Organic Peroxides in Aerosol: Key Reactive Intermediates for Multiphase Processes in the Atmosphere

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(4), P. 1635 - 1679

Published: Jan. 11, 2023

Organic peroxides (POs) are organic molecules with one or more peroxide (−O–O−) functional groups. POs commonly regarded as chemically labile termination products from gas-phase radical chemistry and therefore serve temporary reservoirs for oxidative radicals (HOx ROx) in the atmosphere. Owing to their ubiquity, active gas-particle partitioning behavior, reactivity, key reactive intermediates atmospheric multiphase processes determining life cycle (formation, growth, aging), climate, health impacts of aerosol. However, there remain substantial gaps origin, molecular diversity, fate due complex nature dynamic behavior. Here, we summarize current understanding on POs, a focus identification quantification, state-of-the-art analytical developments, molecular-level formation mechanisms, chemical transformation pathways, well environmental impacts. We find that interactions SO2 transition metal ions generally fast PO pathways liquid water, lifetimes estimated be minutes hours, while hydrolysis is particularly important α-substituted hydroperoxides. Meanwhile, photolysis thermolysis likely minor sinks POs. These distinctly different fates, such reaction OH radicals, which highlights need understand By summarizing advances remaining challenges investigation propose future research priorities regarding fate,

Language: Английский

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Tropical and Boreal Forest – Atmosphere Interactions: A Review

Tellus B, Journal Year: 2022, Volume and Issue: 74(1), P. 24 - 24

Published: March 25, 2022

This review presents how the boreal and tropical forests affect atmosphere, its chemical composition, function, further that affects climate and, in return, ecosystems through feedback processes. Observations from key tower sites standing out due to their long-term comprehensive observations: The Amazon Tall Tower Observatory Central Amazonia, Zotino Siberia, Station Measure Ecosystem-Atmosphere Relations at Hyytiäla Finland. is complemented by short-term observations networks large experiments. discusses atmospheric chemistry observations, aerosol formation processing, physiochemical aerosol, cloud condensation nuclei properties finds surprising similarities important differences two ecosystems. concentrations are similar, particularly concerning main components, both dominated an organic fraction, while ecosystem has generally higher of inorganics, influence long-range transported air pollution. emissions biogenic volatile compounds isoprene monoterpene regions, respectively, being precursors fraction. modeling studies show change deforestation such carbon hydrological cycles Amazonia changing neutrality precipitation downwind. In Africa, so far maintaining sink. It urgent better understand interaction between these major ecosystems, climate, which calls for more observation sites, providing data on water, carbon, other biogeochemical cycles. essential finding a sustainable balance forest preservation reforestation versus potential increase food production biofuels, critical services global stability. Reducing warming vital forests.

Language: Английский

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Formation of secondary organic aerosol from wildfire emissions enhanced by long-time ageing

Nature Geoscience, Journal Year: 2024, Volume and Issue: 17(2), P. 124 - 129

Published: Jan. 9, 2024

Language: Английский

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Global variability in atmospheric new particle formation mechanisms

Nature, Journal Year: 2024, Volume and Issue: 631(8019), P. 98 - 105

Published: June 12, 2024

A key challenge in aerosol pollution studies and climate change assessment is to understand how atmospheric particles are initially formed

Language: Английский

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Synergistic HNO3–H2SO4–NH3 upper tropospheric particle formation

Nature, Journal Year: 2022, Volume and Issue: 605(7910), P. 483 - 489

Published: May 18, 2022

Abstract New particle formation in the upper free troposphere is a major global source of cloud condensation nuclei (CCN) 1–4 . However, precursor vapours that drive process are not well understood. With experiments performed under tropospheric conditions CERN CLOUD chamber, we show nitric acid, sulfuric acid and ammonia form particles synergistically, at rates orders magnitude faster than those from any two three components. The importance this mechanism depends on availability ammonia, which was previously thought to be efficiently scavenged by droplets during convection. surprisingly high concentrations ammonium nitrate have recently been observed over Asian monsoon region 5,6 Once formed, co-condensation abundant alone sufficient rapid growth CCN sizes with only trace sulfate. Moreover, our measurements these also highly efficient ice nucleating particles—comparable desert dust. Our model simulations confirm convected aloft monsoon, driving rapid, multi-acid HNO 3 –H 2 SO 4 –NH nucleation producing spread across mid-latitude Northern Hemisphere.

Language: Английский

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Occurrence and growth of sub-50 nm aerosol particles in the Amazonian boundary layer

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(5), P. 3469 - 3492

Published: March 16, 2022

Abstract. New particle formation (NPF), referring to the nucleation of molecular clusters and their subsequent growth into cloud condensation nuclei (CCN) size range, is a globally significant climate-relevant source atmospheric aerosols. Classical NPF exhibiting continuous from few nanometers Aitken mode around 60–70 nm widely observed in planetary boundary layer (PBL) world but not central Amazonia. Here, classical events are rarely within PBL, instead, begins upper troposphere (UT), followed by downdraft injection sub-50 (CN<50) particles PBL growth. Central aspects our understanding these processes Amazon have remained enigmatic, however. Based on more than 6 years aerosol meteorological data Tall Tower Observatory (ATTO; February 2014 September 2020), we analyzed diurnal seasonal patterns as well conditions during 254 such Amazonian 217 event days, which show sudden occurrence between 10 50 CCN sizes. The was significantly higher wet season, with 88 % all January June, dry 12 July December, probably due differences sink (CS), load, conditions. Across events, median rate (GR) 5.2 h−1 CS 1.1 × 10−3 s−1 were observed. frequent daytime (74 %) showed GR (5.9 h−1) compared nighttime (4.0 h−1), emphasizing role photochemistry evolution About 70 negative anomaly equivalent potential temperature (Δθe′) – marker for downdrafts low satellite brightness (Tir) deep convective clouds good agreement UT course strong activity. 30 however, occurred absence convection, partly under clear-sky conditions, positive Δθe′ anomaly. Therefore, do appear be related transport suggest existence other currently unknown sources particles.

Language: Английский

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Tight Coupling of Surface and In-Plant Biochemistry and Convection Governs Key Fine Particulate Components over the Amazon Rainforest

ACS Earth and Space Chemistry, Journal Year: 2022, Volume and Issue: 6(2), P. 380 - 390

Published: Jan. 12, 2022

Combining unique high-altitude aircraft measurements and detailed regional model simulations, we show that in-plant biochemistry plays a central but previously unidentified role in fine particulate-forming processes atmosphere–biosphere–climate interactions over the Amazon rainforest. Isoprene epoxydiol secondary organic aerosols (IEPOX-SOA) are key components of sub-micrometer aerosol particle mass throughout troposphere rainforest traditionally thought to form by multiphase chemical pathways. Here, these pathways strongly inhibited solid thermodynamic phase state particles lack cloud liquid water upper troposphere. Strong diffusion limitations within coatings prevailing at low temperatures relative humidity inhibit reactive uptake IEPOX inorganic aerosols. We find direct emissions 2-methyltetrol gases formed biochemical oxidation and/or deposited on surfaces soils leaves their transport updrafts followed condensation could explain 90% IEPOX-SOA concentrations Our simulations indicate even near surface, represent ubiquitous, unaccounted for, source IEPOX-SOA. results provide compelling evidence for new related land surface–aerosol–cloud have not been considered previously.

Language: Английский

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Role of sesquiterpenes in biogenic new particle formation

Science Advances, Journal Year: 2023, Volume and Issue: 9(36)

Published: Sept. 8, 2023

Biogenic vapors form new particles in the atmosphere, affecting global climate. The contributions of monoterpenes and isoprene to particle formation (NPF) have been extensively studied. However, sesquiterpenes received little attention despite a potentially important role due their high molecular weight. Via chamber experiments performed under atmospheric conditions, we report biogenic NPF resulting from oxidation pure mixtures β-caryophyllene, α-pinene, isoprene, which produces oxygenated compounds over wide range volatilities. We find that class termed ultralow-volatility organic (ULVOCs) are highly efficient nucleators quantitatively determine efficiency. When compared with mixture monoterpene alone, adding only 2% sesquiterpene increases ULVOC yield doubles rate. Thus, emissions need be included assessments aerosol concentrations pristine climates where is expected major source cloud condensation nuclei.

Language: Английский

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New particle formation induced by anthropogenic–biogenic interactions on the southeastern Tibetan Plateau

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(4), P. 2535 - 2553

Published: Feb. 28, 2024

Abstract. New particle formation (NPF) plays a crucial role in the atmospheric aerosol population and has significant implications on climate dynamics, particularly climate-sensitive zones such as Tibetan Plateau (TP). However, our understanding of NPF TP is still limited due to lack comprehensive measurements verified model simulations. To fill this knowledge gap, we conducted an integrated study combining field chemical transport modeling investigate events southeastern during pre-monsoon season. was observed occur frequently clear-sky days TP, contributing significantly cloud condensation nuclei (CCN) budget region. The observational evidence suggests that highly oxygenated organic molecules (HOMs) from monoterpene oxidation participate nucleation TP. After updating chemistry schemes meteorology–chemistry model, well reproduces reveals extensive occurrence across dominant mechanism synergistic sulfuric acid, ammonia, HOMs, driven by anthropogenic precursors South Asia presence abundant biogenic gases. By investigating vertical distribution NPF, find influence More specifically, strong near surface leads intense small particles, which are subsequently transported upward. These particles experience enhanced growth larger sizes upper planetary boundary layer (PBL) favorable conditions lower temperatures reduced sink. As PBL evolves, brought back ground, resulting pronounced increase near-surface concentrations. This highlights important roles anthropogenic–biogenic interactions meteorological dynamics

Language: Английский

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Isoprene nitrates drive new particle formation in Amazon’s upper troposphere

Nature, Journal Year: 2024, Volume and Issue: 636(8041), P. 124 - 130

Published: Dec. 4, 2024

Abstract New particle formation (NPF) in the tropical upper troposphere is a globally important source of atmospheric aerosols 1–4 . It known to occur over Amazon basin, but nucleation mechanism and chemical precursors have yet be identified 2 Here we present comprehensive situ aircraft measurements showing that extremely low-volatile oxidation products isoprene, particularly certain organonitrates, drive NPF Amazonian troposphere. The organonitrates originate from OH-initiated isoprene forest emissions presence nitrogen oxides lightning. Nucleation bursts start about h after sunrise outflow nocturnal deep convection, producing high aerosol concentrations more than 50,000 particles cm − 3 We report characteristic diurnal cycles precursor gases particles. Our observations show interplay between biogenic convection with associated lightning, photochemistry low ambient temperature uniquely promotes NPF. grow time, undergo long-range transport descend through subsidence lower troposphere, which they can serve as cloud condensation nuclei (CCN) influence Earth’s hydrological cycle, radiation budget climate 1,4–8

Language: Английский

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