Characterization of a mobile atmospheric simulation chamber for laboratory and field studies: DouAir

2021 ◽  
Author(s):  
Hichem Bouzidi ◽  
Ahmad Lahib ◽  
Nina Reijrink ◽  
Marius Duncianu ◽  
Emilie Perraudin ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Field Studies ◽  
Peroxy Radicals ◽  
Chemical Mechanisms ◽  
Analytical Instruments ◽  
Inorganic Species ◽  
Volatile Organic ◽  
Reactive Trace Gases ◽  
Simulation Chamber

<p>Atmospheric transformation processes have been extensively studied in the laboratory using simulation chambers with various designs and materials. These tools allow  kinetic experiments to be performed under well-controlled conditions whereby a selected volatile organic compound (VOC) is usually oxidized in synthetic air. While atmospheric chambers are invaluable to provide kinetic parameters that are needed in atmospheric chemical mechanisms, their limitation is that they do not test these chemical mechanisms under conditions that are representative of the complex atmosphere, i.e. containing multiple VOCs and inorganic species.</p><p>In the present work, a mobile rectangular atmospheric simulation chamber of ~ 9 m<sup>3</sup>, made of Teflon FEP foils, was built at IMT Lille Douai for laboratory and field studies. The whole setup – called DouAir – can be easily disassembled, transported and deployed in the field. This new tool allows trapping of real air masses on-site, providing observations on the fate of reactive trace gases, which when compared to box model simulations can provide a critical test of our understanding of atmospheric chemistry. The chamber allows both solar and artificial irradiation, the irradiance being monitored by spectroradiometry. The chamber is equipped with a large array of analytical instruments, including PTR-ToFMS and GC-MS for VOC measurements, CRM for total OH reactivity, PERCA for peroxy radicals, O<sub>3</sub> and NO<sub>x</sub> analyzers, and SMPS for aerosols. Here we describe the DouAir setup and will discuss characterization experiments carried out to validate the chamber. DouAir was tested for the first time during an intensive field campaign in the Landes forest (France) during summer 2018: CERVOLAND (Characterization of Emissions and Reactivity of Volatile Organic Compounds in the Landes Forest). Examples of experiments performed during CERVOLAND will be presented.</p>

scholarly journals OH and HO<sub>2</sub> radical chemistry during PROPHET 2008 and CABINEX 2009 – Part 1: Measurements and model comparison

2013 ◽  
Vol 13 (11) ◽  
pp. 5403-5423 ◽  
Author(s):  
S. M. Griffith ◽  
R. F. Hansen ◽  
S. Dusanter ◽  
P. S. Stevens ◽  
M. Alaghmand ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Model Comparison ◽  
Peroxy Radical ◽  
Box Model ◽  
Peroxy Radicals ◽  
Inorganic Species ◽  
Key Species ◽  
Volatile Organic

Abstract. Hydroxyl (OH) and hydroperoxyl (HO2) radicals are key species driving the oxidation of volatile organic compounds that can lead to the production of ozone and secondary organic aerosols. Previous measurements of these radicals in forest environments with high isoprene, low NOx conditions have shown serious discrepancies with modeled concentrations, bringing into question the current understanding of isoprene oxidation chemistry in these environments. During the summers of 2008 and 2009, OH and peroxy radical concentrations were measured using a laser-induced fluorescence instrument as part of the PROPHET (Program for Research on Oxidants: PHotochemistry, Emissions, and Transport) and CABINEX (Community Atmosphere-Biosphere INteractions EXperiment) campaigns at a forested site in northern Michigan. Supporting measurements of photolysis rates, volatile organic compounds, NOx (NO + NO2 and other inorganic species were used to constrain a zero-dimensional box model based on the Regional Atmospheric Chemistry Mechanism, modified to include the Mainz Isoprene Mechanism (RACM-MIM). The CABINEX model OH predictions were in good agreement with the measured OH concentrations, with an observed-to-modeled ratio near one (0.70 ± 0.31) for isoprene mixing ratios between 1–2 ppb on average. The measured peroxy radical concentrations, reflecting the sum of HO2 and isoprene-based peroxy radicals, were generally lower than predicted by the box model in both years.

scholarly journals OH and HO<sub>2</sub> radical chemistry during PROPHET 2008 and CABINEX 2009 – Part 1: Measurements and model comparison

2012 ◽  
Vol 12 (12) ◽  
pp. 33165-33218
Author(s):  
S. M. Griffith ◽  
R. F. Hansen ◽  
S. Dusanter ◽  
P. S. Stevens ◽  
M. Alaghmand ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Model Comparison ◽  
Peroxy Radical ◽  
Box Model ◽  
Peroxy Radicals ◽  
Inorganic Species ◽  
Key Species ◽  
Volatile Organic

Abstract. Hydroxyl (OH) and hydroperoxyl (HO2) radicals are key species driving the oxidation of volatile organic compounds that can lead to the production of ozone and secondary organic aerosols. Previous measurements of these radicals in forest environments with high isoprene, low NOx conditions have shown serious discrepancies with modeled concentrations, bringing into question the current understanding of isoprene oxidation chemistry in these environments. During the summers of 2008 and 2009, OH and peroxy radical concentrations were measured using a laser-induced fluorescence instrument as part of the PROPHET (Program for Research on Oxidants: PHotochemistry, Emissions, and Transport) and CABINEX (Community Atmosphere-Biosphere INteractions EXperiment) campaigns at a forested site in northern Michigan. Supporting measurements of photolysis rates, volatile organic compounds, NOx (NO + NO2) and other inorganic species were used to constrain a zero-dimensional box model based on the Regional Atmospheric Chemistry Mechanism, modified to include the Mainz Isoprene Mechanism (RACM-MIM). The CABINEX model OH predictions were in good agreement with the measured OH concentrations, with an observed-to-modeled ratio near one (0.70 ± 0.31) for isoprene mixing ratios between 1–2 ppb on average. The measured peroxy radical concentrations, reflecting the sum of HO2 and isoprene-based peroxy radicals, were generally lower than predicted by the box model in both years.

Unexpected Fast Monoterpene Oxidation In Eastern China

2021 ◽  
Author(s):  
Haichao Wang
Keyword(s):  
Eastern China ◽  
Field Measurements ◽  
Ozone Production ◽  
Nitrate Radical ◽  
Peroxy Radicals ◽  
Ozone Pollution ◽  
Volatile Organic ◽  
Secondary Aerosols ◽  
Photochemical Ozone

&lt;p&gt;Monoterpene plays an important role in the formation of secondary aerosols and ozone in the troposphere. However, the field characterization of monoterpene chemistry in ozone pollution is still very sparse. Here we report fast daytime oxidation of monoterpene by hydroxyl radical, nitrate radical and ozone based on field measurements in Eastern China. We find fast monoterpene oxidation produces peroxy radicals efficiently and enhances the photochemical ozone production largely with an additional 8.6 ppb of ozone production per day on average (14%), whose effect was even more important than that of isoprene chemistry in the analyzed dataset. We propose that the reduction of anthropogenic volatile organic compounds should be much more stringent in the presence of high monoterpenes to alleviating ozone pollution.&lt;/p&gt;

scholarly journals Characterization of ozone production in San Antonio, Texas, using measurements of total peroxy radicals

2019 ◽  
Vol 19 (5) ◽  
pp. 2845-2860 ◽  
Author(s):  
Daniel C. Anderson ◽  
Jessica Pavelec ◽  
Conner Daube ◽  
Scott C. Herndon ◽  
Walter B. Knighton ◽  
...  
Keyword(s):  
San Antonio ◽  
Peroxy Radical ◽  
Ozone Production ◽  
Peroxy Radicals ◽  
Entire Region ◽  
Volatile Organic ◽  
In Situ Observations ◽  
Study Sites

Abstract. Observations of total peroxy radical concentrations ([XO2] ≡ [RO2] + [HO2]) made by the Ethane CHemical AMPlifier (ECHAMP) and concomitant observations of additional trace gases made on board the Aerodyne Mobile Laboratory (AML) during May 2017 were used to characterize ozone production at three sites in the San Antonio, Texas, region. Median daytime [O3] was 48 ppbv at the site downwind of central San Antonio. Higher concentrations of NO and XO2 at the downwind site also led to median daytime ozone production rates (P(O3)) of 4.2 ppbv h−1, a factor of 2 higher than at the two upwind sites. The 95th percentile of P(O3) at the upwind site was 15.1 ppbv h−1, significantly lower than values observed in Houston. In situ observations, as well as satellite retrievals of HCHO and NO2, suggest that the region was predominantly NOx-limited. Only approximately 20 % of observations were in the VOC-limited regime, predominantly before 11:00 EST, when ozone production was low. Biogenic volatile organic compounds (VOCs) comprised 55 % of total OH reactivity at the downwind site, with alkanes and non-biogenic alkenes responsible for less than 10 % of total OH reactivity in the afternoon, when ozone production was highest. To control ozone formation rates at the three study sites effectively, policy efforts should be directed at reducing NOx emissions. Observations in the urban center of San Antonio are needed to determine whether this policy is true for the entire region.

scholarly journals The community atmospheric chemistry box model CAABA/MECCA-4.0

2019 ◽  
Vol 12 (4) ◽  
pp. 1365-1385 ◽  
Author(s):  
Rolf Sander ◽  
Andreas Baumgaertner ◽  
David Cabrera-Perez ◽  
Franziska Frank ◽  
Sergey Gromov ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Box Model ◽  
Chemical Mechanism ◽  
Chemical Mechanisms ◽  
Community Model ◽  
Volatile Organic ◽  
Master Chemical Mechanism ◽  
New Feature ◽  
User Friendly ◽  
Skeletal Mechanism

Abstract. We present version 4.0 of the atmospheric chemistry box model CAABA/MECCA that now includes a number of new features: (i) skeletal mechanism reduction, (ii) the Mainz Organic Mechanism (MOM) chemical mechanism for volatile organic compounds, (iii) an option to include reactions from the Master Chemical Mechanism (MCM) and other chemical mechanisms, (iv) updated isotope tagging, and (v) improved and new photolysis modules (JVAL, RADJIMT, DISSOC). Further, when MECCA is connected to a global model, the new feature of coexisting multiple chemistry mechanisms (PolyMECCA/CHEMGLUE) can be used. Additional changes have been implemented to make the code more user-friendly and to facilitate the analysis of the model results. Like earlier versions, CAABA/MECCA-4.0 is a community model published under the GNU General Public License.

Emission of volatile organic compounds from petunia flowers is facilitated by an ABC transporter

Science ◽  
2017 ◽  
Vol 356 (6345) ◽  
pp. 1386-1388 ◽  
Author(s):  
Funmilayo Adebesin ◽  
Joshua R. Widhalm ◽  
Benoît Boachon ◽  
François Lefèvre ◽  
Baptiste Pierman ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Rna Interference ◽  
Abc Transporter ◽  
Atmospheric Chemistry ◽  
Petunia Hybrida ◽  
Direct Proof ◽  
Plant Volatile ◽  
Volatile Organic ◽  
Default Assumption

Plants synthesize a diversity of volatile molecules that are important for reproduction and defense, serve as practical products for humans, and influence atmospheric chemistry and climate. Despite progress in deciphering plant volatile biosynthesis, their release from the cell has been poorly understood. The default assumption has been that volatiles passively diffuse out of cells. By characterization of aPetunia hybridaadenosine triphosphate–binding cassette (ABC) transporter, PhABCG1, we demonstrate that passage of volatiles across the plasma membrane relies on active transport.PhABCG1down-regulation by RNA interference results in decreased emission of volatiles, which accumulate to toxic levels in the plasma membrane. This study provides direct proof of a biologically mediated mechanism of volatile emission.

scholarly journals A new plant chamber facility, PLUS, coupled to the atmosphere simulation chamber SAPHIR

2016 ◽  
Vol 9 (3) ◽  
pp. 1247-1259 ◽  
Author(s):  
T. Hohaus ◽  
U. Kuhn ◽  
S. Andres ◽  
M. Kaminski ◽  
F. Rohrer ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Exchange ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Quercus Ilex ◽  
Light Emitting Diode ◽  
Volatile Organic ◽  
The Impact ◽  
Atmosphere Simulation Chamber ◽  
Simulation Chamber

Abstract. A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been built and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow-through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees is mixed with synthetic air and transferred to the SAPHIR chamber, where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOCs) can be studied in detail. In PLUS all important environmental parameters (e.g., temperature, photosynthetically active radiation (PAR), soil relative humidity (RH)) are well controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leaves of the plants is constructed such that gases are exposed to only fluorinated ethylene propylene (FEP) Teflon film and other Teflon surfaces to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 light-emitting diode (LED) panels, which have an emission strength up to 800 µmol m−2 s−1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOCs) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light- and temperature- dependent BVOC emissions are studied using six Quercus ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental setup and the utility of the newly added plant chamber.

scholarly journals Characterization of Ozone Production in San Antonio, Texas Using Observations of Total Peroxy Radicals

2018 ◽  
Author(s):  
Daniel C. Anderson ◽  
Jessica Pavelec ◽  
Conner Daube ◽  
Scott C. Herndon ◽  
W. Berk Knighton ◽  
...  
Keyword(s):  
San Antonio ◽  
Ozone Production ◽  
Peroxy Radicals ◽  
Urban Center ◽  
Entire Region ◽  
Volatile Organic ◽  
In Situ Observations ◽  
Study Sites

Abstract. Observations of total peroxy radicals (XO2 = RO2 + HO2) made by the Ethane CHemical AMPlifier (ECHAMP) and concomitant observations of additional trace gases made onboard the Aerodyne Mobile Laboratory (AML) during May 2017 were used to characterize ozone production at three sites in the San Antonio, Texas region. Median daytime [O3] was 48 ppbv at the site downwind of central San Antonio. Higher concentrations of NO and XO2 at the downwind site also led to median daytime ozone production rates (P(O3)) of 4.2 ppbv hr−1, a factor of two higher than at the two upwind sites. The 95th percentile of P(O3) at the upwind site was 15.1 ppbv hr−1, significantly lower than values observed in Houston. In situ observations, as well as satellite retrievals of HCHO and NO3, suggest that the region is NOx limited for times after approximately 09:00 local time, before which ozone production is VOC-limited. Biogenic volatile organic compounds (VOC) comprised 55 % of total OH reactivity at the downwind site, with alkanes and non-biogenic alkenes responsible for less than 10 % of total OH reactivity in the afternoon, when ozone production was highest. To control ozone formation rates at the three study sites effectively, policy efforts should be directed at reducing NOx emissions. Observations in the urban center of San Antonio are needed to determine whether this policy is true for the entire region.

scholarly journals A new plant chamber facility PLUS coupled to the atmospheric simulation chamber SAPHIR

2015 ◽  
Vol 8 (11) ◽  
pp. 11779-11816
Author(s):  
T. Hohaus ◽  
U. Kuhn ◽  
S. Andres ◽  
M. Kaminski ◽  
F. Rohrer ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Exchange ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Quercus Ilex ◽  
Reaction Chamber ◽  
Volatile Organic ◽  
Controlled Flow ◽  
The Impact ◽  
Simulation Chamber

Abstract. A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been build and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees are mixed with synthetic air and are transferred to the SAPHIR chamber where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOC) can be studied in detail. In PLUS all important enviromental parameters (e.g. temperature, PAR, soil RH etc.) are well-controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leafes of the plants is constructed such that gases are exposed to FEP Teflon film and other Teflon surfaces only to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 LED panels which have an emission strength up to 800 μmol m−2 s−1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOC) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light and temperature dependent BVOC emissions are studied using six Quercus Ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus Ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental set up and the utility of the newly added plant chamber.

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