scholarly journals Anthropogenic pollution elevates the peak height of new particle formation from planetary boundary layer to lower free troposphere

2017 ◽  
Vol 44 (14) ◽  
pp. 7537-7543 ◽  
Author(s):  
Jiannong Quan ◽  
Yangang Liu ◽  
Quan Liu ◽  
Xingcan Jia ◽  
Xia Li ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Anthropogenic Pollution ◽  
Peak Height ◽  
Particle Formation ◽  
Free Troposphere ◽  
New Particle Formation

scholarly journals New Particle Formation and impact on CCN concentrations in the boundary layer and free troposphere at the high altitude station of Chacaltaya (5240 m a.s.l.), Bolivia

2016 ◽  
Author(s):  
C. Rose ◽  
K. Sellegri ◽  
I. Moreno ◽  
F. Velarde ◽  
M. Ramonet ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Particle Number ◽  
Particle Growth ◽  
Particle Formation ◽  
Number Concentration ◽  
Particle Number Concentration ◽  
Free Troposphere ◽  
New Particle Formation ◽  
Radiative Processes ◽  
The Impact

Abstract. Global models predict that new particle formation (NPF) is, in some environments, responsible for a substantial fraction of the total atmospheric particle number concentration and subsequently contribute significantly to cloud condensation nuclei (CCN) concentrations. NPF events were frequently observed at the highest atmospheric observatory in the world, Chacaltaya (5240 m a.s.l.), Bolivia. The present study focuses on the impact of NPF on CCN population. Neutral cluster and Air Ion Spectrometer and mobility particle size spectrometer measurements were simultaneously used to follow the growth of particles from cluster sizes down to ~ 2 nm up to CCN threshold sizes set to 50, 80 and 100 nm. Using measurements performed between January 1 and December 31 2012, we found that 61% of the 94 analysed events showed a clear particle growth and significant enhancement of the CCN-relevant particle number concentration. We evaluated the contribution of NPF events relative to the transport of pre-existing particles to the site. The averaged production of 50 nm particles during those events was 5072 cm−3, and 1481 cm−3 for 100 nm particles, with a larger contribution of NPF compared to transport, especially during the wet season. The data set was further segregated into boundary layer (BL) and free troposphere (FT) conditions at the site. The NPF frequency of occurrence was higher in the BL (48 %) compared to the FT (39 %). Particle condensational growth was more frequently observed for events initiated in the FT, but on average faster for those initiated in the BL, when the amount of condensable species was most probably larger. As a result, the potential to form new CCN was higher for events initiated in the BL (67 % against 56 % in the FT). In contrast, higher CCN number concentration increases were found when the NPF process initially occurred in the FT, under less polluted conditions. This work highlights the competition between particle growth and the removal of freshly nucleated particles by coagulation processes. The results support model predictions which suggest that NPF is an effective source of CCN in some environments, and thus may influence regional climate through cloud related radiative processes.

Does the onset of new particle formation occur in the planetary boundary layer?

2013 ◽  
Author(s):  
Hanna E. Manninen ◽  
Sander Mirme ◽  
Mikael Ehn ◽  
Katri Leino ◽  
Siegfried Schobesberger ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Particle Formation ◽  
New Particle Formation

Regional modelling of aerosol interaction with deep convection and the effect on new particle formation over Amazonia

2020 ◽  
Author(s):  
Xuemei Wang ◽  
Daniel Grosvenor ◽  
Hamish Gordon ◽  
Meinrat O. Andreae ◽  
Ken Carslaw
Keyword(s):  
Boundary Layer ◽  
Cloud Condensation Nuclei ◽  
Deep Convection ◽  
Particle Formation ◽  
Nucleation Mechanism ◽  
Transport Processes ◽  
Radiative Properties ◽  
Free Troposphere ◽  
New Particle Formation ◽  
New Particles

<p>It has been estimated that over 50% of the present-day global low-level cloud condensation nuclei (CCN) are formed from new particle formation (NPF), and that this process has a substantial effect on the radiative properties of shallow clouds (Gordon et al. 2017). In contrast, we have a very limited understanding of how NPF affects deep convective clouds. Deep clouds could interact strongly with NPF because they extend into the high free troposphere where most new particles are formed, and they are responsible for most of the vertical transport of the nucleating vapours. Andreae et al. (2018) hypothesised from ACRIDICON-CHUVA campaign that organic gas molecules are transported by deep convection to the upper troposphere where they are oxidised and produce new particles, which are then be entrained into the boundary layer and grow to CCN-relevent sizes.</p><p>Here we study the interaction of deep convection and NPF using the United Kingdom Chemistry and Aerosols (UKCA) model coupled with the Cloud-AeroSol Interacting Microphyics (CASIM) embedded in the regional configuration of UK Met Office Hadley Centre Global Environment Model (HadGEM3). We simulate several days over a 1000 km region of the Amazon at 4 km resolution. We then compare the regional model, which resolves cloud up- and downdrafts, with the global model with parameterised convection and low resolution.</p><p>Our simulations highlight three findings. Firstly, solely using a binary H<sub>2</sub>SO<sub>4</sub>-H<sub>2</sub>O nucleation mechanism strongly underestimates total aerosol concentrations compared to observations by a factor of 1.5-8 below 3 km over the Amazon. This points to the potential role of an additional nucleation mechanism, most likely involving biogenic compounds that occurs throughout more of the free troposphere. Secondly, deep convection transports insoluble gases such as DMS and monoterpenes vertically but not SO<sub>2</sub> or H<sub>2</sub>SO<sub>4</sub>. The time scale for DMS oxidation (~ 1 day) is much longer than for monoterpene (1-2 hours), which points to the importance of simulating biogenic nucleation over the Amazon in a cloud-resolving model, while lower-resolution global models may adequately capture DMS effects on H<sub>2</sub>SO<sub>4</sub> nucleation. Finally, we also examine the Andreae et al (2018) hypothesis of aerosol supply to the boundary layer by quantifying cloud-free and cloudy up- and downdraft transport. The transport of newly formed aerosols into the boundary layer is 8 times greater in cloud-free regions than in the clouds, but these transport processes are of similar magnitude for large aerosols.</p>

scholarly journals Roll vortices induce new particle formation bursts in the planetary boundary layer

2020 ◽  
Author(s):  
Janne Lampilahti ◽  
Hanna Elina Manninen ◽  
Katri Leino ◽  
Riikka Väänänen ◽  
Antti Manninen ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Particle Production ◽  
Aerosol Particles ◽  
Regional Scale ◽  
Particle Formation ◽  
Forest Site ◽  
New Particle Formation ◽  
Roll Vortices ◽  
The Impact

Abstract. Recent studies have shown the importance of new particle formation (NPF) to global cloud concensation nuclei (CCN) production, as well as to air pollution in megacities. In addition to the necessary presence of low-volatility vapors that can form the new aerosol particles, both numerical and observational studies have shown that the dynamics of the planetary boundary layer (BL) plays an important role in NPF. Evidence from field observations suggests that roll vortices might be favorable for inducing NPF in a convective BL. However, direct observations and estimates on the potential importance of this phenomenon to the production of new aerosol particles are lacking. Here we show that rolls frequently induce NPF bursts along the horizontal circulations, and that the small clusters and particles originating from these bursts grow in size similar to particles typically ascribed to regional-scale atmospheric NPF. We outline a method to identify roll-induced NPF from measurements and, based on the collected data, estimate the impact of roll vortices on the overall aerosol particle production due to NPF at a boreal forest site (83 ± 34 % and 26 ± 8 % overall enhancement in particle formation for 3-nm and 10-nm particles respectively). We conclude that the formation of roll vortices should be taken into account when estimating particle number budgets in the atmospheric BL.

scholarly journals Zeppelin-led study on the onset of new particle formation in the planetary boundary layer

2021 ◽  
Vol 21 (16) ◽  
pp. 12649-12663
Author(s):  
Janne Lampilahti ◽  
Hanna E. Manninen ◽  
Tuomo Nieminen ◽  
Sander Mirme ◽  
Mikael Ehn ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Particle Formation ◽  
New Particle Formation ◽  
Subsequent Growth ◽  
Local Enhancement ◽  
Urban Background ◽  
Airborne Measurements ◽  
Po Valley ◽  
Different Parts

Abstract. We compared observations of aerosol particle formation and growth in different parts of the planetary boundary layer at two different environments that have frequent new particle formation (NPF) events. In summer 2012 we had a campaign in Po Valley, Italy (urban background), and in spring 2013 a similar campaign took place in Hyytiälä, Finland (rural background). Our study consists of three case studies of airborne and ground-based measurements of ion and particle size distribution from ∼1 nm. The airborne measurements were performed using a Zeppelin inside the boundary layer up to 1000 m altitude. Our observations show the onset of regional NPF and the subsequent growth of the aerosol particles happening almost uniformly inside the mixed layer (ML) in both locations. However, in Hyytiälä we noticed local enhancement in the intensity of NPF caused by mesoscale boundary layer (BL) dynamics. Additionally, our observations indicate that in Hyytiälä NPF was probably also taking place above the ML. In Po Valley we observed NPF that was limited to a specific air mass.

scholarly journals Roll vortices induce new particle formation bursts in the planetary boundary layer

2020 ◽  
Vol 20 (20) ◽  
pp. 11841-11854
Author(s):  
Janne Lampilahti ◽  
Hanna Elina Manninen ◽  
Katri Leino ◽  
Riikka Väänänen ◽  
Antti Manninen ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Particle Production ◽  
Aerosol Particles ◽  
Regional Scale ◽  
Particle Formation ◽  
Forest Site ◽  
New Particle Formation ◽  
Roll Vortices ◽  
The Impact

Abstract. Recent studies have shown the importance of new particle formation (NPF) to global cloud condensation nuclei (CCN) production, as well as to air pollution in megacities. In addition to the necessary presence of low-volatility vapors that can form new aerosol particles, both numerical and observational studies have shown that the dynamics of the planetary boundary layer (BL) plays an important role in NPF. Evidence from field observations suggests that roll vortices might be favorable for inducing NPF in a convective BL. However, direct observations and estimates of the potential importance of this phenomenon to the production of new aerosol particles are lacking. Here we show that rolls frequently induce NPF bursts along the horizontal circulations and that the small clusters and particles originating from these localized bursts grow in size similar to particles typically ascribed to atmospheric NPF that occur almost homogeneously at a regional scale. We outline a method to identify roll-induced NPF from measurements and, based on the collected data, estimate the impact of roll vortices on the overall aerosol particle production due to NPF at a boreal forest site (83 % ± 34 % and 26 % ± 8 % overall enhancement in particle formation for 3 and 10 nm particles, respectively). We conclude that the formation of roll vortices should be taken into account when estimating particle number budgets in the atmospheric BL.

scholarly journals Zeppelin-led study on the onset of new particle formation in the planetary boundary layer

2021 ◽  
Author(s):  
Janne Lampilahti ◽  
Hanna E. Manninen ◽  
Tuomo Nieminen ◽  
Sander Mirme ◽  
Mikael Ehn ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Particle Formation ◽  
New Particle Formation ◽  
Subsequent Growth ◽  
Local Enhancement ◽  
Urban Background ◽  
Airborne Measurements ◽  
Po Valley ◽  
Different Parts

Abstract. We compared observations of aerosol particle formation and growth in different parts of the planetary boundary layer at two different environments that have frequent new particle formation (NPF) events. In summer 2012 we had a campaign in Po Valley, Italy (urban background) and in spring 2013 a similar campaign took place in Hyytiälä, Finland (rural background). Our study consists of airborne and ground-based measurements of ion and particle size distribution from ~1 nm. The airborne measurements were performed using a Zeppelin inside the boundary layer up to 1000 m altitude. Our observations show the onset of regional NPF and the subsequent growth of the aerosol particles happening uniformly inside the mixed layer (ML) in both locations. However, in Hyytiälä we noticed local enhancement in the intensity of NPF caused by mesoscale BL dynamics. Additionally, our observations indicate that in Hyytiälä NPF was probably also taking place above the ML. In Po Valley we observed NPF that was limited to a specific air mass.

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