Using a region-specific ice-nucleating particle parameterization improves the representation of Arctic clouds in a global climate model

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(3), P. 1617 - 1637

Published: Feb. 5, 2025

Abstract. Projections of global climate change and Arctic amplification are sensitive to the representation low-level cloud phase in models. Ice-nucleating particles (INPs) necessary for primary ice formation at temperatures above approximately −38 °C thus significantly affect radiative effect (CRE). Due their complex insufficiently understood variability, INPs constitute an important modelling challenge, especially remote regions with few observations, such as Arctic. In this study, INP observations were carried out Andenes, Norway, March 2021. These used a basis Arctic-specific purely temperature-dependent parameterization, which was implemented into Norwegian Earth System Model (NorESM). This implementation results annual average increase liquid water path (CLWP) 70 % improves compared satellite observations. The CLWP boreal autumn winter is found likely be dominant contributor net surface CRE 2 W m−2. large flux brings simulation better agreement ground-based measurements. Despite fact that model cannot respond fully parameterization due fixed sea temperatures, air temperature increases by 0.7 autumn. findings indicate could have significant impact on region-specific can useful tool improve region.

Language: Английский

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Immersion Freezing in Particle‐Based Aerosol‐Cloud Microphysics: A Probabilistic Perspective on Singular and Time‐Dependent Models

Journal of Advances in Modeling Earth Systems, Journal Year: 2025, Volume and Issue: 17(4)

Published: April 1, 2025

Abstract Cloud droplets containing immersed ice‐nucleating particles (INPs) may freeze at temperatures above the homogeneous freezing threshold temperature in a process referred to as immersion freezing. In modeling studies, is often described using either so‐called “singular” or “time‐dependent” parameterizations. Here, we compare both approaches and discuss them context of probabilistic particle‐based (super‐droplet) cloud microphysics modeling. First, box model, contrast how parameterizations respond idealized ambient cooling rate profiles quantify impact polydispersity surface spectrum on frozen fraction evolution. Presented simulations highlight that singular approach, constituting time‐integrated form more general time‐dependent only accurate under limited range rates. The approach free from this limitation. Second, prescribed‐flow two‐dimensional illustrate macroscopic differences evolution time ice particle concentrations with flow regimes relevant conditions. flow‐coupled aerosol‐budget‐resolving benefits challenges condensation nuclei activation insoluble super‐particle methods. stem, one hand, heterogeneous nucleation being contingent presence relatively sparse INPs, other need represent vast population few super (each representing multiplicity real particles). We critical role sampling strategy for attributes, including INP size, (for scheme) multiplicity.

Language: Английский

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Impact of wildfire smoke on Arctic cirrus formation – Part 2: Simulation of MOSAiC 2019–2020 cases

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(9), P. 4867 - 4884

Published: May 9, 2025

Abstract. A simulation study of the potential impact wildfire smoke on Arctic cirrus formation is presented. The simulations complement MOSAiC (Multidisciplinary drifting Observatory for Study Climate) field observations, discussed in Part 1 (Ansmann et al., 2025) this work. observations suggest that Siberian had a strong winter 2019–2020. Via simulations, detailed insight into to influence as function observed meteorological and environmental conditions (temperature, relative humidity, large-scale gravity-wave-induced lofting conditions, ice-nucleating particle (INP) concentration) provided. Lidar-derived values INP concentration serve input, ice crystal number (ICNC) retrieved from combined lidar–radar are used comparison with results. show pollution levels upper troposphere were high enough trigger nucleation. also corroborate hypothesis stated 2025): persistent layer, continuously over central during half year 2019–2020, was able widely suppress homogeneous freezing so aerosol most probably controlled properties. reservoir refilled lower stratosphere. Furthermore, confirm saturation ratios 1.3–1.5 North Pole region at tops (with top temperatures −60 −75 °C) point inefficient INPs, expected when particles (organic particles) INPs. Finally, revealed nucleation widespread frequently occurring shallow updrafts low amplitudes) seems be responsible ICNC typically 1–50 crystals L−1 virga.

Language: Английский

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Measurement report: Atmospheric ice nuclei in the Changbai Mountains (2623 m a.s.l.) in northeastern Asia

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(5), P. 3241 - 3256

Published: March 15, 2024

Abstract. Atmospheric ice nucleation plays an important role in modulating the global hydrological cycle and atmospheric radiation balance. To date, few comprehensive field observations of nuclei have been carried out at high-altitude sites, which are close to height mixed-phase cloud formation. In this study, we measured concentration ice-nucleating particles (INPs) immersion freezing mode summit Changbai Mountains (2623 m above sea level), northeast Asia, summer 2021. The cumulative number INPs varied from 1.6 × 10−3 78.3 L−1 over temperature range −5.5 −29.0 °C. Proteinaceous-based biological materials accounted for majority INPs, with proportion (bio-INPs) exceeding 67 % across entire freezing-temperature range, even 90 −13.0 At temperatures ranging −11.0 −8.0 °C, bio-INPs were found significantly correlate wind speed (r = 0.5–0.8, p < 0.05) Ca2+ 0.6–0.9), good but not significant correlation was isoprene 0.6–0.7) its oxidation products (isoprene O3) 0.7), suggesting that aerosols may attach or mix soil dust contribute INPs. During daytime, showed a positive planetary boundary layer (PBL) −22.0 −19.5 °C > 0.7, 0.05), valley breezes southern mountainous regions also influencing Moreover, long-distance transport air mass Japan Sea South Korea contributed high concentrations bio-INPs. Our study emphasizes sources atmosphere northeastern Asia contribution long-range INP region.

Language: Английский

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High ice-nucleating particle concentrations associated with Arctic haze in springtime cold-air outbreaks

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(24), P. 14045 - 14072

Published: Dec. 17, 2024

Abstract. The global variation in ice-nucleating particle (INP) concentrations is an important modulator of the cloud-phase feedback, where albedo mixed-phase clouds increases a warming climate. Shallow clouds, such as those observed cold-air outbreaks (CAOs), are particularly for feedbacks and highly sensitive to INPs. To investigate sources INPs CAOs, we made airborne measurements over Norwegian Barents seas part March 2022 Arctic Cold-Air Outbreak (ACAO) field campaign. Aerosol samples were collected on filters at locations above, below upstream CAO cloud decks. Throughout campaign, INP comparable highest previously Arctic. Scanning electron microscopy analysis taken decks showed that supermicron aerosol was dominated by mineral dusts. Analysis size obtain active site density suggested sea spray unlikely be dominant type. These densities also too great components alone type above −20 °C. Accordingly, it likely dust mixed with other materials, possibly biogenic origin. Back-trajectory meteorological conditions lack local sources. We therefore hypothesise high concentration most associated aged haze has undergone long-range transport from lower-latitude regions.

Language: Английский

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Diverse sources and aging change the mixing state and ice nucleation properties of aerosol particles over the western Pacific and Southern Ocean

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(13), P. 7731 - 7754

Published: July 9, 2024

Abstract. Atmospheric particles can impact cloud formation and play a critical role in regulating properties. However, particle characteristics at the single-particle level their ability to act as ice-nucleating (INPs) over marine atmosphere are poorly understood. In this study, we present micro-spectroscopic characterizations ice nucleation properties of collected during cruise from South Korea Antarctica 2019. Most samples were dominated by fresh sea salt, aged salt mixed with sulfate particles, total number percentages ranging 48 % 99 western Pacific Southern Ocean. The mixing-state index population ranged 50 95 Northern Hemisphere Hemisphere. Multiphase processes on resulted chlorine deficiency. This selective aging process made more externally mixed. Ice onset conditions primarily for deposition mode measured investigated showed diverse abilities. organic coatings exhibited highest relative humidity respect low 121 %. was enriched INPs factor 1.9. Aging affected both mixing state Our analysis shows that assuming an internally lead errors several orders magnitude predicting rates.

Language: Английский

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Single particle characteristics and ice nucleation potential of particles collected during Asian dust storms in 2021

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 948, P. 174829 - 174829

Published: July 20, 2024

Language: Английский

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Microanalysis Techniques to Study Atmospheric Ice Nucleation and Ice Crystal Growth

Geophysical monograph, Journal Year: 2024, Volume and Issue: unknown, P. 223 - 252

Published: Dec. 13, 2024

Atmospheric ice crystal formation impacts the hydrological cycle and climate. Ice-nucleating particles (INPs), typically consisting of sub- supermicrometer-sized particles, initiate heterogeneous nucleation processes leading to formation. Ice commences on nanoscale at substrate surface depends ambient temperature humidity. This chapter provides an overview microanalysis techniques that examine process explore complex morphologies crystals. The first section introduces different pathways, a brief outline underlying theory, describes habits. second experiments study INPs or ice-nucleating substrates, including multimodal instrument approaches in situ studies. Examples include Raman, atomic force, electron, X-ray microscopy, techniques' unique capabilities physical chemical properties are discussed. third presents electron microscopy studies crystals during growth sublimation, displaying morphological complexities Finally, fourth discusses experimental requirements, sample sizes, radiation effects, role standard INPs.

Language: Английский

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Spatiotemporal estimates and health risks of atmospheric trace metals across Hong Kong during 2016–2020

Air Quality Atmosphere & Health, Journal Year: 2024, Volume and Issue: 18(2), P. 605 - 614

Published: Nov. 12, 2024

Language: Английский

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Analysis of Individual Atmospheric Particles

Geophysical monograph, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 54

Published: Dec. 13, 2024

Investigations into atmospheric aerosols are key to understanding how chemical and physical processes within the atmosphere contribute climate change, affect public health, impact visibility. Determinations of particulate matter at microscopic, or single-particle, level offer distinct advantages over determinations in bulk form. These include composition with respect particle size, shape, mixing state along properties particles, particularly surface properties, as they formation lifetime clouds haze. This chapter is an overview various static techniques that allow detailed physicochemical interrogation single particles benefit these studies. A general description followed by their use studying particles. Included scanning transmission electron microscopies associated such X-ray spectroscopy, diffraction, energy loss spectroscopy; micro-Raman spectroscopy optical tweezers, surface-enhanced Raman, tip-enhanced Raman; atomic force microscopy; microscopy. Dynamic single-particle aerosol time-of-flight mass spectrometry, which can be appreciated only from analysis ensembles, briefly mentioned.

Language: Английский

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