Modelling wintertime sea-spray aerosols under Arctic haze conditions

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(10), P. 5641 - 5678

Published: May 22, 2023

Abstract. Anthropogenic and natural emissions contribute to enhanced concentrations of aerosols in the Arctic winter early spring, with most attention being paid anthropogenic that so-called haze. Less-well-studied wintertime sea-spray (SSAs) under haze conditions are focus this study, since they can make an important contribution aerosol abundances. Analysis field campaign data shows evidence for local sources SSAs, including marine organics at Utqiaġvik (formerly known as Barrow) northern Alaska, United States, during 2014. Models tend underestimate sub-micron SSAs overestimate super-micron winter, base version Weather Research Forecast coupled Chemistry (WRF-Chem) model used here, which includes a widely SSA source function based on Gong et al. (1997). Quasi-hemispheric simulations 2014 updated wind speed sea-surface temperature (SST) emission dependencies sea-salt sulfate lead significantly improved performance compared observations remote sites, notably coarse-mode sodium chloride, reduced. The also simulates more realistic contributions inorganic different ranging from 20 %–93 % observations. Two-thirds is inclusion dependence SSTs. simulation nitrate due less heterogeneous uptake nitric acid coarse mode related increases fine-mode nitrate. This highlights importance interactions between Simulation organic fraction However, underestimates episodes elevated observed components non-sea-salt some Utqiaġvik. Possible reasons explored higher-resolution runs over Alaska periods corresponding January February addition organics, data, modelled Alaska. comparison previous available suggests open leads, well sources, underestimated model. Missing may explain low (sub-micron) introduction higher emissions, reduces biases while sea-ice fractions, shown be factor controlling super-micron, rather than sub-micron, north coast regional results presented here show sensitive but modelling distributions needed organics. study supports findings leads primary fresh aged aerosols, Utqiaġvik; these do not suggest influence blowing snow frost flowers. To improve new processes production, particular understanding about possible sources.

Language: Английский

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Evaluating modelled tropospheric columns of CH₄, CO, and O₃ in the Arctic using ground-based Fourier transform infrared (FTIR) measurements

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(2), P. 1079 - 1118

Published: Jan. 24, 2024

Abstract. This study evaluates tropospheric columns of methane, carbon monoxide, and ozone in the Arctic simulated by 11 models. The is warming at nearly 4 times global average rate, with changing emissions near region, it important to understand atmospheric composition how changing. Both measurements modelling air pollution are difficult, making model validation local valuable. Evaluations performed using data from five high-latitude ground-based Fourier transform infrared (FTIR) spectrometers Network for Detection Atmospheric Composition Change (NDACC). models were selected as part 2021 Monitoring Assessment Programme (AMAP) report on short-lived climate forcers. work augments model–measurement comparisons presented that including a new source: column-integrated FTIR measurements, whose spatial temporal footprint more representative free troposphere than situ satellite measurements. Mixing ratios trace gases modelled 3-hourly intervals CESM, CMAM, DEHM, EMEP MSC-W, GEM-MACH, GEOS-Chem, MATCH, MATCH-SALSA, MRI-ESM2, UKESM1, WRF-Chem years 2008, 2009, 2014, 2015. focus (0–7 km partial columns) Eureka, Canada; Thule, Greenland; Ny Ålesund, Norway; Kiruna, Sweden; Harestua, Norway. Overall, biased low column, −9.7 % CH4, −21 CO, −18 O3. Results CH4 relatively consistent across years, whereas CO has maximum negative bias spring minimum summer O3 difference centered around summer. differences within uncertainties approximately 15 model–location comparisons.

Language: Английский

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Universal thermal climate index in the Arctic in an era of climate change: Alaska and Chukotka as a case study

International Journal of Biometeorology, Journal Year: 2023, Volume and Issue: 67(11), P. 1703 - 1721

Published: Aug. 12, 2023

The modern unambiguous climate change reveals in a rapid increase of air temperature, which is more distinctly expressed the Arctic than any other part world, affecting people health and well-being. main objective current research to explore inter- intra-annual changes thermal stress for Arctic, specifically two parts Beringia: Alaska, USA, Chukotka, Russia, using climatology universal index (UTCI). Data 39 locations are taken from ERA5-HEAT reanalysis period 1979-2020. Climatologically, study area divided into four subregions Alaska: North, Interior, West South, Chukotka: Interior Coast. extreme coldest UTCI categories (1 2) most common coastal northern Alaska where strong winds exacerbate low temperatures during winter. results show that frequency category 1 (UTCI<-40°C) varies spatially quarter all hours annually North almost zero South. On hand, warmest rarely reached everywhere even 7 8 (UTCI between +26 +38°C) found occasionally only at interior locations. Category 6 with no +9 and+26°C) has frequencies up 3% 25% respectively. extremely cold have substantially decreased over 1979-2020 period, especially Chukotka At same time, number comfortable perception increased depending on subregion, 25 203 h/year. Overall, decrease coupled an range both Chukotka. salient conclusion that, point view comfort safety, global warming positive impact providing advantages development tourism recreation.

Language: Английский

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Characterization of size-segregated particles' turbulent flux and deposition velocity by eddy correlation method at an Arctic site

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(13), P. 7425 - 7445

Published: July 6, 2023

Abstract. Estimating aerosol depositions on snow and ice surfaces assessing the lifecycle in Arctic region is challenged by scarce measurement data available for particle surface fluxes. This work aims at deposition velocity of atmospheric particles an site (Ny-Ålesund, Svalbard islands) over snow, during melting season, dry tundra. The measurements were performed using eddy covariance method from March to August 2021. system was based a condensation counter (CPC) ultrafine (UFP; < 0.25 µm) fluxes optical (OPC) evaluating size accumulation mode (ACC; dp 0.7 quasi-coarse (CRS; 0.8 3 µm). Turbulent range prevalently downward, especially summertime. In contrast, more frequently positive, colder months, pointing sources from, example, sea spray, sublimation, or local pollution. overall median (Vd+) values 0.90, 0.62, 4.42 mm s−1 UFP, ACC, CRS, respectively. Deposition velocities smaller, average, snowpack, with 0.73, 0.42, 3.50 s−1. observed differ less than 50 % respect previous literature analogous environments (i.e. ice/snow) 0.01–1 µm. At same time, agreement results predictive models found only few parameterizations, particular Slinn (1982), while large biases other models, 0.3–10 µm, diameters. Our observations show better fit predicting minimum small-accumulation-mode sizes (0.1–0.3 rather larger ones (about 1 µm), which could result efficient interception are rougher stickier idealized ones. Finally, polynomial investigated (for ACC-CRS range) describe properly represents their dependence magnitude. Even if this numerical driven purely not underlying chemical–physical processes, it be very useful future model parameterizations.

Language: Английский

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Assessing the climate and air quality effects of future aerosol mitigation in India using a global climate model combined with statistical downscaling

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(6), P. 3471 - 3491

Published: March 20, 2023

Abstract. We studied the potential of using machine learning to downscale global-scale climate model output towards ground station data. The aim was simultaneously analyze both city-level air quality and regional- radiative forcing values for anthropogenic aerosols. As pollution are typically underestimated in models, we used a approach fine particulate (PM2.5) concentrations measured values. first simulated global with aerosol–climate ECHAM-HAMMOZ corrected PM2.5 Indian megacity New Delhi. downscaling procedure clearly improved seasonal variation trends were much better captured than original when compared reference from stations. However, short-term variations showed less extreme approach. applied also simulations where aerosol emissions following two different future scenarios: one current legislation assuming currently maximum feasible emission reductions. year 2030 that mitigating aerosols improves local Delhi, organic carbon reductions contributing most these improvements. In addition, mitigation resulted negative over India. This mainly due absorbing black emissions. For scenarios modeled, aerosol–radiation interactions India -0.09±0.26 -0.53±0.31 W m−2, respectively, while effective -2.1±4.6 0.06±3.39 respectively. Although accompanied by relatively large uncertainties, obtained results indicate could bring double benefit India: decreased warming climate. Our demonstrate bias correction allow more versatile utilization models. With help downscaling, models can be applications aims regional effects policies related

Language: Английский

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Aerosol processes in high-latitude environments and the effects on climate

Elsevier eBooks, Journal Year: 2022, Volume and Issue: unknown, P. 651 - 706

Published: Jan. 1, 2022

Language: Английский

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Controlling factors of spatiotemporal variations in black carbon concentrations over the Arctic region by using a WRF/CMAQ simulation on the Northern Hemisphere scale

Polar Science, Journal Year: 2024, Volume and Issue: 41, P. 101093 - 101093

Published: June 6, 2024

Language: Английский

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A Comprehensive Evaluation of Black Carbon in Snow and Its Radiative Forcing in CMIP5 and CMIP6 Models Based on Global Field Observations

Journal of Geophysical Research Atmospheres, Journal Year: 2024, Volume and Issue: 129(14)

Published: July 22, 2024

Abstract Black carbon in snow (BCS) is a crucial parameter Earth System modeling, as it influences global radiative balance. Here, simulated BCS from Coupled Model Intercomparison Project Phase 5 and 6 (CMIP5 CMIP6) that provided model output were evaluated. In comparison with observations, CMIP5/6 models successfully reproduced long‐term historical trends linked to human activities, but struggled capturing decadal variability caused by natural climate variability. CMIP6 NorESM2‐MM, NorESM2‐LM, TaiESM1 yielded the most accurate simulations of concentration modest overestimation <50%, while four CESM2 underestimated concentrations up ∼80%. These errors effectively balanced for multi‐model ensemble mean (MME), which had relative error (RE) −37%. However, CMIP5 MME was less reliable due extreme 8,000% three MIROC models. The significant mainly handling BC processes. Conversely, marked improvements NorESM, only common both CMIP6, improved simulation black deposition. significantly impacted forcing estimates, particularly at poles, where reached several thousandfold. exhibited superior results compared CMIP5, achieving RE −33% estimates. it's worth noting currently limited, seven available each here. Additional simulating are desirable next CMIP generations.

Language: Английский

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Contributions of biomass burning in 2019 and 2020 to Arctic black carbon and its transport pathways

Atmospheric Research, Journal Year: 2023, Volume and Issue: 296, P. 107069 - 107069

Published: Oct. 21, 2023

Language: Английский

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Shipborne observations of black carbon aerosols in the western Arctic Ocean during summer and autumn 2016–2020: impact of boreal fires

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(10), P. 6339 - 6357

Published: May 30, 2024

Abstract. Black carbon (BC) aerosol is considered one of the most important contributors to rapid climate warming as well snow and sea ice melting in Arctic, yet observations BC aerosols Arctic Ocean have been limited due infrastructural logistical difficulties. We observed mass concentrations (mBC) using light absorption methods on board icebreaker R/V Araon (< 80° N 166° E 156° W) North Pacific summer early autumn 2016–2020. The levels, interannual variations, pollution episodes mBC were examined, emission sources responsible for high-BC analyzed with global chemistry-transport-model simulations. average surface air over (72–80° N) by 2019 cruise exceeded 70 ng m−3, which was substantially higher than that cruises other years (approximately 10 m−3). much perhaps more frequent wildfires occurring region years. model suggested biomass burning contributed western marginal seas. For these 5 years, we identified north 65° N, including 2018 associated co-enhancements CO CH4 but not CO2 O3. analysis indicated certain attributed BC-containing masses transported from boreal fire regions Ocean, some transport near others mid-troposphere. This study provides crucial datasets mixing ratios O3, CH4, CO, regions, it highlights significant impact fires during months.

Language: Английский

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