scholarly journals The formaldehyde budget as seen by a global-scale multi-constraint and multi-species inversion system

2012 ◽  
Vol 12 (3) ◽  
pp. 6909-6955
Author(s):  
A. Fortems-Cheiney ◽  
F. Chevallier ◽  
I. Pison ◽  
P. Bousquet ◽  
M. Saunois ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Organic Compounds ◽  
Global Scale ◽  
Surface Fluxes ◽  
Atmospheric Methane ◽  
Mixing Ratios ◽  
Volatile Organic ◽  
Satellite Retrievals ◽  
Surface Measurements ◽  
First Time

Abstract. For the first time, carbon monoxide (CO) and formaldehyde (HCHO) satellite retrievals have been used together with methane (CH4) and methyl choloroform (CH3CCl3 or MCF) surface measurements in a complex inversion system. The CO and HCHO are, respectively from MOPITT and OMI instruments. The multi-species and multi-satellite dataset inversion is done for the 2005–2008 period. The robustness of our results is evaluated by comparing our posterior-modeled concentrations with several sets of independent measurements of atmospheric mixing ratios. The inversion results lead to significant changes from the prior to the posterior, in terms of magnitude and seasonality of the CO and CH4 surface fluxes and of the 3-D HCHO production by non-methane volatile organic compounds (NMVOCs). The latter is significantly decreased, indicating an overestimation of the biogenic NMVOCs emissions, such as isoprene, in the GEIA inventory. CO and CH4 surface emissions are increased by the inversion, from 1037 to 1409 Tg CO and from 489 to 528 TgCH4 on average for the 2005–2008 period. CH4 emissions present significant interannual variability and a joint CO–CH4 fluxes analysis reveals that tropical biomass burning probably played a role in the recent increase of atmospheric methane.

scholarly journals The formaldehyde budget as seen by a global-scale multi-constraint and multi-species inversion system

2012 ◽  
Vol 12 (15) ◽  
pp. 6699-6721 ◽  
Author(s):  
A. Fortems-Cheiney ◽  
F. Chevallier ◽  
I. Pison ◽  
P. Bousquet ◽  
M. Saunois ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Organic Compounds ◽  
Global Scale ◽  
Surface Fluxes ◽  
Atmospheric Methane ◽  
Mixing Ratios ◽  
Volatile Organic ◽  
Satellite Retrievals ◽  
Surface Measurements ◽  
First Time

Abstract. For the first time, carbon monoxide (CO) and formaldehyde (HCHO) satellite retrievals are used together with methane (CH4) and methyl choloroform (CH3CCl3 or MCF) surface measurements in an advanced inversion system. The CO and HCHO are respectively from the MOPITT and OMI instruments. The multi-species and multi-satellite dataset inversion is done for the 2005–2010 period. The robustness of our results is evaluated by comparing our posterior-modeled concentrations with several sets of independent measurements of atmospheric mixing ratios. The inversion leads to significant changes from the prior to the posterior, in terms of magnitude and seasonality of the CO and CH4 surface fluxes and of the HCHO production by non-methane volatile organic compounds (NMVOC). The latter is significantly decreased, indicating an overestimation of the biogenic NMVOC emissions, such as isoprene, in the GEIA inventory. CO and CH4 surface emissions are increased by the inversion, from 1037 to 1394 TgCO and from 489 to 529 TgCH4 on average for the 2005–2010 period. CH4 emissions present significant interannual variability and a joint CO-CH4 fluxes analysis reveals that tropical biomass burning probably played a role in the recent increase of atmospheric methane.

scholarly journals Mapping Asian anthropogenic emissions of non-methane volatile organic compounds to multiple chemical mechanisms

2013 ◽  
Vol 13 (12) ◽  
pp. 32649-32701 ◽  
Author(s):  
M. Li ◽  
Q. Zhang ◽  
D. G. Streets ◽  
K. B. He ◽  
Y. F. Cheng ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Individual Species ◽  
Chemical Mechanisms ◽  
Mixing Ratios ◽  
Wide Range ◽  
Oxygenated Volatile Organic Compounds ◽  
Volatile Organic ◽  
Species Mapping ◽  
Multiple Chemical

Abstract. An accurate speciation mapping of non-methane volatile organic compounds (NMVOC) emissions has an important impact on the performance of chemical transport models (CTMs) in simulating ozone mixing ratios and secondary organic aerosols. In this work, we developed an improved speciation framework to generate model-ready anthropogenic Asian NMVOC emissions for various gas-phase chemical mechanisms commonly used in CTMs by using an explicit assignment approach and updated NMVOC profiles, based on the total NMVOC emissions in the INTEX-B Asian inventory for the year 2006. NMVOC profiles were selected and aggregated from a wide range of new measurements and the SPECIATE database. To reduce potential uncertainty from individual measurements, composite profiles were developed by grouping and averaging source profiles from the same category. The fractions of oxygenated volatile organic compounds (OVOC) were corrected during the compositing process for those profiles which used improper sampling and analyzing methods. Emissions of individual species were then lumped into species in different chemical mechanisms used in CTMs by applying mechanism-dependent species mapping tables, which overcomes the weakness of inaccurate mapping in previous studies. Gridded emissions for eight chemical mechanisms are developed at 30 min × 30 min resolution using various spatial proxies and are provided through the website: http://mic.greenresource.cn/intex-b2006. Emission estimates for individual NMVOC species differ between one and three orders of magnitude for some species when different sets of profiles are used, indicating that source profile is the most important source of uncertainties of individual species emissions. However, those differences are diminished in lumped species as a result of the lumping in the chemical mechanisms.

A rationally designed vapoluminescent compound with adsorptive channels and responsive luminophores for volatile organic compounds (VOCs)

2019 ◽  
Vol 48 (4) ◽  
pp. 1179-1183 ◽  
Author(s):  
Mingxue Yang ◽  
Xiao-Ning Li ◽  
Ji-Hui Jia ◽  
Xu-Lin Chen ◽  
Can-Zhong Lu
Keyword(s):  
Volatile Organic Compounds ◽  
Solvent Effect ◽  
Organic Compounds ◽  
Organic Molecules ◽  
Volatile Organic ◽  
First Time

We designed a sensor compound which for the first time combines the solvent effect of ICT organic molecules with large channels adsorbing VOCs.

scholarly journals Underway seawater and atmospheric measurements of volatile organic compounds in the Southern Ocean

2020 ◽  
Vol 17 (9) ◽  
pp. 2593-2619 ◽  
Author(s):  
Charel Wohl ◽  
Ian Brown ◽  
Vassilis Kitidis ◽  
Anna E. Jones ◽  
William T. Sturges ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Southern Ocean ◽  
Organic Compounds ◽  
Dimethyl Sulfide ◽  
Ambient Air ◽  
Atmospheric Measurements ◽  
Mixing Ratios ◽  
Volatile Organic ◽  
Air Mixing ◽  
Net Flux

Abstract. Dimethyl sulfide and volatile organic compounds (VOCs) are important for atmospheric chemistry. The emissions of biogenically derived organic gases, including dimethyl sulfide and especially isoprene, are not well constrained in the Southern Ocean. Due to a paucity of measurements, the role of the ocean in the atmospheric budgets of atmospheric methanol, acetone, and acetaldehyde is even more poorly known. In order to quantify the air–sea fluxes of these gases, we measured their seawater concentrations and air mixing ratios in the Atlantic sector of the Southern Ocean, along a ∼ 11 000 km long transect at approximately 60∘ S in February–April 2019. Concentrations, oceanic saturations, and estimated fluxes of five simultaneously sampled gases (dimethyl sulfide, isoprene, methanol, acetone, and acetaldehyde) are presented here. Campaign mean (±1σ) surface water concentrations of dimethyl sulfide, isoprene, methanol, acetone, and acetaldehyde were 2.60 (±3.94), 0.0133 (±0.0063), 67 (±35), 5.5 (±2.5), and 2.6 (±2.7) nmol dm−3 respectively. In this dataset, seawater isoprene and methanol concentrations correlated positively. Furthermore, seawater acetone, methanol, and isoprene concentrations were found to correlate negatively with the fugacity of carbon dioxide, possibly due to a common biological origin. Campaign mean (±1σ) air mixing ratios of dimethyl sulfide, isoprene, methanol, acetone, and acetaldehyde were 0.17 (±0.09), 0.053 (±0.034), 0.17 (±0.08), 0.081 (±0.031), and 0.049 (±0.040) ppbv. We observed diel changes in averaged acetaldehyde concentrations in seawater and ambient air (and to a lesser degree also for acetone and isoprene), which suggest light-driven production. Campaign mean (±1σ) fluxes of 4.3 (±7.4) µmol m−2 d−1 DMS and 0.028 (±0.021) µmol m−2 d−1 isoprene are determined where a positive flux indicates from the ocean to the atmosphere. Methanol was largely undersaturated in the surface ocean with a mean (±1σ) net flux of −2.4 (±4.7) µmol m−2 d−1, but it also had a few occasional episodes of outgassing. This section of the Southern Ocean was found to be a source and a sink for acetone and acetaldehyde this time of the year, depending on location, resulting in a mean net flux of −0.55 (±1.14) µmol m−2 d−1 for acetone and −0.28 (±1.22) µmol m−2 d−1 for acetaldehyde. The data collected here will be important for constraining the air–sea exchange, cycling, and atmospheric impact of these gases, especially over the Southern Ocean.

scholarly journals Fast and selective detection of volatile organic compounds using a novel pseudo spin-ladder compound CaCu2O3

2020 ◽  
Vol 1 (7) ◽  
pp. 2368-2379
Author(s):  
N. Lavanya ◽  
G. Veerapandi ◽  
S. G. Leonardi ◽  
N. Donato ◽  
G. Neri ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Volatile Organic Compounds ◽  
Gas Sensor ◽  
Organic Compounds ◽  
Spin Ladder ◽  
Selective Detection ◽  
Volatile Organic ◽  
First Time

A novel pseudo spin-ladder CaCu2O3 compound (2-leg) based conductometric gas sensor has been proposed, for the first time, for the detection of volatile organic compounds (VOCs); (a) the proposed reaction mechanism in air, and (b) in the presence of acetone and ethanol.

scholarly journals An Endophytic Diaporthe apiculatum Produces Monoterpenes with Inhibitory Activity against Phytopathogenic Fungi

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 231
Author(s):  
Xiao-Yu Song ◽  
Huihua Wang ◽  
Fei Ren ◽  
Kaiying Wang ◽  
Guiming Dou ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Organic Compounds ◽  
Endophytic Fungi ◽  
Leucaena Leucocephala ◽  
Plant Pathogens ◽  
Phytopathogenic Fungi ◽  
Multigene Phylogeny ◽  
Volatile Organic ◽  
Petri Plate ◽  
First Time

Volatile organic compounds (VOCs) from endophytic fungi are becoming a potential antibiotic resource. The inhibitive effects of VOCs produced by an endophytic fungus in Leucaena leucocephala were investigated on plant pathogens in this study. Using standard morphological methods and multigene phylogeny, the fungus was identified as Diaporthe apiculatum strain FPYF 3052. Utilizing a two- compartment Petri plate bioassay method, the VOCs from this fungus showed bioactivity ranging from 23.8% to 66.7% inhibition on eight plant pathogens within 24 hours. The SPME-GC/MS technique identified fifteen volatile compounds with dominant terpenoids γ-terpinene (39.8%), α-terpinene (17.2%), and (-)-4-terpineol (8.4%) from the VOCs. Commercial α-terpinene, γ-terpinene, and (-)-4-terpineol demonstrated inhibition on the tested pathogens at concentrations from 0.2 to 1.0 µl/ml within 72 h in the bioassay system. The inhibition rates were from 28% to 100% percent using 1.0 µl/ml within 48 h. (-)-4-Terpineol was the most active of the terpenoids causing up to 100% inhibition. The data illustrate that these monoterpenes play an important role in the inhibitive bioactivity of the VOCs of D. apiculatum FPYF 3052. Most importantly, (-)-4-terpineol is now for the first time, reported to have capability of strong antifungal activity and could be developed as an antibiotic substance.

Variation of atmospheric volatile organic compounds over the Southern Indian Ocean (30 - 49°S)

2009 ◽  
Vol 6 (1) ◽  
pp. 70 ◽  
Author(s):  
Aurélie Colomb ◽  
Valérie Gros ◽  
Séverine Alvain ◽  
Roland Sarda-Esteve ◽  
Bernard Bonsang ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Indian Ocean ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Marine Boundary Layer ◽  
Global Scale ◽  
Climate Impacts ◽  
Southern Indian Ocean ◽  
Oceanic Fronts ◽  
Volatile Organic

Environmental context. Oceans represent 70% of the blue planet, and surprisingly, ocean emission in term of volatile organic compounds is poorly understood. The potential climate impacts on a global scale of various trace organic gases have been established, and the terrestrial inputs are well studied, but little is known about which of these can be emitted from oceanic sources. In the present study, atmospheric samples were taken over the Southern Indian Ocean, while crossing some oceanic fronts and different phytoplankton species. Such a study should aid in understanding oceanic emission, especially from phytoplankton, and will help modellers to determine concentrations of organic traces in the remote marine troposphere. Abstract. Considering its size and potential importance, the ocean is poorly characterised in terms of volatile organic compounds (VOC) that play important roles in global atmospheric chemistry. In order to better understand their potential sources and sinks over the Southern Indian Austral Ocean, shipborne measurements of selected species were made during the MANCHOT campaign during December 2004, on board the research vessel Marion Dufresne. Along the transect La Réunion to Kerguelen Island, air measurements of selected VOC (including dimethylsulfide (DMS) isoprene, carbonyls and organohalogens), carbon monoxide and ozone were performed, crossing subtropical, temperate and sub-Antarctic waters as well as pronounced subtropical and sub-Antarctic oceanic fronts. The remote marine boundary layer was characterised at latitudes 45–50°S. Oceanic fronts were associated with enhanced chlorophyll and biological activity in the seawater and elevated DMS and organohalogens in the atmosphere. These were compared with a satellite-derived phytoplankton distribution (PHYSAT). Diurnal variation for isoprene, terpenes, acetone and acetaldehyde was observed, analogously to recent results observed in mesocosm experiments.

scholarly journals Aircraft observations of water-soluble dicarboxylic acids in the aerosols over China

2016 ◽  
Author(s):  
Yan-Lin Zhang ◽  
Kimitaka Kawamura ◽  
Ping Qing Fu ◽  
Suresh K. R. Boreddy ◽  
Tomomi Watanabe ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Organic Compounds ◽  
Aqueous Phase ◽  
Dicarboxylic Acids ◽  
Liquid Water Content ◽  
Water Soluble ◽  
Aircraft Observations ◽  
Volatile Organic ◽  
Intercontinental Transport ◽  
Surface Measurements

Abstract. Vertical profiles of low molecular weight dicarboxylic acids, related organic compounds and SOA tracer compounds in particle phase have not yet been simultaneously explored in East Asia, although there is growing evidence that aqueous phase oxidation of volatile organic compounds may be responsible for the elevated organic aerosols (OA) in the free troposphere. Here, we found consistently good correlation of oxalic acid, the most abundant organics globally, with its precursors as well as biogenic-derived secondary OA (SOA) compounds in Chinese tropospheric aerosols by aircraft measurements. Anthropogenically derived dicarboxylic acids (i.e., C5 and C6 diacids) at high altitudes were 4–20 times higher than those from surface measurements and even occasionally dominant over oxalic acid at altitude higher than 2 km, which is in contrast to the predominance of oxalic acid previously reported globally including the tropospheric and surface aerosols. This indicates an enhancement of tropospheric SOA formation from anthropogenic precursors. Furthermore, oxalic acid-tosulfate ratio maximized at altitude of ~2 km, explaining aqueous-phase SOA production that was supported by good correlations with predicted liquid water content, organic carbon and biogenic SOA tracers. These results demonstrate that elevated oxalic acid and related SOA compounds from both the anthropogenic and biogenic sources may substantially contribute to tropospheric OA burden over polluted regions of China, implying aerosol-associated climate effects and intercontinental transport.

Sign in / Sign up

Export Citation Format

Share Document