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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Forcing for varying boundary layer stability across Antarctica

Weather and Climate Dynamics, Journal Year: 2024, Volume and Issue: 5(1), P. 369 - 394

Published: March 13, 2024

Abstract. The relative importance of changes in radiative forcing (downwelling longwave radiation) and mechanical mixing (20 m wind speed) controlling boundary layer stability annually seasonally at five study sites across the Antarctica continent is presented. From near neutral to extremely strong near-surface stability, decreases with increasing as expected, shown be a major driving force behind variations all sites. Mechanical usually for regimes weak stability. For cases where neutral, very shallow mixed, occur, speed mixed case weaker compared cases, while largest cases. This finding an important distinguishing factor unique present, indicating that this likely responsible shallower defines regime. enhanced above lower downwelling radiation promotes persistence stronger aloft, winds act maintain immediately surface, resulting two-layer

Language: Английский

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ALICENET – an Italian network of automated lidar ceilometers for four-dimensional aerosol monitoring: infrastructure, data processing, and applications

Atmospheric measurement techniques, Journal Year: 2024, Volume and Issue: 17(20), P. 6119 - 6144

Published: Oct. 22, 2024

Abstract. ​​​​​​​Vertically resolved information on aerosol particles represents a key aspect in many atmospheric studies, including aerosol–climate interactions and impacts air quality human health. This is primarily derived by lidar active remote sensing, particular with extensive networks currently operation worldwide. In Italy, the Institute of Atmospheric Sciences Climate (ISAC) National Research Council (CNR) established ALICENET network automated ceilometers (ALCs) 2015. Since then, has grown as cooperative effort Italian institutions dealing science monitoring, it includes instruments run regional environmental protection agencies, universities, research centres, private companies. current configuration, makes use both single-channel ALCs dual-channel, polarisation-sensitive-system (referred to PLCs). The systems operate very different environments (urban, coastal, mountainous, volcanic areas) from northern southern thus allowing continuous monitoring vertical distribution across country. also contributes EUMETNET programme E-PROFILE, filling an observational gap compared other EU member states, which generally extended ALC through national meteorological services. this work, we present infrastructure specifically developed data processing centralised at CNR-ISAC, converting raw instrumental into quantitative, quality-controlled properties ranging attenuated backscatter mass stratifications. setup allows us get insights 4D field over Italy applications near-real-time long-term analyses, examples are reported work. Specific comparisons products independent measurements obtained techniques, such particulate matter (PM) concentrations situ samplers optical depth (AOD) sun photometers, included here, revealing good performances algorithms. Overall, valuable resource extend capabilities Mediterranean area, bridging between its application specific sectors, among quality, solar energy, aviation safety.

Language: Английский

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Atmospheric Boundary Layer Stability in Urban Beijing: Insights from Meteorological Tower and Doppler Wind Lidar

Remote Sensing, Journal Year: 2024, Volume and Issue: 16(22), P. 4246 - 4246

Published: Nov. 14, 2024

The limited understanding of the structure urban surface atmospheric boundary layer can be attributed to its inherent complexity, as well a deficiency in comprehensive measurements. We analyzed one year meteorological data and Doppler wind lidar measurements Beijing explore how stability is influenced by speed, radiation, turbulence, pollution levels. Results indicate that predominant state layers an active condition (characterized strong unstable regimes) throughout day, significant heat storage capacity canopy. Strong stable regimes are more frequently observed during winter autumn, peaking transitions from night day. Furthermore, both occur under very weak conditions (indicating dynamic instability), with instability associated high net radiation levels while correlates low (indicative robust thermal stability). regime manifests winds (reflecting instability) alongside moderate environments, characterized elevated values turbulence kinetic energy height, highlighting critical role mechanical generation periods activity. Additionally, six instances pronounced daytime partially coupled pollutant concentrations near surface, resulting prolonged temperature inversions due intense radiative cooling effects forcing. Our findings presented herein expected have climate environment implications for other cities dense infrastructure all over world.

Language: Английский

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Evaluation of the Coupled Arctic Forecast System’s representation of the Arctic atmospheric boundary layer vertical structure during MOSAiC

Elementa Science of the Anthropocene, Journal Year: 2024, Volume and Issue: 12(1)

Published: Jan. 1, 2024

Observations from the Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) were used to evaluate Coupled Forecast System (CAFS) model’s ability simulate atmospheric boundary layer (ABL) structure in central Arctic. MOSAiC observations lower atmosphere radiosondes, downwelling longwave radiation (LWD) a pyranometer, and near-surface wind conditions meteorological tower compared 6-hourly CAFS output. A self-organizing map (SOM) analysis reveals that reproduces range stability structures identified by SOM trained with virtual potential temperature (θv) profiles, but not necessarily correct frequency or at time. Additionally, speed profiles corresponding particular θv profile are consistent between observations. When categorizing static stability, it was revealed simulates all observed regimes, overrepresents strong underrepresents top ABL 1 km. The 10 m speeds each regime consistently have larger values versus observed, this offset increases decreasing stability. Whether LWD is over underestimated dependent on regime. Both variables most greatly overestimated spring, leading largest bias, greatest underrepresentation spring. results article serve highlight positive aspects representing reveal impacts misrepresentations physical processes dictating energy, moisture, momentum transfer troposphere simulation This highlights areas improvement other numerical weather prediction models. SOM-based especially provides unique opportunity process-based model evaluation.

Language: Английский

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Standardized Daily High‐Resolution Large‐Eddy Simulations of the Arctic Boundary Layer and Clouds During the Complete MOSAiC Drift

Journal of Advances in Modeling Earth Systems, Journal Year: 2024, Volume and Issue: 16(11)

Published: Nov. 1, 2024

Abstract This study utilizes the wealth of observational data collected during recent Multidisciplinary drifting Observatory for Study Arctic Climate ( MOSAiC ) drift experiment to constrain and evaluate close two‐hundred daily Large‐Eddy Simulations (LES) boundary layers clouds at high resolutions. A standardized approach is adopted tightly integrate field measurements into experimental configuration. Covering full represents a step forward from single‐case LES studies, allows robust assessment model performance against independent under range atmospheric conditions. homogeneously forced domain simulated in Lagrangian frame reference, initialized with radiosonde value‐added cloud profiles. Prescribed conditions include various measured surface characteristics. Time‐constant composite forcing applied, primarily consisting subsidence rates sampled reanalysis data. The simulations run 3 hours, allowing turbulence spin up while still facilitating direct comparison Key aspects such as vertical thermodynamic structure, properties, energy fluxes are well reproduced maintained. captures bimodal distribution states that typical climate. Selected days investigated more closely assess model's skill maintaining observed layer structure. sensitivity configuration physics tested. input output available scientific community, supplementing archive. agreement meteorology justifies use gaining further insight processes their role climate change.

Language: Английский

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