scholarly journals The potential role of organics in new particle formation and initial growth in the remote tropical upper troposphere

2020 ◽  
Author(s):  
Agnieszka Kupc ◽  
Christina J. Williamson ◽  
Anna L. Hodshire ◽  
Jan Kazil ◽  
Eric Ray ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Cloud Condensation Nuclei ◽  
Lower Troposphere ◽  
Particle Formation ◽  
Initial Growth ◽  
New Particle Formation ◽  
Upper Troposphere ◽  
Model Studies ◽  
Nucleation Mechanisms

Abstract. Global observations and model studies indicate that new particle formation (NPF) in the upper troposphere (UT) and subsequent particles supply 40–60 % of cloud condensation nuclei (CCN) in the lower troposphere, thus affecting the Earth's radiative budget. There are several plausible nucleation mechanisms and precursor species in this atmospheric region, which, in the absence of observational constraints, lead to uncertainties in modeled aerosols. In particular, the type of nucleation mechanism and concentrations of nucleation precursors, in part, determine the spatial distribution of new particles and resulting spatial distribution of CCN from this source. Although substantial advances in understanding NPF have been made in recent years, NPF processes in the UT in pristine marine regions are still poorly understood and are inadequately represented in global models. Here, we evaluate commonly used and state-of-the-art NPF schemes in a Lagrangian box model to assess which schemes and precursor concentrations best reproduce detailed in situ observations. Using measurements of aerosol size distributions (0.003 

scholarly journals Wintertime new particle formation and its contribution to cloud condensation nuclei in the Northeastern United States

2020 ◽  
Vol 20 (4) ◽  
pp. 2591-2601
Author(s):  
Fangqun Yu ◽  
Gan Luo ◽  
Arshad Arjunan Nair ◽  
James J. Schwab ◽  
James P. Sherman ◽  
...  
Keyword(s):  
United States ◽  
Particle Number ◽  
Hydrological Cycle ◽  
Cloud Condensation Nuclei ◽  
Particle Formation ◽  
New Particle Formation ◽  
Northeastern United States ◽  
Condensation Nuclei ◽  
Upper Troposphere ◽  
Inorganic Species

Abstract. Atmospheric particles can act as cloud condensation nuclei (CCN) and modify cloud properties and precipitation and thus indirectly impact the hydrological cycle and climate. New particle formation (NPF or nucleation), frequently observed at locations around the globe, is an important source of ultrafine particles and CCN in the atmosphere. In this study, wintertime NPF over the Northeastern United States (NEUS) is simulated with WRF-Chem coupled with a size-resolved (sectional) advanced particle microphysics (APM) model. Model-simulated variations in particle number concentrations during a 2-month period (November–December 2013) are in agreement with corresponding measurements taken at Pinnacle State Park (PSP), New York, and Appalachian State University (APP), North Carolina. We show that, even during wintertime, regional nucleation occurs and contributes significantly to ultrafine-particle and CCN number concentrations over the NEUS. The model shows that, due to low biogenic emissions during this period, wintertime regional nucleation is solely controlled by inorganic species and the newly developed ternary ion-mediated nucleation scheme is able to capture the variations in observed particle number concentrations (ranging from ∼200 to 20 000 cm−3) at both PSP and APP. Total particle and CCN number concentrations dramatically increase following NPF events and have the highest values over the Ohio Valley region, where elevated [SO2] is sustained by power plants. Secondary particles dominate particle number abundance over the NEUS, and their fraction increases with altitude from ≳85 % near the surface to ≳95 % in the upper troposphere. The secondary fraction of CCN also increases with altitude, from 20 %–50 % in the lower boundary layer to 50 %–60 % in the middle troposphere to 70 %–85 % in the upper troposphere.

scholarly journals Evaluation on the role of sulfuric acid in the mechanisms of new particle formation for Beijing case

2011 ◽  
Vol 11 (8) ◽  
pp. 24165-24189 ◽  
Author(s):  
Z. B. Wang ◽  
M. Hu ◽  
D. L. Yue ◽  
J. Zheng ◽  
R. Y. Zhang ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Particle Number ◽  
Particle Formation ◽  
Urban Atmosphere ◽  
Limiting Factors ◽  
New Particle Formation ◽  
H2so4 Concentration ◽  
Nucleation Mechanisms ◽  
Better Than

Abstract. New particle formation (NPF) is considered as an important mechanism for gas-to-particle transformation, and gaseous sulfuric acid is believed as a curcial precursor. Up to now few field-based studies on nucleation mechanisms and the role of sulfuric acid were conducted in China. In this study, simultaneously measurements of particle number size distributions and gaseous sulfuric acid concentrations were performed from July to September in 2008. Totally, 22 new particle formation events were observed during the entire 85 campaign days. The results show that the condensation sink of pre-existing particles is one of the limiting factors to determine the occurrence of nucleation events in Beijing. The concentrations of gaseous sulfuric acid show good correlations with freshly nucleated particles (N3–6) and formation rates (J3 and J1.5). The power-law relationship between H2SO4 concentration and N3–6 or J was adopted to explore the nucleation mechanism. The exponents range from 1 to 5. More than half of the NPF events exhibit an exponent larger than 2.5. For these cases, the thermodynamic process works better than the activation or kinetic nucleation theories to explain the nucleation events in urban atmosphere of Beijing.

scholarly journals Impact of temperature dependence on the possible contribution of organics to new particle formation in the atmosphere

2017 ◽  
Vol 17 (8) ◽  
pp. 4997-5005 ◽  
Author(s):  
Fangqun Yu ◽  
Gan Luo ◽  
Alexey B. Nadykto ◽  
Jason Herb
Keyword(s):  
North America ◽  
Temperature Dependence ◽  
Radiative Forcing ◽  
Particle Number ◽  
Cloud Condensation Nuclei ◽  
Lower Troposphere ◽  
Particle Formation ◽  
Strong Impact ◽  
New Particle Formation ◽  
Aerosol Model

Abstract. Secondary particles formed via new particle formation (NPF) dominate cloud condensation nuclei (CCN) abundance in most parts of the troposphere and are important for aerosol indirect radiative forcing (IRF). Laboratory measurements have shown that certain organic compounds can significantly enhance the binary nucleation of sulfuric acid and H2O. According to our recent study comparing particle size distributions measured in nine forest areas in North America with those predicted by a global size-resolved aerosol model, current H2SO4–organics nucleation parameterizations appear to significantly overpredict NPF and particle number concentrations in summer. The lack of temperature dependence in the current H2SO4–organics nucleation parameterization has been suggested to be a possible reason for the observed overprediction. In this work, H2SO4–organics clustering thermodynamics from quantum chemical studies has been employed to develop a scheme to incorporate temperature dependence into H2SO4–organics nucleation parameterization. We show that temperature has a strong impact on H2SO4–organics nucleation rates and may reduce the nucleation rate by  ∼  1 order of magnitude per 10 K of temperature increase. The particle number concentrations in summer over North America based on the revised scheme is a factor of more than 2 lower, which is in much better agreement with the observations. With the temperature-dependent H2SO4–organics nucleation parameterization, the summer CCN concentrations in the lower troposphere in the Northern Hemisphere are about 10–30 % lower compared to the temperature-independent parameterization. This study highlights the importance of the temperature effect and its impacts on NPF in the global modeling of aerosol number abundance.

Studies of the connection between condensable trace gases and aerosol particles in Svalbard

2021 ◽  
Author(s):  
Tuuli Lehmusjärvi ◽  
Roseline Thakur ◽  
Lisa Beck ◽  
Mikko Sipilä ◽  
Tuija Jokinen
Keyword(s):  
Cloud Condensation Nuclei ◽  
Regional Climate ◽  
High Arctic ◽  
Particle Formation ◽  
Urban Environments ◽  
The Arctic ◽  
New Particle Formation ◽  
Iodic Acid ◽  
Summer Time

<p>In the high Arctic, the climate is warming faster than in the lower latitudes due to the Arctic amplification. Sea ice is melting and permafrost is thawing, and the scarce vegetation of the Arctic is changing rapidly. All these varying conditions will have an impact on possible emission sources of aerosol precursor gases, thus affecting the New Particle Formation (NPF) in the Arctic atmosphere, of which we still know very little. It is important to study the NPF events, which parameters affect the aerosol phase and how these newly formed aerosols can grow into cloud condensation nuclei sizes. Only then, it is possible to understand how climate change is affecting the aerosol population, clouds and regional climate of the pristine Arctic. The role of the precursor gases like Sulphuric Acid (SA), Iodic Acid (IA), Methane Sulphonic Acid (MSA) and Highly Oxygenated organic Molecules (HOM) in NPF in boreal and urban environments has been explored to a great extent. However, the role of these precursor gases in NPF events in remote locations - devoid of pollution sources and the vegetation - is still ambiguous. Therefore, it is crucial to conduct long-term measurements to study the composition and concentrations of aerosol precursors molecules, nanoparticles and air ions in remote and climatically fragile place like Ny-Ålesund in the Arctic. This research location is not only a natural pristine laboratory to understand the atmospheric processes but also acts as a climate mirror reflecting the most drastic changes happening in the atmosphere and cryosphere. In this study, we aim to enhance the understanding of the role of aerosol precursor gases in new particle formation in Ny-Ålesund, Svalbard.</p><p>            We have studied aerosol particle formation now for almost three years in the Ny-Ålesund research village in Svalbard (78° 55' 24.7368'' N, 11° 54' 35.6220'' E.) with the Neutral cluster and Air Ion Spectrometer (NAIS) measuring ~1-40 nm particles and ions. We have conducted measurements with a Chemical Ionization Atmospheric Pressure interface Time Of Flight (CI-APi-TOF) mass spectrometer to understand the chemical composition of organic precursors vapours and abundance of inorganic aerosol precursor gases such as SA, MSA and IA. Additionally,  we have studied the emission and composition of volatile organic compounds on the site during summer-time.</p><p>            In this study, we report the time series concentrations of the most common aerosol precursor gases like SA, MSA, IA and HOM from the period 28.6.-25.7.2019, which are responsible for the initiation and/or growth of particles. The variability in the concentrations of these vapours is compared between NPF event and non-event days. The study explores also the role of meteorological parameters like wind speed, wind direction, temperature and humidity on NPF processes.</p>

scholarly journals Evaluation on the role of sulfuric acid in the mechanisms of new particle formation for Beijing case

2011 ◽  
Vol 11 (24) ◽  
pp. 12663-12671 ◽  
Author(s):  
Z. B. Wang ◽  
M. Hu ◽  
D. L. Yue ◽  
J. Zheng ◽  
R. Y. Zhang ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Particle Formation ◽  
Urban Atmosphere ◽  
Limiting Factor ◽  
New Particle Formation ◽  
H2so4 Concentration ◽  
Nucleation Mechanisms ◽  
Source And Sink ◽  
Better Than

Abstract. New particle formation (NPF) is considered as an important mechanism for gas-to-particle transformation, and gaseous sulfuric acid is believed as a crucial precursor. Up to now few field-based studies on nucleation mechanisms and the role of sulfuric acid were conducted in China. In this study, simultaneously measurements of particle number size distributions and gaseous sulfuric acid concentrations were performed from July to September in 2008. Totally, 22 new particle formation events were observed during the entire 85 campaign days. The results show that in the case of both higher source and sink values, the result of the competition between source and sink is more likely the key limiting factor to determine the observation of NPF events in Beijing. The concentrations of gaseous sulfuric acid show good correlations with freshly nucleated particles (N3-6 and formation rates (J3 and J1.5. The power-law relationship between H2SO4 concentration and N3-6 or J is adopted to explore the nucleation mechanism. The exponents are showed a great range (from 1 to 7). More than half of the NPF events exhibit an exponent larger than 2.5. For these cases, the thermodynamic process works better than the activation or kinetic nucleation theories to explain the nucleation events in urban atmosphere of Beijing.

scholarly journals Impact of temperature dependence on the possible contribution of organics to new particle formation in the atmosphere

2016 ◽  
Author(s):  
Fangqun Yu ◽  
Gan Luo ◽  
Alexey B. Nadykto ◽  
Jason Herb
Keyword(s):  
North America ◽  
Temperature Dependence ◽  
Radiative Forcing ◽  
Particle Number ◽  
Cloud Condensation Nuclei ◽  
Lower Troposphere ◽  
Particle Formation ◽  
Strong Impact ◽  
New Particle Formation ◽  
Aerosol Model

Abstract. Secondary particles formed via new particle formation (NPF) dominate cloud condensation nuclei (CCN) abundance in most parts of the troposphere and are important for aerosol indirect radiative forcing (IRF). Laboratory measurements have shown that certain organic compounds can significantly enhance binary nucleation of sulfuric acid and H2O. According to our recent study comparing particle size distributions measured in nine forest areas in North America with those predicted by a global size-resolved aerosol model, current H2SO4-Organics nucleation parameterizations appear to significantly over-predict NPF and particle number concentrations in summer. The lack of the temperature dependence in the current H2SO4-Organics nucleation parameterization has been suggested to be a possible reason for the observed over-prediction. In this work, H2SO4-Organics clustering thermodynamics from quantum-chemical studies has been employed to develop a scheme to incorporate temperature dependence into H2SO4-Organics nucleation parameterization. We show that temperature has a strong impact on H2SO4-Organics nucleation rates, and may reduce nucleation rate by ~ one order of magnitude per 10 K of the temperature increase. The particle number concentrations in summer over North America based on the revised scheme is a factor of more than two lower, in much better agreement with the observations. With the temperature-dependent H2SO4-Organics nucleation parameterization, the summer month CCN concentrations in the lower troposphere in the northern hemisphere are about 10–30 % lower and the aerosol first IRF about 0.5–1.0 W/m2 less negative compared to the temperature independent one. This study highlights the importance of the temperature effect and its impacts on NPF in global modeling of aerosol IRF.

Particle production in the upper troposphere over the Amazon Basin

2020 ◽  
Author(s):  
Lixia Liu ◽  
Hang Su ◽  
Ulrich Pöschl ◽  
Yafang Cheng
Keyword(s):  
Amazon Basin ◽  
Particle Production ◽  
Cloud Condensation Nuclei ◽  
Aerosol Particles ◽  
Particle Formation ◽  
Dry Season ◽  
New Particle Formation ◽  
High Concentration ◽  
Fine Grid ◽  
Upper Troposphere

<p>Particle production in the upper troposphere has been reported as an important source of aerosol particles and cloud condensation nuclei in pristine environment and tropical regions and exerts significant climate effects. In this work, we develop a new organic nucleation scheme to the WRF-Chem model with extended particle size bins from 1nm to 10μm. We improve on previous coarse-resolution global simulations that approximate the highly oxygenated multifunctional organic compounds (HOMs) in a thermodynamic state by implementing kinetic calculation of HOMs and using fine-grid regional simulations. Sensitivity studies are conducted over the Amazon Basin during the dry season in 2014 to characterize the HOMs-induced new particle formation and identify its key controlling factors in Amazon. The model simulations are evaluated using aircraft observations of profiles of aerosol particles during the 2014 ACRIDICON-CHUVA campaign. We show that the new particle formation occurs mostly at the upper troposphere and modestly in the planetary boundary layer, driven by low temperature and high concentration of biogenic precursors, respectively. Including the HOMs-induced biogenic new particle formation mechanism decreases the model prediction bias of the particle number concentration in the upper troposphere by over 50%, suggesting an important role of the HOMs-induced biogenic new particle formation in the dry season over the Amazon region.</p>

scholarly journals Wintertime New Particle Formation and Its Contribution to Cloud Condensation Nuclei in the Northeastern United States

2019 ◽  
Author(s):  
Fangqun Yu ◽  
Gan Luo ◽  
Arshad Nair ◽  
James J. Schwab ◽  
James P. Sherman ◽  
...  
Keyword(s):  
United States ◽  
Particle Number ◽  
Cloud Condensation Nuclei ◽  
Particle Formation ◽  
New Particle Formation ◽  
Northeastern United States ◽  
Condensation Nuclei ◽  
Near Surface ◽  
Upper Troposphere ◽  
Inorganic Species

Abstract. Atmospheric particles can act as cloud condensation nuclei (CCN) and modify cloud properties and precipitation and thus indirectly impact the hydrological cycle and climate. New particle formation (NPF or nucleation), frequently observed at locations around the globe, is an important source of ultrafine particles and CCN in the atmosphere. In this study, wintertime NPF over the Northeastern United States (NEUS) is simulated with WRF-Chem coupled with a size-resolved (sectional) advanced particle microphysics (APM) model. Model simulated variations of particle number concentrations during a two-month period (November–December 2013) are in agreement with corresponding measurements taken at Pinnacle State Park (PSP), New York and Appalachian State University (APP), North Carolina. We show that even during wintertime, regional nucleation occurs and contributes significantly to ultrafine particle and CCN number concentrations over the NEUS. Due to low biogenic emissions during this period, wintertime regional nucleation is solely controlled by inorganic species and the newly developed ternary ion-mediated nucleation scheme is able to capture the variations of observed particle number concentrations (ranging from ~ 200–20 000 cm−3) at both PSP and APP. Total particle and CCN number concentrations dramatically increase following NPF events and have highest values over the Ohio Valley region, where elevated [SO2] is sustained by power plants. Secondary particles dominate particle number abundance over the NEUS and their fraction increases with altitude from > ~ 85 % near surface to > ~ 95 % in the upper troposphere. The secondary fraction of CCN also increases with altitude, from 20–50 % in the lower boundary layer to 50–60 % in the middle troposphere to 70–85 % in the upper troposphere. This significant contribution of wintertime nucleation to aerosols, especially those that can act as CCN, is important considering the changing paradigm of wintertime precipitation over the NEUS.

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