ARMTRAJ: a set of multipurpose trajectory datasets augmenting the Atmospheric Radiation Measurement (ARM) user facility measurements

Earth system science data, Journal Year: 2025, Volume and Issue: 17(1), P. 29 - 42

Published: Jan. 8, 2025

Abstract. Ground-based instruments offer unique capabilities such as detailed atmospheric, thermodynamic, cloud, and aerosol profiling at a high temporal sampling rate. The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility provides comprehensive datasets from key locations around the globe, facilitating long-term characterization process-level understanding clouds, aerosol, aerosol–cloud interactions. However, with other ground-based datasets, fixed (Eulerian) nature these measurements often introduces knowledge gap in relating those observations air-mass hysteresis. Here, we describe ARMTRAJ (https://doi.org/10.5439/2309851, Silber, 2024a; https://doi.org/10.5439/2309849, 2024b; https://doi.org/10.5439/2309850, 2024c; https://doi.org/10.5439/2309848, 2024d), set multipurpose trajectory that helps close this ARM deployments. Each dataset targets different aspect atmospheric research, including analysis surface, planetary boundary layer, distinct liquid-bearing cloud layers, (primary) decks. Trajectories are calculated using Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model informed by European Centre for Medium-Range Weather Forecasts ERA5 reanalysis its highest spatial resolution (0.25°) initialized datasets. include information about coordinates state variables extracted before after site overpass. Ensemble runs generated each initialization enhance consistency, while ensemble variability serves valuable uncertainty metric reported variables. Following description processing structure, demonstrate applications to case study few bulk analyses collected during ARM's Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE) field deployment. will soon become near real-time product accompanying new deployments an augmenting ongoing previous deployments, promoting reaching science goals research relying on observations.

Language: Английский

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Micro-spectroscopic and freezing characterization of ice-nucleating particles collected in the marine boundary layer in the eastern North Atlantic

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(8), P. 5377 - 5398

Published: April 25, 2022

Abstract. Formation of atmospheric ice plays a crucial role in the microphysical evolution mixed-phase and cirrus clouds thus climate. How aerosol particles impact crystal formation by acting as ice-nucleating (INPs) is subject intense research activities. To improve understanding INPs, we examined daytime nighttime collected during Aerosol Cloud Experiments Eastern North Atlantic (ACE-ENA) field campaign conducted summer 2017. Collected particles, representative remote marine environment, were investigated for their propensity to serve INPs immersion freezing (IMF) deposition nucleation (DIN) modes. The particle population was characterized chemical imaging techniques such computer-controlled scanning electron microscopy with energy-dispersive X-ray analysis (CCSEM/EDX) transmission near-edge absorption fine-structure spectroscopy (STXM/NEXAFS). Four major particle-type classes identified where internally mixed inorganic–organic make up majority analyzed particles. Following experiments, individual SEM/EDX. INP types belong consisting fresh sea salt organics or processed containing dust sulfur organics. Ice experiments show IMF events at temperatures low 231 K, including subsaturated regime. DIN observed lower 210 K. observations regard activated fraction, ice-nucleation active site (INAS) densities, water activity-based model (ABIFM) yielding heterogeneous rate coefficients. Observed corresponding derived rates demonstrate that boundary layer can under typical cloud conditions. parameterizations allow implementation climate models evaluate predictive effects formation.

Language: Английский

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Optical Properties of Individual Tar Balls in the Free Troposphere

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(44), P. 16834 - 16842

Published: Oct. 19, 2023

Tar balls are brown carbonaceous particles that highly viscous, spherical, amorphous, and light absorbing. They believed to form in biomass burning smoke plumes during transport the troposphere. also have a significant impact on Earth's radiative balance, but due poorly characterized optical properties, this is uncertain. Here, we used two nighttime samples investigate chemical composition properties of individual tar transported free troposphere Climate Observatory "Ottavio Vittori" Mt. Cimone, Italy, using multimodal microspectroscopy. In our samples, contributed 50% by number. Of those balls, 16% were inhomogeneously mixed with other constituents. Using electron energy loss spectroscopy, retrieved complex refractive index (RI) for wavelength range from 200 1200 nm both homogeneously balls. We found no difference average RI (1.40–0.03i 1.36–0.03i at 550 nm, respectively). Furthermore, estimated top atmosphere forcing Santa Barbara DISORT Atmospheric Radiative Transfer model layer only an depth 0.1 above vegetation would exert positive ranging 2.8 W m–2 (on clear sky day) 9.5 (when clouds below aerosol layer). Understanding can help reduce uncertainties associated contribution biomass-burning current climate models.

Language: Английский

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Emerging investigator series: surfactants, films, and coatings on atmospheric aerosol particles: a review

Environmental Science Atmospheres, Journal Year: 2022, Volume and Issue: 2(5), P. 775 - 828

Published: Jan. 1, 2022

Surfactants alter the physical and chemical properties of atmospheric aerosol particles.

Language: Английский

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Wildfire smoke triggers cirrus formation: lidar observations over the eastern Mediterranean

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(22), P. 14097 - 14114

Published: Nov. 14, 2023

Abstract. The number of intense wildfires may increase further in upcoming years as a consequence climate change. It is therefore necessary to improve our knowledge about the role smoke system, with emphasis on impact particles evolution clouds, precipitation, and cloud radiative properties. Presently, one key aspect research whether or not wildfire can initiate cirrus formation. In this study, we present lidar observations over Limassol, Cyprus, from 27 October 3 November 2020, when extended fields crossed Mediterranean Basin Portugal Cyprus. We found strong evidence that aged (organic aerosol particles) originating North America triggered significant ice nucleation at temperatures −47 −53 ∘C caused formation layers. suggest crystals were nucleated just below tropopause presence serving ice-nucleating (INPs). main part 2–3 km thick layer was, however, lower stratosphere above tropopause. With actual radiosonde temperature relative humidity lidar-derived particle surface area concentrations used starting values, gravity wave simulations show lofting air by 100–200 m sufficient particles, leading crystal 1–100 L−1.

Language: Английский

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Wildfire smoke triggers cirrus formation: Lidar observations over the Eastern Mediterranean (Cyprus)

Published: May 24, 2023

Abstract. The number of intense wildfires may increase in the upcoming years as a consequence climate change. Changing aerosol conditions lead to changes regional and global cloud precipitation pattern. One key aspect research is presently whether or not wildfire smoke particles can initiate ice nucleation. We found strong evidence that aged (dominated by organic particles) originating from North America triggered significant nucleation at temperatures −47 −53 °C caused formation extended cirrus layers. Our study based on lidar observations over Limassol, Cyprus, 27 October 3 November 2020 when fields crossed Mediterranean Basin Portugal Cyprus. suggest crystals were nucleated just below tropopause presence serving ice-nucleating (INPs). main part 2–3 km thick layer was, however, lower stratosphere above tropopause. With actual radiosonde temperature relative humidity lidar-derived particle surface area concentrations starting values, gravity wave simulations show lofting 90–180 m sufficient particles, expressed crystal 1–100 L−1.

Language: Английский

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Physicochemical characterization of free troposphere and marine boundary layer ice-nucleating particles collected by aircraft in the eastern North Atlantic

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(15), P. 8659 - 8681

Published: Aug. 8, 2023

Abstract. Atmospheric ice nucleation impacts the hydrological cycle and climate by modifying radiative properties of clouds. To improve our predictive understanding formation, ambient ice-nucleating particles (INPs) need to be collected characterized. Measurements INPs at lower latitudes in a remote marine region are scarce. The Aerosol Cloud Experiments Eastern North Atlantic (ACE-ENA) campaign, Azores islands, provided opportunity collect boundary layer (MBL) free troposphere (FT) aircraft during campaign's summer winter intensive operation period. particle population samples was examined scanning transmission X-ray microscopy with near-edge absorption fine structure spectroscopy. identified were analyzed electron energy-dispersive analysis. We observed differences characteristics terms diversity, mixing state, organic volume fraction between seasons, mostly due dry intrusion events winter, as well sampling locations MBL FT. These also reflected temperature humidity conditions under which water uptake, immersion freezing (IMF), deposition (DIN) proceed. Identified reflect typical types within on include sea salt, salt sulfates, mineral dust, all associated matter, carbonaceous particles. IMF DIN kinetics respect heterogeneous rate coefficients, Jhet, active site density, ns, function criterion Δaw. is contact angles following classical theory. Derived agree previous ACE-ENA ground-site INP measurements. FT show greater propensity compared samples. This study emphasizes that can vary seasonally altitude depending location, thereby showing different propensities, crucial information when representing mixed-phase cloud cirrus microphysics models.

Language: Английский

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Can the COVID‐19 Decrease in Aircraft Flights Inform us of Whether the Addition of Efficient INP to Cirrus Altitudes Cools the Climate?

Published: Jan. 6, 2025

One of the few major observational tests how cirrus clouds will respond to addition ice nucleating particles (INPs) may be their response overwhelming decrease aircraft flights during April and May 2020 COVID-19 pandemic. Not only was this an unusual "experiment" test effects soot on cirrus, but it also allow us determine whether by much purposeful efficient INPs regime might change number concentrations (Ni) climate forcing. In article, we summarize what know about emissions clouds, relate presence other increases in Ni can seen data COVID-19. We discuss provides a sufficient global models for INP reduction as well portend possible purposely reduce temperatures from greenhouse gas warming.

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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Particle phase-state variability in the North Atlantic free troposphere during summertime is determined by atmospheric transport patterns and sources

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(13), P. 9033 - 9057

Published: July 13, 2022

Abstract. Free tropospheric aerosol particles have important but poorly constrained climate effects due to transformations of their physicochemical properties during long-range transport. In this study, we investigate the chemical composition and provide an overview phase states individual that undergone transport over North Atlantic Ocean in June July 2014, 2015, 2017 Observatory Mount Pico (OMP) Azores. The OMP is ideal site for studying long-range-transported free because local emissions a negligible influence contributions from boundary layer are rare. We used FLEXible PARTicle Lagrangian particle dispersion model (FLEXPART) determine origins trajectories sampled air masses found most them originated America recirculated Ocean. FLEXPART analysis showed were highly aged (average plume age >10 d). Size-resolved compositions probed using computer-controlled scanning electron microscopy with energy-dispersive X-ray spectrometer (CCSEM-EDX) transmission near-edge absorption fine structure spectroscopy (STXM-NEXAFS). CCSEM-EDX results abundant types carbonaceous (∼ 29.9 % 82.0 %), sea salt 0.3 31.6 sulfate 2.4 31.5 %). tilted stage interfaced within environmental microscope (ESEM) submicron particles. 47 99 %) liquid state at time collection inorganic inclusions. Moreover, also observed substantial fractions solid semisolid 0 30 ∼ 1 42 %, respectively) different patterns events, reflecting particles' phase-state variability atmospheric events sources. Combining measurements CO tracer analysis, wildfire-influenced plumes can result wide range viscosities after troposphere. temperature RH values extracted Global Forecast System (GFS) along FLEXPART-simulated path predict neglecting internal mixing inorganics would lead overestimation viscosity Our findings warrant future investigation aiming quantitative assessment on This study provides insights into particles, which help models reduce uncertainties about ambient climate.

Language: Английский

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