scholarly journals Anonymous review of manuscript "Emissions Relationships in Western Forest Fire Plumes: I. Reducing the Effect of Mixing Errors on Emission Factors"

2019 ◽  
Author(s):  
Anonymous
Keyword(s):  
Forest Fire ◽  
Emission Factors ◽  
Fire Plumes

scholarly journals Emissions relationships in western forest fire plumes – Part 1: Reducing the effect of mixing errors on emission factors

2020 ◽  
Vol 13 (12) ◽  
pp. 7069-7096
Author(s):  
Robert B. Chatfield ◽  
Meinrat O. Andreae ◽  
◽  
Keyword(s):  
Forest Fire ◽  
Dry Mass ◽  
Emission Factors ◽  
Theoretical Description ◽  
Total Carbon ◽  
Theoretical Development ◽  
Atmospheric Composition ◽  
Fire Plume ◽  
Fire Plumes ◽  
Carbon Mass

Abstract. Studies of emission factors from biomass burning using aircraft data complement the results of lab studies and extend them to conditions of immense hot conflagrations. A new theoretical development of plume theory for multiple tracers is developed after examining aircraft samples. We illustrate and discuss emissions relationships for 422 individual samples from many forest fire plumes in the Western USA. Samples are from two NASA investigations: ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) and SEAC4RS (Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys). This work provides sample-by-sample enhancement ratios (EnRs) for 23 gases and particulate properties. Many EnRs provide candidates for emission ratios (ERs, corresponding to the EnR at the source) when the origin and degree of transformation is understood. From these, emission factors (EFs) can be estimated, provided the fuel dry mass consumed is known or can be estimated using the carbon mass budget approach. This analysis requires understanding the interplay of mixing of the plume with surrounding air. Some initial examples emphasize that measured Ctot=CO2+CO in a fire plume does not necessarily describe the emissions of the total carbon liberated in the flames, Cburn. Rather, it represents Ctot=Cburn+Cbkgd, which includes possibly varying background concentrations for entrained air. Consequently, we present a simple theoretical description for plume entrainment for multiple tracers from the flame tops to hundreds of kilometers downwind and illustrate some intrinsic linear behaviors. The analysis suggests a mixed-effects regression emission technique (MERET), which can eliminate occasional strong biases associated with the commonly used normalized excess mixing ratio (NEMR) method. MERET splits Ctot to reveal Cburn by exploiting the fact that Cburn and all tracers respond linearly to dilution, while each tracer has consistent EnR behavior (slope of tracer concentration with respect to Cburn). The two effects are separable. Two or three or preferably more emission indicators are required as a minimum; here we used eight. In summary, MERET allows a fine spatial resolution (EnRs for individual observations) and comparison of similar plumes that are distant in time and space. Alkene ratios provide us with an approximate photochemical timescale. This allows discrimination and definition, by fire situation, of ERs, allowing us to estimate emission factors.

scholarly journals Emissions Relationships in Western Forest Fire Plumes: I. Reducing the Effect of Mixing Errors on Emission Factors

2019 ◽  
Author(s):  
Robert B. Chatfield ◽  
Meinrat O. Andreae ◽  
◽  
Keyword(s):  
Forest Fire ◽  
Dry Mass ◽  
Combustion Efficiency ◽  
Emission Factors ◽  
Theoretical Description ◽  
Total Carbon ◽  
Fire Plume ◽  
Fire Plumes ◽  
Western Us ◽  
Carbon Mass

Abstract. Studies of emission factors from biomass burning using aircraft data complement the results of lab studies and extend them to conditions of immense hot conflagrations. We illustrate and discuss emission relationships for 422 individual samples from many forest-fire plumes in the Western US. The samples are from two NASA investigations: ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) and SEAC4RS (Studies of Emissions and Atmospher-ic Composition, Clouds, and Climate Coupling by Regional Surveys). This work provides sample-by-sample enhancement ratios (EnRs) for 23 gases and particulate properties. Many EnRs provide candidates for emission ratios (ERs, corresponding to the EnR at the source) when the origin and degree of transformation is understood and appropriate. From these, emission factors (EFs) can be estimated when the fuel dry mass consumed is known or can be estimated using the carbon mass budget approach. This analysis requires understanding the interplay of mixing of the plume with surrounding air. Some initial examples emphasize that measured Ctot = CO2 + CO in a fire plume does not necessarily describe the emissions of the total carbon liberated in the flames, Cburn. Rather, it represents Ctot = Cburn + Cbkgd, which includes possibly varying background concentrations for en-trained air. Consequently, we present a simple theoretical description for plume entrainment for multiple tracers from flame to hundreds of kilometers downwind and illustrate some intrinsic linear behaviors. The analysis suggests a Mixed Effects Regression Emission Technique (MERET), which can eliminate occasional strong biases associated with the commonly used normalized excess mix-ing ratio (NEMR) method. MERET splits Ctot to reveal Cburn by exploiting the fact that Cburn and all tracers respond linearly to dilution, while each tracer has consistent EnR behavior (slope of tracer concentration with respect to Cburn). The two effects are separable. Two or three or preferably more emission indicators are required as a minimum; here we used ten. Limited variations in the EnRs for each tracer can be incorporated and the variations and co-variations analyzed. The percentage CO yield (or the modified combustion efficiency) plays some role. Other co-relationships involving ni-trogen and organic classes are more prominent; these have strong relationships to the Cburn to O3 emission relationship. In summary, MERET allows fine spatial resolution (EnRs for individual ob-servations) and comparison of similar plumes distant in time and space. Alkene ratios provide us with an approximate photochemical timescale. This allows discrimination and definition, by fire sit-uation, of ERs, allowing us to estimate emission factors.

scholarly journals Production of peroxy nitrates in boreal biomass burning plumes over Canada during the BORTAS campaign

2016 ◽  
Vol 16 (5) ◽  
pp. 3485-3497 ◽  
Author(s):  
Marcella Busilacchio ◽  
Piero Di Carlo ◽  
Eleonora Aruffo ◽  
Fabio Biancofiore ◽  
Cesare Dari Salisburgo ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Forest Fire ◽  
Biomass Burning ◽  
Forest Fires ◽  
Chemical Mechanism ◽  
Fire Emissions ◽  
Fire Plumes ◽  
Peroxy Nitrates ◽  
In Fire ◽  
The Impact

Abstract. The observations collected during the BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS) campaign in summer 2011 over Canada are analysed to study the impact of forest fire emissions on the formation of ozone (O3) and total peroxy nitrates ∑PNs, ∑ROONO2). The suite of measurements on board the BAe-146 aircraft, deployed in this campaign, allows us to calculate the production of O3 and of  ∑PNs, a long-lived NOx reservoir whose concentration is supposed to be impacted by biomass burning emissions. In fire plumes, profiles of carbon monoxide (CO), which is a well-established tracer of pyrogenic emission, show concentration enhancements that are in strong correspondence with a significant increase of concentrations of ∑PNs, whereas minimal increase of the concentrations of O3 and NO2 is observed. The ∑PN and O3 productions have been calculated using the rate constants of the first- and second-order reactions of volatile organic compound (VOC) oxidation. The ∑PN and O3 productions have also been quantified by 0-D model simulation based on the Master Chemical Mechanism. Both methods show that in fire plumes the average production of ∑PNs and O3 are greater than in the background plumes, but the increase of ∑PN production is more pronounced than the O3 production. The average ∑PN production in fire plumes is from 7 to 12 times greater than in the background, whereas the average O3 production in fire plumes is from 2 to 5 times greater than in the background. These results suggest that, at least for boreal forest fires and for the measurements recorded during the BORTAS campaign, fire emissions impact both the oxidized NOy and O3,  but (1 ∑PN production is amplified significantly more than O3 production and (2) in the forest fire plumes the ratio between the O3 production and the ∑PN production is lower than the ratio evaluated in the background air masses, thus confirming that the role played by the ∑PNs produced during biomass burning is significant in the O3 budget. The implication of these observations is that fire emissions in some cases, for example boreal forest fires and in the conditions reported here, may influence more long-lived precursors of O3 than short-lived pollutants, which in turn can be transported and eventually diluted in a wide area.

scholarly journals In-situ observations of mid-latitude forest fire plumes deep in the stratosphere

2004 ◽  
Vol 31 (11) ◽  
pp. n/a-n/a ◽  
Author(s):  
Hans-Jürg Jost ◽  
Katja Drdla ◽  
Andreas Stohl ◽  
Leonhard Pfister ◽  
Max Loewenstein ◽  
...  
Keyword(s):  
Forest Fire ◽  
Fire Plumes ◽  
In Situ Observations

scholarly journals Volatile organic compounds composition of merged and aged forest fire plumes from Alaska and western Canada

2006 ◽  
Vol 111 (D10) ◽  
pp. n/a-n/a ◽  
Author(s):  
J. A. de Gouw ◽  
C. Warneke ◽  
A. Stohl ◽  
A. G. Wollny ◽  
C. A. Brock ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Forest Fire ◽  
Western Canada ◽  
Fire Plumes ◽  
Volatile Organic

scholarly journals A subsiding regional forest fire aerosol layer at Whistler, BC: implications for interpretation of mountaintop chemistry observations

2010 ◽  
Vol 10 (8) ◽  
pp. 20303-20327
Author(s):  
I. G. Mc Kendry ◽  
J. Gallagher ◽  
P. Campuzano Jost ◽  
A. Bertram ◽  
K. Strawbridge ◽  
...  
Keyword(s):  
Forest Fire ◽  
Forest Fires ◽  
Aerosol Layer ◽  
Synoptic Scale ◽  
Fire Plume ◽  
Fire Plumes ◽  
Physico Chemical ◽  
Air Chemistry ◽  
Regional Forest ◽  
Remote Sensing Methods

Abstract. On 30 August 2009, intense forest fires in interior BC, together with synoptic scale meteorological subsidence and easterly winds resulted in transport of a broad forest fire plume across southwestern BC. The physico-chemical and optical characteristics of the plume as observed from Saturna island (AERONET), CORALNet-UBC and the Whistler Mountain air chemistry facility were consistent with forest fire plumes that have been observed elsewhere in continental North America. However, the importance of smoke plume subsidence in relation to the interpretation of mountaintop chemistry observations is highlighted on the basis of deployment both a CL31 ceilometer and a single particle mass spectrometer (SPMS) in a mountainous setting. The SPMS was used to identify the biomass plume based on levoglucosan and potassium markers. Data from the SPMS are also used to show that the biomass plume was correlated with nitrate, but not correlated with sulphate or sodium. This study not only provides baseline measurements of biomass burning plume physico-chemical characteristics in western Canada, but also highlights the importance of lidar remote sensing methods in the interpretation of mountaintop chemistry measurements.

scholarly journals Quantitation of 11 alkylamines in atmospheric samples: separating structural isomers by ion chromatography

2017 ◽  
Vol 10 (3) ◽  
pp. 1061-1078 ◽  
Author(s):  
Bryan K. Place ◽  
Aleya T. Quilty ◽  
Robert A. Di Lorenzo ◽  
Susan E. Ziegler ◽  
Trevor C. VandenBoer
Keyword(s):  
Forest Fire ◽  
Standard Addition ◽  
Molar Ratio ◽  
Structural Isomers ◽  
Molar Ratios ◽  
Fire Plumes ◽  
Inorganic Cation ◽  
Successful Separation ◽  
Fine Mode ◽  
Earth’S Climate

Abstract. Amines are important drivers in particle formation and growth, which have implications for Earth's climate. In this work, we developed an ion chromatographic (IC) method using sample cation-exchange preconcentration for separating and quantifying the nine most abundant atmospheric alkylamines (monomethylamine (MMAH+), dimethylamine (DMAH+), trimethylamine (TMAH+), monoethylamine (MEAH+), diethylamine (DEAH+), triethylamine (TEAH+), monopropylamine (MPAH+), isomonopropylamine (iMPAH+), and monobutylamine (MBAH+)) and two alkyl diamines (1, 4-diaminobutane (DABH+) and 1, 5-diaminopentane (DAPH+)). Further, the developed method separates the suite of amines from five common atmospheric inorganic cations (Na+, NH4+, K+, Mg2+, Ca2+). All 16 cations are greater than 95 % baseline resolved and elute in a runtime of 35 min. This paper describes the first successful separation of DEAH+ and TMAH+ by IC and achieves separation between three sets of structural isomers, providing specificity not possible by mass spectrometry. The method detection limits for the alkylamines are in the picogram per injection range and the method precision (±1σ) analyzed over 3 months was within 16 % for all the cations. The performance of the IC method for atmospheric application was tested with biomass-burning (BB) particle extracts collected from two forest fire plumes in Canada. In extracts of a size-resolved BB sample from an aged plume, we detected and quantified MMAH+, DMAH+, TMAH+, MEAH+, DEAH+, and TEAH+ in the presence of Na+, NH4+, and K+ at molar ratios of amine to inorganic cation ranging from 1 : 2 to 1 : 1000. Quantities of DEAH+ and DMAH+ of 0.2–200 and 3–1200 ng m−3, respectively, were present in the extracts and an unprecedented amine-to-ammonium molar ratio greater than 1 was observed in particles with diameters spanning 56–180 nm. Extracts of respirable fine-mode particles (PM2. 5) from a summer forest fire in British Columbia in 2015 were found to contain iMPAH+, TMAH+, DEAH+ and TEAH+ at molar ratios of 1 : 300 with the dominant cations. The amine-to-ammonium ratio in a time series of samples never exceeded 0.15 during the sampling of the plume. These results and an amine standard addition demonstrate the robustness and sensitivity of the developed method when applied to the complex matrix of BB particle samples. The detection of multiple alkylamines in the analyzed BB samples indicates that this speciation and quantitation approach can be used to constrain BB emission estimates and the biogeochemical cycling of these reduced nitrogen species.

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