scholarly journals Supplementary material to "Fossil fuel combustion, biomass burning and biogenic sources of fine carbonaceous aerosol in the Carpathian Basin"

Author(s):  
Imre Salma ◽  
Anikó Vasanits-Zsigrai ◽  
Attila Machon ◽  
Tamás Varga ◽  
István Major ◽  
...  
2019 ◽  
Author(s):  
Imre Salma ◽  
Anikó Vasanits-Zsigrai ◽  
Attila Machon ◽  
Tamás Varga ◽  
István Major ◽  
...  

Abstract. Fine-fraction aerosol samples were collected, air pollutants and meteorological properties were measured in-situ in regional background environment of the Carpathian Basin, a suburban area and central part of its largest city, Budapest in each season for 1 year-long time interval. The samples were analysed for PM2.5 mass, organic carbon (OC), elemental carbon (EC), water-soluble OC (WSOC), radiocarbon, levoglucosan (LVG) and its stereoisomers, and some chemical elements. Carbonaceous aerosol species made up 36 % of the PM2.5 mass with a modest seasonal variation and with a slightly increasing tendency from the regional background to the city centre (from 32 to 39 %). Coupled radiocarbon-LVG marker method was applied to apportion the total carbon (TC = OC + EC) into contributions of EC and OC from fossil fuel (FF) combustion (ECFF and OCFF, respectively), EC and OC from biomass burning (BB) (ECBB and OCBB, respectively) and OC from biogenic sources (OCBIO). Fossil fuel combustion showed rather constant daily or seasonal mean contributions (of 35 %) to the TC in the whole year in all atmospheric environments, while the daily contributions of BB and biogenic sources changed radically (from


2020 ◽  
Vol 20 (7) ◽  
pp. 4295-4312 ◽  
Author(s):  
Imre Salma ◽  
Anikó Vasanits-Zsigrai ◽  
Attila Machon ◽  
Tamás Varga ◽  
István Major ◽  
...  

Abstract. Fine-fraction aerosol samples were collected, and air pollutants and meteorological properties were measured in situ in the regional background environment of the Carpathian Basin, a suburban area and central part of its largest city, Budapest, in each season for a 1-year-long time interval. The samples were analysed for PM2.5 mass, organic carbon (OC), elemental carbon (EC), water-soluble OC (WSOC), radiocarbon, levoglucosan (LVG) and its stereoisomers, and some chemical elements. Carbonaceous aerosol species made up 36 % of the PM2.5 mass, with a modest seasonal variation and with a slightly increasing tendency from the regional background to the city centre (from 32 % to 39 %). A coupled radiocarbon-LVG marker method was applied to apportion the total carbon (TC = OC + EC) into contributions of EC and OC from fossil fuel (FF) combustion (ECFF and OCFF, respectively), EC and OC from biomass burning (BB) (ECBB and OCBB, respectively), and OC from biogenic sources (OCBIO). Fossil fuel combustion showed rather constant daily or monthly mean contributions (of 35 %) to the TC in the whole year in all atmospheric environments, while the daily contributions of BB and biogenic sources changed radically (from <2 % up to 70 %–85 %) at all locations and over the years. In October, the three major sources contributed equally to the TC in all environments. In January, it was the BB that was the major source, with a share of 70 % at all sites. The contributions from biogenic sources in January were the smallest. In April, FF combustion and biogenic sources were the largest two contributors at all locations with typical shares of 45 %–50 % each. In July, biogenic sources became the major source type with a monotonically increasing tendency (from 56 % to 72 %) from the city centre to the regional background. The share of BB was hardly quantifiable in July. The ECFF made up more than 90 % of EC in April and July, while in October and January, the contributions of ECBB were considerable. Biomass burning in winter and autumn offers the largest and most considerable potential for improving the air quality in cities as well as in rural areas of the Carpathian Basin.


2020 ◽  
Vol 20 (24) ◽  
pp. 16041-16053
Author(s):  
Haiyan Ni ◽  
Ru-Jin Huang ◽  
Max M. Cosijn ◽  
Lu Yang ◽  
Jie Guo ◽  
...  

Abstract. To mitigate haze pollution in China, a better understanding of the sources of carbonaceous aerosols is required due to the complexity in multiple emissions and atmospheric processes. Here we combined the analysis of radiocarbon and the stable isotope 13C to investigate the sources and formation of carbonaceous aerosols collected in two Chinese megacities (Beijing and Xi'an) during severe haze events of a “red alarm” level from December 2016 to January 2017. The haze periods with daily PM2.5 concentrations as high as ∼ 400 µg m−3 were compared to subsequent clean periods (i.e., PM2.5 less than median concentrations during the winter 2016/2017) with PM2.5 concentrations below 100 µg m−3 in Xi'an and below 20 µg m−3 in Beijing. In Xi'an, liquid fossil fuel combustion was the dominant source of elemental carbon (EC; 44 %–57 %), followed by biomass burning (25 %–29 %) and coal combustion (17 %–29 %). In Beijing, coal combustion contributed 45 %–61 % of EC, and biomass burning (17 %–24 %) and liquid fossil fuel combustion (22 %–33 %) contributed less. Non-fossil sources contributed 51 %–56 % of organic carbon (OC) in Xi'an, and fossil sources contributed 63 %–69 % of OC in Beijing. Secondary OC (SOC) was largely contributed by non-fossil sources in Xi'an (56±6 %) and by fossil sources in Beijing (75±10 %), especially during haze periods. The fossil vs. non-fossil contributions to OC and EC did not change drastically during haze events in both Xi'an and Beijing. However, compared to clean periods, the contribution of coal combustion to EC during haze periods increased in Xi'an and decreased in Beijing. During clean periods, primary OC from biomass burning and fossil sources constituted ∼ 70 % of OC in Xi'an and ∼ 53 % of OC in Beijing. From clean to haze periods, the contribution of SOC to total OC increased in Xi'an but decreased in Beijing, suggesting that the contribution of secondary organic aerosol formation to increased OC during haze periods was more efficient in Xi'an than in Beijing. In Beijing, the high SOC fraction in total OC during clean periods was mainly due to an elevated contribution from non-fossil SOC. In Xi'an, a slight day–night difference was observed during the clean period with enhanced fossil contributions to OC and EC during the day. This day–night difference was negligible during severe haze periods, likely due to the enhanced accumulation of pollutants under stagnant weather conditions.


2021 ◽  
Author(s):  
Haiyan Ni ◽  
Ru-Jin Huang ◽  
Ulrike Dusek

&lt;p&gt;To mitigate haze pollution in China, a better understanding of the sources of carbonaceous aerosols is required due to the complexity in multiple emissions and atmospheric processes. Here we combined the analysis of radiocarbon and the stable isotope &lt;sup&gt;13&lt;/sup&gt;C to investigate the sources and formation of carbonaceous aerosols collected in two Chinese megacities (Beijing and Xi&amp;#8217;an) during severe haze events of &amp;#8220;red alarm&amp;#8221; level from December 2016 to January 2017. The haze periods with daily PM&lt;sub&gt;2.5&lt;/sub&gt; concentrations as high as ~400 &amp;#181;g m&lt;sup&gt;-3&lt;/sup&gt; were compared to subsequent clean periods (i.e., PM&lt;sub&gt;2.5 &lt;/sub&gt;&lt; median concentrations during the winter 2016/2017), with PM&lt;sub&gt;2.5 &lt;/sub&gt;concentrations&lt;sub&gt;&lt;/sub&gt;below 100 &amp;#181;g m&lt;sup&gt;-3&lt;/sup&gt; in Xi&amp;#8217;an and below 20 &amp;#181;g m&lt;sup&gt;-3&lt;/sup&gt; in Beijing. In Xi&amp;#8217;an, liquid fossil fuel combustion was the dominant source of elemental carbon (EC; 44%&amp;#8211;57%), followed by biomass burning (25%&amp;#8211;29%) and coal combustion (17%&amp;#8211;29%). In Beijing, coal combustion contributed 45%&amp;#8211;61% of EC and biomass burning (17%&amp;#8211;24%) and liquid fossil fuel combustion (22%&amp;#8211;33%) contributed less. Non-fossil sources contributed 51%&amp;#8211;56% of organic carbon (OC) in Xi&amp;#8217;an and fossil sources contributed 63%&amp;#8211;69% of OC in Beijing. Secondary OC (SOC) was largely contributed by non-fossil sources in Xi&amp;#8217;an (56 &amp;#177; 6%) and by fossil sources in Beijing (75 &amp;#177; 10%), especially during haze periods. The fossil vs. non-fossil contributions to OC and EC did not change drastically during haze events in both Xi&amp;#8217;an and Beijing. However, compared to clean periods, the contribution of coal combustion to EC during haze periods increased in Xi&amp;#8217;an and decreased in Beijing. During clean periods, primary OC from biomass burning and fossil sources constituted ~70% of OC in Xi&amp;#8217;an and ~53% of OC in Beijing. From clean to haze periods, the contribution of SOC to total OC increased in Xi&amp;#8217;an, but decreased in Beijing, suggesting that contribution of secondary organic aerosol formation to increased OC during haze periods was more efficient in Xi&amp;#8217;an than in Beijing. In Beijing, the high SOC fraction in total OC during clean periods was mainly due to elevated contribution from non-fossil SOC. In Xi&amp;#8217;an, a slight day-night difference was observed during the clean period, with enhanced fossil contributions to OC and EC during the day. This day-night difference was negligible during severe haze periods, likely due to enhanced accumulation of pollutants under stagnant weather conditions.&lt;/p&gt;


2020 ◽  
Author(s):  
Haiyan Ni ◽  
Ru-Jin Huang ◽  
Max M. Cosijn ◽  
Lu Yang ◽  
Jie Guo ◽  
...  

Abstract. To mitigate haze pollution in China, a better understanding of the sources of carbonaceous aerosols is required due to the complexity in multiple emissions and atmospheric processes. Here we combined the analysis of radiocarbon and the stable isotope 13C to investigate the sources and formation of carbonaceous aerosols collected in two Chinese megacities (Beijing and Xi’an) during severe haze events of “red alarm” level from December 2016 to January 2017. In Xi’an, liquid fossil fuel combustion was the dominant source of elemental carbon (EC; 44 %–57 %), followed by biomass burning (25 %–29 %) and coal combustion (17 %–29 %). In Beijing, coal combustion contributed 45%–61% of EC and biomass burning (17 %–24 %) and liquid fossil fuel combustion (22 %–33 %) contributed less. Non-fossil sources contributed 51 %–56 % of organic carbon (OC) in Xi’an and fossil sources contributed 63 %–69 % of OC in Beijing. Secondary OC (SOC) was largely contributed by non-fossil sources in Xi’an (56 ± 6 %) and by fossil sources in Beijing (75 ± 10 %), especially during haze periods. The fossil vs. non-fossil contributions to OC and EC did not change drastically during haze events in both Xi’an and Beijing. However, compared to clean periods, the contribution of coal combustion to EC during haze periods increased in Xi’an and decreased in Beijing. During clean periods, primary OC from biomass burning and fossil sources constituted ~ 70 % of OC in Xi’an and ~ 53 % of OC in Beijing. From clean to haze periods, the contribution of SOC to total OC increased in Xi’an, but decreased in Beijing, suggesting that contribution of secondary organic aerosol formation to increased OC during haze periods was more efficient in Xi’an than in Beijing. In Beijing, the high SOC fraction in total OC during clean periods was mainly due to elevated contribution from non-fossil SOC. In Xi’an, a slight day-night difference was observed during clean period, with enhanced fossil contributions to OC and EC during the day. This day-night difference was negligible during severe haze periods, likely due to enhanced accumulation of pollutants under stagnant weather conditions.


2020 ◽  
Author(s):  
Haiyan Ni ◽  
Ru-Jin Huang ◽  
Ulrike Dusek

&lt;p&gt;To investigate the sources and formation mechanisms of carbonaceous aerosols, a major contributor to severe particulate air pollution, radiocarbon&amp;#160;(&lt;span&gt;&lt;sup&gt;14&lt;/sup&gt;C&lt;/span&gt;) measurements were conducted on aerosols sampled from November&amp;#160;2015 to November&amp;#160;2016 in Xi'an, China. Based on the&amp;#160;&lt;span&gt;&lt;sup&gt;14&lt;/sup&gt;C&lt;/span&gt;&amp;#160;content in elemental carbon&amp;#160;(EC), organic carbon&amp;#160;(OC) and water-insoluble OC&amp;#160;(WIOC), contributions of major sources to carbonaceous aerosols are estimated over a whole seasonal cycle: primary and secondary fossil sources, primary biomass burning, and other non-fossil carbon formed mainly from secondary processes. Primary fossil sources of&amp;#160;EC were further sub-divided into coal and liquid fossil fuel combustion by complementing&amp;#160;&lt;span&gt;&lt;sup&gt;14&lt;/sup&gt;C&lt;/span&gt;&amp;#160;data with stable carbon isotopic signatures.&lt;/p&gt;&lt;p&gt;The dominant EC&amp;#160;source was liquid fossil fuel combustion (i.e., vehicle emissions), accounting for 64&amp;#8201;% (median; 45&amp;#8201;%&amp;#8211;74&amp;#8201;%, interquartile range) of&amp;#160;EC in autumn, 60&amp;#8201;% (41&amp;#8201;%&amp;#8211;72&amp;#8201;%) in summer, 53&amp;#8201;% (33&amp;#8201;%&amp;#8211;69&amp;#8201;%) in spring and 46&amp;#8201;% (29&amp;#8201;%&amp;#8211;59&amp;#8201;%) in winter. An increased contribution from biomass burning to&amp;#160;EC was observed in winter (&lt;span&gt;&amp;#8764;28&lt;/span&gt;&amp;#8201;%) compared to other seasons (warm period;&amp;#160;&lt;span&gt;&amp;#8764;15&lt;/span&gt;&amp;#8201;%). In winter, coal combustion (&lt;span&gt;&amp;#8764;25&lt;/span&gt;&amp;#8201;%) and biomass burning equally contributed to&amp;#160;EC, whereas in the warm period, coal combustion accounted for a larger fraction of&amp;#160;EC than biomass burning. The relative contribution of fossil sources to&amp;#160;OC was consistently lower than that to&amp;#160;EC, with an annual average of&amp;#160;&lt;span&gt;47&amp;#177;4&lt;/span&gt;&amp;#8201;%. Non-fossil OC&amp;#160;of secondary origin was an important contributor to total&amp;#160;OC (&lt;span&gt;35&amp;#177;4&lt;/span&gt;&amp;#8201;%) and accounted for more than half of non-fossil&amp;#160;OC (&lt;span&gt;67&amp;#177;6&lt;/span&gt;&amp;#8201;%) throughout the year. Secondary fossil&amp;#160;OC&amp;#160;(SOC&lt;span&gt;&lt;sub&gt;fossil&lt;/sub&gt;&lt;/span&gt;) concentrations were higher than primary fossil&amp;#160;OC&amp;#160;(POC&lt;span&gt;&lt;sub&gt;fossil&lt;/sub&gt;&lt;/span&gt;) concentrations in winter but lower than POC&lt;span&gt;&lt;sub&gt;fossil&lt;/sub&gt;&lt;/span&gt;&amp;#160;in the warm period.&lt;/p&gt;&lt;p&gt;Fossil WIOC and water-soluble&amp;#160;OC&amp;#160;(WSOC) have been widely used as proxies for POC&lt;span&gt;&lt;sub&gt;fossil&lt;/sub&gt;&lt;/span&gt;&amp;#160;and SOC&lt;span&gt;&lt;sub&gt;fossil&lt;/sub&gt;&lt;/span&gt;, respectively. This assumption was evaluated by (1)&amp;#160;comparing their mass concentrations with POC&lt;span&gt;&lt;sub&gt;fossil&lt;/sub&gt;&lt;/span&gt;&amp;#160;and SOC&lt;span&gt;&lt;sub&gt;fossil&lt;/sub&gt;&lt;/span&gt;&amp;#160;and (2)&amp;#160;comparing ratios of fossil WIOC to fossil&amp;#160;EC to typical primary&amp;#160;OC-to-EC ratios from fossil sources including both coal combustion and vehicle emissions. The results suggest that fossil WIOC and fossil WSOC are probably a better approximation for primary and secondary fossil&amp;#160;OC, respectively, than POC&lt;span&gt;&lt;sub&gt;fossil&lt;/sub&gt;&lt;/span&gt;&amp;#160;and SOC&lt;span&gt;&lt;sub&gt;fossil&lt;/sub&gt;&lt;/span&gt;&amp;#160;estimated using the EC&amp;#160;tracer method.&lt;/p&gt;


2012 ◽  
Vol 12 (2) ◽  
pp. 815-828 ◽  
Author(s):  
T. Ridder ◽  
C. Gerbig ◽  
J. Notholt ◽  
M. Rex ◽  
O. Schrems ◽  
...  

Abstract. Carbon monoxide (CO) and ozone (O3) have been measured in the Western Pacific (43° N to 35° S) during a ship campaign with Research Vessel Sonne in fall 2009. Observations have been performed using ship-based solar absorption Fourier Transform infrared spectrometry, flask sampling, balloon sounding, and in-situ Fourier Transform infrared analysis. The results obtained are compared to the GEOS-Chem global 3-D chemistry transport model for atmospheric composition. In general, a very good agreement is found between the GEOS-Chem model and all instruments. The CO and O3 distributions show a comparable variability suggesting an impact from the same source regions. Tagged-CO simulations implemented in the GEOS-Chem model make it possible to differentiate between different source processes and source regions. The source regions are verified with HYSPLIT backward trajectory calculations. In the Northern Hemisphere fossil fuel combustion in Asia is the dominant source. European and North American fossil fuel combustion also contribute to Northern Hemispheric CO pollution. In the Southern Hemisphere contributions from biomass burning and fossil fuel combustion are dominant; African biomass burning has a significant impact on Western Pacific CO pollution. Furthermore, in the tropical Western Pacific enhanced upper tropospheric CO within the tropical tropopause layer mainly originates from Indonesian fossil fuel combustion and can be transported into the stratosphere. The source regions of the measured O3 pollution are simulated with a tagged-O3 simulation implemented in the GEOS-Chem model. Similar source regions compared to the tagged-CO simulations are identified by the model. In the Northern Hemisphere contributions from Asia, Europe, and North America are significant. In the Southern Hemisphere emissions from South America, south-east Africa, and Oceania significantly contribute to the measured O3 pollution.


2019 ◽  
Vol 19 (24) ◽  
pp. 15609-15628 ◽  
Author(s):  
Haiyan Ni ◽  
Ru-Jin Huang ◽  
Junji Cao ◽  
Jie Guo ◽  
Haoyue Deng ◽  
...  

Abstract. To investigate the sources and formation mechanisms of carbonaceous aerosols, a major contributor to severe particulate air pollution, radiocarbon (14C) measurements were conducted on aerosols sampled from November 2015 to November 2016 in Xi'an, China. Based on the 14C content in elemental carbon (EC), organic carbon (OC) and water-insoluble OC (WIOC), contributions of major sources to carbonaceous aerosols are estimated over a whole seasonal cycle: primary and secondary fossil sources, primary biomass burning, and other non-fossil carbon formed mainly from secondary processes. Primary fossil sources of EC were further sub-divided into coal and liquid fossil fuel combustion by complementing 14C data with stable carbon isotopic signatures. The dominant EC source was liquid fossil fuel combustion (i.e., vehicle emissions), accounting for 64 % (median; 45 %–74 %, interquartile range) of EC in autumn, 60 % (41 %–72 %) in summer, 53 % (33 %–69 %) in spring and 46 % (29 %–59 %) in winter. An increased contribution from biomass burning to EC was observed in winter (∼28 %) compared to other seasons (warm period; ∼15 %). In winter, coal combustion (∼25 %) and biomass burning equally contributed to EC, whereas in the warm period, coal combustion accounted for a larger fraction of EC than biomass burning. The relative contribution of fossil sources to OC was consistently lower than that to EC, with an annual average of 47±4 %. Non-fossil OC of secondary origin was an important contributor to total OC (35±4 %) and accounted for more than half of non-fossil OC (67±6 %) throughout the year. Secondary fossil OC (SOCfossil) concentrations were higher than primary fossil OC (POCfossil) concentrations in winter but lower than POCfossil in the warm period. Fossil WIOC and water-soluble OC (WSOC) have been widely used as proxies for POCfossil and SOCfossil, respectively. This assumption was evaluated by (1) comparing their mass concentrations with POCfossil and SOCfossil and (2) comparing ratios of fossil WIOC to fossil EC to typical primary OC-to-EC ratios from fossil sources including both coal combustion and vehicle emissions. The results suggest that fossil WIOC and fossil WSOC are probably a better approximation for primary and secondary fossil OC, respectively, than POCfossil and SOCfossil estimated using the EC tracer method.


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