Aerosol pH and liquid water content determine when particulate matter is sensitive to ammonia and nitrate availability

Nenes, Athanasios; Pandis, Spyros N.; Weber, R. J.; Russell, Armistead G.

doi:10.5194/acp-2019-840

Cited by 5 publications

(4 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition to the major species NH4 + /NH3, SO4 2-, and NO3 -/HNO3, the dataset also contained variable concentrations of Cl -/HCl and the non-volatile species Na + , Ca 2+ , K + and Mg 2+ (not shown in the table). A total of more than 7700 data points were available for evaluation (Nenes et al, 2019), with ~7200 data points having relative humidities above 35 % and spanning a temperature range from 252 to 305 K. Given that the MOSAIC box model requiredin its current implementationa manual setup of each input condition, a few data points were selected from the total available in each dataset to compare against the corresponding predictions from the other models. The points were selected to span the range of RH and sulfate amounts encountered in the datasets.…”

Section: Description Of Datasets and Calculationsmentioning

confidence: 99%

The Acidity of Atmospheric Particles and Clouds

Pye¹,

Nenes²,

Alexander³

et al. 2019

Preprint

Self Cite

166

View full text Add to dashboard Cite

Abstract. Acidity, defined as pH, is a central component of aqueous chemistry. In the atmosphere, the acidity of condensed phases (aerosol particles, cloud water, and fog droplets) governs the phase partitioning of semi-volatile gases such as HNO3, NH3, and HCl, as well as chemical reaction rates. It has implications for the atmospheric lifetime of pollutants, deposition, and human health. Despite its fundamental role in atmospheric processes, only recently has this field seen a growth in the number of studies on particle acidity. Even with this growth, many fine particle pH estimates must be based on thermodynamic model calculations since no operational techniques exist for direct measurements. Current information indicates acidic fine particles are ubiquitous, but observationally-constrained pH estimates are limited in spatial and temporal coverage. Clouds and fogs are also generally acidic, but to a lesser degree than particles, and have a range of pH that is quite sensitive to anthropogenic emissions of sulfur and nitrogen oxides, as well as ambient ammonia. Historical measurements indicate that cloud and fog droplet pH has changed in recent decades in response to controls on anthropogenic emissions, while the limited trend data for aerosol particles indicates acidity may be relatively constant due to the semi-volatile nature of the key acids and bases and buffering in particles. This paper reviews and synthesizes the current state of knowledge on the acidity of atmospheric condensed phases, specifically particles and cloud droplets. It includes recommendations for estimating acidity and pH, standard nomenclature, a synthesis of current pH estimates based on observations, and new model calculations on the local and global scale.

show abstract

Section: Description Of Datasets and Calculationsmentioning

confidence: 99%

The Acidity of Atmospheric Particles and Clouds

Pye¹,

Nenes²,

Alexander³

et al. 2019

Preprint

Self Cite

166

View full text Add to dashboard Cite

show abstract

“…For instance, 7 y were required for the Rockies to show a significant decrease of NO 3 − wet deposition, while clear and rapid (1-2 y after 2002) responses were found in the Upper Midwest, Northeast, South, and Central United States. Response times between decreases of NO x emissions and NO y wet deposition were associated with the reduction rates of NO x emissions, and the atmospheric acidity and humidity (23)(24)(25), which determine the gas-aerosol partitioning of NO 3 − . Overall, clear consistency exists between changes of NO x emissions and NO y wet deposition in the temporal trends in all regions.…”

Section: Significancementioning

confidence: 99%

Ammonia emission abatement does not fully control reduced forms of nitrogen deposition

Tan

Seinfeld

2020

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Human activities and population growth have increased the natural burden of reactive nitrogen (N) in the environment. Excessive N deposition on Earth’s surface leads to adverse feedbacks on ecosystems and humans. Similar to that of air pollution, emission control is recognized as an efficient means to control acid deposition. Control of nitrogen oxides (NOx = NO + NO2) emissions has led to reduction in deposition of oxidized nitrogen (NOy, the sum of all oxidized nitrogen species, except nitrous oxide [N2O]). Reduced forms of nitrogen (NHx = ammonia [NH3] + ammonium [NH4+]) deposition have, otherwise, increased, offsetting the benefit of reduction in NOy deposition. Stringent control of NH3 emissions is being considered. In this study, we assess the response of N deposition to N emission control on continental regions. We show that significant reduction of NHx deposition is unlikely to be achieved at the early stages of implementing NH3 emission abatement. Per-unit NH3 emission abatement is shown to result in only 60–80% reduction in NHx deposition, which is significantly lower than the demonstrated 80–120% benefit of controlling NOx emissions on NOy deposition. This 60–80% effectiveness of NHx deposition reduction per unit NH3 emission abatement reflects, in part, the effects of simultaneous reductions in NOx and SO2 emissions.

show abstract

“…Zheng et al, 2015) might alternatively be the neutralizing agent for those acidic gases. However, there is little investigation on the competition between the most studied NH 3 and other alkaline species in particulate sulfate and nitrate formation (Guo et al, 2018;Vasilakos et al, 2018;Nenes et al, 2019). Given the large number of megacities in eastern coastal China where sea salt influence can be significant and the severely polluted megacities in northwest China where dust influence is strong, such investigation is highly desirable.…”

Section: Introductionmentioning

confidence: 99%

Effects of NH3 and alkaline metals on the formation of particulate sulfate and nitrate in wintertime Beijing

Huang

Duan

et al. 2020

Science of The Total Environment

View full text Add to dashboard Cite

Nitrate Ammonia Alkaline metals of H 2 SO 4 and HNO 3 to form particulate SO 4 2− and NO 3 −. The relationships between mass fractions of SO 4 2− and NO 3 − in those ranges of different alkaline metal ion content also suggested that alkaline metal ions participate in the competing neutralization reaction of sulfate and nitrate. The implication of the current study is that in some regions the chemistry to incorporate sulfur and nitrogen into particle phase might be largely affected by desert/fugitive dust and sea salt, besides NH 3 . This implication is particularly relevant in coastal China and those areas with strong influence of dust storm in the North China Plain (NCP), both of which host a number of megacities with deteriorating air quality.

show abstract

Aerosol pH and liquid water content determine when particulate matter is sensitive to ammonia and nitrate availability

Cited by 5 publications

References 18 publications

The Acidity of Atmospheric Particles and Clouds

The Acidity of Atmospheric Particles and Clouds

Ammonia emission abatement does not fully control reduced forms of nitrogen deposition

Effects of NH3 and alkaline metals on the formation of particulate sulfate and nitrate in wintertime Beijing

Contact Info

Product

Resources

About