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Athanassiadis, G.; Rao, S. Trivikrama; Ku, Jia‐Yeong; Clark, Richard D.

doi:10.1023/a:1020456018087

Cited by 27 publications

(10 citation statements)

References 18 publications

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“…The range of NME for different measurement sites is also the lowest for peak hours. Model-measurements differences during mornings and evenings are partially caused by the way the model resolves PBL, because vertical mixing is the primary factor determining morning ozone buildup (Zwoździak et al 2008;Athanassiadis et al 2002;Lee et al 2006). This factor is important especially in clear-sky conditions, characteristic for high ozone episodes.…”

Section: Model Evaluationmentioning

confidence: 99%

The role of precursor emissions on ground level ozone concentration during summer season in Poland

2017

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Three online coupled chemical transport model simulations were analyzed for three summer months of 2015 in Poland. One of them was run with default emission inventory, the other two with NO x and VOC emissions reduced by 30%, respectively. Obtained ozone concentrations were evaluated with data from air quality measurement stations and ozone sensitivity to precursor emissions was estimated by ozone concentration differences between simulations and with the use of indicator ratios. They were calculated based on modeled mixing ratios of ozone, total reactive nitrogen and its components, nitric acid and hydrogen peroxide. The results show that the model overestimates ozone concentrations with the largest errors in the morning and evening, which is primarily related to the way vertical mixing is resolved by the model. Better model performance for ozone is achieved in rural than urban environment, as PBL and mixing mechanisms play more significant role in urban areas. Modeled ozone shows mixed sensitivity to precursor concentrations, similarly to other European regions, but indicator ratios have different values than are found in literature, particularly H 2 O 2 /HNO 3 is larger than in southern Europe. However, indicator ratios often differ between locations and transition values need to be established individually for a given region.

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Section: Model Evaluationmentioning

confidence: 99%

The role of precursor emissions on ground level ozone concentration during summer season in Poland

2017

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“…To compare ventilation conditions between the two different simulation scenarios in the target area, the ventilation rate [or ventilation coefficient (VC)] was estimated using the Penn State/NCAR meteorological model (MM5, Grell et al 1994). In general, the VC (m 2 s -1 )[= h (m) × U (m s -1 )] below the planetary boundary layer (PBL) can be defined as the product of the mixing height (MH, h) and the wind speed ( U ), simulated by the MM5, vertically averaged over the mixing layer during morning hours (e.g., 0700 -1000 LST) (Athanassiadis et al 2002). Table 1 provides the comparison of VCs between HV and LV conditions (from 0700 to 1000 LST).…”

Section: Study Approachmentioning

confidence: 99%

“…A comparison of SO 2 concentrations between the TO-TAL (TOTAL_HV and TOTAL_LV) and BASE cases (BASE_HV and BASE_LV) under different ventilation conditions indicates that considerable quantities of SO 2 on 16 October can be produced in the source regions due to the ventilation effect during the early morning and daytime photochemistry. Note that the early morning is defined as the time when the ventilation rate is high (0700 -1000 LST, Athanassiadis et al 2002) and the daytime as the time when photochemical reactions are active (0600 -1800 LST). Table 4 shows the simulated SO 2 concentrations for TOTAL_HV and TOTAL_LV and without photochemical oxidation of the four RSCs (BASE_HV and BASE_LV) in the target source region (YS) and its downwind regions (e.g., MY and BS) during the study period.…”

Section: Effects Of Ventilation and Photochemical Oxidation Of Rscs Omentioning

confidence: 99%

“…In general, air pollutants (and/or RSCs) released from various urban emission sources are transported to nearby dwellings and communities, and thus can lead to serious air pollution problems, and are affected by meteorological conditions and geographical features (Berman et al 1999;Athanassiadis et al 2002;Wargocki et al 2002). For example, ventilation affects ozone (O 3 ) accumulation in the northeastern United States (Berman et al 1999).…”

Section: Introductionmentioning

confidence: 99%

“…On high-O 3 episode days, the ventilation rate during the early morning hours was nearly 50% lower than that on non-episode days. Under a high-pressure system with low and/or closed ventilations, high concentrations (about 120 ppb) of air pollutants (e.g., O 3 ) occurred in downtown Philadelphia, Pennsylvania in July 1999 (Athanassiadis et al 2002). Some previous reports on the dispersion of odorous pollutants such as RSCs and their impact on air quality in downwind regions are available (Mussio et al 2001;Lin et al 2006;Song et al 2008Song et al , 2009a.…”

Section: Introductionmentioning

confidence: 99%

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Meteorological and Chemical Behavior of Gaseous Sulfur Compounds in and around an Urban Valley

Song¹,

Kim²,

Shon³

2010

Terr. Atmos. Ocean. Sci.

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The effects of photochemical oxidation of reduced sulfur compounds (RSCs: H 2 S, CH 3 SH, DMS, and DMDS) on SO 2 production were evaluated at high (HV) and low ventilation (LV) conditions, based on a CALPUFF dispersion model coupled with photo-chemical oxidation mechanisms for four RSCs. The RSC emission concentrations used in the modeling were measured in and around an urban valley during a field campaign held in October 2008. SO 2 production with LV (up to 156 ppb at 0900 LST) was found to be significantly higher than that with HV (up to 30 ppb). SO 2 produced by photochemical oxidation of RSCs with LV (78% of total SO 2 concentrations) was much higher than that with HV (27%), while the predominant RSC species were similar: DMDS (≥ 60% of the total contributions) with HV and LV when compared to three other RSCs (< 20%). The difference in SO 2 concentration between HV and LV might be caused by the combined effects of photochemical oxidation of RSCs and ventilation condition.

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Relationship between boundary layer heights and growth rates with ground‐level ozone in Houston, Texas

et al. 2014

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Measurements and predictions of ambient ozone (O 3 ), planetary boundary layer (PBL) height, the surface energy budget, wind speed, and other meteorological parameters were made near downtown Houston, Texas, and were used to investigate meteorological controls on elevated levels of ground-level O 3 . Days during the study period (1 April 2009 to 31 December 2010 for measurements and 15 April 2009 to 17 October 2009 for modeled) were classified into low (LO 3 ) and high ozone (HO 3 ) days. The majority of observed high HO 3 days occurred in a postfrontal environment. Observations showed there is not a significant difference in daily maximum PBL heights on HO 3 and LO 3 days. Modeling results showed large differences between maximum PBL heights on HO 3 and LO 3 days. Nighttime and early morning observed and modeled PBL heights are consistently lower on HO 3 days than on LO 3 days. The observed spring LO 3 days had the most rapid early morning PBL growth (~350 m h À1 ) while the fall HO 3 group had the slowest (~200 m h À1 ). The predicted maximum average hourly morning PBL growth rates were greater on HO 3(624 m h À1 ) days than LO 3 days (361 m h À1 ). Observed turbulent mixing parameters were up to 2-3 times weaker on HO 3 days, which indicate large-scale subsidence associated with high-pressure systems (leading to clear skies and weak winds) substantially suppresses mixing. Lower surface layer ventilation coefficients were present in the morning on HO 3 days in the spring and fall, which promotes the accumulation of O 3 precursors near the surface.

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Untitled

Cited by 27 publications

References 18 publications

The role of precursor emissions on ground level ozone concentration during summer season in Poland

The role of precursor emissions on ground level ozone concentration during summer season in Poland

Meteorological and Chemical Behavior of Gaseous Sulfur Compounds in and around an Urban Valley

Relationship between boundary layer heights and growth rates with ground‐level ozone in Houston, Texas

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