Effect of aqueous-phase processing on the formation and evolution of organic aerosol (OA) under different stages of fog life cycles

Mandariya, Anil Kumar; Gupta, Tarun; Tripathi, S. N.

doi:10.1016/j.atmosenv.2019.02.047

Cited by 35 publications

(40 citation statements)

References 71 publications

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“…Three fog episodes were observed (the nights of 19–20, 20–21, and 21–22 September) during the study period, while the fourth night (22–23 September) was characterized by high moist conditions with high RH (RH > 96%) but no visually discernable fog. Based on the transition point times of the aerosol compounds (that is, a noticeable or step change in concentration), as well as RH and solar irradiation variations, the entire fog event life cycle was divided into five fog processing phases or periods in a manner similar to a previous study (Mandariya et al, 2019), namely, fog_before_forming (F‐B), fog_forming (F‐F), fog_scavenging (F‐S), fog_dissipating (F‐D), and fog_post_dissipating (F‐P). The detailed properties for each fog phase can be found in the supporting information (Text S4 and Table S2).…”

Section: Resultsmentioning

confidence: 99%

“…During the fog scavenging periods for each day, as shown in Figures 1 and S10, most of the aerosol compound mass concentrations experienced significant reductions. We define the scavenging efficiency (Table S3) that occurred during these periods as (Mandariya et al, 2019)

SE = \frac{C_{normalF - normalB} - C_{normalF - normalS}}{{normalC}_{F - B}} \times 100 %

where SE is the scavenging efficiency and C is the mass concentration for all aerosol compounds except BSOA and NO 3 . For BSOA, C F‐F was used to replace C F‐B due to their enhancement during the F‐F period.…”

Section: Resultsmentioning

confidence: 99%

“…Under supersaturated conditions, such aerosols continue growing through additional water vapor condensation and can be activated to form fog or cloud drops (Gilardoni et al, 2014). In the case of fog formation, fog drops also scavenge some fraction of the unactivated interstitial aerosols, and the compounds in fog drops may undergo aqueous reaction or be removed through direct droplet deposition (i.e., impaction or sedimentation) (Mandariya et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Evolution of Aerosol Under Moist and Fog Conditions in a Rural Forest Environment: Insights From High‐Resolution Aerosol Mass Spectrometry

Zhang

Lance

Marto

et al. 2020

Geophysical Research Letters

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The effect of foggy/moist conditions on the characteristics of secondary organic aerosol (SOA) was studied. Analysis of the high-resolution time-of-flight aerosol mass spectrometer measurements identified two fresh biogenic SOA factors (BSOA: BSOA-1 and BSOA-2), hypothesized to be formed through the nighttime reaction of biogenic volatile organic compounds with nitrate radical. During foggy periods, the more oxidized oxygenated OA (MO-OOA) was scavenged most efficiently (86% removal), followed by the less oxidized OOA (LO-OOA) (55%), SO 4 (53%), and BSOA (25%). Aerosol mass increased during fog events, and the post-fog aerosol mass was higher (11%) than during the prefog period, with a reduction for MO-OOA and an enhancement for LO-OOA and BSOA. The high positive correlation observed between aerosol liquid water (ALW) and BSOA suggests the importance of aqueous-phase processing on the BSOA formation, and an increase in log 10 (ALW) of 1 corresponded to an average increase of about 0.9 μg m −3 in BSOA. Plain Language Summary Ground-level aerosols impact human health, climate, and ecosystem health. Aerosols have complex chemical composition, and the chemistry of the carbonaceous fraction is a topic of great interest to atmospheric chemistry and air quality. Aerosol liquid water is an important component of these particles in humid environments, and it becomes the dominant component if the particle grows to become a fog or cloud droplet. In addition to influencing particle growth, the aerosol liquid water provides another medium in which chemical reactions can occur and produces species that remain in the condensed phase and thereby increase aerosol mass loading. This study investigated the evolution of aerosol mass and chemical composition in moist and foggy nighttime environments in a rural forested area of the Northeast U.S. Organic aerosols that were identified as biogenic secondary organic aerosols were observed to increase in mass concentration during foggy conditions, and in this environment, they increased linearly in mass as a function of the base 10 logarithm of aerosol liquid water over a wide range. The influence of aerosol liquid water on the chemical reactivity of aerosols could help to bridge the gap between modeled and observed secondary organic aerosol mass.

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Section: Resultsmentioning

confidence: 99%

SE = \frac{C_{normalF - normalB} - C_{normalF - normalS}}{{normalC}_{F - B}} \times 100 %

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evolution of Aerosol Under Moist and Fog Conditions in a Rural Forest Environment: Insights From High‐Resolution Aerosol Mass Spectrometry

Zhang

Lance

Marto

et al. 2020

Geophysical Research Letters

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“…The chemical composition of SOA is very complex. The average carbon oxidation state (OSC) has been shown to be an ideal conceptual framework to describe changes in the degree of oxidation undergone by SOA (Kroll et al, 2011), and has been widely applied in field and laboratory studies (Chen et al, 2018;Mandariya et al, 2019). OSC The OSC increased over time for all SOAs that were formed in the absence of NH3.…”

Section: Soa Chemical Compositionmentioning

confidence: 99%

Reviewer comment on acp-2021-560

2021

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“…The range of possible organics is broad, including both hydrophilic (soluble or partially soluble) and hydrophobic molecules (Rangognio et al 2009) with contradictory behavior in the process of aerosol activation. Although the hygroscopicity of organic species is generally lower than that of inorganics (Petters andKreidenweis 2007, 2008), organic molecules seem to participate significantly in the formation of aerosols in fog (Mandariya et al 2019;Kim et al 2019).…”

Section: Introductionmentioning

confidence: 99%

Variability in Activation Properties in Relation to Meteorological Phenomena

Zíková

Pokorná

Makeš

et al. 2021

Journal of Hydrometeorology

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In situ campaigns focused on aerosol-cloud interactions were performed to describe the size-dependent activation of aerosols of various origins during variable meteorological conditions. Low cloud episodes, coded as fog, freezing fog, or rain with fog, were compared with non-phenomenon episodes. From the difference in aerosols measured behind the whole air inlet and PM2.5 inlets, the activated fraction (AF, a share of activated particles from all those available) was calculated.For fog, the AF was stable, resulting in a small variability in the activated size. During freezing fog, a higher variability in supersaturation was deduced from larger variability in the AF and smaller effective radii of cloud droplets. The AF during rain with fog showed a connection to the air mass origin, less effective activation and smaller cloud droplets.The analysis of the relationship between meteorological conditions and activations suggested that the different hydrometeors were connected with different air masses. No effect of photochemistry was found; in contrast, some dependence on relative humidity, temperature, wind speed, and liquid water content (LWC) was described. With increasing humidity, smaller particles were able to activate. For lower RH, the importance of supersaturation fluctuations increased, moving to a fluctuation-influenced regime. The strongest connection was found between activation and LWC; for the LWC below 0.10 g/m3, a strong decrease in activated particle size was found with increasing LWC, due to turbulence, number of particles, and availability of condensable water. From 0.10 g/m3 LWC and higher, the LWC and the connected supersaturation could be the main factors influencing the activation.

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Effect of aqueous-phase processing on the formation and evolution of organic aerosol (OA) under different stages of fog life cycles

Cited by 35 publications

References 71 publications

Evolution of Aerosol Under Moist and Fog Conditions in a Rural Forest Environment: Insights From High‐Resolution Aerosol Mass Spectrometry

Evolution of Aerosol Under Moist and Fog Conditions in a Rural Forest Environment: Insights From High‐Resolution Aerosol Mass Spectrometry

Reviewer comment on acp-2021-560

Variability in Activation Properties in Relation to Meteorological Phenomena

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