scholarly journals Tropospheric carbonyl sulfide mass-balance based on direct measurements of sulfur isotopes

2020 ◽  
Author(s):  
Chen Davidson ◽  
Alon Amrani ◽  
Alon Angert
Keyword(s):  
Mass Balance ◽  
Sulfur Isotopes ◽  
Gross Primary Production ◽  
Carbonyl Sulfide ◽  
Relative Magnitude ◽  
Anthropogenic Source ◽  
Sources And Sinks ◽  
Relative Contribution ◽  
Direct Measurements ◽  
Isotopic Signal

Abstract Carbonyl sulfide (COS) is the major long-lived sulfur bearing gas in the atmosphere and a promising proxy for terrestrial gross primary production (GPP; CO2 uptake). However, large uncertainties in estimating the relative magnitude of the COS sources and sinks limit this approach. Isotopic measurements have been suggested as a novel tool to constrain COS sources, yet such measurements are currently scarce. Here we present, for the first time, a complete data-based tropospheric COS isotopic mass balance, which allows improved partition of the sources. We found an isotopic (δ34S±SE) value of 13.9±0.1‰ (versus V-CDT standard) for the troposphere, with an isotopic seasonal cycle driven by plant uptake. This seasonality agrees with a fractionation of -1.9±0.3‰ which we measured in plant-chamber experiments. Anthropogenic-influenced air samples indicated an anthropogenic COS isotopic signal of 8±1‰. Samples of seawater-equilibrated-air indicate that marine COS emissions have an isotopic signal of 13±0.4‰. Using our new data-based mass balance, we constrained the relative contribution of the two main tropospheric COS sources resulting in 26±11% for the anthropogenic source and 74±23% for the oceanic source. This constraint is important for a better understanding of the global COS budget and its improved use for GPP determination.

scholarly journals Tropospheric carbonyl sulfide mass balance based on direct measurements of sulfur isotopes

2021 ◽  
Vol 118 (6) ◽  
pp. e2020060118
Author(s):  
Chen Davidson ◽  
Alon Amrani ◽  
Alon Angert
Keyword(s):  
Mass Balance ◽  
Plant Uptake ◽  
Sulfur Isotopes ◽  
Gross Primary Production ◽  
Carbonyl Sulfide ◽  
Relative Magnitude ◽  
Anthropogenic Source ◽  
Sources And Sinks ◽  
Relative Contribution ◽  
Marine Source

Robust estimates for the rates and trends in terrestrial gross primary production (GPP; plant CO2 uptake) are needed. Carbonyl sulfide (COS) is the major long-lived sulfur-bearing gas in the atmosphere and a promising proxy for GPP. Large uncertainties in estimating the relative magnitude of the COS sources and sinks limit this approach. Sulfur isotope measurements (34S/32S; δ34S) have been suggested as a useful tool to constrain COS sources. Yet such measurements are currently scarce for the atmosphere and absent for the marine source and the plant sink, which are two main fluxes. Here we present sulfur isotopes measurements of marine and atmospheric COS, and of plant-uptake fractionation experiments. These measurements resulted in a complete data-based tropospheric COS isotopic mass balance, which allows improved partition of the sources. We found an isotopic (δ34S ± SE) value of 13.9 ± 0.1‰ for the troposphere, with an isotopic seasonal cycle driven by plant uptake. This seasonality agrees with a fractionation of −1.9 ± 0.3‰ which we measured in plant-chamber experiments. Air samples with strong anthropogenic influence indicated an anthropogenic COS isotopic value of 8 ± 1‰. Samples of seawater-equilibrated-air indicate that the marine COS source has an isotopic value of 14.7 ± 1‰. Using our data-based mass balance, we constrained the relative contribution of the two main tropospheric COS sources resulting in 40 ± 17% for the anthropogenic source and 60 ± 20% for the oceanic source. This constraint is important for a better understanding of the global COS budget and its improved use for GPP determination.

Identification and quantification of sources and sinks of carbonyl sulfide

2021 ◽  
Author(s):  
Alessandro Zanchetta ◽  
Linda M.J. Kooijmans ◽  
Steven van Heuven ◽  
Andrea Scifo ◽  
Bert Scheeren ◽  
...  
Keyword(s):  
Gross Primary Production ◽  
Carbonyl Sulfide ◽  
Terrestrial Ecosystems ◽  
Lagrangian Model ◽  
Atmospheric Measurements ◽  
Model Framework ◽  
Sources And Sinks ◽  
Quantum Cascade ◽  
Production Facilities

<p>Carbonyl sulfide (COS) is the most abundant reduced sulfur gas in the atmosphere and is used as a tracer for gross primary production (GPP) of terrestrial ecosystems and stomatal conductance of leaves. At present, its usefulness is limited by the uncertainties in the estimation of its sources and sinks. In this study, we aim to understand the COS budget using atmospheric COS enhancements at the Lutjewad tower (53°24’N, 6°21’E, 1m a.s.l.) and atmospheric measurements of COS in the province of Groningen using a mobile van. We infer the sources and sinks of COS using continuous in situ mole fraction profile measurements of COS at Lutjewad. We determined the nighttime COS fluxes to be -3.0 ± 2.6 pmol m<sup>-2</sup> s<sup>-1</sup> using the radon-tracer correlation approach. We observed enhancements of COS mole fractions on the order of 100 ppt (lasting a few days) to 1000 ppt (lasting a few hours) at three occasions. To quantify potentially unidentified COS sources, we have made additional measurements by collecting air flasks that were analyzed later in the laboratory and with a continuous quantum cascade laser spectrometer. We have identified multiple COS sources, such as biodigesters, sugar production facilities and silicon carbide production facilities. Furthermore, we simulate the Lutjewad COS mole fractions in a Lagrangian model framework to quantitatively understand the COS sources and sinks. These results are useful for improving our understanding of the sources and sinks of COS, contributing to the use of COS as a tracer for GPP.</p>

Inverse modelling of Carbonyl Sulfide (COS): towards nonlinear model and satellite data assimilation

2021 ◽  
Author(s):  
Jin Ma ◽  
Linda M.J Kooijmans ◽  
Ara Cho ◽  
Stephen A. Montzka ◽  
Norbert Glatthor ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Satellite Data ◽  
Transport Model ◽  
Gross Primary Production ◽  
Current Model ◽  
Carbonyl Sulfide ◽  
Linear Inversion ◽  
Sources And Sinks ◽  
First Order ◽  
The Tropics

<p>Atmospheric Carbonyl Sulfide (COS) is a useful tracer for assessing gross primary production (GPP). COS is also an important contributor to stratospheric sulfate aerosols (SSA) which cool the climate. However, the global budget of COS remains unresolved due to insufficient observations. We implemented a linear inversion framework within the TM5-4DVAR global chemistry transport model constrained by NOAA surface network to investigate the sources and sinks of COS (Ma et al., 2020). To close the gap between sources and sinks, we focused on inversions that optimize what is thought to be a “missing” source amounting to 432 GgS a<sup>-1</sup>. We found that a tropical missing source was likely, which could either be an indication of an underestimated ocean source, or overestimated biosphere uptake. Additionally, we found the biosphere uptake to be underestimated at higher latitudes of the Northern Hemisphere. Inversions were validated with HIPPO aircraft data, NOAA airborne profiles and satellite data (MIPAS, TES and ACE-FTS), indicating an underestimation of COS in troposphere. We further implemented a first-order dependency of COS biosphere flux on COS mole fractions in the atmosphere boundary layer, which renders the inversions nonlinear. As expected based on the known drawdown of COS by biosphere uptake, it is found that the dependence of the biosphere flux on COS mole fractions reduced the budget gap by 137 GgS a<sup>-1</sup>. We further optimized COS fluxes separately over ocean and land, accounting for the first-order dependency of biosphere uptake on COS mole fractions. These results suggest that the missing COS sources may originate from the ocean (207 GgS a<sup>-1</sup>), despite recent work in which the ocean is explicitly studied suggesting otherwise.  Understanding this apparent discrepancy will be an important topic to elucidate. In the future, we plan to take the advantage of available satellite data products to better constrain the COS flux budget in the tropics. COS products from the MIPAS and TES satellites are good candidates for data assimilation in the current model.</p>

scholarly journals Sulfur isotopes ratio of atmospheric carbonyl sulfide constrains its sources

2018 ◽  
Author(s):  
Alon Angert ◽  
Ward Said-Ahmad ◽  
Chen Davidson ◽  
Alon Amrani
Keyword(s):  
Sulfur Isotopes ◽  
Carbonyl Sulfide

Retrievals of Atmospheric Carbonyl Sulfide from IASI

2021 ◽  
Author(s):  
Michael P. Cartwright ◽  
Jeremy J. Harrison ◽  
David P. Moore
Keyword(s):  
Gross Primary Production ◽  
Carbonyl Sulfide ◽  
Optimal Estimation ◽  
Stratospheric Aerosol ◽  
Data Set ◽  
Spatial Coverage ◽  
Retrieval Scheme ◽  
The University ◽  
Fresh Insight

<p>Carbonyl sulfide (OCS) is the most abundant sulfur containing gas in the atmosphere and is an important source of stratospheric aerosol. Furthermore, it has been shown that OCS can be used as a proxy for photosynthesis, which is a powerful tool in quantifying global gross primary production. While considerable improvements have been made in our understanding of the location and magnitude of OCS fluxes over the past few decades, recent studies highlight the need for a new satellite dataset to help reduce the uncertainties in current estimations. The Infrared Atmospheric Sounding Interferometer (IASI) instruments on-board the MetOp satellites offer over 14 years of nadir viewing radiance measurements with excellent spatial coverage. Given that there are currently three IASI instruments in operation, there is the potential for a significantly larger OCS dataset than is currently available elsewhere. Retrievals of OCS from these IASI radiances have been made using an adapted version of the University of Leicester IASI Retrieval Scheme (ULIRS). OCS total column amounts are calculated from profiles retrieved on a 31-layer equidistant pressure grid, using an optimal estimation approach for microwindows in the range 2000 – 2100 cm<sup>-1</sup> wavenumbers. Sensitivity of the measurements peak in the mid-troposphere, between 5 – 10 km.</p><p>The outlook of this work is to produce a long-term OCS satellite observational data set that provides fresh insight to the spatial distribution and trend of atmospheric OCS. Here, we present subsets of data in the form of case studies for different geographic regions and time periods.</p>

scholarly journals A new model of the global biogeochemical cycle of carbonyl sulfide – Part 2: Use of ocs to constrain gross primary productivity of current vegetation models

2014 ◽  
Vol 14 (20) ◽  
pp. 27663-27729 ◽  
Author(s):  
T. Launois ◽  
P. Peylin ◽  
S. Belviso ◽  
B. Poulter
Keyword(s):  
Northern Hemisphere ◽  
Seasonal Variations ◽  
Gross Primary Production ◽  
Experimental Studies ◽  
Carbonyl Sulfide ◽  
Surface Fluxes ◽  
Atmospheric Measurements ◽  
Mixing Ratios ◽  
Co2 Diffusion ◽  
Vegetation Models

Abstract. Clear analogies between carbonyl sulfide (OCS) and carbon dioxide (CO2) diffusion pathways through leaves have been revealed by experimental studies with plant uptake playing an important role for the atmospheric budget of both species. Here we use atmospheric OCS to evaluate the gross primary production (GPP) of three dynamic global vegetation models (LPJ, NCAR-CLM4 and ORCHIDEE). Vegetation uptake of OCS is modeled as a linear function of GPP and LRU, the ratio of OCS to CO2 deposition velocities to plants. New parameterizations for the non-photosynthetic sinks (oxic soils, atmospheric oxidation) and biogenic sources (oceans and anoxic soils) of OCS are also provided. Despite new large oceanic emissions, global OCS budgets created with each vegetation model show exceeding sinks by several hundreds of Gg S yr−1. An inversion of the surface fluxes (optimization of a global scalar which accounts for flux uncertainties) led to balanced OCS global budgets, as atmospheric measurements suggest, mainly by drastic reduction (−30%) of soil and vegetation uptakes. The amplitude of variations in atmospheric OCS mixing ratios is mainly dictated by the vegetation sink over the Northern Hemisphere. This allows for bias recognition in the GPP representations of the three selected models. Main bias patterns are (i) the terrestrial GPP of ORCHIDEE at high Northern latitudes is currently over-estimated, (ii) the seasonal variations of the GPP are out of phase in the NCAR-CLM4 model, showing a maximum carbon uptake too early in spring in the northernmost ecosystems, (iii) the overall amplitude of the seasonal variations of GPP in NCAR-CLM4 is too small, and (iv) for the LPJ model, the GPP is slightly out of phase for northernmost ecosystems and the respiration fluxes might be too large in summer in the Northern Hemisphere.

scholarly journals Temporal and spatial variability of the stable isotopic composition of atmospheric molecular hydrogen: observations at six EUROHYDROS stations

2011 ◽  
Vol 11 (3) ◽  
pp. 10087-10120 ◽  
Author(s):  
A. M. Batenburg ◽  
S. Walter ◽  
G. Pieterse ◽  
I. Levin ◽  
M. Schmidt ◽  
...  
Keyword(s):  
Phase Shift ◽  
Isotopic Composition ◽  
Molecular Hydrogen ◽  
Sink Strength ◽  
Sources And Sinks ◽  
Ground Station ◽  
Relative Contribution ◽  
Temporal And Spatial Variability ◽  
Stable Isotopic ◽  
D Values

Abstract. Despite the potential of isotope measurements to improve our understanding of the global atmospheric molecular hydrogen (H2) cycle, few H2 isotope data have been published so far. Now, within the EUROpean network for atmospheric HYDRogen Observations and Studies project (EUROHYDROS), weekly to monthly air samples from six locations in a global sampling network have been analysed for hydrogen mixing ratio (m(H2)) and the stable hydrogen isotopic composition of H2 (δ(D,H2), hereafter referred to as δ(D)). The time series thus obtained now cover one to five years for all stations. This is the largest set of ground station observations of δ(D) so far. Annual average δ(D) values are higher at the Southern Hemisphere (SH) than at the Northern Hemisphere (NH) stations; the maximum is observed at Neumayer (Antarctica), and the minimum at the NH midlatitude or subtropical stations. The maximum seasonal differences in δ(D) range from ≈18‰ at Neumayer to ≈45‰ at Schauinsland (Southern Germany); in general, seasonal variability is largest at the NH stations. The timing of minima and maxima differs per station as well. In Alert (Arctic Canada), the variations in δ(D) and m(H2) can be approximated as simple harmonic functions with a ≈5-month phase shift. This out-of-phase seasonal behaviour of δ(D) and m(H2) can also be detected, but with a ≈6-month phase shift, at Mace Head and Cape Verde. However, no seasonal δ(D) cycle could be observed at Schauinsland, which likely reflects the larger influence of local sources and sinks at this continental station. At the two SH stations, no seasonal cycle could be detected in the δ(D) data. Assuming that the sink processes are the main drivers of the observed seasonality in m(H2) and δ(D) on the NH, the relative seasonal variations can be used to estimate the relative sink strength of the two major sinks, deposition to soils and atmospheric oxidation by the hydroxyl (OH) radical. For the NH coastal and marine stations this analysis shows that the relative contribution of soil uptake to the total sink processes increases with latitude.

Isotopic constraints on the tropospheric carbonyl sulfide budget

2021 ◽  
Author(s):  
Kazuki Kamezaki ◽  
Shohei Hattori ◽  
Naohiro Yoshida
Keyword(s):  
Transport Model ◽  
Gross Primary Production ◽  
Carbonyl Sulfide ◽  
Anthropogenic Sources ◽  
Ambient Atmosphere ◽  
Chemical Transport Model ◽  
Sampling System ◽  
Keeling Plot ◽  
The Western Pacific ◽  
Sulfur Containing

<p>Carbonyl sulfide (OCS), the most abundant sulfur-containing gas in the ambient atmosphere, possesses great potential for tracer of the carbon cycle. Sulfur isotopic composition (<sup>34</sup>S/<sup>32</sup>S ratio, δ<sup>34</sup>S) on OCS is a feasible tool to evaluate the OCS budget. We applied the sulfur isotope measurement for the tropospheric OCS cycle and distinguished OCS sources from oceanic and anthropogenic emissions.</p><p> </p><p>Here, we present a developed measurement system of δ<sup>34</sup>S of OCS and the result of latitudinal (north-south) observations of OCS within Japan using the method. The OCS sampling system was carried to three sampling sites in Japan: Miyakojima (24°8’N, 125°3’E), Yokohama (35°5’N, 139°5’E), and Otaru (43°1’N, 141°2’E). The observed δ<sup>34</sup>Sof OCS ranging from 9.7 to 14.5‰ reflects the tropospheric OCS cycle. Particularly in winter, latitudinal decreases in δ<sup>34</sup>Svalues were found to be correlated with increases in OCS concentrations, resulting in an intercept of (4.7 ± 0.8)‰ in the Keeling plot approach. This trend suggests the transport of anthropogenic OCS emissions from the Asian continent to the western Pacific by the Asian monsoon outflow.</p><p> </p><p>The estimated background δ<sup>34</sup>S of OCS in eastern Asia is consistent with the δ<sup>34</sup>S of OCS previously reported in Israel and the Canary Islands, suggesting that the background δ<sup>34</sup>S of OCS in the Northern Hemisphere ranges from 12.0 to 13.5‰. Our constructed sulfur isotopic mass balance of OCS revealed that anthropogenic sources, not merely oceanic sources, account for much of the missing source of atmospheric OCS. This sulfur isotopic constraint on atmospheric OCS is an important step together with isotopic characterizations and analysis using a chemical transport model, will enable detailed quantitative OCS budget and estimation of gross primary production.</p>

Determination of the volatilization of ammonia from surface-applied cattle slurry by the micrometeorological mass balance method

1987 ◽  
Vol 109 (1) ◽  
pp. 205-207 ◽  
Author(s):  
R. J. Stevens ◽  
H. J. Logan
Keyword(s):  
Mass Balance ◽  
Field Trials ◽  
Balance Method ◽  
Cattle Slurry ◽  
Ammonia Loss ◽  
Mass Balance Method ◽  
Direct Measurements ◽  
Balance Technique ◽  
Land Surfaces ◽  
Grass Growth

Agronomic experiments have shown that nitrogen applied in organic manures gives variable responses in grass growth (van Dijk & Sturm, 1983; Smith, Unwin & Williams, 1985). In a series of field trials in southern England, the average apparent recovery in herbage of the nitrogen from cow slurry was only 13% (Unwin, Pain & Whinham, 1986). The volatilization of ammonia from spread slurry is one possible mechanism for the nitrogen inefficiency (Freney, Simpson & Denmead, 1983; Ryden, 1984). Direct measurements of ammonia loss from land surfaces can be made by micrometeorological methods (Denmead, 1983) and, using the micrometeorological mass balance technique, high rates of ammonia loss were recorded after the land spreading of liquid dairy cattle manure in Canada (Beauchamp, Kidd & Thurtell, 1982). The micrometeorological mass balance method has been used in England to measure ammonia loss from a grazed sward (Ryden & McNeill, 1984). This paper presents the results of an experiment where the same method was used to measure the ammonia loss after land-spreading cattle slurry in Northern Ireland.

Relative magnitude of tonic and phasic synaptic excitation of medullary inspiratory neurons in dogs

2000 ◽  
Vol 279 (2) ◽  
pp. R639-R649 ◽  
Author(s):  
M. Krolo ◽  
E. A. Stuth ◽  
M. Tonkovic-Capin ◽  
F. A. Hopp ◽  
D. R. McCrimmon ◽  
...  
Keyword(s):  
Nmda Receptors ◽  
Late Onset ◽  
Relative Magnitude ◽  
Cholinergic Receptors ◽  
Aminobutyric Acid ◽  
Tonic Activity ◽  
Synaptic Excitation ◽  
Relative Contribution ◽  
Discharge Patterns ◽  
Excitatory Drive

The relative contribution of phasic and tonic excitatory synaptic drives to the augmenting discharge patterns of inspiratory (I) neurons within the ventral respiratory group (VRG) was studied in anesthetized, ventilated, paralyzed, and vagotomized dogs. Multibarrel micropipettes were used to record simultaneously single-unit neuronal activity and pressure microejected antagonists of GABAergic, glycinergic, N-methyl-d-aspartate (NMDA) and non-NMDA glutamatergic, and cholinergic receptors. The discharge patterns were quantified via cycle-trigger histograms. The findings suggest that two-thirds of the excitatory drive to caudal VRG I neurons is tonic and mediated by NMDA receptors and the other third is ramp-like phasic and mediated by non-NMDA receptors. Cholinergic receptors do not appear to be involved. The silent expiratory phase is produced by phasic inhibition of the tonic activity, and ≈80% of this inhibition is mediated by γ-aminobutyric acid receptors (GABAA) and ≈20% by glycine receptors. Phasic I inhibition by the I decrementing neurons does not appear to contribute to the predominantly step-ramp patterns of these I neurons. However, this decrementing inhibition may be very prominent in controlling the rate of augmentation in late-onset I neurons and those with ramp patterns lacking the step component.

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