Pan-Arctic seasonal cycles and long-term trends of aerosol properties from 10 observatories

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(5), P. 3067 - 3096

Published: March 8, 2022

Abstract. Even though the Arctic is remote, aerosol properties observed there are strongly influenced by anthropogenic emissions from outside Arctic. This particularly true for so-called haze season (January through April). In summer (June September), when atmospheric transport patterns change, and precipitation more frequent, local sources, i.e., natural sources of aerosols precursors, play an important role. Over last few decades, significant reductions in have taken place. At same time a large body literature shows evidence that undergoing fundamental environmental changes due to climate forcing, leading enhanced processes may impact properties. this study, we analyze 9 chemical species 4 particle optical 10 observatories (Alert, Kevo, Pallas, Summit, Thule, Tiksi, Barrow/Utqiaġvik, Villum, Gruvebadet Zeppelin Observatory – both at Ny-Ålesund Research Station) understand contributions. Variables include equivalent black carbon, particulate sulfate, nitrate, ammonium, methanesulfonic acid, sodium, iron, calcium potassium, as well scattering absorption coefficients, single albedo Ångström exponent. First, annual cycles investigated, which despite emission still show phenomenon. Second, long-term trends studied using Mann–Kendall Theil–Sen slope method. We find total 41 over full station records, spanning than decade, compared 26 decadal trends. The majority significantly declining tracers occurred during period, driven between 1990 2000. For no uniform picture has emerged. Twenty-six percent trends, 19 out 73, significant, those 5 positive 14 negative. Negative not only such carbon but also indicators acid non-sea-salt Alert. Positive sulfate Gruvebadet. No clear change contribution can be yet. However, testing sensitivity method, monotonic around % yr−1 property needed detect trend within one decade. highlights efforts beyond decade capture smaller changes. It ongoing Arctic, where interannual variability high, with forest fire their influence on population. To investigate climate-change-induced population resulting feedback, observations specific needed, microphysical size distributions, used identify populations captured mass-oriented methods bulk composition.

Language: Английский

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Thin and transient meltwater layers and false bottoms in the Arctic sea ice pack—Recent insights on these historically overlooked features

Elementa Science of the Anthropocene, Journal Year: 2023, Volume and Issue: 11(1)

Published: Jan. 1, 2023

The rapid melt of snow and sea ice during the Arctic summer provides a significant source low-salinity meltwater to surface ocean on local scale. accumulation this on, under, around floes can result in relatively thin layers upper ocean. Due small-scale nature these upper-ocean features, typically order 1 m thick or less, they are rarely detected by standard methods, but nevertheless pervasive critically important summer. Observations Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition 2020 focused evolution such made advancements understanding their role coupled system. Here we provide review Arctic, with emphasis new findings from MOSAiC. Both prior recent observational datasets indicate an intermittent yet long-lasting (weeks months) layer 0.1 1.0 thickness, large spatial range. presence impacts physical system reducing bottom allowing formation via false growth. Collectively, bottoms reduce atmosphere-ocean exchanges momentum, energy, material. far-reaching, including acting as barrier nutrient gas exchange impacting ecosystem diversity productivity.

Language: Английский

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A full year of aerosol size distribution data from the central Arctic under an extreme positive Arctic Oscillation: insights from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(1), P. 389 - 415

Published: Jan. 11, 2023

Abstract. The Arctic environment is rapidly changing due to accelerated warming in the region. trend driving a decline sea ice extent, which thereby enhances feedback loops surface energy budget Arctic. aerosols play an important role radiative balance and hence climate response region, yet direct observations of over Ocean are limited. In this study, we investigate annual cycle aerosol particle number size distribution (PNSD), concentration (PNC), black carbon (BC) mass central during Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition. This first continuous, year-long data set PNSD ever collected Ocean. We use k-means cluster analysis, FLEXPART simulations, inverse modeling evaluate seasonal patterns influence different source regions on population. Furthermore, compare land-based sites across Arctic, using both long-term measurements year MOSAiC expedition (2019–2020), interannual variability give context characteristics from within Our analysis identifies that, overall, exhibits typical aerosols, including anthropogenic haze winter secondary processes summer. pattern corresponds global radiation, air temperature, timing melting/freezing, drive changes transport processes. winter, Norilsk region Russia/Siberia was dominant signals BC observations, contributed higher accumulation-mode PNC concentrations than at observatories. also show that wintertime Oscillation (AO) phenomenon, reported achieve record-breaking positive phase January–March 2020, explains unusual magnitude compared longer-term observations. summer, PNCs nucleation Aitken modes enhanced; however, were notably lower pack further south. presented herein provides current snapshot characterized by rapid changes, will be crucial improving model predictions, understanding linkages between environmental processes, investigating impacts change future studies.

Language: Английский

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Observations of high-time-resolution and size-resolved aerosol chemical composition and microphysics in the central Arctic: implications for climate-relevant particle properties

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(4), P. 2207 - 2241

Published: Feb. 19, 2025

Abstract. Aerosols play a critical role in the Arctic's radiative balance, influencing solar radiation and cloud formation. Limited observations central Arctic leave gaps understanding aerosol dynamics year-round, affecting model predictions of climate-relevant properties. Here, we present first annual high-time-resolution submicron chemical composition during Ocean 2018 (AO2018) 2019–2020 Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expeditions. Seasonal variations mass concentrations were found to be driven by typical seasonal regimes resemble those pan-Arctic land-based stations. Organic aerosols dominated pristine summer, while anthropogenic sulfate prevailed autumn spring under haze conditions. Ammonium, which impacts acidity, was consistently less abundant, relative sulfate, compared lower latitudes Arctic. Cyclonic (storm) activity have significant influence on variability enhancing emissions from local sources transport remote aerosol. Local wind-generated particles contributed up 80 % (20 %) condensation nuclei population (spring). While analysis presented herein provides current baseline, will serve improve climate region, it also underscores importance integrating short-timescale processes, such as wind-driven blowing snow open leads/ocean simulations. This is particularly important, given decline mid-latitude increase ones.

Language: Английский

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Automated identification of local contamination in remote atmospheric composition time series

Atmospheric measurement techniques, Journal Year: 2022, Volume and Issue: 15(14), P. 4195 - 4224

Published: July 20, 2022

Abstract. Atmospheric observations in remote locations offer a possibility of exploring trace gas and particle concentrations pristine environments. However, data from areas are often contaminated by pollution local sources. Detecting this contamination is thus central frequently encountered issue. Consequently, many different methods exist today to identify atmospheric composition measurement time series, but no single method has been widely accepted. In study, we present new primary datasets, e.g., ship campaigns or stations with low background signal compared the signal. The detection algorithm (PDA) identifies flags periods polluted five steps. first most important step based on derivative (time derivative) concentration over time. If exceeds given threshold, flagged as polluted. Further identification steps simple threshold filter, neighboring points filter (optional), median, sparse (optional). PDA only relies target dataset itself independent ancillary datasets such meteorological variables. All parameters each adjustable so that can be “tuned” more less stringent (e.g., flag fewer contaminated). was developed tested number collected during Multidisciplinary drifting Observatory for Study Arctic Climate (MOSAiC) expedition Arctic. Using strict settings, identified 62 % influenced contamination. second also MOSAiC, evaluated performance against same cleaned visual inspection. two agreed 94 cases. Additionally, successfully applied (CO2), another dataset, at high-altitude station Jungfraujoch, Switzerland. Thus, proves useful flexible tool affected without need measurements. It best representing pollution. user-friendly open-access code enables reproducible application wide suite datasets. available https://doi.org/10.5281/zenodo.5761101 (Beck et al., 2021).

Language: Английский

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Collective geographical ecoregions and precursor sources driving Arctic new particle formation

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(3), P. 2183 - 2198

Published: Feb. 14, 2023

Abstract. The Arctic is a rapidly changing ecosystem, with complex ice–ocean–atmosphere feedbacks. An important process new particle formation (NPF), from gas-phase precursors, which provides climate forcing effect. NPF has been studied comprehensively at different sites in the Arctic, ranging those High and Svalbard to continental but no harmonised analysis performed on all simultaneously, calculations of key parameters available for some sites. Here, we analyse growth particles six long-term ground-based stations (Alert, Villum, Tiksi, Zeppelin Mountain, Gruvebadet, Utqiaġvik). Our rates addition back-trajectory shows summertime maxima frequency rate sites, although mean themselves vary greatly between highest lowest Arctic. rate, condensational sinks, vapour source show slight bias towards southernmost varying by around an order magnitude northernmost Air masses back-trajectories during these are associated large areas sea ice snow, whereas events more ocean regions. Events land ice. These results emphasise how understanding geographical variation surface type across secondary aerosol sources providing

Language: Английский

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Polar oceans and sea ice in a changing climate

Elementa Science of the Anthropocene, Journal Year: 2023, Volume and Issue: 11(1)

Published: Jan. 1, 2023

Polar oceans and sea ice cover 15% of the Earth’s ocean surface, environment is changing rapidly at both poles. Improving knowledge on interactions between atmospheric oceanic realms in polar regions, a Surface Ocean–Lower Atmosphere Study (SOLAS) project key focus, essential to understanding Earth system context climate change. However, our ability monitor pace magnitude changes regions evaluate their impacts for rest globe limited by remoteness sea-ice coverage. Sea not only supports biological activity mediates gas aerosol exchange but can also hinder some in-situ remote sensing observations. While satellite provides baseline record properties extent, these techniques cannot provide variables within below ice. Recent robotics, modeling, measurement advances have opened new possibilities ocean–sea ice–atmosphere system, critical gaps remain. Seasonal long-term observations are clearly lacking across all phases. Observational modeling efforts sea-ice, ocean, domains must be better linked achieve system-level environments. As warming becoming thinner more ephemeral than before, dramatic over suite physicochemical biogeochemical processes expected, if already underway. These conditions will affect modifying production aerosols, precursors, reactive halogens oxidants, greenhouse gases. Quantifying which enhanced or reduced change calls tailored monitoring programs high-latitude Open questions this coupled best resolved leveraging ongoing international multidisciplinary programs, such as led SOLAS, link research interface.

Language: Английский

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Cold Air Outbreaks Promote New Particle Formation Off the U.S. East Coast

Geophysical Research Letters, Journal Year: 2022, Volume and Issue: 49(5)

Published: Feb. 25, 2022

Abstract New particle formation (NPF) is the dominant contributor to total number concentration and plays an important role in cloud condensation nuclei budget. Airborne data from Aerosol Cloud meTeorology Interactions oVer western ATlantic Experiment (ACTIVATE) are used address seasonal NPF statistics factors related around clouds. Higher ratios of concentrations greater than 3 versus 10 nm (N /N ) were mainly observed above boundary layer tops during winter as compared summer. Cold dry air low aerosol surface area facilitate over ACTIVATE region; these conditions especially prevalent flights coinciding with cold outbreaks.

Language: Английский

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Diurnal evolution of negative atmospheric ions above the boreal forest: from ground level to the free troposphere

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(13), P. 8547 - 8577

Published: July 5, 2022

Abstract. At SMEAR II research station in Hyytiälä, located the Finnish boreal forest, process of new particle formation and role ions has been investigated for almost 20 years near ground at canopy level. However, above II, vertical distribution diurnal variation these different atmospheric are poorly characterized. In this study, we assess ion composition stable boundary layer, residual mixing free troposphere, evolution due to photochemistry turbulent through day. To measure profile ions, developed a tailored set-up online mass spectrometric measurements, capable being deployed Cessna 172 with minimal modifications. Simultaneously, instruments dedicated aerosol properties made measurements second Cessna. We conducted total 16 measurement flights May 2017, during spring, which is most active season. A flight day typically consisted three distinct (dawn, morning, afternoon) observe altitudes (from 100 3200 m ground), capture layer development from troposphere. Our observations showed that distinctly each depends on air origin time Before sunrise, layers separated other have their own chemistry. observed present within same as measured During daytime when evolved compounds vertically mixed, highly oxidized organic molecules distributed top layer. The varies day, showing similarities either or Finally, detected variety carboxylic acids likely containing halogens, originating Arctic Sea.

Language: Английский

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Measurement report: High Arctic aerosol hygroscopicity at sub- and supersaturated conditions during spring and summer

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(8), P. 4931 - 4953

Published: April 28, 2023

Abstract. Aerosol hygroscopic growth and cloud droplet formation influence the radiation transfer budget of atmosphere thereby climate. In Arctic, these aerosol properties may have a more pronounced effect on climate compared to midlatitudes. Hygroscopic condensation nuclei (CCN) concentrations high Arctic aerosols were measured during two field studies in spring summer 2016. The study site was Villum Research Station (Villum) at Nord northeastern region Greenland. with tandem differential mobility analyzer (HTDMA) over total 23 d, CCN period 95 d. Continuous particle number size distributions recorded, facilitating calculations activation diameters κ values. spring, average concentrations, supersaturations (SSs) 0.1 % 0.3 %, ranged from 53.7 85.3 cm−3, critical ranging 130.2 80.2 nm κCCN 0.28–0.35. summer, 20.8 47.6 while 137.1 76.7 0.23–0.35, respectively. Mean factors 1.60 1.75 90 relative humidity values between 1.47 1.67 observed depending initial dry size. Although characterized by frequent new events, population cloud-relevant determined accumulation-mode aerosols.

Language: Английский

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