Trends in atmospheric methane concentrations since 1990 were driven and modified by anthropogenic emissions

Communications Earth & Environment, Journal Year: 2023, Volume and Issue: 4(1)

Published: Sept. 8, 2023

Abstract The atmospheric methane trend is not fully understood. Here we investigate the role of main sink, natural source, and anthropogenic emissions on growth rate over last three decades using numerical models emission inventories. We find that long-term driven by increased emissions, while wetland show large variability can modify trend. influence hydroxyl radical, through nitrogen oxides carbon monoxide has modified contributed to stabilization from 2000 2007. radical increase prior this period might have decline in isotopic ratio after 2007 due time dependent response radical. Emission reductions COVID-19 restrictions via possibly approximately two thirds 2019 2020.

Language: Английский

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Physical and Chemical Properties of Cloud Droplet Residuals and Aerosol Particles During the Arctic Ocean 2018 Expedition

Journal of Geophysical Research Atmospheres, Journal Year: 2022, Volume and Issue: 127(11)

Published: May 25, 2022

Detailed knowledge of the physical and chemical properties sources particles that form clouds is especially important in pristine areas like Arctic, where particle concentrations are often low observations sparse. Here, we present situ cloud aerosol measurements from central Arctic Ocean August-September 2018 combined with air parcel source analysis. We provide direct experimental evidence Aitken mode (particles diameters ≲70 nm) significantly contribute to condensation nuclei (CCN) or droplet residuals, after freeze-up sea ice transition toward fall. These were associated spent more time over pack ice, while size distributions dominated by accumulation ≳70 showed a stronger contribution oceanic slightly different regions. This was accompanied changes average composition an increased relative organic material Addition mass due aqueous-phase chemistry during in-cloud processing probably small given fact observed very similar both whole-air residual data. aerosol-cloud interaction valuable insight into origin CCN Ocean.

Language: Английский

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Long-term observations of black carbon and carbon monoxide in the Poker Flat Research Range, central Alaska, with a focus on forest wildfire emissions

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(1), P. 143 - 156

Published: Jan. 8, 2025

Abstract. Forest wildfires in interior Alaska represent an important black carbon (BC) source for the Arctic and sub-Arctic. However, BC observations have not been sufficient to constrain range of existing emissions. Here, we show our mass concentrations monoxide (CO) mixing ratios Poker Flat Research Range (65.12° N, 147.43° W), located central Alaska, from April 2016 December 2020. The medians, 10th percentile ranges, 90th ranges hourly concentration CO ratio throughout observation period were 13, 2.9, 56 ng m−3 124.7, 98.7, 148.3 ppb, respectively. Sporadically large peaks observed at same time, indicating influences common sources. These coincided with other comparative sites emissions Alaska. Source estimation by FLEXPART-WRF (Flexible Particle Dispersion–Weather Forecast) confirmed a contribution boreal forest western Canada when high observed. For these cases, found positive correlation (r=0.44) between BC/ΔCO fire radiative power (FRP) Canada. This finding implies that variability emission is associated intensity time progress suggests factor and/or inventory could be potentially improved FRP. We recommend FRP integrated into future bottom-up inventories achieve better understanding dynamics pollutants frequently occurring under rapidly changing climate Arctic.

Language: Английский

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Atmospheric concentrations of black carbon are substantially higher in spring than summer in the Arctic

Communications Earth & Environment, Journal Year: 2023, Volume and Issue: 4(1)

Published: March 24, 2023

Abstract A key driving factor behind rapid Arctic climate change is black carbon, the atmospheric aerosol that most efficiently absorbs sunlight. Our knowledge about carbon in scarce, mainly limited to long-term measurements of a few ground stations and snap-shots by aircraft observations. Here, we combine observations from campaigns performed over nine years, present vertically resolved average properties. four higher mass concentration (21.6 ng m −3 average, 14.3 median) was found spring, compared summer (4.7 3.9 median). In much inter-annual geographic variability prevailed stable situation summer. The shape size distributions remained constant between seasons with an mean diameter 202 nm spring 210 Comparison concentrations simulated global model shows notable discrepancies, highlighting need for further developments intensified measurements.

Language: Английский

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Arctic tropospheric ozone: assessment of current knowledge and model performance

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(1), P. 637 - 661

Published: Jan. 16, 2023

Abstract. As the third most important greenhouse gas (GHG) after carbon dioxide (CO2) and methane (CH4), tropospheric ozone (O3) is also an air pollutant causing damage to human health ecosystems. This study brings together recent research on observations modeling of O3 in Arctic, a rapidly warming sensitive environment. At different locations observed surface seasonal cycles are quite different. Coastal Arctic locations, for example, have minimum springtime due depletion events resulting from bromine chemistry. In contrast, other maximum spring. The 12 state-of-the-art models used this lack halogen chemistry needed simulate coastal springtime; however, multi-model median (MMM) has accurate at non-coastal locations. There large amount variability among models, which been previously reported, we show that there continues be no convergence or improved accuracy simulating its precursor species. MMM underestimates by 5 % 15 depending location. vertical distribution studied ozonesonde measurements models. highly variable, free-tropospheric within range ±50 model altitude. performs best, ±8 seasons. However, nearly all overestimate near tropopause (∼300 hPa ∼8 km), likely ongoing issues with underestimating altitude excessive downward transport stratospheric high latitudes. For biased about 20 Eureka. Observed simulated precursors (CO, NOx, reservoir PAN) evaluated throughout troposphere. Models underestimate wintertime CO everywhere, combination emissions possibly overestimating OH. Throughout profile (compared aircraft measurements), both NOx but overestimates PAN. Perhaps as result competing deficiencies, matches reasonably well. Our findings suggest despite updates over last decade, results variable ever not increased representing O3.

Language: Английский

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Assessment of the Spatial Structure of Black Carbon Concentrations in the Near-Surface Arctic Atmosphere

Atmosphere, Journal Year: 2023, Volume and Issue: 14(1), P. 139 - 139

Published: Jan. 8, 2023

The results of the research are numerical estimates average fields black carbon mass concentration in surface layer atmosphere Arctic region obtained using numeric technology referred to as fluid location (FLA). modelling has been based on measurements concentrations near-surface during two cruises Professor Multanovskiy (28 July–7 September 2019) and Akademik Mstislav Keldysh (31 July–24 August 2020) vessels. These have supplemented by at stationary monitoring points located Spitsbergen Severnaya Zemlya archipelagoes. simulation summertime demonstrates that areas increased were observed over Northern Europe and, 2019, also Laptev Sea basin. spatial distribution qualitatively agreed with same data derived from second Modern-Era Retrospective analysis for Research Applications (MERRA-2) but showed quantitative differences. values zones follows: 85.3 ng/m3 (2019) 53.6 (2020) reconstructed FLA technology; 261.69 131.8 MERRA-2 data.

Language: Английский

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Arctic Tropospheric Ozone Trends

Geophysical Research Letters, Journal Year: 2023, Volume and Issue: 50(22)

Published: Nov. 20, 2023

Abstract Observed trends in tropospheric ozone, an important air pollutant and short‐lived climate forcer (SLCF), are estimated using available surface ozonesonde profile data for 1993–2019, a coherent methodology, compared to modeled (1995–2015) from the Arctic Monitoring Assessment Program SLCF 2021 assessment. Increases observed ozone at coastal sites, notably during winter, concurrent decreasing carbon monoxide, generally captured by multi‐model median trends. Wintertime increases also free troposphere most with decreases spring months. Winter tend be overestimated medians. Springtime northern Alaska not simulated while negative springtime Scandinavia always reproduced. Possible reasons changes model performance discussed including precursor emissions, changing dry deposition, variability large‐scale meteorology.

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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Characteristics of atmospheric black carbon and other aerosol particles over the Arctic Ocean in early autumn 2016: Influence from biomass burning as assessed with observed microphysical properties and model simulations

The Science of The Total Environment, Journal Year: 2022, Volume and Issue: 848, P. 157671 - 157671

Published: July 27, 2022

Language: Английский

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Airborne investigation of black carbon interaction with low-level, persistent, mixed-phase clouds in the Arctic summer

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(14), P. 7955 - 7973

Published: July 18, 2023

Abstract. Aerosol–cloud interaction is considered one of the largest sources uncertainty in radiative forcing estimations. To better understand role black carbon (BC) aerosol as a cloud nucleus and impact clouds on its vertical distribution Arctic, we report airborne situ measurements BC particles European Arctic near Svalbard during “Arctic CLoud Observations Using polar Day” (ACLOUD) campaign held summer 2017. was measured with single-particle soot photometer aboard Polar 6 research aircraft from lowest atmospheric layer up to approximately 3500 m a.s.l (metres above sea level). During in-cloud flight transects, contained liquid droplets (BC residuals) were sampled through counterflow virtual impactor (CVI) inlet. Four flights, conducted presence low-level, surface-coupled, inside-inversion, mixed-phase over ice, selected address variability above, below, within layer. First, increase size coating thickness free troposphere cloud-dominated boundary confirmed that ground observations not representative upper layers. Second, although only 1 % particle, higher number concentration residuals than below indicated totality below-cloud activated by nucleation scavenging but also alternative processes such activation free-tropospheric at top might occur. Third, efficient exchange bottom similarity cloud. Last, residual (+31 %) geometric mean diameter (+38 absolute enrichment larger compared outside supported hypothesis concomitant mechanisms suggested formation agglomerates caused processing. The evolution properties inside an bottom, which include activation, processing, sub-cloud release processed agglomerates. In case persistent low-level clouds, this cycle may reiterate multiple times, adding additional degree complexity understanding processing Arctic.

Language: Английский

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