Quantifying black carbon from biomass burning by means of levoglucosan – a one year time series at the Arctic observatory Zeppelin

Abstract. Levoglucosan, a highly specific tracer of particulate matter from biomass burning, has been used to study the influence of residential wood burning, agricultural waste burning and boreal forest fire emissions on the Arctic atmosphere black carbon (BC) concentration. A one year time series from March 2008 to March 2009 of levoglucosan has been established at the Zeppelin Observatory in the European Arctic. Elevated concentrations of levoglucosan in winter (Mean: 1.02 ng m−3) compared to summer (Mean: 0.13 ng m−3) were observed, resembling the seasonal variation seen for e.g. sulphate and BC. The mean concentration in the winter period was two to three orders of magnitude lower than typical values reported for European urban areas in winter, and one to two orders of magnitude lower than European rural background concentrations. Episodes of elevated levoglucosan concentration were more frequent in winter than in summer and peak values were higher, exceeding 10 ng m−3 at the most. Concentrations of elemental carbon from biomass burning (ECbb) were obtained by combining measured concentrations of levoglucosan and emission ratios of levoglucosan and EC for wild/agricultural fires and for residential wood burning. Neglecting chemical degradation by OH provides minimum levoglucosan concentrations, corresponding to a mean ECbb concentration of 3.7±1.2 ng m−3 in winter (October–April) and 0.8±0.3 ng m−3 in summer (May–September) or 8.8±4.5% of the measured equivalent black carbon (EBC) concentration in winter and 6.1±3.4% in summer. When accounting for chemical degradation of levoglucosan by OH, an upper estimate of 31–45% of EBC could be attributed to ECbb* (ECbb adjusted for chemical degradation) in winter and <65% in summer. Hence, fossil fuel sources appear to dominate the European Arctic BC concentrations in winter, whereas the very wide range obtained for summer does not allow us to conclude upon this for the warm season. Calculations using the Lagrangian particle dispersion model FLEXPART show that the seasonal variation of the modelled ECbb (ECbb,m) concentration compared relatively well with observationally derived ECbb from agricultural/wild fires during summer, and residential wood burning in winter. The model overestimates by a factor of 2.2 in winter and 4.4 in summer when compared to the observationally derived mean ECbb concentration, which provides the minimum estimate, whereas it underestimates by a factor of 2.3–3.3 in winter and a factor of 4.5 in summer when compared to ECbb*, which provides the upper estimate. There are indications of too low emissions of residential wood burning in Northern Russia, a region of great importance with respect to observed concentrations of BC in the European Arctic.

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Quantifying black carbon from biomass burning by means of levoglucosan – a one-year time series at the Arctic observatory Zeppelin

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-6427-2014 ◽

2014 ◽

Vol 14 (12) ◽

pp. 6427-6442 ◽

Cited By ~ 49

Author(s):

K. E. Yttri ◽

C. Lund Myhre ◽

S. Eckhardt ◽

M. Fiebig ◽

C. Dye ◽

...

Keyword(s):

Time Series ◽

Seasonal Variation ◽

Black Carbon ◽

Biomass Burning ◽

Chemical Degradation ◽

The Arctic ◽

Wood Burning ◽

European Arctic ◽

One Year ◽

Upper Estimate

Abstract. Levoglucosan, a highly specific tracer of particulate matter from biomass burning, has been used to study the influence of residential wood burning, agricultural waste burning and Boreal forest fire emissions on the Arctic atmosphere black carbon (BC) concentration. A one-year time series from March 2008 to March 2009 of levoglucosan has been established at the Zeppelin observatory in the European Arctic. Elevated concentrations of levoglucosan in winter (mean: 1.02 ng m−3) compared to summer (mean: 0.13 ng m−3) were observed, resembling the seasonal variation seen for e.g. sulfate and BC. The mean concentration in the winter period was 2–3 orders of magnitude lower than typical values reported for European urban areas in winter, and 1–2 orders of magnitude lower than European rural background concentrations. Episodes of elevated levoglucosan concentration lasting from 1 to 6 days were more frequent in winter than in summer and peak values were higher, exceeding 10 ng m−3 at the most. Concentrations of elemental carbon from biomass burning (ECbb) were obtained by combining measured concentrations of levoglucosan and emission ratios of levoglucosan and EC for wildfires/agricultural fires and for residential wood burning. Neglecting chemical degradation by OH provides minimum levoglucosan concentrations, corresponding to a mean ECbb concentration of 3.7 ± 1.2 ng m−3 in winter (October–April) and 0.8 ± 0.3 ng m−3 in summer (May–September), or 8.8 ± 4.5% of the measured equivalent black carbon (EBC) concentration in winter and 6.1 ± 3.4% in summer. When accounting for chemical degradation of levoglucosan by OH, an upper estimate of 31–45% of EBC could be attributed to ECbb* (ECbb adjusted for chemical degradation) in winter, whereas no reliable (<100%) upper estimate could be provided for summer for the degradation rates applied. Hence, fossil fuel sources appear to dominate the European Arctic BC concentrations in winter, whereas the very wide range obtained for summer does not allow us to conclude upon this for the warm season. Calculations using the Lagrangian particle dispersion model FLEXPART show that the seasonal variation of the modeled ECbb (ECbb,m) concentration compared relatively well with observationally derived ECbb from agricultural fires/wildfires during summer, and residential wood burning in winter. The model overestimates by a factor of 2.2 in winter and 4.4 in summer when compared to the observationally derived mean ECbb concentration, which provides the minimum estimate, whereas it underestimates by a factor of 2.3–3.3 in winter and a factor of 4.5 in summer when compared to ECbb*, which provides the upper estimate. There are indications of too-low emissions of residential wood burning in northern Russia, a region of great importance with respect to observed concentrations of BC in the European Arctic.

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The importance of Asia as a source of black carbon to the European Arctic during springtime 2013

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-11537-2015 ◽

2015 ◽

Vol 15 (20) ◽

pp. 11537-11555 ◽

Cited By ~ 37

Author(s):

D. Liu ◽

B. Quennehen ◽

E. Darbyshire ◽

J. D. Allan ◽

P. I. Williams ◽

...

Keyword(s):

Black Carbon ◽

Arctic Sea Ice ◽

Anthropogenic Sources ◽

The Arctic ◽

Geometric Standard Deviation ◽

Free Troposphere ◽

Aerosol Composition ◽

Upper Troposphere ◽

European Arctic ◽

Mean Concentration

Abstract. Black carbon aerosol (BC) deposited to the Arctic sea ice or present in the free troposphere can significantly affect the Earth's radiation budget at high latitudes yet the BC burden in these regions and the regional source contributions are poorly constrained. Aircraft measurements of aerosol composition in the European Arctic were conducted during the Aerosol–Cloud Coupling And Climate Interactions in the Arctic (ACCACIA) campaign in March 2013. Pollutant plumes were encountered throughout the lower to upper Arctic troposphere featuring enhancements in CO and aerosol mass loadings, which were chemically speciated into BC and non-refractory sulphate and organic matter. FLEXPART-WRF simulations have been performed to evaluate the likely contribution to the pollutants from regional ground sources. By combining up-to-date anthropogenic and open fire biomass burning (OBB) inventories, we have been able to compare the contributions made to the observed pollution layers from the sources of eastern/northern Asia (AS), Europe (EU) and North America (NA). Over 90 % of the contribution to the BC was shown to arise from non-OBB anthropogenic sources. AS sources were found to be the major contributor to the BC burden, increasing background BC loadings by a factor of 3–5 to 100.8 ± 48.4 ng sm−3 (in standard air m3 at 273.15 K and 1013.25 mbar) and 55.8 ± 22.4 ng sm−3 in the middle and upper troposphere respectively. AS plumes close to the tropopause (about 7.5–8 km) were also observed, with BC concentrations ranging from 55 to 73 ng sm−3, which will potentially have a significant radiative impact. EU sources influenced the middle troposphere with a BC mean concentration of 70.8 ± 39.1 ng sm−3 but made a minor contribution to the upper troposphere due to the relatively high latitude of the source region. The contribution of NA was shown to be much lower at all altitudes with BC mean concentration of 20 ng sm−3. The BC transported to the Arctic is mixed with a non-BC volume fraction representing between 90–95 % of the mass, and has a relatively uniform core size distribution with mass median diameter 190–210 nm and geometric standard deviation σg = 1.55–1.65 and this varied little across all source regions. It is estimated that 60–95 % of BC is scavenged between emission and receptor based on BC / ΔCO comparisons between source inventories and measurement. We show that during the springtime of 2013, the anthropogenic pollution particularly from sources in Asia, contributed significantly to BC across the European Arctic free troposphere. In contrast to previous studies, the contribution from open wildfires was minimal. Given that Asian pollution is likely to continue to rise over the coming years, it is likely that the radiative forcing in the Arctic will also continue to increase.

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Reviews and syntheses: Arctic fire regimes and emissions in the 21st century

Biogeosciences ◽

10.5194/bg-18-5053-2021 ◽

2021 ◽

Vol 18 (18) ◽

pp. 5053-5083

Author(s):

Jessica L. McCarty ◽

Juha Aalto ◽

Ville-Veikko Paunu ◽

Steve R. Arnold ◽

Sabine Eckhardt ◽

...

Keyword(s):

Climate Change ◽

Land Use ◽

Black Carbon ◽

Biomass Burning ◽

Fire Regimes ◽

Future Climate ◽

The Arctic ◽

Future Climate Change ◽

Fire Emissions ◽

Extreme Fire

Abstract. In recent years, the pan-Arctic region has experienced increasingly extreme fire seasons. Fires in the northern high latitudes are driven by current and future climate change, lightning, fuel conditions, and human activity. In this context, conceptualizing and parameterizing current and future Arctic fire regimes will be important for fire and land management as well as understanding current and predicting future fire emissions. The objectives of this review were driven by policy questions identified by the Arctic Monitoring and Assessment Programme (AMAP) Working Group and posed to its Expert Group on Short-Lived Climate Forcers. This review synthesizes current understanding of the changing Arctic and boreal fire regimes, particularly as fire activity and its response to future climate change in the pan-Arctic have consequences for Arctic Council states aiming to mitigate and adapt to climate change in the north. The conclusions from our synthesis are the following. (1) Current and future Arctic fires, and the adjacent boreal region, are driven by natural (i.e. lightning) and human-caused ignition sources, including fires caused by timber and energy extraction, prescribed burning for landscape management, and tourism activities. Little is published in the scientific literature about cultural burning by Indigenous populations across the pan-Arctic, and questions remain on the source of ignitions above 70∘ N in Arctic Russia. (2) Climate change is expected to make Arctic fires more likely by increasing the likelihood of extreme fire weather, increased lightning activity, and drier vegetative and ground fuel conditions. (3) To some extent, shifting agricultural land use and forest transitions from forest–steppe to steppe, tundra to taiga, and coniferous to deciduous in a warmer climate may increase and decrease open biomass burning, depending on land use in addition to climate-driven biome shifts. However, at the country and landscape scales, these relationships are not well established. (4) Current black carbon and PM2.5 emissions from wildfires above 50 and 65∘ N are larger than emissions from the anthropogenic sectors of residential combustion, transportation, and flaring. Wildfire emissions have increased from 2010 to 2020, particularly above 60∘ N, with 56 % of black carbon emissions above 65∘ N in 2020 attributed to open biomass burning – indicating how extreme the 2020 wildfire season was and how severe future Arctic wildfire seasons can potentially be. (5) What works in the boreal zones to prevent and fight wildfires may not work in the Arctic. Fire management will need to adapt to a changing climate, economic development, the Indigenous and local communities, and fragile northern ecosystems, including permafrost and peatlands. (6) Factors contributing to the uncertainty of predicting and quantifying future Arctic fire regimes include underestimation of Arctic fires by satellite systems, lack of agreement between Earth observations and official statistics, and still needed refinements of location, conditions, and previous fire return intervals on peat and permafrost landscapes. This review highlights that much research is needed in order to understand the local and regional impacts of the changing Arctic fire regime on emissions and the global climate, ecosystems, and pan-Arctic communities.

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Sources of Springtime Surface Black Carbon in the Arctic: An Adjoint Analysis

10.5194/acp-2016-1112 ◽

2017 ◽

Cited By ~ 1

Author(s):

Ling Qi ◽

Qinbin Li ◽

Daven K. Henze ◽

Hsien-Liang Tseng ◽

Cenlin He

Keyword(s):

Natural Gas ◽

Black Carbon ◽

Biomass Burning ◽

Transport Model ◽

Lower Troposphere ◽

Anthropogenic Sources ◽

The Arctic ◽

Anthropogenic Source ◽

Gas Flaring ◽

Arctic Front

Abstract. We quantify source contributions to springtime (April 2008) surface black carbon (BC) in the Arctic by interpreting surface observations of BC at five receptor sites (Denali, Barrow, Alert, Zeppelin, and Summit) using a global chemical transport model (GEOS-Chem) and its adjoint. Contributions to BC at Barrow, Alert, and Zeppelin are dominated by Asian anthropogenic sources (40–43 %) before April 18 and by Siberian open biomass burning emissions (29–41 %) afterward. In contrast, Summit, a mostly free tropospheric site, has predominantly an Asian anthropogenic source contribution (24–68 %, with an average of 45 %). We compute the adjoint sensitivity of BC concentrations at the five sites during a pollution episode (April 20–25) to global emissions from March 1 to April 25. The associated contributions are the combined results of these sensitivities and BC emissions. Local and regional anthropogenic sources in Alaska are the largest anthropogenic sources of BC at Denali (63 %), and natural gas flaring emissions in the Western Extreme North of Russia (WENR) are the largest anthropogenic sources of BC at Zeppelin (26 %) and Alert (13 %). We find that long-range transport of emissions from Beijing-Tianjin-Hebei (also known as Jing-Jin-Ji), the biggest urbanized region in Northern China, contribute significantly (~ 10 %) to surface BC across the Arctic. On average it takes ~ 12 days for Asian anthropogenic emissions and Siberian biomass burning emissions to reach Arctic lower troposphere, supporting earlier studies. Natural gas flaring emissions from the WENR reach Zeppelin in about a week. We find that episodic, direct transport events dominate BC at Denali (87 %), a site outside the Arctic front, a strong transport barrier. The relative contribution of direct transport to surface BC within the Arctic front is much smaller (~ 50 % at Barrow and Zeppelin and ~ 10 % at Alert). The large contributions from Asian anthropogenic sources are predominately in the form of ‘chronic’ pollution (~ 40 % at Barrow and 65 % at Alert and 57 % at Zeppelin) on 1–2 month timescales. As such, it is likely that previous studies using 5- or 10-day trajectory analyses strongly underestimated the contribution from Asia to surface BC in the Arctic. Both finer temporal resolution of biomass burning emissions and accounting for the Wegener-Bergeron-Findeisen (WBF) process in wet scavenging improve the source attribution estimates.

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Tagged tracer simulations of black carbon in the Arctic: Transport, source contributions, and budget

10.5194/acp-2017-237 ◽

2017 ◽

Author(s):

Kohei Ikeda ◽

Hiroshi Tanimoto ◽

Takafumi Sugita ◽

Hideharu Akiyoshi ◽

Yugo Kanaya ◽

...

Keyword(s):

East Asia ◽

Black Carbon ◽

Long Range ◽

Biomass Burning ◽

East Asian ◽

The Arctic ◽

Long Range Transport ◽

Middle Troposphere ◽

Source Contributions ◽

Range Transport

Abstract. We implemented a tagged tracer method of black carbon (BC) into a global chemistry-transport model GEOS-Chem, examined the pathways and efficiency of long-range transport from a variety of anthropogenic and biomass burning emission sources to the Arctic, and quantified the source contributions of individual emissions. Firstly, we evaluated the simulated BC by comparing it with observations at the Arctic sites and found that the simulated seasonal variations were improved by implementing an aging parameterization and reducing the wet scavenging rate by ice clouds. For tagging BC, we added BC tracers distinguished by source types (anthropogenic and biomass burning) and regions; the global domain was divided into 16 and 27 regions for anthropogenic and biomass burning emissions, respectively. Our simulations showed that BC emitted from Europe and Russia was transported to the Arctic mainly in the lower troposphere during winter and spring. In particular, BC transported from Russia was widely spread over the Arctic in winter and spring, leading to a dominant contribution of 62 % to the Arctic BC near the surface as the annual mean. In contrast, BC emitted from East Asia was found to be transported in the middle troposphere into the Arctic mainly over the Okhotsk Sea and East Siberia during winter and spring. We identified an important window area, which allowed a strong incoming of East Asian BC to the Arctic (130°–180° E and 3–8 km altitude at 66° N). The model demonstrated that the contribution from East Asia to the Arctic had a maximum at about 5 km altitude due to uplifting during the long-range transport in early spring. The efficiency of BC transport from East Asia to the Arctic was smaller than that from other large source regions such as Europe, Russia and North America. However, the East Asian contribution was most important for BC in the middle troposphere (41 %) and BC burden over the Arctic (27 %) because of the large emissions from this region. These results suggested that the main sources of the Arctic BC differed with altitude. The contribution of all the anthropogenic sources to Arctic BC concentrations near the surface was dominant (90 %) on an annual basis. The contributions of biomass burning in boreal regions (Siberia, Alaska and Canada) to the annual total BC deposition onto the Arctic were estimated to be 12–15 %, which became the maximum during summer.

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Arctic black carbon during PAMARCMiP 2018 and previous aircraft experiments in spring

10.5194/acp-2021-349 ◽

2021 ◽

Author(s):

Sho Ohata ◽

Makoto Koike ◽

Atsushi Yoshida ◽

Nobuhiro Moteki ◽

Kouji Adachi ◽

...

Keyword(s):

Numerical Model ◽

Black Carbon ◽

Biomass Burning ◽

Base Station ◽

Anthropogenic Sources ◽

The Arctic ◽

Core Diameter ◽

Model Simulations ◽

Anthropogenic Contributions ◽

Mass Concentrations

Abstract. Vertical profiles of the mass concentration of black carbon (BC) were measured at altitudes up to 5 km during the PAMARCMiP aircraft-based field experiment conducted around the Northern Greenland Sea (Fram Strait) during March and April 2018, with operation base Station Nord (81.6° N, 16.7° W). Median BC mass concentrations in individual altitude ranges were 7–18 ng m–3 at standard temperature and pressure at altitudes below 4.5 km. These concentrations were systematically lower than previous observations in the Arctic in spring conducted by ARCTAS-A in 2008 and NETCARE in 2015 and similar to those observed during HIPPO3 in 2010. Column amounts of BC for altitudes below 5 km in the Arctic (> 66.5° N, COLBC), observed during the ARCTAS-A and NETCARE experiments were higher by factors of 4.2 and 2.7, respectively, than those of the PAMARCMiP experiment. These differences could not be explained solely by the different locations of the experiments. The year-to-year variation of COLBC values generally corresponded to that of biomass burning activities in northern high latitudes over western and eastern Eurasia. Furthermore, numerical model simulations estimated the year-to-year variation of contributions from anthropogenic sources to be smaller than 30–40 %. These results suggest that the year-to-year variation of biomass burning activities likely affected BC amounts in the Arctic troposphere in spring, at least in the years examined in this study. The year-to-year variations in BC mass concentrations were also observed at the surface at high Arctic sites Ny-Ålesund and Barrow, although their magnitudes were slightly lower than those in COLBC. Numerical model simulations in general successfully reproduced the observed COLBC values for PAMARCMiP and HIPPO3 (within a factor of 2), whereas they markedly underestimated the values for ARCTAS-A and NETCARE by factors of 3.7–5.8 and 3.3–5.0, respectively. Because anthropogenic contributions account for nearly all of the COLBC (82–98 %) in PAMARCMiP and HIPPO3, the good agreements between the observations and calculations for these two experiments suggest that anthropogenic contributions were generally well reproduced. However, the significant underestimations of COLBC for ARCTAS-A and NETCARE suggest that biomass burning contributions were underestimated. In this study, we also investigated plumes with enhanced BC mass concentrations, which were affected by biomass burning emissions, observed at 5 km altitude. Interestingly, the mass-averaged diameter of BC (core) and the shell-to-core diameter ratio of BC-containing particles in the plumes were generally not very different from those in other air sampled, which were considered to be mostly aged anthropogenic BC. These observations provide useful bases to evaluate numerical model simulations of the BC radiative effect in the Arctic region in spring.

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Aircraft observations of enhancement and depletion of black carbon mass in the springtime Arctic

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-10-15167-2010 ◽

2010 ◽

Vol 10 (6) ◽

pp. 15167-15196

Author(s):

J. R. Spackman ◽

R. S. Gao ◽

W. D. Neff ◽

J. P. Schwarz ◽

L. A. Watts ◽

...

Keyword(s):

Boundary Layer ◽

Black Carbon ◽

Biomass Burning ◽

Boundary Layer Transition ◽

Arctic Climate ◽

The Arctic ◽

Vertical Profiles ◽

Free Troposphere ◽

Air Mass ◽

The Impact

Abstract. Understanding the processes controlling black carbon (BC) in the Arctic is crucial for evaluating the impact of anthropogenic and natural sources of BC on Arctic climate. Vertical profiles of BC mass were observed from the surface to near 7-km altitude in April 2008 using a Single-Particle Soot Photometer (SP2) during flights on the NOAA WP-3D research aircraft from Fairbanks, Alaska. These measurements were conducted during the NOAA-sponsored Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC) project as part of POLARCAT, an International Polar Year (IPY) activity. In the free troposphere, the Arctic air mass was influenced by long-range transport from biomass-burning and anthropogenic source regions at lower latitudes especially during the latter part of the campaign. Maximum average BC mass loadings of 150 ng kg−1 were observed near 5.5-km altitude in the aged Arctic air mass. In biomass-burning plumes, BC was enhanced from near the top of the Arctic boundary layer (ABL) to 5.5 km compared to the aged Arctic air mass. At the bottom of some of the profiles, positive vertical gradients in BC were observed in the vicinity of open leads in the sea-ice. BC mass loadings increased by about a factor of two across the boundary layer transition in the ABL in these cases while carbon monoxide (CO) remained constant, evidence for depletion of BC in the ABL. BC mass loadings were positively correlated with O3 in ozone depletion events (ODEs) for all the observations in the ABL suggesting that BC was removed by dry deposition of BC on the snow or ice because molecular bromine, Br2, which photolyzes and catalytically destroys O3, is thought to be released near the open leads in regions of ice formation. We estimate the deposition flux of BC mass to the snow using a box model constrained by the vertical profiles of BC in the ABL. The open leads may increase vertical mixing in the ABL and entrainment of pollution from the free troposphere possibly enhancing the deposition of BC to the snow.

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Wildfires in Northern Eurasia affect the budget of black carbon in the Arctic. A 12-year retrospective synopsis (2002–2013).

10.5194/acp-2015-994 ◽

2016 ◽

Cited By ~ 1

Author(s):

N. Evangeliou ◽

Y. Balkanski ◽

W. M. Hao ◽

A. Petkov ◽

R. P. Silverstein ◽

...

Keyword(s):

Black Carbon ◽

Northern Hemisphere ◽

Biomass Burning ◽

Emission Inventory ◽

Atmospheric Composition ◽

Anthropogenic Sources ◽

The Arctic ◽

Northern Eurasia ◽

Fire Emissions ◽

Vegetation Fires

Abstract. In recent decades much attention has been given to the Arctic environment, where climate change is happening rapidly. Black carbon (BC) has been shown to be a major component of Arctic pollution that also affects the radiative balance. In the present study, we focused on how vegetation fires that occurred in Northern Eurasia during the period of 2002–2013 influenced the budget of BC in the Arctic. For simulating the transport of fire emissions from Northern Eurasia to the Arctic, we adopted BC fire emission estimates developed independently by GFED3 (Global Fire Emissions Database) and FEI-NE (Fire Emission Inventory – Northern Eurasia). Both datasets were based on fire locations and burned areas detected by MODIS (MODerate resolution Imaging Spectroradiometer) instruments on NASA's (National Aeronautics and Space Administration) Terra and Aqua satellites. Anthropogenic sources of BC were estimated using the MACCity (Monitoring Atmospheric Composition & Climate/megaCITY – Zoom for the ENvironment) emission inventory. During the 12-year period, an average area of 250,000 km2 yr−1 was burned in Northern Eurasia and the global emissions of BC ranged between 8.0 and 9.5 Tg yr−1. For the BC emitted in the Northern Hemisphere, about 70 % originated from anthropogenic sources and the rest from biomass burning (BB). Using the FEI-NE inventory, we found that 102 ± 29 kt yr−1 BC from biomass burning was deposited on the Arctic (defined here as the area north of 67º N) during the 12 years simulated, which was twice as much as when using MACCity inventory (56 ± 8 kt yr−1). The annual mass of BC deposited in the Arctic from all sources (FEI-NE in Northern Eurasia, MACCity elsewhere) is significantly higher by about 37 % in 2009 to 181 % in 2012, compared to the BC deposited using just the MACCity emission inventory. Deposition of BC in the Arctic from BB sources in the Northern Hemisphere thus represents 68 % of the BC deposited from all BC sources (the remaining being due to anthropogenic sources). Northern Eurasian vegetation fires (FEI-NE) contributed 85 % (79–91 %) to the BC deposited over the Arctic from all BB sources in the Northern Hemisphere. Arctic total BC burden showed strong seasonal variations, with highest values during the Arctic Haze season. High winter–spring values of BC burden were caused by transport of BC mainly from anthropogenic sources in Europe, whereas the peak in summer was mainly due to the fire emissions in Northern Eurasia. BC particles emitted from fires in lower latitudes (35° N–40° N) were found to remain the longest in the atmosphere due to the high release altitudes of smoke plumes, exhibit tropospheric transport resulting in a high summer peak of burden, and grow by condensation processes. In regards to the geographic contribution on the deposition of BC, we estimated that about 46 % of the BC deposited over the Arctic from vegetation fires in Northern Eurasia originated from Siberia, 6 % from Kazakhstan, 5 % from Europe, and about 1 % from Mongolia. The remaining 42 % originated from other areas in Northern Eurasia. For spring and summer, we computed that 42 % of the BC released from Northern Eurasian vegetation fires was deposited over the Arctic (annual average: 17 %). Vegetation fires in Northern Eurasia contributed to 14 % to 57 % of BC surface concentrations at the Arctic stations (Alert, Barrow, Zeppelin, Villum, and Tiksi), with fires in Siberia contributing the largest share. However, anthropogenic sources in the Northern Hemisphere remain essential, contributing 29 % to 54 % to the surface concentrations at the Arctic monitoring stations. The rest originated from North American fires.

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Sources and contributions of wood smoke during winter in London: assessing local and regional influences

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-27459-2014 ◽

2014 ◽

Vol 14 (19) ◽

pp. 27459-27530 ◽

Cited By ~ 3

Author(s):

L. R. Crilley ◽

W. J. Bloss ◽

J. Yin ◽

D. C. S. Beddows ◽

R. M. Harrison ◽

...

Keyword(s):

Black Carbon ◽

Source Apportionment ◽

Biomass Burning ◽

Traffic Emissions ◽

Total Carbon ◽

Local Source ◽

Wood Smoke ◽

Biomass Smoke ◽

Domestic Heating ◽

Wood Burning

Abstract. Determining the contribution of wood smoke to air pollution in large cities such as London is becoming increasingly important due to the changing nature of domestic heating in urban areas. During winter, biomass burning emissions can exceed the contributions from traffic emissions, and have been identified as a major cause of exceedences of European air quality limits. The aim of this work was to quantify the contribution of biomass burning in London to concentrations of PM2.5 and determine whether local emissions or regional contributions were the main source of biomass smoke. To achieve this, a number of biomass burning chemical tracers were analysed at a site within central London and two sites in surrounding rural areas. Concentrations of levoglucosan, elemental carbon (EC), organic carbon (OC) and K+ were generally well correlated across the three sites. At all the sites, biomass burning was found to be a source of OC and EC, with the largest contribution of EC from traffic emissions, while for OC the dominant fraction likely included contributions from secondary organic aerosols, primary biogenic and cooking sources. Source apportionment of the EC and OC using average source ratios from published data was found to give reasonable estimation of the total carbon from non-fossil and fossil fuel sources based upon comparison with estimates derived from 14C analysis. Black carbon (BC) data from 2 and 7 wavelength Aethalometers were also apportioned into the contributions from biomass burning and traffic, based upon the enhanced absorption of wood smoke at UV wavelengths compared to BC. While the source apportionment of BC using this approach found similar trends to that observed for EC, higher percentage contributions of wood burning to BC were estimated. Based on a wood smoke mass conversion factor for levoglucosan, mean wood smoke mass at the sites was found to range from 0.78–1.0 μg m−3 during the campaign in January–February 2012. Measurements on a 160 m tower in London suggested a similar ratio of brown to black carbon (reflecting wood burning and traffic respectively) in regional and London air. Peaks in the levoglucosan and K+ concentrations were observed to coincide with low ambient temperature, consistent with domestic heating as a major contributing local source in London. Overall, the source of biomass smoke in London was concluded to be a background regional source overlaid by contributions from local domestic burning emissions. This could have implications when considering future emission control strategies during winter and may be the focus of future work in order to better determine the contributing local sources.

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An 800 year high-resolution black carbon ice-core record from Lomonosovfonna, Svalbard

10.5194/acp-2018-244 ◽

2018 ◽

Cited By ~ 2

Author(s):

Dimitri Osmont ◽

Isabel A. Wendl ◽

Loïc Schmidely ◽

Michael Sigl ◽

Carmen P. Vega ◽

...

Keyword(s):

High Resolution ◽

Black Carbon ◽

20Th Century ◽

Biomass Burning ◽

Ice Core ◽

Ice Cores ◽

The Arctic ◽

Snow Albedo ◽

Decadal Scale

Abstract. Produced by the incomplete combustion of fossil fuel and biomass, black carbon (BC) contributes to Arctic warming by reducing snow albedo and thus triggering a snow-albedo feedback leading to increased snow melting. Therefore, it is of high importance to assess past BC emissions to better understand and constrain their role. However, only few long-term BC records are available from the Arctic, mainly originating from Greenland ice cores. Here, we present the first long-term and high-resolution refractory black carbon (rBC) record from Svalbard, derived from the analysis of two ice cores drilled at the Lomonosovfonna ice field in 2009 (LF-09) and 2011 (LF-11) and covering 800 years of atmospheric emissions. Our results show that rBC concentrations strongly increased from 1860 on due to anthropogenic emissions and reached two maxima, at the end of the 19th century and in the middle of the 20th century. No increase in rBC concentrations during the last decades was observed, which is corroborated by atmospheric measurements elsewhere in the Arctic but contradicts a previous study from another ice core from Svalbard. While melting may affect BC concentrations during periods of high temperatures, rBC concentrations remain well-preserved prior to the 20th century due to lower temperatures inducing little melt. Therefore, the preindustrial rBC record (before 1800), along with ammonium (NH4+), formate (HCOO−) and specific organic markers (vanillic acid (VA) and p-hydroxybenzoic acid (p-HBA)), was used as a proxy for biomass burning. Despite numerous single events, no long-term trend was observed over the time period 1222–1800 for rBC and NH4+. In contrast, formate, VA and p-HBA experience multi-decadal peaks reflecting periods of enhanced biomass burning. Most of the background variations and single peak events are corroborated by other ice-core records from Greenland and Siberia. We suggest that the paleofire record from the LF ice core primarily reflects biomass burning episodes from Northern Eurasia, induced by decadal-scale climatic variations.

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