scholarly journals Uncertainty in fire emission factors and the impact on modeled atmospheric CO and O3

2021 ◽  
Author(s):  
Rebecca Buchholz ◽  
Wenfu Tang ◽  
Louisa Emmons ◽  
Benjamin Gaubert ◽  
Forrest Lacey ◽  
...  
Keyword(s):  
In Fire ◽  
Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 190
Author(s):  
William Hicks ◽  
Sean Beevers ◽  
Anja H. Tremper ◽  
Gregor Stewart ◽  
Max Priestman ◽  
...  

This research quantifies current sources of non-exhaust particulate matter traffic emissions in London using simultaneous, highly time-resolved, atmospheric particulate matter mass and chemical composition measurements. The measurement campaign ran at Marylebone Road (roadside) and Honor Oak Park (background) urban monitoring sites over a 12-month period between 1 September 2019 and 31 August 2020. The measurement data were used to determine the traffic increment (roadside–background) and covered a range of meteorological conditions, seasons, and driving styles, as well as the influence of the COVID-19 “lockdown” on non-exhaust concentrations. Non-exhaust particulate matter (PM)10 concentrations were calculated using chemical tracer scaling factors for brake wear (barium), tyre wear (zinc), and resuspension (silicon) and as average vehicle fleet non-exhaust emission factors, using a CO2 “dilution approach”. The effect of lockdown, which saw a 32% reduction in traffic volume and a 15% increase in average speed on Marylebone Road, resulted in lower PM10 and PM2.5 traffic increments and brake wear concentrations but similar tyre and resuspension concentrations, confirming that factors that determine non-exhaust emissions are complex. Brake wear was found to be the highest average non-exhaust emission source. In addition, results indicate that non-exhaust emission factors were dependent upon speed and road surface wetness conditions. Further statistical analysis incorporating a wider variability in vehicle mix, speeds, and meteorological conditions, as well as advanced source apportionment of the PM measurement data, were undertaken to enhance our understanding of these important vehicle sources.


2021 ◽  
pp. 67-72
Author(s):  
Владимир Леонидович Малкин ◽  
Владимир Александрович Угорелов ◽  
Петр Алексеевич Леончук ◽  
Руслан Андреевич Загуменников

Разработана методика проведения испытаний технических средств защиты стальных сварных бытовых баллонов для сжиженных углеводородных газов (СУГ) от физического разрушения при воздействии на них пожара. В методике содержатся требования к отбору газовых баллонов, рассматриваемым модельным сценариям, установке для испытаний, мероприятиям по подготовке испытаний, порядку их проведения, к отчету о проведении испытаний. Использование предлагаемой методики позволит с высокой степенью достоверности оценивать эффективность применения технических средств защиты стальных бытовых баллонов для СУГ от физического разрушения при воздействии пожара. The paper contains proposals for inclusion in the testing methodology for technical means of protecting gas cylinders from physical destruction. The proposals relate to the choice of typical scenarios characteristic for emergencies and fire development in a room with LPG cylinders: the ingress of cylinders into the fire center, the impact on the cylinder surface of the heat flow of the adjacent fire center; the impact on the surface of the cylinder of LPG vapors jet combustion, simulating the effect of combustion of LPG vapors coming out of the outlet of the valve (safety valve or membrane) of the adjacent cylinder. The design of the installation for testing cylinders in accordance with the above scenarios is presented. There are given requirements for the test preparation procedure, including the verification of documentation, installation of technical protective equipment, filling and delivery of cylinders, checking for gas leaks from cylinders after delivery, installation for testing. A detailed description of the installation procedure is given in accordance with the presented diagrams for various test scenarios. The basic diagrams of the measuring system for the pressure inside the cylinder, mounting of thermocouples on the wall of the cylinder, and remote supply of liquid fuel to trays are described. There is described the test procedure, which consists of turning on the recording systems, gas supplying to the installation, activating the cylinder heating system, video recording of the experiment with timing, closing the valve in front of the pressure sensor after the end of combustion, discharging LPG from the sealed cylinder to the burner. The requirements for the composition of the test report are given, which make it possible to confirm the reliability of the experiments.


2018 ◽  
Vol 373 (1761) ◽  
pp. 20170443 ◽  
Author(s):  
Christopher N. Johnson ◽  
Lynda D. Prior ◽  
Sally Archibald ◽  
Helen M. Poulos ◽  
Andrew M. Barton ◽  
...  

Large vertebrates affect fire regimes in several ways: by consuming plant matter that would otherwise accumulate as fuel; by controlling and varying the density of vegetation; and by engineering the soil and litter layer. These processes can regulate the frequency, intensity and extent of fire. The evidence for these effects is strongest in environments with intermediate rainfall, warm temperatures and graminoid-dominated ground vegetation. Probably, extinction of Quaternary megafauna triggered increased biomass burning in many such environments. Recent and continuing declines of large vertebrates are likely to be significant contributors to changes in fire regimes and vegetation that are currently being experienced in many parts of the world. To date, rewilding projects that aim to restore large herbivores have paid little attention to the value of large animals in moderating fire regimes. Rewilding potentially offers a powerful tool for managing the risks of wildfire and its impacts on natural and human values. This article is part of the theme issue ‘Trophic rewilding: consequences for ecosystems under global change’.


2021 ◽  
Author(s):  
Yicheng Shen ◽  
Luke Sweeney ◽  
Mengmeng Liu ◽  
Jose Antonio Lopez Saez ◽  
Sebastián Pérez-Díaz ◽  
...  

Abstract. Charcoal accumulated in lake, bog or other anoxic sediments through time has been used to document the geographical patterns in changes in fire regimes. Such reconstructions are useful to explore the impact of climate and vegetation changes on fire during periods when the human influence was less prevalent than today. However, charcoal records only provide semi-quantitative estimates of change in biomass burning. Here we derive quantitative estimates of burnt area from vegetation data in two stages. First, we relate the modern charcoal abundance to burnt area using a conversion factor derived from a generalized linear model of burnt area probability based on eight environmental predictors. Then, we establish the relationship between fossil pollen assemblages and burnt area using Tolerance-weighted Weighted Averaging Partial Least-Squares with sampling frequency correction (fxTWA-PLS). We test this approach using the Iberian Peninsula as a case study because it is a fire-prone region with abundant pollen and charcoal records covering the Holocene. We derive the vegetation-burnt area relationship using the 29 records that have both modern and fossil charcoal and pollen data, and then reconstruct palaeo-burnt area for the 114 records with Holocene pollen records. The pollen data predict charcoal abundances through time relatively well (R2 = 0.47) and the changes in reconstructed burnt area are synchronous with known climate changes through the Holocene. This new method opens up the possibility of reconstructing changes in fire regimes quantitatively from pollen records, which are far more numerous than charcoal records.


2016 ◽  
Vol 16 (5) ◽  
pp. 3485-3497 ◽  
Author(s):  
Marcella Busilacchio ◽  
Piero Di Carlo ◽  
Eleonora Aruffo ◽  
Fabio Biancofiore ◽  
Cesare Dari Salisburgo ◽  
...  

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.


2021 ◽  
Vol 39 (3_suppl) ◽  
pp. 118-118
Author(s):  
Jingyuan Wang ◽  
Joshua Millstein ◽  
Fotios Loupakis ◽  
Sebastian Stintzing ◽  
Hiroyuki Arai ◽  
...  

118 Background: Antiangiogenic drug (AAD)-triggered oxygen and nutrient depletion through suppression of angiogenesis switches the glucose-dependent metabolism to lipid-dependent metabolism. Blocking fatty acid oxidation can enhance AAD-mediated anti-tumor effects in colorectal cancer. Previous reports suggested that polymorphisms of the lipid metabolism-related genes are associated with the increased risk of CRC and poor clinical outcome in CRC. Therefore, we hypothesized that genetic variants in the lipid metabolism pathway may predict first-line treatment outcome in mCRC pts. Methods: Genomic DNA from blood samples of pts enrolled in two independent randomized trials, FIRE-3 and MAVERICC, was genotyped through the OncoArray, a customized array manufactured by Illumina including approximately 530K SNP markers. The impact on outcome of 25 selected SNPs in 10 genes involved in the lipid metabolism pathway (CD36, FABP4, LPCAT1, LPCAT2, PPARG, CPT1A, ACSS2, SREBF1, FASN, ACACA) was analyzed. Those treated with FOLFIRI/ bevacizumab (bev) in FIRE-3 (n = 107) and MAVERICC (n = 163) served as discovery and validation cohorts respectively, while FIRE-3 FOLFIRI/ cetuximab (cet) (n = 129) arm was used as the control. Interaction between each SNP and treatment was evaluated in FIRE-3 (FOLFIRI/bev arm vs. FOLFIRI/cet arm). Results: In the discovery (FIRE-3 bev) cohort, pts with FASN rs4485435 any C allele (N = 21) showed significantly shorter progression-free survival (PFS) (8.69 vs 13.48 months) compared to carriers of G/G (N = 62) in both univariate (hazard ratio [HR] = 2.88; 95% confidence interval [CI]: 1.57-5.29; p = 0.00037) and multivariate (HR = 2.87; 95%CI 1.4-5.9; p = 0.00675) analyses. These data were validated in the MAVERICC bev cohort in multivariate analysis (11.17 vs 14.06 months; HR = 2.07; 95%CI: 1.15-3.74; p = 0.02). Pts carrying any T allele in PPARG rs3856806 (N = 36) showed significantly longer overall survival (OS) (Not reached vs 42 months) than carriers of C/C (n = 93) in the FIRE-3 cet cohort in both univariate (HR = 0.4; 95%CI 0.17-0.92; p = 0.03) and multivariate (HR = 0.37; 95%CI 0.15-0.93; p = 0.02) analyses, but the association was not observed in the bev cohort of MAVERICC and FIRE-3. In the comparison of bev arm vs cet arm in FIRE-3, interactions were shown with FASN rs4485435 (p = 0.017) on PFS and PPARG rs3856806 (p = 0.059) on OS. Conclusions: Our study demonstrates for the first time that FASN polymorphism could predict outcomes of bev-based treatment in mCRC patients; Meanwhile PPARG polymorphism could predict outcomes of cet-based treatment in mCRC patients. These findings support a possible role of the lipid metabolism pathway in contributing to resistance to anti-VEGF/EGFR treatment.


Fire ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 18 ◽  
Author(s):  
Ginny Marshall ◽  
Dan Thompson ◽  
Kerry Anderson ◽  
Brian Simpson ◽  
Rodman Linn ◽  
...  

Current methods of predicting fire spread in Canadian forests are suited to large wildfires that spread through natural forests. Recently, the use of mechanical and thinning treatments of forests in the wildland-urban interface of Canada has increased. To assist in community wildfire protection planning in forests not covered by existing operational fire spread models, we use FIRETEC to simulate fire spread in lowland black spruce fuel structures, the most common tree stand in Canada. The simulated treatments included the mechanical mulching of strips, and larger, irregularly shaped areas. In all cases, the removal of fuel by mulch strips broke up the fuels, but also caused wind speed increases, so little decrease in fire spread rate was modelled. For large irregular clearings, the fire spread slowly through the mulched wood chips, and large decreases in fire spread and intensity were simulated. Furthermore, some treatments in the black spruce forest were found to be effective in decreasing the distance and/or density of firebrands. The simulations conducted can be used alongside experimental fires and documented wildfires to examine the effectiveness of differing fuel treatment options to alter multiple components of fire behavior.


2016 ◽  
Author(s):  
Cathy M. Trudinger ◽  
Paul J. Fraser ◽  
David M. Etheridge ◽  
William T. Sturges ◽  
Martin K. Vollmer ◽  
...  

Abstract. Perfluorocarbons (PFCs) are very potent and long-lived greenhouse gases in the atmosphere, released predominantly during aluminium production and semiconductor manufacture. They have been targeted for emission controls under the United Nations Framework Convention on Climate Change. Here we present the first continuous records of the atmospheric abundance and global emissions of CF4 (PFC-14), C2F6 (PFC-116) and C3F8 (PFC-218) from 1900 to 2014. The records are derived from high precision measurements of PFCs in air extracted from polar firn or ice at six sites (DE08, DE08-2, DSSW20K, EDML, NEEM and South Pole) and air archive tanks and atmospheric air sampled from both hemispheres. We take proper account of the age characteristics of the firn and ice core air samples and demonstrate excellent consistency between the ice core, firn and atmospheric measurements. In addition to an inversion for global emissions from 1900 to 2014, we also formulate the inversion to directly infer emission factors for PFC emissions due to aluminium production prior to the 1980s. We show that the late-Holocene pre-industrial level was 34.05 ± 0.33 ppt for CF4, and below detection limits of 0.002 ppt and 0.01 ppt for C2F6 and C3F8, respectively. We find a significant peak in CF4 and C2F6 emissions around 1940, most likely due to the high demand for aluminium during World War II, for example for construction of aircraft. The PFC emission factors for aluminium production in the early twentieth century were significantly higher than today, but have decreased since then due to improvements and better control of the smelting process. We see a temporary reduction of around 15 % in CF4 emissions in 2009, presumably associated with the impact of the Global Financial Crisis on aluminium and semiconductor production.


Fire ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 38
Author(s):  
Matthew P Thompson ◽  
Jude Bayham ◽  
Erin Belval

The global COVID-19 pandemic will pose unique challenges to the management of wildland fire in 2020. Fire camps may provide an ideal setting for the transmission of SARS-CoV-2, the virus that causes COVID-19. However, intervention strategies can help minimize disease spread and reduce the risk to the firefighting community. We developed a COVID-19 epidemic model to highlight the risks posed by the disease during wildland fire incidents. Our model accounts for the transient nature of the population on a wildland fire incident, which poses unique risks to the management of communicable diseases in fire camps. We used the model to assess the impact of two types of interventions: the screening of a firefighter arriving on an incident, and social distancing measures. Our results suggest that both interventions are important to mitigate the risks posed by the SARS-CoV-2 virus. However, screening is relatively more effective on short incidents, whereas social distancing is relatively more effective during extended campaigns. We conclude with a discussion of model limitations and potential extensions to the model.


1997 ◽  
Vol 3 (3) ◽  
pp. 206 ◽  
Author(s):  
G. Barry Baker ◽  
E. Belinda Dettmann ◽  
Stephen J. Wilson

Survival rate, population size, recruitment and probability of capture, derived from a long-term study of 20 passerine species in wet sclerophyll forest near Canberra, were used to measure the impact of a high intensity wildfire which burnt 70% of the study area. The wildfire significantly affected the population size of 13 species for a period of up to six years following the fire. Survival and recruitment were the least sensitive measures of impact and indicated a significant response to fire for only 2 of 10 species. We detected measurable effects of the fire for 17 of the 20 species studied. Many of these species had returned to prefire levels within three years, but for nine species the effects were still apparent six years later. Mark-recapture methodology provides an effective way of measuring the impact of fire regimes in forest environments. Long-term monitoring programmes should be established in fire-prone forest environments to contribute toward our understanding of fire, and its effect on avian populations. Such programmes have resource implications and researchers are urged to encourage the participation of the amateur bird banding community to contribute to such projects.


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