scholarly journals Contribution of organic carbon to wood smoke particulate matter absorption of solar radiation

2012 ◽  
Vol 12 (2) ◽  
pp. 5803-5816 ◽  
Author(s):  
T. W. Kirchstetter ◽  
T. L. Thatcher
Keyword(s):  
Particulate Matter ◽  
Organic Carbon ◽  
Solar Radiation ◽  
Radiative Forcing ◽  
Solar Spectrum ◽  
Atmospheric Particulate Matter ◽  
Biomass Combustion ◽  
Wood Smoke ◽  
Spectral Selectivity ◽  
Tropospheric Photochemistry

Abstract. Spectroscopic analysis shows that 115 residential wood smoke-dominated particulate matter samples absorb light with strong spectral selectivity, consistent with prior work that has demonstrated that organic carbon (OC), in addition to black carbon (BC), appreciably absorbs solar radiation in the visible and ultraviolet spectral regions. Apportionment of light absorption yields the absorption Ångström exponent of the light absorbing OC in these samples, which ranges from 3.0 to 7.4 and averages 5.0, and indicates that OC and BC, respectively, would account for 14% and 86% of solar radiation absorbed by the wood smoke in the atmosphere (integrated over the solar spectrum from 300 to 2500 nm). OC would contribute 49% of the wood smoke particulate matter absorption of ultraviolet solar radiation at wavelengths below 400 nm. These results illustrate that BC is the dominant light absorbing particulate matter species in atmospheres burdened with residential wood smoke and OC absorption is secondary but not insignificant. Further, since biomass combustion generates a major portion of atmospheric particulate matter globally, these results suggest that OC absorption should be included when particulate matter effects on the radiative forcing of climate are considered, and that OC absorption may affect the ultraviolet actinic flux and thus tropospheric photochemistry.

scholarly journals Contribution of organic carbon to wood smoke particulate matter absorption of solar radiation

2012 ◽  
Vol 12 (14) ◽  
pp. 6067-6072 ◽  
Author(s):  
T. W. Kirchstetter ◽  
T. L. Thatcher
Keyword(s):  
Particulate Matter ◽  
Organic Carbon ◽  
Solar Radiation ◽  
Spectroscopic Analysis ◽  
Solar Spectrum ◽  
Wood Smoke ◽  
Matter Effects ◽  
Spectral Selectivity ◽  
Tropospheric Photochemistry ◽  
Ultraviolet Solar Radiation

Abstract. A spectroscopic analysis of 115 wintertime particulate matter samples collected in rural California shows that wood smoke absorbs solar radiation with a strong spectral selectivity. This is consistent with prior work that has demonstrated that organic carbon (OC), in addition to black carbon (BC), appreciably absorbs solar radiation in the visible and ultraviolet spectral regions. We apportion light absorption to OC and BC and find that the absorption Ångström exponent of the light-absorbing OC in these samples ranges from 3.0 to 7.4 and averages 5.0. Further, we calculate that OC would account for 14% and BC would account for 86% of solar radiation absorbed by the wood smoke in the atmosphere (integrated over the solar spectrum from 300 to 2500 nm). OC would contribute 49% of the wood smoke particulate matter absorption of ultraviolet solar radiation at wavelengths below 400 nm and, therefore, may affect tropospheric photochemistry. These results illustrate that BC is the dominant light-absorbing particulate matter species in atmospheres burdened with residential wood smoke and OC absorption is secondary but not insignificant. Further, these results add to the growing body of evidence that light-absorbing OC is ubiquitous in atmospheres influenced by biomass burning and may be important to include when considering particulate matter effects on climate.

scholarly journals Fossil vs. non-fossil sources of fine carbonaceous aerosols in four Chinese cities during the extreme winter haze episode of 2013

2015 ◽  
Vol 15 (3) ◽  
pp. 1299-1312 ◽  
Author(s):  
Y.-L. Zhang ◽  
R.-J. Huang ◽  
I. El Haddad ◽  
K.-F. Ho ◽  
J.-J. Cao ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Organic Carbon ◽  
Biomass Burning ◽  
Water Soluble ◽  
Total Carbon ◽  
World Health ◽  
Biomass Combustion ◽  
Carbonaceous Aerosols ◽  
Haze Episode ◽  
Mass Concentrations

Abstract. During winter 2013, extremely high concentrations (i.e., 4–20 times higher than the World Health Organization guideline) of PM2.5 (particulate matter with an aerodynamic diameter < 2.5 μm) mass concentrations (24 h samples) were found in four major cities in China including Xi'an, Beijing, Shanghai and Guangzhou. Statistical analysis of a combined data set from elemental carbon (EC), organic carbon (OC), 14C and biomass-burning marker measurements using Latin hypercube sampling allowed a quantitative source apportionment of carbonaceous aerosols. Based on 14C measurements of EC fractions (six samples each city), we found that fossil emissions from coal combustion and vehicle exhaust dominated EC with a mean contribution of 75 ± 8% across all sites. The remaining 25 ± 8% was exclusively attributed to biomass combustion, consistent with the measurements of biomass-burning markers such as anhydrosugars (levoglucosan and mannosan) and water-soluble potassium (K+). With a combination of the levoglucosan-to-mannosan and levoglucosan-to-K+ ratios, the major source of biomass burning in winter in China is suggested to be combustion of crop residues. The contribution of fossil sources to OC was highest in Beijing (58 ± 5%) and decreased from Shanghai (49 ± 2%) to Xi'an (38 ± 3%) and Guangzhou (35 ± 7%). Generally, a larger fraction of fossil OC was from secondary origins than primary sources for all sites. Non-fossil sources accounted on average for 55 ± 10 and 48 ± 9% of OC and total carbon (TC), respectively, which suggests that non-fossil emissions were very important contributors of urban carbonaceous aerosols in China. The primary biomass-burning emissions accounted for 40 ± 8, 48 ± 18, 53 ± 4 and 65 ± 26% of non-fossil OC for Xi'an, Beijing, Shanghai and Guangzhou, respectively. Other non-fossil sources excluding primary biomass burning were mainly attributed to formation of secondary organic carbon (SOC) from non-fossil precursors such as biomass-burning emissions. For each site, we also compared samples from moderately to heavily polluted days according to particulate matter mass. Despite a significant increase of the absolute mass concentrations of primary emissions from both fossil and non-fossil sources during the heavily polluted events, their relative contribution to TC was even decreased, whereas the portion of SOC was consistently increased at all sites. This observation indicates that SOC was an important fraction in the increment of carbonaceous aerosols during the haze episode in China.

scholarly journals The effect of optically thin cirrus clouds on solar radiation in Camagüey, Cuba

2011 ◽  
Vol 11 (3) ◽  
pp. 8777-8799
Author(s):  
B. Barja ◽  
J. C. Antuña
Keyword(s):  
Solar Radiation ◽  
Radiative Forcing ◽  
Near Infrared ◽  
Local Heating ◽  
Spectral Band ◽  
Solar Spectrum ◽  
Cirrus Clouds ◽  
Radiation Budget ◽  
Earth System ◽  
The Earth

Abstract. Cirrus clouds play a key role in the radiation budget of the Earth system. They are an important aspect in the climate system, as they interact with the atmospheric radiation field. They control both the solar radiation that reaches the Earth surface and the longwave radiation that leaves the Earth system. The feedback produced by cirrus clouds in climate is not well understood. Therefore it is necessary to improve the understanding and characterization of the radiative forcing of cirrus clouds. We analyze the effect of optically thin cirrus clouds characterized with the lidar technique in Camagüey, Cuba, on solar radiation, by numerical simulation. Nature and amplitude of the effect of cirrus clouds on solar radiation is evaluated. Cirrus clouds have a cooling effect in the solar spectrum at the Top of the Atmosphere (TOA) and at the surface (SFC). The daily mean value of solar cirrus cloud radiative forcing (SCRF) has an average value of −9.1 W m−2 at TOA and −5.6 W m−2 at SFC. The cirrus clouds also have a local heating effect on the atmospheric layer where they are located. Cirrus clouds have mean daily values of heating rates of 0.63 K day−1 with a range between 0.35 K day−1 and 1.24 K day−1. The principal effect is in the near infrared spectral band of the solar spectrum. There is a linear relation between SCRF and cirrus clouds optical depth (COD), with −30 W m−2 COD−1 and −26 W m−2 COD−1, values for the slopes of the fits at the TOA and SFC, respectively in the broadband solar spectrum. Also there is a relation between the solar zenith angle and cirrus clouds radiative forcing displayed in the diurnal cycle.

scholarly journals The effect of optically thin cirrus clouds on solar radiation in Camagüey, Cuba

2011 ◽  
Vol 11 (16) ◽  
pp. 8625-8634 ◽  
Author(s):  
B. Barja ◽  
J. C. Antuña
Keyword(s):  
Solar Radiation ◽  
Radiative Forcing ◽  
Near Infrared ◽  
Local Heating ◽  
Spectral Band ◽  
Solar Spectrum ◽  
Cirrus Clouds ◽  
Cloud Base ◽  
Cirrus Cloud ◽  
Heating Rates

Abstract. The effect of optically thin cirrus clouds on solar radiation is analyzed by numerical simulation, using lidar measurements of cirrus conducted at Camagüey, Cuba. Sign and amplitude of the cirrus clouds effect on solar radiation is evaluated. There is a relation between the solar zenith angle and solar cirrus cloud radiative forcing (SCRF) present in the diurnal cycle of the SCRF. Maximums of SCRF out of noon located at the cirrus cloud base height are found for the thin and opaque cirrus clouds. The cirrus clouds optical depth (COD) threshold for having double SCRF maximum out of noon instead of a single one at noon was 0.083. In contrast, the heating rate shows a maximum at noon in the location of cirrus clouds maximum extinction values. Cirrus clouds have a cooling effect in the solar spectrum at the Top of the Atmosphere (TOA) and at the surface (SFC). The daily mean value of SCRF has an average value of −9.1 W m−2 at TOA and −5.6 W m−2 at SFC. The cirrus clouds also have a local heating effect on the atmospheric layer where they are located. Cirrus clouds have mean daily values of heating rates of 0.63 K day−1 with a range between 0.35 K day−1 and 1.24 K day−1. The principal effect is in the near-infrared spectral band of the solar spectrum. There is a linear relation between SCRF and COD, with −30 W m−2 COD−1 and −26 W m−2 COD−1, values for the slopes of the fits at the TOA and SFC, respectively, in the broadband solar spectrum.

scholarly journals Polar organic tracers in PM<sub>2.5</sub> aerosols from forests in eastern China

2008 ◽  
Vol 8 (24) ◽  
pp. 7507-7518 ◽  
Author(s):  
W. Wang ◽  
M. H. Wu ◽  
L. Li ◽  
T. Zhang ◽  
X. D. Liu ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Organic Carbon ◽  
Organic Compounds ◽  
Meteorological Parameters ◽  
Nature Reserve ◽  
Trace Gases ◽  
Eastern China ◽  
Atmospheric Particulate Matter ◽  
Oxidation Products ◽  
Anthropogenic Sources

Abstract. Photooxidation products of biogenic volatile organic compounds, mainly isoprene and monoterpenes, are significant sources of atmospheric particulate matter in forested regions. The objectives of this study were to examine time series and diel variations of polar organic tracers for the photooxidation of isoprene and α-pinene to investigate whether they are linked with meteorological parameters or trace gases, and to determine their carbon contributions. In addition, the biogenic secondary organic carbon contributions from isoprene were estimated. PM2.5 (particulate matter with an aerodynamic diameter <2.5 μm) aerosol samples were collected from forests in eastern China and compared with data from forested sites in Europe and America. Aerosol sampling was conducted at four sites located along a gradient of ecological succession in four different regions, i.e. Changbai Mountain Nature Reserve (boreal-temperate), Chongming National Forest Park (temperate), Dinghu Mountain Nature Reserve (subtropical) and Jianfengling Nature Reserve in Hainan (tropical) during summer periods when the meteorological conditions are believed to be favorable for photochemical processes. Fifty PM2.5 samples were collected; eighteen organic compounds, organic carbon (OC), elemental carbon and trace gases were measured. Results indicate that the concentration trends of the secondary organic compounds reflected those of the trace gases and meteorological parameters. Very good correlations between the sum concentrations of isoprene oxidation products and atmospheric SO2, O3, NO2, NOx, as well as CO2, at the Changbai site were found. The secondary OC due to isoprene was relatively high in tropical Hainan (0.27 μgC/m3) where isoprene-emitting broadleaf species are dominant, but was comparable in boreal Changbai (0.32 μgC/m3) where coniferous species are prevalent. The contribution of malic acid, which may have both biogenic and anthropogenic sources, to the OC mass was comparable at the four sites.

scholarly journals Extractable Organic Carbon and its Differentiation by Polarity in Diesel Exhaust, Wood Smoke, and Urban Particulate Matter

2009 ◽  
Vol 43 (7) ◽  
pp. 714-729 ◽  
Author(s):  
Alena Kubátová ◽  
Tylor J. Lahren ◽  
Josef Beránek ◽  
Irina P. Smoliakova ◽  
Artur Braun ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Organic Carbon ◽  
Diesel Exhaust ◽  
Wood Smoke ◽  
Urban Particulate Matter
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