Investigating processes influencing simulation of local Arctic wintertime anthropogenic pollution in Fairbanks, Alaska, during ALPACA-2022

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(2), P. 1063 - 1104

Published: Jan. 28, 2025

Abstract. Lagrangian tracer simulations are deployed to investigate processes influencing vertical and horizontal dispersion of anthropogenic pollution in Fairbanks, Alaska, during the Alaskan Layered Pollution Chemical Analysis (ALPACA) 2022 field campaign. Simulated concentrations carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), including surface elevated sources, highest at under very cold stable conditions. enhancements above (50–300 m) mainly attributed power plant emissions. Both sources contribute Fairbanks' regional that is transported downwind, primarily south-west, may wintertime Arctic haze. Inclusion a novel plume rise treatment considers presence temperature inversion layers leads improved agreement with observed CO NOx plumes, discrepancies to, for example, displacement plumes by modelled winds. At surface, model results show variability largely driven meteorology and, lesser extent, emissions, although simulated tracers sensitive dispersion. Modelled underestimation polluted conditions considerably following inclusion substantial increases diesel vehicle emissions temperatures (e.g. factor 6 −30 °C). In contrast, overestimation SO2 deficiencies (5–18 space heating This study highlights need improvements local simulation boundary layers.

Language: Английский

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Sensitivity of Wintertime Arctic Black Carbon to Removal Processes and Regional Alaskan Sources

Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(7)

Published: April 8, 2025

Abstract Air pollutants are primarily transported from midlatitude emission regions in winter and early spring, leading to elevated concentrations of aerosols, including black carbon (BC), the Arctic, a phenomenon known as Arctic haze. The Weather Research Forecasting model coupled with chemistry is used investigate potential causes uncertainties modeling BC for 2014. captures observed variability at surface sites, reproducing Zeppelin but showing low bias Tiksi, Alert, Utqiaġvik/Barrow. influence removal processes on biases explored by switching off dry or wet deposition. Wet deposition, during transport North Atlantic storm track, locally over Svalbard, dominates Zeppelin, while Pacific track influences Alert Dry Asian source Alaska affects Utqiaġvik/Barrow, larger than Tiksi due proximity local/regional anthropogenic sources. Regional runs northern late January show improved simulated compared observations part, better resolution processes, emissions. Sensitivity also that regional Alaskan sources, notably Slope oil fields, may be contributing 30%–50%, average, Utqiaġvik/Barrow February 2014, remainder outside region. These findings highlight importance local emissions, need inventories Arctic.

Language: Английский

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Aerosol Background Concentrations Influence Aerosol‐Cloud Interactions as Much as the Choice of Aerosol‐Cloud Parameterization

Geophysical Research Letters, Journal Year: 2025, Volume and Issue: 52(8)

Published: April 21, 2025

Abstract We use an independent observational estimate of aerosol‐cloud interactions (ACI) during the 2014 Holuhraun volcanic eruption in Iceland to evaluate four ACI parameterizations a regional model. All reproduce observed pattern liquid cloud droplet size reduction eruption, but strongly differ on its magnitude and resulting effective radiative forcing (ERF). Our results contradict earlier findings that this could be used constrain water path (LWP) adjustments models, except exclude extremely high LWP more than 20 . The modeled ERF is very sensitive non‐volcanic background aerosol concentration: doubling weakens by Since biases climate models can order or more, these suggest concentrations major under‐examined source uncertainty for modeling ACI.

Language: Английский

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Impacts of sea ice leads on sea salt aerosols and atmospheric chemistry in the Arctic

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(8), P. 4531 - 4545

Published: April 24, 2025

Abstract. The processes contributing to Arctic cold-season (November–April) sea salt aerosols (SSAs) remain uncertain. Observations from coastal Alaska suggest that emissions open leads in ice, which are not included climate models, may play a dominant role. Their Arctic-wide significance has yet been quantified. Here, we create an emission parameterization of SSAs by combining satellite data lead area (the Advanced Microwave Scanning Radiometer–Earth Observation System (AMSR-E) product) and chemical transport model (GEOS-Chem) quantify pan-Arctic SSA during the cold season 2002 2008 predict their impacts on atmospheric chemistry, evaluating results our simulated against situ observations. AMSR-E product detects large with certainty (> 3 km size), and, hence, study is limited quantifying leads. Lead vary seasonally interannually. Simulated total monthly increase 1.1 %–1.8 % (≥60° N latitude) 5.6 %–7.5 (≥75° N) for 2002–2008 seasons. concentrations primarily at location leads, where standard low. GEOS-Chem overestimates sites compared ground observations, even when included, suggesting underestimation sinks and/or uncertainties blowing snow ocean. Multi-year mean surface bromine atom (Br) 2.8 %–8.8 due Changes ozone negligible. While contribute < 10 years 2002–2008, these occur regions low background aerosol concentrations. Leads frequency under future change, could

Language: Английский

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Modeling the contribution of leads to sea spray aerosol in the high Arctic

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(21), P. 12107 - 12132

Published: Oct. 30, 2024

Abstract. Elongated open-water areas in sea ice (leads) release spray particles to the atmosphere. However, there is limited knowledge on amount, properties and drivers of emitted from leads, no existing parameterization this process available for use models. In work, we measurements aerosol fluxes Nilsson et al. (2001) produce an estimate location, timing amount emissions leads at scale Arctic Ocean 1 year. Lead fractions are derived using data sets numerical models satellite detection. The proposed estimates that account 0.3 %–9.8 % annual salt number regions where concentration greater than 80 %. Assuming similar size distributions those open ocean, 30 %–85 mass regions. total 0.1–2.1 Tg yr−1, comparable transported above according MERRA-2 reanalysis. addition providing first possible upper lower bounds conceptual model developed work implemented tested regional atmospheric chemistry WRF-Chem. Given obtained impact clouds radiative budget needs be further explored.

Language: Английский

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Global Observations of Tropospheric Bromine Monoxide (BrO) Columns From TROPOMI

Journal of Geophysical Research Atmospheres, Journal Year: 2023, Volume and Issue: 128(24)

Published: Dec. 21, 2023

Abstract Bromine monoxide (BrO) plays an important role in tropospheric chemistry. The state‐of‐the‐science TROPOspheric Monitoring Instrument (TROPOMI) offers the potential to monitor atmospheric composition with a fine spatial resolution of up 5.5 × 3.5 km 2 . We present here retrieval BrO columns from TROPOMI. implement stratospheric correction scheme using climatological approach based on latest GEOS‐Chem High Performance chemical transport model, and improve air mass factor calculation TROPOMI surface albedo data accounting for geometrical dependency. Our product presents good level consistency comparison measurements ground‐based zenith‐sky differential optical absorption spectroscopy ( r = 0.67), aircrafts 0.46), satellites (similar distributions columns). Furthermore, our captures enhancements polar springtime values 7.8 10 13 molecules cm −2 identifies small‐scale emission sources such as volcanoes salt marshes. Based data, we probe blowing snow aerosol bromine mechanism which salinity is reduced better match simulation observation. contributes high‐resolution global information studies investigating

Language: Английский

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Seasonal dynamics of airborne biomolecules influence the size distribution of Arctic aerosols

Environmental Science and Ecotechnology, Journal Year: 2024, Volume and Issue: 22, P. 100458 - 100458

Published: July 18, 2024

Organic matter is crucial in aerosol–climate interactions, yet the physicochemical properties and origins of organic aerosols remain poorly understood. Here we show seasonal characteristics submicron Arctic Svalbard during spring summer, emphasizing their connection to transport patterns particle size distribution. Microbial-derived (MOM) terrestrial-derived (TOM) accounted for over 90% total mass these seasons, comprising carbohydrate/protein-like lignin/tannin-like compounds, respectively. In spring, showed high TOM low MOM intensities due biomass-burning influx central Arctic. contrast, summer exhibited elevated intensity, attributed shift predominant atmospheric from biologically active Greenland Sea. were associated with Aitken mode particles (<100 nm diameter) accumulation (>100 diameter), This association linked molecular biomolecules, impacting number concentrations corresponding aerosol classes. These findings highlight importance considering source-dependent distributions assessing changing

Language: Английский

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