scholarly journals Temporal variability and sources of VOCs in urban areas of Eastern Mediterranean

2016 ◽  
Author(s):  
Christos Kaltsonoudis ◽  
Evangelia Kostenidou ◽  
Kalliopi Florou ◽  
Magda Psichoudaki ◽  
Spyros N. Pandis
Keyword(s):  
Biomass Burning ◽  
Urban Areas ◽  
Eastern Mediterranean ◽  
Proton Transfer Reaction ◽  
Oxidation Products ◽  
Residential Heating ◽  
Volatile Organic ◽  
Biogenic Compounds ◽  
The City ◽  
Emission Ratios

Abstract. During the summer of 2012 volatile organic compounds (VOCs) were monitored by Proton Transfer Reaction – Mass Spectrometry (PTR-MS) in urban backgrounds sites, in Athens and Patras, two of the largest cities in Greece. Also during the winter of 2013 PTR-MS measurements were conducted in the center of the city of Athens. Positive matrix factorization (PMF) was applied to the VOC measurements to gain insights about their sources. In summer most of the measured VOCs were due to biogenic and traffic emissions. Isoprene, monoterpenes and several oxygenated VOCs (oVOCs) originated mainly from vegetation either directly or as oxidation products. Isoprene average concentrations in Patras and Athens were 1 ppb and 0.7 ppb respectively while the monoterpene concentrations were 0.3 ppb and 0.9 ppb respectively. Traffic was the main source of aromatic compounds during summer. For Patras and Athens the average concentrations of benzene were 0.1 ppb and 0.2 ppb, of toluene 0.3 ppb and 0.8 ppb and of the xylenes 0.3 ppb and 0.7 ppb respectively. Winter measurements in Athens revealed that biomass burning used for residential heating was a major VOC source contributing both biogenic compounds such as isoprene and the monoterpenes, and aromatic VOCs. Several episodes related to biomass burning were identified and emission ratios (ER) and emission factors (EF) were estimated.

scholarly journals Temporal variability and sources of VOCs in urban areas of the eastern Mediterranean

2016 ◽  
Vol 16 (23) ◽  
pp. 14825-14842 ◽  
Author(s):  
Christos Kaltsonoudis ◽  
Evangelia Kostenidou ◽  
Kalliopi Florou ◽  
Magda Psichoudaki ◽  
Spyros N. Pandis
Keyword(s):  
Biomass Burning ◽  
Urban Areas ◽  
Eastern Mediterranean ◽  
Proton Transfer Reaction ◽  
Oxidation Products ◽  
Residential Heating ◽  
Biogenic Compounds ◽  
The City ◽  
Urban Sites ◽  
Emission Ratios

Abstract. During the summer of 2012 volatile organic compounds (VOCs) were monitored by proton transfer reaction mass spectrometry (PTR-MS) in urban sites, in Athens and Patras, two of the largest cities in Greece. Also, during the winter of 2013, PTR-MS measurements were conducted in the center of the city of Athens. Positive matrix factorization (PMF) was applied to the VOC measurements to gain insights about their sources. In summer most of the measured VOCs were due to biogenic and traffic emissions. Isoprene, monoterpenes, and several oxygenated VOCs (oVOCs) originated mainly from vegetation either directly or as oxidation products. Isoprene average concentrations in Patras and Athens were 1 and 0.7 ppb respectively, while the monoterpene concentrations were 0.3 and 0.9 ppb respectively. Traffic was the main source of aromatic compounds during summer. For Patras and Athens the average concentrations of benzene were 0.1 and 0.2 ppb, of toluene 0.3 and 0.8 ppb, and of the xylenes 0.3 and 0.7 ppb respectively. Winter measurements in Athens revealed that biomass burning used for residential heating was a major VOC source contributing both aromatic VOCs and biogenic compounds such as monoterpenes. Several episodes related to biomass burning were identified and emission ratios (ERs) and emission factors (EFs) were estimated.

scholarly journals The tropical forest and fire emissions experiment: method evaluation of volatile organic compound emissions measured by PTR-MS, FTIR, and GC from tropical biomass burning

2007 ◽  
Vol 7 (3) ◽  
pp. 8755-8793 ◽  
Author(s):  
T. G. Karl ◽  
T. J. Christian ◽  
R. J. Yokelson ◽  
P. Artaxo ◽  
W. Min Hao ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Organic Compound ◽  
Tropical Forest ◽  
Biomass Burning ◽  
Volatile Organic Compound ◽  
Charge Ratio ◽  
Voc Emissions ◽  
Fire Emissions ◽  
Volatile Organic ◽  
Emission Ratios

Abstract. Volatile Organic Compound (VOC) emissions from fires in tropical forest fuels were quantified using Proton-Transfer-Reaction Mass Spectrometry (PTRMS), Fourier Transformation Infrared Spectroscopy (FTIR) and gas chromatography (GC) coupled to PTRMS (GC-PTR-MS). We investigated VOC emissions from 19 controlled laboratory fires at the USFS Fire Sciences Laboratory and 16 fires during an intensive airborne field campaign during the peak of the burning season in Brazil in 2004. The VOC emissions were dominated by oxygenated VOCs (OVOC) (OVOC/NMHC ~4:1, NMHC: non-methane hydrocarbons) The specificity of the PTR-MS instrument, which measures the mass to charge ratio of VOCs ionized by H3O+ ions, was validated by gas chromatography and by intercomparing in-situ measurements with those obtained from an open path FTIR instrument. Emission ratios for methyl vinyl ketone, methacrolein, crotonaldehyde, acrylonitrile and pyrrole were measured in the field for the first time. Our measurements show a higher contribution of OVOCs than previously assumed for modeling purposes. Comparison of fresh (<15 min) and aged (>1hour-1day) smoke suggests altered emission ratios due to gas phase chemistry for acetone but not for acetaldehyde and methanol. Emission ratios for numerous, important, reactive VOCs with respect to acetonitrile (a biomass burning tracer) are presented.

scholarly journals Measurements of volatile organic compounds over West Africa

2010 ◽  
Vol 10 (2) ◽  
pp. 3861-3892 ◽  
Author(s):  
J. G. Murphy ◽  
D. E. Oram ◽  
C. E. Reeves
Keyword(s):  
Boundary Layer ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Marine Boundary Layer ◽  
Deep Convection ◽  
Proton Transfer Reaction ◽  
Oxidation Products ◽  
High Time Resolution ◽  
Airborne Measurements ◽  
Volatile Organic

Abstract. In this paper we describe measurements of volatile organic compounds (VOCs) made using a Proton Transfer Reaction Mass Spectrometer (PTR-MS) aboard the UK Facility for Atmospheric Airborne Measurements during the African Monsoon Multidisciplinary Analyses (AMMA) campaign. Observations were made during approximately 85 h of flying time between 17 July and 17 August 2006, above an area between 4° N and 18° N and 3° W and 4° E, encompassing ocean, mosaic forest, and the Sahel desert. High time resolution observations of counts at mass to charge (m/z) ratios of 42, 59, 69, 71, and 79 were used to calculate mixing ratios of acetonitrile, acetone, isoprene, the sum of methyl vinyl ketone and methacrolein, and benzene, respectively using laboratory-derived humidity-dependent calibration factors. Strong spatial associations between vegetation and isoprene and its oxidation products were observed in the boundary layer, consistent with biogenic emissions followed by rapid atmospheric oxidation. Acetonitrile, benzene, and acetone were all enhanced in airmasses which had been heavily influenced by biomass burning. Benzene and acetone were also elevated in airmasses with urban influence from cities such as Lagos, Cotonou, and Niamey. The observations provide evidence that both deep convection and mixing associated with fair-weather cumulus were responsible for vertical redistribution of VOCs emitted from the surface. Profiles over the ocean showed a depletion of acetone in the marine boundary layer, but no significant decrease for acetonitrile.

scholarly journals Exploiting stagnant conditions to derive robust emission ratio estimates for CO<sub>2</sub>, CO and volatile organic compounds in Paris

2016 ◽  
Vol 16 (24) ◽  
pp. 15653-15664 ◽  
Author(s):  
Lamia Ammoura ◽  
Irène Xueref-Remy ◽  
Felix Vogel ◽  
Valérie Gros ◽  
Alexia Baudic ◽  
...  
Keyword(s):  
Extreme Values ◽  
Background Level ◽  
Atmospheric Temperature ◽  
Atmospheric Concentration ◽  
Low Wind Speed ◽  
Volatile Organic ◽  
Regional Background Level ◽  
Autumn And Winter ◽  
The City ◽  
Emission Ratios

Abstract. We propose an approach to estimate urban emission ratios that takes advantage of the enhanced local urban signal in the atmosphere at low wind speed. We apply it to estimate monthly ratios between CO2, CO and some VOCs from several atmospheric concentration measurement datasets acquired in the centre of Paris between 2010 and 2014. We find that this approach is not very sensitive to the regional background level definition and that, in the case of Paris, it samples all days (weekdays and weekends) and all hours of the day evenly. A large seasonal variability of the ΔCO ∕ ΔCO2 ratio in Paris is shown, with a difference of around 60 % between the extreme values and a strong anti-correlation (r2 = 0.75) with atmospheric temperature. The comparison of the ratios obtained for two short measurement campaigns conducted in two different districts and two different periods (autumn and winter) shows differences ranging from −120 to +63 %. A comparison with a highly resolved regional emission inventory suggests some spatial variations of the ratio within the city.

scholarly journals Characteristics of wintertime VOCs in suburban and urban Beijing: concentrations, emission ratios, and festival effects

2019 ◽  
Author(s):  
Kun Li ◽  
Junling Li ◽  
Shengrui Tong ◽  
Weigang Wang ◽  
Ru-Jin Huang ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Urban Areas ◽  
Diurnal Variations ◽  
Urban Site ◽  
Anthropogenic Emissions ◽  
Suburban Areas ◽  
Key Characteristics ◽  
Volatile Organic ◽  
Suburban Site ◽  
Emission Ratios

Abstract. Measurements of volatile organic compounds (VOCs) were performed at a suburban site and an urban site in Beijing during the winter of 2014–2015. The VOC concentrations and emission ratios (ERs) to CO were compared at these two sites. It is found that though the VOC concentrations at the urban site are 2.67 ± 1.15 times of those at the suburban site, the ERs are similar (within a factor of 1.5). It is indicated that: (1) the VOCs at suburban areas are mainly from the transportation from the urban areas; (2) the ERs measured at the urban areas are also valid for the surrounding suburban areas. By comparing the diurnal variations and the contribution of anthropogenic emissions at both sites, we find that the photochemical processes are very active at the urban site, and these processes play an important role in the daytime oxygenated VOCs (OVOCs) formation. The methanol at the urban site and the formic acid at the suburban site probably have additional sources, which are attributed to be solvent use and soil/agriculture, respectively. The festival effects from Chinese New Year (CNY) were investigated. The VOC concentrations decreased ~ 60 % during CNY holidays, probably due to the population migration during festival holidays. In addition, fireworks are found to be an important source of acetonitrile, aromatics, and some OVOCs during CNY festival, and should be controlled more strictly. This study provides key characteristics of wintertime VOCs in suburban and urban Beijing, and has implications for better understanding the atmospheric chemistry of VOCs in and around this megacity.

scholarly journals Oxygenated compounds in aged biomass burning plumes over the Eastern Mediterranean: evidence for strong secondary production of methanol and acetone

2005 ◽  
Vol 5 (1) ◽  
pp. 39-46 ◽  
Author(s):  
R. Holzinger ◽  
J. Williams ◽  
G. Salisbury ◽  
T. Klüpfel ◽  
M. de Reus ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Secondary Production ◽  
Eastern Mediterranean ◽  
Proton Transfer Reaction ◽  
Tunable Diode Laser ◽  
Airborne Measurements ◽  
Mixing Ratios ◽  
Oxygenated Compounds ◽  
Laser Absorption ◽  
Secondary Formation

Abstract. Airborne measurements of acetone, methanol, PAN, acetonitrile (by Proton Transfer Reaction Mass Spectrometry), and CO (by Tunable Diode Laser Absorption Spectroscopy) have been performed during the Mediterranean Intensive Oxidants Study (MINOS August 2001). We have identified ten biomass burning plumes from strongly elevated acetonitrile mixing ratios. The characteristic biomass burning signatures obtained from these plumes reveal secondary production of acetone and methanol, while CO photochemically declines in the plumes. Mean excess mixing ratios - normalized to CO - of 1.8%, 0.20%, 3.8%, and 0.65% for acetone, acetonitrile, methanol, and PAN, respectively, were found. By scaling to an assumed global annual source of 663-807Tg CO, biomass burning emissions of 25-31 and 29-35 Tg/yr for acetone and methanol are estimated, respectively. Our measurements suggest that the present biomass burning contributions of acetone and methanol are significantly underestimated due to the neglect of secondary formation within the plume. Median acetonitrile mixing ratios throughout the troposphere were around 150pmol/mol, in accord with current biomass burning inventories and an atmospheric lifetime of ~6 months.

scholarly journals Secondary organic aerosol formation and primary organic aerosol oxidation from biomass-burning smoke in a flow reactor during FLAME-3

2013 ◽  
Vol 13 (22) ◽  
pp. 11551-11571 ◽  
Author(s):  
A. M. Ortega ◽  
D. A. Day ◽  
M. J. Cubison ◽  
W. H. Brune ◽  
D. Bon ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Biomass Burning ◽  
Flow Reactor ◽  
Organic Aerosol ◽  
Proton Transfer Reaction ◽  
Oxidation Products ◽  
Chemical Transformations ◽  
Aerosol Formation ◽  
Aerosol Mass ◽  
Smog Chambers

Abstract. We report the physical and chemical effects of photochemically aging dilute biomass-burning smoke. A "potential aerosol mass" (PAM) flow reactor was used with analysis by a high-resolution aerosol mass spectrometer and a proton-transfer-reaction ion-trap mass spectrometer during the FLAME-3 campaign. Hydroxyl (OH) radical concentrations in the reactor reached up to ~1000 times average tropospheric levels, producing effective OH exposures equivalent to up to 5 days of aging in the atmosphere, and allowing for us to extend the investigation of smoke aging beyond the oxidation levels achieved in traditional smog chambers. Volatile organic compound (VOC) observations show aromatics and terpenes decrease with aging, while formic acid and other unidentified oxidation products increase. Unidentified gas-phase oxidation products, previously observed in atmospheric and laboratory measurements, were observed here, including evidence of multiple generations of photochemistry. Substantial new organic aerosol (OA) mass ("net SOA"; secondary OA) was observed from aging biomass-burning smoke, resulting in total OA average of 1.42 ± 0.36 times the initial primary OA (POA) after oxidation. This study confirms that the net-SOA-to-POA ratio of biomass-burning smoke is far lower on average than that observed for urban emissions. Although most fuels were very reproducible, significant differences were observed among the biomasses, with some fuels resulting in a doubling of the OA mass, while for others a very small increase or even a decrease was observed. Net SOA formation in the photochemical reactor increased with OH exposure (OHexp), typically peaking around three days of equivalent atmospheric photochemical age (OHexp~3.9 × 1011 molecules cm−3 s), then leveling off at higher exposures. The amount of additional OA mass added from aging is positively correlated with initial POA concentration, but not with the total VOC concentration or the concentration of known SOA precursors. The mass of SOA formed often exceeded the mass of the known VOC precursors, indicating the likely importance of primary semivolatile/intermediate volatility species, and possibly of unidentified VOCs as SOA precursors in biomass burning smoke. Chemical transformations continued even after mass concentration stabilized. Changes in the biomass-burning tracer f60 ranged from substantially decreasing to remaining constant with increased aging. With increased OHexp, oxidation was always detected (as indicated by f44 and O/C). POA O/C ranged from 0.15 to 0.5, while aged OA O/C reached up to 0.87. The rate of oxidation and maximum O/C achieved differs for each biomass, and appears to increase with the initial O/C of the POA.

scholarly journals Direct ecosystem fluxes of volatile organic compounds from oil palms in South-East Asia

2011 ◽  
Vol 11 (17) ◽  
pp. 8995-9017 ◽  
Author(s):  
P. K. Misztal ◽  
E. Nemitz ◽  
B. Langford ◽  
C. F. Di Marco ◽  
G. J. Phillips ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Canopy Temperature ◽  
Proton Transfer Reaction ◽  
Oxidation Products ◽  
Palm Trees ◽  
Volatile Organic ◽  
Resistance Approach ◽  
Oil Palms ◽  
Malaysian Borneo

Abstract. This paper reports the first direct eddy covariance fluxes of reactive biogenic volatile organic compounds (BVOCs) from oil palms to the atmosphere using proton-transfer-reaction mass spectrometry (PTR-MS), measured at a plantation in Malaysian Borneo. At midday, net isoprene flux constituted the largest fraction (84 %) of all emitted BVOCs measured, at up to 30 mg m−2 h−1 over 12 days. By contrast, the sum of its oxidation products methyl vinyl ketone (MVK) and methacrolein (MACR) exhibited clear deposition of 1 mg m−2 h−1, with a small average canopy resistance of 230 s m−1. Approximately 15 % of the resolved BVOC flux from oil palm trees could be attributed to floral emissions, which are thought to be the largest reported biogenic source of estragole and possibly also toluene. Although on average the midday volume mixing ratio of estragole exceeded that of toluene by almost a factor of two, the corresponding fluxes of these two compounds were nearly the same, amounting to 0.81 and 0.76 mg m−2 h−1, respectively. By fitting the canopy temperature and PAR response of the MEGAN emissions algorithm for isoprene and other emitted BVOCs a basal emission rate of isoprene of 7.8 mg m−2 h−1 was derived. We parameterise fluxes of depositing compounds using a resistance approach using direct canopy measurements of deposition. Consistent with Karl et al. (2010), we also propose that it is important to include deposition in flux models, especially for secondary oxidation products, in order to improve flux predictions.

scholarly journals Measurements of volatile organic compounds over West Africa

2010 ◽  
Vol 10 (12) ◽  
pp. 5281-5294 ◽  
Author(s):  
J. G. Murphy ◽  
D. E. Oram ◽  
C. E. Reeves
Keyword(s):  
Boundary Layer ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Marine Boundary Layer ◽  
Deep Convection ◽  
Proton Transfer Reaction ◽  
Oxidation Products ◽  
High Time Resolution ◽  
Airborne Measurements ◽  
Volatile Organic

Abstract. In this paper we describe measurements of volatile organic compounds (VOC) made using a Proton Transfer Reaction Mass Spectrometer (PTR-MS) aboard the UK Facility for Atmospheric Airborne Measurements during the African Monsoon Multidisciplinary Analyses (AMMA) campaign. Observations were made during approximately 85 h of flying time between 17 July and 17 August 2006, above an area between 4° N and 18° N and 3° W and 4° E, encompassing ocean, mosaic forest, and the Sahel desert. High time resolution observations of counts at mass to charge (m/z) ratios of 42, 59, 69, 71, and 79 were used to calculate mixing ratios of acetonitrile, acetone, isoprene, the sum of methyl vinyl ketone and methacrolein, and benzene respectively using laboratory-derived humidity-dependent calibration factors. Strong spatial associations between vegetation and isoprene and its oxidation products were observed in the boundary layer, consistent with biogenic emissions followed by rapid atmospheric oxidation. Acetonitrile, benzene, and acetone were all enhanced in airmasses which had been heavily influenced by biomass burning. Benzene and acetone were also elevated in airmasses with urban influence from cities such as Lagos, Cotonou, and Niamey. The observations provide evidence that both deep convection and mixing associated with fair-weather cumulus were responsible for vertical redistribution of VOC emitted from the surface. Profiles over the ocean showed a depletion of acetone in the marine boundary layer, but no significant decrease for acetonitrile.

Landsat MSS Imagery to Estimate Residential Heat-Load Density

1987 ◽  
Vol 19 (12) ◽  
pp. 1597-1610 ◽  
Author(s):  
P J Curran ◽  
T A Hobson
Keyword(s):  
Urban Areas ◽  
Heat Load ◽  
Electricity Generation ◽  
Waste Heat ◽  
Unit Area ◽  
Scanning System ◽  
Residential Areas ◽  
Remotely Sensed Data ◽  
Residential Heating ◽  
The City

Combined heat and power (CHP) schemes have the potential for reducing residential heating costs. As these schemes use waste heat from electricity generation, the power station associated with them must, for reasons of efficiency, be near to a region where the heat usage per unit area (heat-load density) is high. To plan CHP schemes, the heat-load density of urban areas needs to be mapped and monitored. To calculate heat-load density for residential areas workers have conventionally multiplied the number of dwellings per unit area by the average heat-load per dwelling. This is time-consuming and must be repeated in full, for each resurvey. In this paper the use of remotely sensed data from the Landsat Multispectral Scanning System (MSS) to estimate heat-load density is proposed. A survey using these data for the City of Sheffield was faster and no less accurate than a survey performed by conventional means. However, Landsat MSS data were unable to discriminate between more than four classes of heat-load density, a level of discrimination that may be increased if Landsat Thematic Mapper (TM) or SPOT High Resolution Visible (HRV) data were to be used in future surveys of this kind.

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