Boundary layer versus free tropospheric submicron particle formation: A case study from NASA DC-8 observations in the Asian continental outflow during the KORUS-AQ campaign

2021 ◽  
Vol 264 ◽  
pp. 105857
Author(s):  
Do-Hyeon Park ◽  
Chaeyoon Cho ◽  
Hyeonmin Kim ◽  
Rokjin J. Park ◽  
Bruce Anderson ◽  
...  
2015 ◽  
Vol 158 (1) ◽  
pp. 67-92 ◽  
Author(s):  
Andreas Platis ◽  
Barbara Altstädter ◽  
Birgit Wehner ◽  
Norman Wildmann ◽  
Astrid Lampert ◽  
...  

2014 ◽  
Vol 14 (16) ◽  
pp. 8763-8779 ◽  
Author(s):  
J. H. Kim ◽  
S. S. Yum ◽  
S. Shim ◽  
W. J. Kim ◽  
M. Park ◽  
...  

Abstract. Total number concentrations of particles having a diameter larger than 10 nm (NCN), cloud condensation nuclei at several supersaturation (S) values (NCCN) and number size distributions of particles with 10–414 nm diameter were measured in Seoul between 2004 and 2010. Overall average values of NCN and geometric mean diameter were 17 811 ± 5581 cm−3 and 48 ± 6 nm. Average NCCN at 0.4, 0.6 and 0.8% S were 4145 ± 2016, 5323 ± 2453 and 6067 ± 2780 cm−3 and corresponding NCCN / NCN were 0.26 ± 0.11, 0.33 ± 0.11 and 0.37 ± 0.12. There is a clear seasonal variation in aerosol concentration, which seems to be due to the monsoon. NCN and NCCN are also found to depend on the volume of traffic and the height of the planetary boundary layer, respectively. During aircraft campaigns in 2009 and 2011, NCN and NCCN at 0.6% S (N0.6%) were measured in and around the Korean Peninsula. During the 2011 campaign, the aerosol scattering coefficient was also measured. NCN and N0.6% in the lower altitudes were generally higher than at higher altitudes, except for cases when particle formation and growth events were thought to occur at higher altitudes. NCN and N0.6% generally show a positive correlation with aerosol scattering coefficients but this correspondence tends to vary with altitude. Occasional instances of low (< 0.3) N0.6% / NCN in the boundary layer are demonstrated to be associated with particle formation and growth events. With the support of ground measurements, it is confirmed that a particle formation and growth event did indeed occur over the Yellow Sea on a flight day, and the areal extent of this event is estimated to be greater than 100 km × 450 km. With the combination of the current and several relevant previous studies, a composite map of NCN and NCCN in and around the Korean Peninsula is produced. Overall, the exhibited concentrations are typical of values measured over polluted regions elsewhere on the globe. Moreover, there is a generally decreasing trend from west to east over the region, implying that the region is constantly under the dominant influence of continental outflow.


Tellus B ◽  
2021 ◽  
Vol 73 (1) ◽  
pp. 1-26
Author(s):  
Piotr Sekuła ◽  
Anita Bokwa ◽  
Zbigniew Ustrnul ◽  
Mirosław Zimnoch ◽  
Bogdan Bochenek

2011 ◽  
Vol 11 (12) ◽  
pp. 5591-5601 ◽  
Author(s):  
J. Lauros ◽  
A. Sogachev ◽  
S. Smolander ◽  
H. Vuollekoski ◽  
S.-L. Sihto ◽  
...  

Abstract. We carried out column model simulations to study particle fluxes and deposition and to evaluate different particle formation mechanisms at a boreal forest site in Finland. We show that kinetic nucleation of sulphuric acid cannot be responsible for new particle formation alone as the simulated vertical profile of particle number concentration does not correspond to observations. Instead organic induced nucleation leads to good agreement confirming the relevance of the aerosol formation mechanism including organic compounds emitted by the biosphere. The simulation of aerosol concentration within the atmospheric boundary layer during nucleation event days shows a highly dynamical picture, where particle formation is coupled with chemistry and turbulent transport. We have demonstrated the suitability of our turbulent mixing scheme in reproducing the most important characteristics of particle dynamics within the boundary layer. Deposition and particle flux simulations show that deposition affects noticeably only the smallest particles in the lowest part of the atmospheric boundary layer.


2008 ◽  
Vol 8 (22) ◽  
pp. 6729-6738 ◽  
Author(s):  
N. Kalivitis ◽  
W. Birmili ◽  
M. Stock ◽  
B. Wehner ◽  
A. Massling ◽  
...  

Abstract. Atmospheric particle size distributions were measured on Crete island, Greece in the Eastern Mediterranean during an intensive field campaign between 28 August and 20 October, 2005. Our instrumentation combined a differential mobility particle sizer (DMPS) and an aerodynamic particle sizer (APS) and measured number size distributions in the size range 0.018 μm–10 μm. Four time periods with distinct aerosol characteristics were discriminated, two corresponding to marine and polluted air masses, respectively. In marine air, the sub-μm size distributions showed two particle modes centered at 67 nm and 195 nm having total number concentrations between 900 and 2000 cm−3. In polluted air masses, the size distributions were mainly unimodal with a mode typically centered at 140 nm, with number concentrations varying between 1800 and 2900 cm−3. Super-μm particles showed number concentrations in the range from 0.01 to 2.5 cm−3 without any clear relation to air mass origin. A small number of short-lived particle nucleation events were recorded, where the calculated particle formation rates ranged between 1.1–1.7 cm−3 s−1. However, no particle nucleation and growth events comparable to those typical for the continental boundary layer were observed. Particles concentrations (Diameter <50 nm) were low compared to continental boundary layer conditions with an average concentration of 300 cm−3. The production of sulfuric acid and its subsequently condensation on preexisting particles was examined with the use of a simplistic box model. These calculations suggested that the day-time evolution of the Aitken particle population was governed mainly by coagulation and that particle formation was absent during most days.


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