Overview of the Alaskan Layered Pollution and Chemical Analysis (ALPACA) Field Experiment

ACS ES&T Air, Год журнала: 2024, Номер 1(3), С. 200 - 222

Опубликована: Фев. 21, 2024

The Alaskan Layered Pollution And Chemical Analysis (ALPACA) field experiment was a collaborative study designed to improve understanding of pollution sources and chemical processes during winter (cold climate low-photochemical activity), investigate indoor pollution, dispersion as affected by frequent temperature inversions. A number the research goals were motivated questions raised residents Fairbanks, Alaska, where held. This paper describes measurement strategies conditions encountered January February 2022 experiment, reports early examples how measurements addressed goals, particularly those interest residents. Outdoor air showed high concentrations particulate matter pollutant gases including volatile organic carbon species. During events, low winds extremely stable atmospheric trapped below 73 m, an shallow vertical scale. Tethered-balloon-based intercepted plumes aloft, which associated with power plant point through transport modeling. Because cold spend much their time indoors, included quality component, made inside outside house infiltration sources. In absence activities such cooking and/or heating pellet stove, lower than outdoors; however, stove burns often caused higher outdoors. mass-normalized oxidative potential, health-relevant property measured here reactivity dithiothreiol, particles varied source, having less potential per mass particles.

Язык: Английский

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

Atmospheric chemistry and physics, Год журнала: 2025, Номер 25(2), С. 1063 - 1104

Опубликована: Янв. 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.

Язык: Английский

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Assessing the Oxidative Potential of Outdoor PM_2.5 in Wintertime Fairbanks, Alaska

ACS ES&T Air, Год журнала: 2024, Номер 1(3), С. 175 - 187

Опубликована: Фев. 10, 2024

The oxidative potential (OP) of outdoor PM2.5 in wintertime Fairbanks, Alaska, is investigated and compared to those Atlanta Los Angeles. Approximately 40 filter samples collected January–February 2022 at a Fairbanks residential site were analyzed for OP utilizing dithiothreitol-depletion (OPDTT) hydroxyl-generation (OPOH) assays. study-average mass concentration was 12.8 μg/m3, with 1 h average maximum 89.0 μg/m3. Regression analysis, correlations source tracers, contrast between cold warmer events indicated that OPDTT mainly sensitive copper, elemental carbon, organic aerosol from wood burning, OPOH iron vehicles. Despite low photochemically-driven oxidation rates, the water-soluble fraction unusually high 77%, burning emissions. In other locations, higher than Angeles, whereas similar, Angeles had highest OPOH. Site differences observed when normalized by both volume air sampled particle concentration, corresponding exposure intrinsic health-related properties PM2.5, respectively. sensitivity assays specific components sources can provide insights beyond assessing quality.

Язык: 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, Год журнала: 2025, Номер 25(4), С. 2207 - 2241

Опубликована: Фев. 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.

Язык: Английский

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More evidence on primary sulfate emission from residential coal combustion in northern China: Insights from the size-segregated chemical profile, morphology, and sulfur isotope

Atmospheric Environment, Год журнала: 2024, Номер 326, С. 120467 - 120467

Опубликована: Март 24, 2024

Язык: Английский

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Using sulfur isotopes to constrain the sources of sulfate in PM2.5 during the winter in Jiaozuo City

Atmospheric Environment, Год журнала: 2024, Номер 332, С. 120618 - 120618

Опубликована: Май 31, 2024

Язык: Английский

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Multi-year, high-time resolution aerosol chemical composition and mass measurements from Fairbanks, Alaska

Environmental Science Atmospheres, Год журнала: 2024, Номер 4(6), С. 685 - 698

Опубликована: Янв. 1, 2024

Fairbanks-North Star Borough, Alaska (FNSB) regularly experiences some of the worst wintertime air quality in United States.

Язык: Английский

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Enhanced aqueous formation and neutralization of fine atmospheric particles driven by extreme cold

Science Advances, Год журнала: 2024, Номер 10(36)

Опубликована: Сен. 4, 2024

The prevailing view for aqueous secondary aerosol formation is that it occurs in clouds and fogs, owing to the large liquid water content compared minute levels fine particles. Our research indicates this may need reevaluation due enhancements reactions highly concentrated small Here, we show low temperature can play a role through unique effect on particle pH substantially modulate formation. Marked increases hydroxymethanesulfonate observed under extreme cold Fairbanks, Alaska, demonstrate effect. These findings provide insight chemistry particles conditions expanding possible regions of are dependent beyond high water.

Язык: Английский

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The Abundance and Sources of Ice Nucleating Particles Within Alaskan Ice Fog

Journal of Geophysical Research Atmospheres, Год журнала: 2024, Номер 129(16)

Опубликована: Авг. 23, 2024

Abstract The Alaskan Layered Pollution and Chemical Analysis (ALPACA) field campaign included deployment of a suite atmospheric measurements in January–February 2022 with the goal better understanding processes pollution under cold dark conditions Fairbanks, Alaska. We report on particle composition, size, ice nucleating (INP) INP size during an fog period (29 January–3 February). During this period, coarse particulate matter (PM 10 ) concentrations increased by 150% association decrease air temperature, stronger temperature inversion, relatively stagnant conditions. Results also show 18%–78% INPs indicating that particles had activated into via nucleation. Peroxide heat treatments performed indicated that, average, largest contributions to population were heat‐labile (potentially biological, 63%), organic (31%), then inorganic (likely dust, 6%). Measurements levoglucosan bulk single‐particle composition corroborate presence dust aerosols from combustion sources. Heat‐labile decreased peak fog, those preferentially activated, while increased, suggesting they remained as interstitial INPs. In general, unexpectedly high Fairbanks compared other locations Arctic winter. fact these likely facilitated formation has implications for latitude subject hazards associated fog.

Язык: Английский

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In situ vertical observations of the layered structure of air pollution in a continental high-latitude urban boundary layer during winter

Atmospheric chemistry and physics, Год журнала: 2025, Номер 25(6), С. 3687 - 3715

Опубликована: Март 27, 2025

Abstract. Vertical in situ measurements of aerosols and trace gases were conducted Fairbanks, Alaska, during winter 2022 as part the Alaskan Layered Pollution Chemical Analysis campaign (ALPACA). Using a tethered balloon, study explores dispersion pollutants continental high-latitude stable boundary layer (SBL). 24 flights revealed stratified SBL structure with different pollution layers lowest tens meters atmosphere, offering unprecedented detail. Surface emissions generally accumulated surface mixing (ML) extending to an average 51 m, well-mixed sublayer (MsL) reaching 22 m. The height concentrations within ML strongly influenced by local wind driven nearby topography under anticyclonic conditions. During strong radiative cooling, drainage flow increased turbulence near surface, altering temperature profile deepening ML. Above ML, decreased but showed clear signs freshly released anthropogenic emissions. Higher above elevated inversions, levels similar previously reported Arctic haze concentrations, even though Fairbanks' outflow below inversions up 6 times higher, likely due power plant In indicated that gas particle tracer ratios plumes differed significantly from those surface. Overall, correlated stratification emission heights, emphasizing need for improved representation sources air quality models enhance forecasts.

Язык: Английский

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