State Measurement of Ozone Production Sensor (MOPS) during the Study of Houston Atmospheric Radical Precursors (SHARP 2009). Measured P(O3) peaked in the late morning, with values between 15 ppbv h−1 and 100 ppbv h−1, although values of 40–80 ppbv h−1 were typical for higher ozone days. These measurements were compared against ozone production rates calculated using measurements of hydroperoxyl (HO2), hydroxyl (OH), and nitric oxide (NO) radicals, called "calculated P(O3)". The same comparison was done using modeled radicals obtained from a box model with the RACM2 mechanism, called "modeled P(O3)". Measured and calculated P(O3) had similar peak values but the calculated P(O3) tended to peak earlier in the morning when NO values were higher. Measured and modeled P(O3) had a similar dependence on NO, but the modeled P(O3) was only half the measured P(O3). This difference indicates possible missing radical sources in the box model with the RACM2 mechanism and thus has implications for the ability of air quality models to accurately predict ozone production rates.

scholarly journals Observed changes in the temperature dependence response of surface ozone under NO<sub><i>x</i></sub> reductions

2020 ◽  
Author(s):  
Noelia Otero ◽  
Henning W. Rust ◽  
Tim Butler
Keyword(s):  
Temperature Dependence ◽  
Surface Ozone ◽  
Additive Models ◽  
Ozone Production ◽  
Temperature Relationship ◽  
Strong Temperature Dependence ◽  
Ozone Pollution ◽  
Production Rates ◽  
Penalty Factor ◽  
Second Period

Abstract. Due to the strong temperature dependence of surface ozone concentrations (O3), future warmer conditions may worsen ozone pollution levels despite continued efforts on emission controls of ozone precursors. Using long-term measurements of hourly O3 concentrations co-located with NOx concentrations in stations distributed throughout Germany, we assess changes in the climate penalty, defined as the slope of ozone-temperature relationship during the period 1999–2018. We find a stronger temperature sensitivity in the urban stations over the southwestern regions, especially in the first period of the study (1999–2008).We show a decrease in the climate penalty in most of stations during the second period of the study (2009–2018), with some exceptions (e.g. Berlin) where the climate penalty did not show significant changes. To examine the impacts of NOx reductions on the O3 sensitivity to temperature, we propose a statistical approach based on generalized additive models (GAMs) to describe ozone production rates, inferred from hourly observations, as a function of NOx and temperature, among other variables relevant during the O3 production. We find lower O3 production rates during the second period (2009–2018) at most stations and a decreasing sensitivity to temperature, pointing out that lowering NOx concentrations resulted in decreasing O3 production rates. However, we also observe changes in the shape of the function representing the O3-temperature relationship, which indicate that NOx reductions alone can not explain the changes in the temperature dependence of O3. Our analysis would suggest that decreasing NOx concentrations are not the only factor causing the observed changes in the climate penalty factor.

scholarly journals Photochemical production of ozone and emissions of NO<sub><i>x</i></sub> and CH<sub>4</sub> in the San Joaquin Valley

2019 ◽  
Vol 19 (16) ◽  
pp. 10697-10716 ◽  
Author(s):  
Justin F. Trousdell ◽  
Dani Caputi ◽  
Jeanelle Smoot ◽  
Stephen A. Conley ◽  
Ian C. Faloona
Keyword(s):  
Potential Temperature ◽  
San Joaquin Valley ◽  
Nitrogen Fertilizers ◽  
Ozone Production ◽  
Highway Traffic ◽  
Production Rates ◽  
Near Surface ◽  
Horizontal Advection ◽  
Photochemical Production ◽  
Entrainment Mixing

Abstract. Midday summertime flight data collected in the atmospheric boundary layer (ABL) of California's San Joaquin Valley (SJV) are used to investigate the scalar budgets of NOx, O3, and CH4, in order to quantify the individual processes that control near-surface concentrations, yet are difficult to constrain from surface measurements alone: these include, most importantly, horizontal advection and entrainment mixing from above. The setting is a large mountain–valley system with a small aspect ratio, where topography and persistent temperature inversions impose strong restraints on ABL ventilation. In conjunction with the observed time rates of change this airborne budgeting technique enables us to deduce net photochemical ozone production rates and emission fluxes of NOx and CH4. Estimated NOx emissions from our principal flight domain averaged 216 (±33) t d−1 over six flights in July and August, which is nearly double the California government's NOx inventory for the surrounding three-county region. We consider several possibilities for this discrepancy, including the influence of wildfires, the temporal bias of the airborne sampling, instrumental interferences, and the recent hypothesis presented by Almaraz et al. (2018) of localized high soil NO emissions from intensive agricultural application of nitrogen fertilizers in the region and find the latter to be the most likely explanation. The methane emission average was 438 Gg yr−1 (±143), which also exceeds the emissions inventory for the region by almost a factor of 2. Measured ABL ozone during the six afternoon flights averaged 74 ppb (σ=9.8 ppb). The average midafternoon ozone rise of 2.8 ppb h−1 was found to be comprised of −0.8 ppb h−1 due to horizontal advection of lower O3 levels upwind, −2.5 ppb h−1 from dry deposition loss, −0.5 ppb h−1 from dilution by entrainment mixing, and 6.9 ppb h−1 net in situ photochemical production. The O3 production rates exhibited a dependence on NO2 concentrations (r2=0.35) and no discernible dependence on methane concentrations (r2∼0.02), which are correlated with many of the dominant volatile organic compounds in the region, suggesting that the ozone chemistry was predominantly NOx-limited on the flight days. Additionally, in order to determine the heterogeneity of the different scalars, autocorrelation lengths were calculated for potential temperature (18 km), water vapor (18 km), ozone (30 km), methane (27 km), and NOx (28 km). The spatially diffuse patterns of CH4 and NOx seem to imply a preponderance of broad areal sources rather than localized emissions from cities and/or highway traffic within the SJV.

scholarly journals Observing Entrainment Mixing, Photochemical Ozone Production, and Regional Methane Emissions by Aircraft Using a Simple Mixed-Layer Model

2016 ◽  
Author(s):  
Justin F. Trousdell ◽  
Stephen A. Conley ◽  
Andy Post ◽  
Ian C. Faloona
Keyword(s):  
Boundary Layer ◽  
Mixed Layer ◽  
Irrigation Management ◽  
Methane Emissions ◽  
Ozone Production ◽  
Published Data ◽  
Layer Model ◽  
Production Rates ◽  
Photochemical Production ◽  
Mixed Layer Model

Abstract. In situ flight data from two distinct campaigns during winter and summer seasons in the San Joaquin Valley (SJV) of California are used to calculate boundary layer entrainment rates, ozone photochemical production rates, and regional methane emissions. Flights near Fresno, California in January and February 2013 were conducted in concert with the NASA DISCOVER–AQ project. The second campaign (ArvinO3), consisting of eleven days of flights spanning June through September 2013 and in June 2014 focused on the southern end of the SJV between Bakersfield and the small town of Arvin, California, a region notorious for frequent violations of ozone air quality standards. Entrainment velocities, the parameterized rates at which free tropospheric air is incorporated into the atmospheric boundary layer (ABL), are estimated from a detailed budget of the inversion base height. During the winter campaign near Fresno, we find an average midday entrainment velocity of 1.5 cm s−1, and a maximum of 2.4 cm s−1. The entrainment velocities derived during the summer months near Bakersfield averaged 3 cm s−1 (ranging from 0.9–6.5 cm s−1), consistent with stronger surface heating in the summer months. Using published data on boundary layer heights we find that entrainment rates across the Central Valley of California have a bimodal annual distribution peaking in spring and fall when the lower tropospheric stability (LTS) is changing most rapidly. Applying the entrainment velocities to a simple mixed–layer model of three other scalars (O3, CH4, and H2O), we solve for ozone photochemical production rates and find wintertime ozone production (2.8 ± 0.7 ppb h−1) to be about one-third as large as in the summer months (8.2 ± 3.1 ppb h−1). Moreover, the summertime ozone production rates observed above Bakersfield/Arvin exhibit an inverse relationship to a proxy for the VOC : NOx ratio (aircraft [CH4] divided by surface [NO2]), consistent with a NOx–limited photochemical environment. A similar budget closure approach is used to derive the regional emissions of methane, yielding 100 Gg yr−1 for the winter near Fresno and 170 Gg yr−1 in the summer around Bakersfield. These estimates are 3.6 and 2.4 times larger, respectively, than current state inventories suggest. Finally, by performing a boundary layer budget for water vapour, surface evapotranspiration rates appear to be consistently ~ 55 % of the reference values reported by the California Irrigation Management Information System (CIMIS) for nearby weather stations.

scholarly journals Constraints on instantaneous ozone production rates and regimes during DOMINO derived using in-situ OH reactivity measurements

2012 ◽  
Vol 12 (15) ◽  
pp. 7269-7283 ◽  
Author(s):  
V. Sinha ◽  
J. Williams ◽  
J. M. Diesch ◽  
F. Drewnick ◽  
M. Martinez ◽  
...  
Keyword(s):  
Nitrogen Oxides ◽  
Point Sources ◽  
Ozone Production ◽  
Strong Wind ◽  
Production Rates ◽  
Air Masses ◽  
North Eastern ◽  
Marine Air ◽  
North Western

Abstract. In this study air masses are characterized in terms of their total OH reactivity which is a robust measure of the "reactive air pollutant loading". The measurements were performed during the DOMINO campaign (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) held from 21/11/2008 to 08/12/2008 at the Atmospheric Sounding Station – El Arenosillo (37.1° N–6.7° W, 40 m a.s.l.). The site was frequently impacted by marine air masses (arriving at the site from the southerly sector) and air masses from the cities of Huelva (located NW of the site), Seville and Madrid (located NNE of the site). OH reactivity values showed strong wind sector dependence. North eastern "continental" air masses were characterized by the highest OH reactivities (average: 31.4 ± 4.5 s−1; range of average diel values: 21.3–40.5 s−1), followed by north western "industrial" air masses (average: 13.8 ± 4.4 s−1; range of average diel values: 7–23.4 s−1) and marine air masses (average: 6.3 ± 6.6 s−1; range of average diel values: below detection limit −21.7 s−1), respectively. The average OH reactivity for the entire campaign period was ~18 s−1 and no pronounced variation was discernible in the diel profiles with the exception of relatively high values from 09:00 to 11:00 UTC on occasions when air masses arrived from the north western and southern wind sectors. The measured OH reactivity was used to constrain both diel instantaneous ozone production potential rates and regimes. Gross ozone production rates at the site were generally limited by the availability of NOx with peak values of around 20 ppbV O3 h−1. Using the OH reactivity based approach, derived ozone production rates indicate that if NOx would no longer be the limiting factor in air masses arriving from the continental north eastern sector, peak ozone production rates could double. We suggest that the new combined approach of in-situ fast measurements of OH reactivity, nitrogen oxides and peroxy radicals for constraining instantaneous ozone production rates, could significantly improve analyses of upwind point sources and their impact on regional ozone levels.

3D analysis of high ozone production rates observed during the ESCOMPTE campaign

2005 ◽  
Vol 74 (1-4) ◽  
pp. 477-505 ◽  
Author(s):  
Isabelle Coll ◽  
Stéphanie Pinceloup ◽  
Pascal E. Perros ◽  
Gérard Laverdet ◽  
Georges Le Bras
Keyword(s):  
Ozone Production ◽  
3D Analysis ◽  
Production Rates

scholarly journals Closing the peroxy acetyl (PA) radical budget: observations of acyl peroxy nitrates (PAN, PPN, and MPAN) during BEARPEX 2007

2009 ◽  
Vol 9 (2) ◽  
pp. 9879-9926 ◽  
Author(s):  
B. W. LaFranchi ◽  
G. M. Wolfe ◽  
J. A. Thornton ◽  
S. A. Harrold ◽  
E. C. Browne ◽  
...  
Keyword(s):  
Urban Areas ◽  
Ozone Production ◽  
Methyl Glyoxal ◽  
Good Test ◽  
Peroxy Nitrates ◽  
Detailed Evaluation ◽  
Urban Plume ◽  
No2 Formation ◽  
Urban Plumes ◽  
Detailed Chemical

Abstract. Acyl peroxy nitrates (APNs, also known as PANs) are formed from the oxidation of aldehydes and other oxygenated VOC (oVOC) in the presence of NO2. Formation of APNs suppresses NOx (NOx≡NO+NO2) in urban areas and enhances NOx downwind in urban plumes, increasing the rate of ozone production throughout an urban plume. APNs also redistribute NOx on global scales, enhancing NOx and thus ozone production. There are both anthropogenic and biogenic oVOC precursors to APNs, but a detailed evaluation of their chemistry against observations has proven elusive. Here we describe measurements of PAN, PPN, and MPAN along with the majority of chemicals that participate in their production and loss, including OH, HO2, numerous oVOC, and NO2. Observations were made during the Biosphere Effects on AeRosols and Photochemistry Experiment (BEARPEX 2007) in the outflow of the Sacramento urban plume. These observations are used to evaluate a detailed chemical model of APN ratios and concentrations. We find the ratios of APNs are nearly independent of the loss mechanisms and thus an especially good test of our understanding of their sources. We show that oxidation of methylvinyl ketone, methacrolein, methyl glyoxal, biacetyl and acetaldehyde are all significant sources of the PAN+peroxy acetyl (PA) radical reservoir, with methylvinyl ketone (MVK) often being the primary non-acetaldehyde source. At high temperatures, oxidation of non-acetaldehyde PA radical sources contributes over 60% to the total PA production rate. An analysis of absolute APN concentrations reveals a missing APN sink that can be resolved by increasing the PA+∑RO2 rate constant by a factor of 3.

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