ISOPRENE EMISSION ESTIMATE IN REGION CONTAINING EUCALYPTUS FOREST AND ITS RELATIONSHIP WITH LOCAL TROPOSPHERIC OZONE: CASE STUDY

2014 ◽  
Vol 32 (2) ◽  
pp. 207
Author(s):  
Ana Paula Dos Santos Zepka ◽  
Kelly Ribeiro
Keyword(s):  
Atmospheric Chemistry ◽  
Tropospheric Ozone ◽  
Chemical Compounds ◽  
Biogenic Emissions ◽  
Mixing Ratios ◽  
Eucalyptus Forest ◽  
Emission Estimate ◽  
Time Required ◽  
Commercial Forest

ABSTRACT. In order to study the biogenic emissions of isoprene by a commercial eucalyptus forest and its relationship with the local tropospheric ozone, two intensivesurveys were conducted in Fibria Celulose e Papel company, Cac¸apava, Vale do Paraíba, São Paulo State, Brazil. The samples were analyzed for isoprene via thermaldesorption gas chromatography. Ozone was monitored using a UV Photometric O3 Analyzer, Model 49i. The highest mixing ratios of isoprene were detected at noonand ranged from the maximum of 8.3 ppbv on November 29, 2010 to 3.5 ppbv on June 30, 2011. On the evaluated days, it was observed that isoprene and ozone peakedwith about two hours delay; this is explained by the time required for the isoprene to react with other precursors and, in the presence of sunlight, to form ozone. Duringthe winter days when both temperature and photosynthetic active radiation are lower, the emission of isoprene was also 65% lower than in the summer. Based on themaximum ozone (27.9 ppbv) detected, the atmosphere in this region is considered clean according to Conselho Nacional do Meio Ambiente (CONAMA) stipulates amaximum of 81.5 ppbv of ozone for good air quality.Keywords: commercial forest, chemical compounds, atmospheric chemistry. RESUMO. Com o objetivo de estudar a emissão de isopreno biogênico por floresta comercial de eucalipto e sua relação com o ozônio troposférico local, foramrealizadas duas campanhas intensivas na companhia Fibria Celulose e Papel, em Caçapava, no Vale do Paraíba Paulista. As amostras coletadas de isopreno foramanalisadas por cromatografia gasosa via dessorção térmica. O ozônio foi monitorado pelo Analisador UV Photometric O3, Modelo 49i. Ao meio-dia foram detectadasas maiores razões de mistura de isopreno, variando do máximo de 8,3 ppbv em 29 de novembro de 2010 a 3,5 ppbv em 30 de junho de 2011. Nos dias avaliados,observou-se que o ozônio apresentou pico máximo atrasado em cerca de duas horas em relação ao máximo de isopreno, o que é justificável devido ao tempo necessário para que este gás reaja com outros precursores, e que na presença de luz solar levem à formação de ozônio. Durante os dias avaliados de inverno, com temperaturae radiação fotossinteticamente ativa menores, a emissão de isopreno foi 65% menor do que na semana estudada do verão. Baseado no máximo detectado de ozônio(27,9 ppbv), a atmosfera dessa região é considerada limpa de acordo com o Conselho Nacional do Meio Ambiente (CONAMA) que estipula o máximo de 81,5 ppbv de ozônio para um ar de boa qualidade.Palavras-chave: floresta comercial, compostos químicos, química atmosférica.

scholarly journals Large estragole fluxes from oil palms in Borneo

2010 ◽  
Vol 10 (1) ◽  
pp. 1517-1557 ◽  
Author(s):  
P. K. Misztal ◽  
S. M. Owen ◽  
A. B. Guenther ◽  
R. Rasmussen ◽  
C. Geron ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Oil Palm ◽  
Ponderosa Pine ◽  
Elaeis Guineensis ◽  
Ambient Air ◽  
Biogenic Emissions ◽  
Main Peak ◽  
Aerosol Formation ◽  
Mixing Ratios ◽  
Oil Palms

Abstract. During two field campaigns (OP3 and ACES), which ran in Borneo in 2008, we measured large emissions of estragole (methyl chavicol; IUPAC systematic name 1-allyl-4-methoxybenzene; CAS number 140-67-0) in ambient air above oil palm canopies (0.81 mg m−2 h−1 and 3.2 ppbv for mean midday fluxes and mixing ratios, respectively) and subsequently from flower enclosures. However, we did not detect this compound at a nearby rainforest. Estragole is a known attractant of the African oil palm weevil (Elaeidobius kamerunicus), which pollinates oil palms (Elaeis guineensis). There has been recent interest in the biogenic emissions of estragole but it is normally not included in atmospheric models of biogenic emissions and atmospheric chemistry despite its relatively high potential for secondary organic aerosol formation from photooxidation and high reactivity with OH radical. We report the first direct canopy-scale measurements of estragole fluxes from tropical oil palms by the virtual disjunct eddy covariance technique and compare them with previously reported data for estragole emissions from Ponderosa pine. Flowers, rather than leaves, appear to be the main source of estragole from oil palms; we derive a global estimate of estragole emissions from oil palm plantations of ~0.5 Tg y−1. The observed ecosystem mean fluxes (0.44 mg m−2 h−1) and mean ambient volume mixing ratios (3.0 ppbv) of estragole are the highest reported so far. The value for midday mixing ratios is not much different from the total average as, unlike other VOCs (e.g. isoprene), the main peak occurred in the evening rather than in the middle of the day. Despite this, we show that the estragole flux can be parameterised using a combination of a modified G06 algorithm for emission and a canopy resistance approach for deposition. However, the model underestimates the afternoon peak even though a similar approach works well for isoprene. Our measurements suggest that this biogenic compound may have an impact on regional atmospheric chemistry that previously has not been accounted for in models and could become more important in the future due to expansion of the areas of oil palm plantation.

scholarly journals Large estragole fluxes from oil palms in Borneo

2010 ◽  
Vol 10 (9) ◽  
pp. 4343-4358 ◽  
Author(s):  
P. K. Misztal ◽  
S. M. Owen ◽  
A. B. Guenther ◽  
R. Rasmussen ◽  
C. Geron ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Oil Palm ◽  
Ponderosa Pine ◽  
Elaeis Guineensis ◽  
Ambient Air ◽  
Biogenic Emissions ◽  
Main Peak ◽  
Aerosol Formation ◽  
Mixing Ratios ◽  
Oil Palms

Abstract. During two field campaigns (OP3 and ACES), which ran in Borneo in 2008, we measured large emissions of estragole (methyl chavicol; IUPAC systematic name 1-allyl-4-methoxybenzene; CAS number 140-67-0) in ambient air above oil palm canopies (0.81 mg m−2 h−1 and 3.2 ppbv for mean midday fluxes and mixing ratios respectively) and subsequently from flower enclosures. However, we did not detect this compound at a nearby rainforest. Estragole is a known attractant of the African oil palm weevil (Elaeidobius kamerunicus), which pollinates oil palms (Elaeis guineensis). There has been recent interest in the biogenic emissions of estragole but it is normally not included in atmospheric models of biogenic emissions and atmospheric chemistry despite its relatively high potential for secondary organic aerosol formation from photooxidation and high reactivity with OH radical. We report the first direct canopy-scale measurements of estragole fluxes from tropical oil palms by the virtual disjunct eddy covariance technique and compare them with previously reported data for estragole emissions from Ponderosa pine. Flowers, rather than leaves, appear to be the main source of estragole from oil palms; we derive a global estimate of estragole emissions from oil palm plantations of ~0.5 Tg y−1. The observed ecosystem mean fluxes (0.44 mg m−2 h−1) and mean ambient volume mixing ratios (3.0 ppbv) of estragole are the highest reported so far. The value for midday mixing ratios is not much different from the total average as, unlike other VOCs (e.g. isoprene), the main peak occurred in the evening rather than in the middle of the day. Despite this, we show that the estragole flux can be parameterised using a modified G06 algorithm for emission. However, the model underestimates the afternoon peak even though a similar approach works well for isoprene. Our measurements suggest that this biogenic compound may have an impact on regional atmospheric chemistry that previously has not been accounted for in models and could become more important in the future due to expansion of the areas of oil palm plantation.

scholarly journals Tropospheric ozone production and chemical regime analysis during the COVID-19 lockdown over Europe

2021 ◽  
Author(s):  
Clara M. Nussbaumer ◽  
Andrea Pozzer ◽  
Ivan Tadic ◽  
Lenard Röder ◽  
Florian Obersteiner ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Tropospheric Ozone ◽  
Ozone Production ◽  
Upper Troposphere ◽  
Mixing Ratios ◽  
Secondary Pollutants ◽  
Tropopause Region ◽  
Research Aircraft ◽  
Business As Usual ◽  
Atmospheric Trace Gas

Abstract. The COVID-19 (Coronavirus disease 2019) European lockdowns have lead to a significant reduction in the emissions of primary pollutants such as NO (nitric oxide) and NO2 (nitrogen dioxide). As most photochemical processes are related to nitrogen oxide (NOx ≡ NO + NO2) chemistry, this event has presented an exceptional opportunity to investigate its effects on air quality and secondary pollutants, such as tropospheric ozone (O3). In this study, we present the effects of the COVID-19 lockdown on atmospheric trace gas concentrations, net ozone production rates (NOPR) and the dominant chemical regime throughout the troposphere based on three different research aircraft campaigns across Europe. These are the UTOPIHAN campaigns in 2003 and 2004, the HOOVER campaigns in 2006 and 2007 and the BLUESKY campaign in 2020, the latter performed during the COVID-19 lockdown. We present in situ observations and simulation results from the ECHAM5/MESSy Atmospheric Chemistry model which allows for scenario calculations with business as usual emissions during the BLUESKY campaign, referred to as "no-lockdown scenario". We show that the COVID-19 lockdown reduced NO and NO2 mixing ratios in the upper troposphere by around 55 % compared to the no-lockdown scenario due to reduced air traffic. O3 production and loss terms reflected this reduction with a deceleration in O3 cycling due to reduced mixing ratios of NOx while NOPRs were largely unaffected. We also study the role of methyl peroxyradicals forming HCHO (αCH3O2) to show that the COVID-19 lockdown shifted the chemistry in the upper troposphere/tropopause region to a NOx limited regime during BLUESKY. In comparison, we find a VOC limited regime to be dominant during UTOPIHAN.

scholarly journals Global distribution and trends of tropospheric ozone: An observation-based review

Elem Sci Anth ◽  
2014 ◽  
Vol 2 ◽  
Author(s):  
O. R. Cooper ◽  
D. D. Parrish ◽  
J. Ziemke ◽  
N. V. Balashov ◽  
M. Cupeiro ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Tropospheric Ozone ◽  
Climate Models ◽  
Surface Ozone ◽  
Air Pollutant ◽  
Global Distribution ◽  
Anthropogenic Sources ◽  
Mixing Ratios ◽  
Ozone Trends ◽  
Ozone Precursor

Abstract Tropospheric ozone plays a major role in Earth’s atmospheric chemistry processes and also acts as an air pollutant and greenhouse gas. Due to its short lifetime, and dependence on sunlight and precursor emissions from natural and anthropogenic sources, tropospheric ozone’s abundance is highly variable in space and time on seasonal, interannual and decadal time-scales. Recent, and sometimes rapid, changes in observed ozone mixing ratios and ozone precursor emissions inspired us to produce this up-to-date overview of tropospheric ozone’s global distribution and trends. Much of the text is a synthesis of in situ and remotely sensed ozone observations reported in the peer-reviewed literature, but we also include some new and extended analyses using well-known and referenced datasets to draw connections between ozone trends and distributions in different regions of the world. In addition, we provide a brief evaluation of the accuracy of rural or remote surface ozone trends calculated by three state-of-the-science chemistry-climate models, the tools used by scientists to fill the gaps in our knowledge of global tropospheric ozone distribution and trends.

scholarly journals Evidence of tropospheric layering: interleaved stratospheric and planetary boundary layer intrusions

2007 ◽  
Vol 7 (1) ◽  
pp. 1119-1142 ◽  
Author(s):  
J. Brioude ◽  
J.-P. Cammas ◽  
R. M. Zbinden ◽  
V. Thouret
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Residence Time ◽  
Atmospheric Chemistry ◽  
Tropospheric Ozone ◽  
Particle Dispersion ◽  
Lagrangian Model ◽  
Residence Times ◽  
Free Troposphere

Abstract. We present a case study of interleaving in the free troposphere of 4 layers of non-tropospheric origin, with emphasis on their residence time in the troposphere. Two layers are stratospheric intrusions at 4.7 and 2.2 km altitude with residence times of about 2 and 6.5 days, respectively. The two other layers at 7 and 3 km altitude were extracted from the maritime planetary boundary layer by warm conveyor belts associated with two extratropical lows and have residence times of about 2 and 5.75 days, respectively. The event took place over Frankfurt (Germany) in February 2002 and was observed by a commercial airliner from the MOZAIC programme with measurements of ozone, carbon monoxide and water vapour. Origins and residence times in the troposphere of these layers are documented with a trajectory and particle dispersion model. The combination of forward and backward simulations of the Lagrangian model allows the period of time during which the residence time can be assessed to be longer, as shown by the capture of the stratospheric-origin signature of the lowest tropopause fold just about to be completely mixed above the planetary boundary layer. This case study is of interest for atmospheric chemistry because it emphasizes the importance of coherent airstreams that produce laminae in the free troposphere and that contribute to the average tropospheric ozone. The interleaving of these 4 layers also provides the conditions for a valuable case study for the validation of global chemistry transport models used to perform tropospheric ozone budgets.

scholarly journals Evaluating Life Cycle of Buildings Using an Integrated Approach Based on Quantitative-Qualitative and Simplified Best-Worst Methods (QQM-SBWM)

2021 ◽  
Vol 13 (8) ◽  
pp. 4487
Author(s):  
Maghsoud Amiri ◽  
Mohammad Hashemi-Tabatabaei ◽  
Mohammad Ghahremanloo ◽  
Mehdi Keshavarz-Ghorabaee ◽  
Edmundas Kazimieras Zavadskas ◽  
...  
Keyword(s):  
Life Cycle ◽  
Computer Software ◽  
Integrated Approach ◽  
Comfort Level ◽  
Combination Method ◽  
New Combination ◽  
Numerical Examples ◽  
Environmental Consequences ◽  
Time Required

Evaluating the life cycle of buildings is a valuable tool for assessing sustainability and analyzing environmental consequences throughout the construction operations of buildings. In this study, in order to determine the importance of building life cycle evaluation indicators, a new combination method was used based on a quantitative-qualitative method (QQM) and a simplified best-worst method (SBWM). The SBWM method was used because it simplifies BWM calculations and does not require solving complex mathematical models. Reducing the time required to perform calculations and eliminating the need for complicated computer software are among the advantages of the proposed method. The QQM method has also been used due to its ability to evaluate quantitative and qualitative criteria simultaneously. The feasibility and applicability of the SBWM were examined using three numerical examples and a case study, and the results were evaluated. The results of the case study showed that the criteria of the estimated cost, comfort level, and basic floor area were, in order, the most important criteria among the others. The results of the numerical examples and the case study showed that the proposed method had a lower total deviation (TD) compared to the basic BWM. Sensitivity analysis results also confirmed that the proposed approach has a high degree of robustness for ranking and weighting criteria.

scholarly journals A Model for Developing Existing Ports Considering Economic Impact and Network Connectivity

2021 ◽  
Vol 13 (7) ◽  
pp. 3705
Author(s):  
Veterina Nosadila Riaventin ◽  
Sofyan Dwi Cahyo ◽  
Ivan Kristianto Singgih
Keyword(s):  
Network Connectivity ◽  
Economic Consequences ◽  
Real Problem ◽  
Container Transportation ◽  
Container Ports ◽  
Investment Priority ◽  
Time Required ◽  
Transportation Flows ◽  
Port Clusters

This study discusses the problem of determining which container port should be developed within an existing network and when this should be carried out. A case study of Indonesia’s port network is presented, where several new ports are to be improved to ensure smooth interisland transportation flows of goods. The effects of the investment on economic consequences and increased network connectivity are assessed. When improving the ports, we consider that the available budget limits the investment. The network connectivity is evaluated by considering the number of reachable ports from the developed ports or transportation time required from other ports within the same port cluster. Based on our knowledge, our study is the first one that discusses the investment problem in multiple container ports under single management, as well as its effects regarding the increase in container flows. The problem is introduced and three mathematical models are proposed and used to solve a real problem. The results show that different models have different improved aspects of container transportation flows—e.g., a balanced improvement of the whole port network (Model 2) and appropriate investment priority for port clusters (Model 3).

scholarly journals Behavior of Offshore Pile in Calcareous Sand—Case Study

2021 ◽  
Vol 9 (8) ◽  
pp. 839
Author(s):  
Tarek N. Salem ◽  
Nadia M. Elkhawas ◽  
Ahmed M. Elnady
Keyword(s):  
Load Capacity ◽  
High Stress ◽  
Embedment Depth ◽  
Shear Stresses ◽  
Northern Coast ◽  
Compression Tests ◽  
Calcareous Sand ◽  
Element Analysis ◽  
Mixing Ratios

The erosion of limestone and calcarenite ridges that existed parallel to the Mediterranean shoreline forms the calcareous sand (CS) formation at the surface layer of Egypt's northern coast. The CS is often combined with broken shells which are considered geotechnically problematic due to their possible crushability and relatively high compressibility. In this research, CS samples collected from a site along the northern coast of Egypt are studied to better understand its behavior under normal and shear stresses. Reconstituted CS specimens with different ratios of broken shells (BS) are also investigated to study the effect of BS ratios on the soil mixture strength behavior. The strength is evaluated using laboratory direct-shear and one-dimensional compression tests (oedometer test). The CS specimens are not exposed to significant crushability even under relatively high-stress levels. In addition, a 3D finite element analysis (FEA) is presented in this paper to study the degradation offshore pile capacity in CS having different percentages of BS. The stress–strain results using oedometer tests are compared with a numerical model, and it gave identical matching for most cases. The effects of pile diameter and embedment depth parameters are then studied for the case study on the northern coast. Three different mixing ratios of CS and BS have been used, CS + 10% BS, CS + 30% BS, and CS + 50% BS, which resulted in a decrease of the ultimate vertical compression pile load capacity by 8.8%, 15%, and 16%, respectively.

scholarly journals Comparisons of observed and modeled OH and HO2concentrations during the ambient measurement period of the HOxComp field campaign

2012 ◽  
Vol 12 (5) ◽  
pp. 2567-2585 ◽  
Author(s):  
Y. Kanaya ◽  
A. Hofzumahaus ◽  
H.-P. Dorn ◽  
T. Brauers ◽  
H. Fuchs ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Chemical Mechanism ◽  
Ozone Production ◽  
High Yield ◽  
Base Case ◽  
Peroxy Radicals ◽  
Field Campaign ◽  
Mixing Ratios ◽  
Measurement Mode ◽  
Single Instrument

Abstract. A photochemical box model constrained by ancillary observations was used to simulate OH and HO2 concentrations for three days of ambient observations during the HOxComp field campaign held in Jülich, Germany in July 2005. Daytime OH levels observed by four instruments were fairly well reproduced to within 33% by a base model run (Regional Atmospheric Chemistry Mechanism with updated isoprene chemistry adapted from Master Chemical Mechanism ver. 3.1) with high R2 values (0.72–0.97) over a range of isoprene (0.3–2 ppb) and NO (0.1–10 ppb) mixing ratios. Daytime HO2(*) levels, reconstructed from the base model results taking into account the sensitivity toward speciated RO2 (organic peroxy) radicals, as recently reported from one of the participating instruments in the HO2 measurement mode, were 93% higher than the observations made by the single instrument. This also indicates an overprediction of the HO2 to OH recycling. Together with the good model-measurement agreement for OH, it implies a missing OH source in the model. Modeled OH and HO2(*) could only be matched to the observations by addition of a strong unknown loss process for HO2(*) that recycles OH at a high yield. Adding to the base model, instead, the recently proposed isomerization mechanism of isoprene peroxy radicals (Peeters and Müller, 2010) increased OH and HO2(*) by 28% and 13% on average. Although these were still only 4% higher than the OH observations made by one of the instruments, larger overestimations (42–70%) occurred with respect to the OH observations made by the other three instruments. The overestimation in OH could be diminished only when reactive alkanes (HC8) were solely introduced to the model to explain the missing fraction of observed OH reactivity. Moreover, the overprediction of HO2(*) became even larger than in the base case. These analyses imply that the rates of the isomerization are not readily supported by the ensemble of radical observations. One of the measurement days was characterized by low isoprene concentrations (∼0.5 ppb) and OH reactivity that was well explained by the observed species, especially before noon. For this selected period, as opposed to the general behavior, the model tended to underestimate HO2(*). We found that this tendency is associated with high NOx concentrations, suggesting that some HO2 production or regeneration processes under high NOx conditions were being overlooked; this might require revision of ozone production regimes.

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