Rapid growth of new atmospheric particles by nitric acid and ammonia condensation

Nature, Journal Year: 2020, Volume and Issue: 581(7807), P. 184 - 189

Published: May 13, 2020

A list of authors and their affiliations appears at the end paper New-particle formation is a major contributor to urban smog1,2, but how it occurs in cities often puzzling3. If growth rates particles are similar those found cleaner environments (1-10 nanometres per hour), then existing understanding suggests that new should be rapidly scavenged by high concentration pre-existing particles. Here we show, through experiments performed under atmospheric conditions CLOUD chamber CERN, below about +5 degrees Celsius, nitric acid ammonia vapours can condense onto freshly nucleated as small few diameter. Moreover, when cold enough (below -15 Celsius), nucleate directly an acid-base stabilization mechanism form ammonium nitrate Given these one thousand times more abundant than sulfuric acid, resulting particle extremely high, reaching well above 100 hour. However, require gas-particle system out equilibrium order sustain gas-phase supersaturations. In view strong temperature dependence measure for supersaturations, expect such transient occur inhomogeneous settings, especially wintertime, driven vertical mixing local sources traffic. Even though rapid from condensation may last only minutes, nonetheless fast shepherd smallest size range where they most vulnerable scavenging loss, thus greatly increasing survival probability. We also nucleation important relatively clean upper free troposphere, convected continental boundary layer electrical storms4,5.

Language: Английский

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Role of iodine oxoacids in atmospheric aerosol nucleation

Science, Journal Year: 2021, Volume and Issue: 371(6529), P. 589 - 595

Published: Feb. 4, 2021

Faster than expected Iodine species are one of only a handful atmospheric vapors known to make new aerosol particles, which play central role in controlling the radiative forcing climate. He et al. report experimental evidence from CERN Cosmics Leaving Outdoor Droplets, or CLOUD, chamber demonstrating that iodic acid and iodous rapidly form particles can compete with sulfuric pristine regions. Science , this issue p. 589

Language: Английский

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Aerosol size distributions during the Atmospheric Tomography Mission (ATom): methods, uncertainties, and data products

Atmospheric measurement techniques, Journal Year: 2019, Volume and Issue: 12(6), P. 3081 - 3099

Published: June 6, 2019

Abstract. From 2016 to 2018 a DC-8 aircraft operated by the US National Aeronautics and Space Administration (NASA) made four series of flights, profiling atmosphere from 180 m ∼12 km above sea level (km a.s.l.) Arctic Antarctic over both Pacific Atlantic oceans. This program, Atmospheric Tomography Mission (ATom), sought sample troposphere in representative manner, making measurements atmospheric composition each season. paper describes aerosol microphysical derived quantities obtained during this mission. Dry size distributions 2.7 nm 4.8 µm diameter were measured situ at 1 Hz using battery instruments: 10 condensation particle counters with different nucleation diameters, two ultra-high-sensitivity spectrometers (UHSASs), one which particles surviving heating 300 ∘C, laser spectrometer (LAS). The dry complemented distribution 0.5 930 near-ambient conditions cloud, aerosol, precipitation (CAPS) mounted under wing DC-8. number, surface area, volume, optical scattering asymmetry parameters several wavelengths near-UV near-IR ranges calculated (2.7 µm). mass was estimated combining data density independent high-resolution single-particle soot photometer. We describe instrumentation fully document inlet flow system, derivation uncertainties, calculation products combined distributions. Comparisons between instruments direct some properties confirm that in-flight performance consistent calibrations within stated uncertainties for deployments analyzed. unique ATom dataset contains accurate, precise, distributions, integral parameters, estimates properties, < can be used evaluate abundance processes global models.

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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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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Molecular understanding of new-particle formation from α-pinene between −50 and +25 °C

Atmospheric chemistry and physics, Journal Year: 2020, Volume and Issue: 20(15), P. 9183 - 9207

Published: Aug. 3, 2020

Abstract. Highly oxygenated organic molecules (HOMs) contribute substantially to the formation and growth of atmospheric aerosol particles, which affect air quality, human health Earth's climate. HOMs are formed by rapid, gas-phase autoxidation volatile compounds (VOCs) such as α-pinene, most abundant monoterpene in atmosphere. Due their abundance low volatility, can play an important role new-particle (NPF) early aerosols, even without any further assistance other low-volatility sulfuric acid. Both reaction forming NPF rates expected be strongly dependent on temperature. However, experimental data both effects limited. Dedicated experiments were performed at CLOUD (Cosmics Leaving OUtdoor Droplets) chamber CERN address this question. In study, we show that a decrease temperature (from +25 −50 ∘C) results reduced HOM yield oxidation state products, whereas (J1.7 nm) increase substantially. Measurements with two different chemical ionization mass spectrometers (using nitrate protonated water reagent ion, respectively) provide molecular composition gaseous two-dimensional volatility basis set (2D VBS) model provides distribution. The decreases from 6.2 % 25 ∘C 0.7 ∘C. there is strong reduction saturation vapor pressure each reduced. Overall, leads nucleation up 3 orders magnitude compared addition, enhancement ions decreasing temperature, since neutral clusters have increased stability against evaporation. resulting quantify how interplay between temperature-dependent pathways associated pressures biogenic level. Our measurements, therefore, improve our understanding pure for wide range tropospheric temperatures precursor concentrations.

Language: Английский

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High concentration of ultrafine particles in the Amazon free troposphere produced by organic new particle formation

Proceedings of the National Academy of Sciences, Journal Year: 2020, Volume and Issue: 117(41), P. 25344 - 25351

Published: Sept. 28, 2020

Significance The high-altitude tropics constitute one of the world’s largest aerosol reservoirs, which may significantly affect clouds, radiation, and hydrological cycle by delivering seeds on clouds form to lower altitudes maintaining stratospheric background. However, formation mechanisms these aerosols remain a scientific mystery. Through systematic experiment-based model representation organic chemistry new particle (NPF) combined with constraints from field measurements, we demonstrate that NPF driven extremely low volatility organics formed biogenic emissions plays key role in producing large number observed Amazon. This mechanism likely also prevailed during preindustrial times hence modulate anthropogenic forcing above baseline.

Language: Английский

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New particle formation in the remote marine boundary layer

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Jan. 22, 2021

Marine low clouds play an important role in the climate system, and their properties are sensitive to cloud condensation nuclei concentrations. While new particle formation represents a major source of globally, prevailing view is that rarely occurs remote marine boundary layer over open oceans. Here we present evidence regular frequent occurrence upper part following cold front passages. The facilitated by combination efficient removal existing particles precipitation, air temperatures, vertical transport reactive gases from ocean surface, high actinic fluxes broken field. newly formed subsequently grow contribute substantially thereby impact clouds.

Language: Английский

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Characterization of organic aerosol across the global remote troposphere: a comparison of ATom measurements and global chemistry models

Atmospheric chemistry and physics, Journal Year: 2020, Volume and Issue: 20(8), P. 4607 - 4635

Published: April 21, 2020

Abstract. The spatial distribution and properties of submicron organic aerosol (OA) are among the key sources uncertainty in our understanding effects on climate. Uncertainties particularly large over remote regions free troposphere Southern Ocean, where very few data have been available OA predictions from AeroCom Phase II global models span 2 to 3 orders magnitude, greatly exceeding model spread source regions. (nearly) pole-to-pole vertical non-refractory aerosols was measured with an mass spectrometer onboard NASA DC-8 aircraft as part Atmospheric Tomography (ATom) mission during Northern Hemisphere summer (August 2016) winter (February 2017). This study presents first extensive characterization concentrations their level oxidation atmosphere. sulfate major contributors by troposphere, together sea salt marine boundary layer. Sulfate dominant lower stratosphere. a strong seasonal zonal variability, highest levels influenced biomass burning Africa (up 10 µg sm−3). Lower (∼0.1–0.3 sm−3) observed northern middle high latitudes low (<0.1 southern latitudes. ATom dataset is used evaluate eight current chemistry that implement variety commonly representations chemistry, well AeroCom-II ensemble. ensemble captures average concentrations, individual remains within factor 5. These results significantly improved ensemble, which shows overestimations these However, some agreement observations occurs for wrong reasons, tendency overestimate primary fraction underestimate secondary fraction. Measured highly oxygenated, carbon (OA ∕ OC) ratios ∼2.2–2.8, 30 %–60 % more oxygenated than models, can lead significant errors concentrations. model–measurement comparisons presented here support concept dynamic system proposed Hodzic et al. (2016), enhanced removal stronger production needed provide better observations.

Language: Английский

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The importance of size ranges in aerosol instrument intercomparisons: a case study for the Atmospheric Tomography Mission

Atmospheric measurement techniques, Journal Year: 2021, Volume and Issue: 14(5), P. 3631 - 3655

Published: May 20, 2021

Abstract. Aerosol intercomparisons are inherently complex as they convolve instrument-dependent detection efficiencies vs. size (which often change with pressure, temperature, or humidity) and variations in the sampled aerosol population, addition to differences chemical principles (e.g., inorganic-only nitrate inorganic plus organic for two instruments). The NASA Atmospheric Tomography Mission (ATom) spanned four separate aircraft deployments which remote marine troposphere from 86∘ S 82∘ N over different seasons a wide range of concentrations compositions. Aerosols were quantified set carefully characterized calibrated instruments, some based on particle sizing composition measurements. This study aims provide critical evaluation inlet transmissions impacting intercomparisons, quantification during ATom, focus mass spectrometer (AMS). volume determined physical instruments (aerosol microphysical properties, AMP, 2.7 nm 4.8 µm optical diameter) is compared detail that derived measurements AMS single soot photometer (SP2). Special attention was paid characterize upper end size-dependent transmission in-field calibrations, we show be accurate comparisons across inevitably cuts. Observed between campaigns emphasize importance characterizing each instrument field meaningful interpretation comparisons. Good agreement (regression slope =0.949 1.083 ATom-1 ATom-2, respectively; SD =0.003) found composition-based (including AMS-quantified sea salt) AMP after applying transmission. captured, average, 95±15 % standard PM1 (referred URG Corp. cut 1 cyclone operated at its nominal efficiency). These results support absence significant unknown biases appropriateness accuracy estimates total mostly aged air masses encountered ATom. ranges (and their altitude dependence) by complementary (such soluble acidic gases aerosol, SAGA, analysis laser spectrometry, PALMS) investigated inform use future studies.

Language: Английский

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