Simple determination of trace gases in air by a paper tape method

AbstractA new extraction system has been constructed and tested which allows the extraction of gases from air bubbles in ice without melting it. An ice sample of up to 20 g is crushed in a sealed container by a milling cutter and the gas escaping from the opened bubbles is flushed with helium to a Porapak column where it is stored until its injection into the gas Chromatograph. To avoid any contamination with CH4produced by friction in the gear section, a helium-flushed rotary feed-through is used. CH4analyses on ice samples of about 10 g from the last 1000 years give precise and reproducible results. In the future, it is planned to measure also the CO2and N2O concentrations on the same sample.

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Determination of an effective trace gas mixing height by differential optical absorption spectroscopy (DOAS)

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-2-1663-2009 ◽

2009 ◽

Vol 2 (4) ◽

pp. 1663-1692 ◽

Cited By ~ 1

Author(s):

B. Zhou ◽

S. N. Yang ◽

S. S. Wang ◽

T. Wagner

Keyword(s):

Trace Gases ◽

Mixing Layer ◽

Correlation Coefficients ◽

Trace Gas ◽

Optical Absorption Spectroscopy ◽

Gas Mixing ◽

Mixing Height ◽

Free Atmosphere ◽

Layer Height

Abstract. A new method for the determination of the Mixing layer Height (MH) by the DOAS technique is proposed in this article. The MH can be retrieved by a combination of active DOAS and passive DOAS observations of atmospheric trace gases; here we focus on observations of NO2. Because our observations are sensitive to the vertical distribution of trace gases, we refer to the retrieved layer height as an ''effective trace gas mixing height'' (ETMH). By analyzing trace gas observations in Shanghai over one year (1017 hourly means in 93 days in 2007), the retrieved ETMH was found to range between 0.1 km and 2.8 km (average is 0.78 km); more than 90% of the measurements yield an ETMH between 0.2 km and 2.0 km. The seasonal and diurnal variation of the ETMH shows good agreement with mixing layer heights derived from meteorological observations. We investigated the relationship of the derived ETMH to temperature and wind speed and found correlation coefficients of 0.65 and 0.37, respectively. Also the wind direction has an impact on the measurement to some extent. Especially in cases when the air flow comes from highly polluted areas and the atmospheric lifetime of NO2 is long (e.g. in winter), the NO2 concentration at high altitudes over the measurement site can be enhanced, which leads to an overestimation of the ETMH. Enhanced NO2 concentrations in the free atmosphere and heterogeneity within the mixing layer can cause additional uncertainties. Our method could be easily extended to other species like e.g. SO2, HCHO or Glyoxal. Simultaneous studies of these molecules could yield valuable information on their respective atmospheric lifetimes.

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MICRU effective cloud fractions for S-5P/TROPOMI

10.5194/egusphere-egu2020-8380 ◽

2020 ◽

Author(s):

Holger Sihler ◽

Sreffen Beirle ◽

Christian Borger ◽

Thomas Wagner

Keyword(s):

Spatial Resolution ◽

Trace Gases ◽

Input Parameter ◽

Cloud Fraction ◽

Vertical Column ◽

Angle Scattering ◽

Vertical Column Density ◽

Reflectance Map ◽

Small Cloud

<pre class="western" lang="en-GB">We present results of effective cloud fractions retrieved from measurements of the TROPOspheric Monitoring Instrument (TROPOMI) using the Mainz Iterative Cloud Retrieval Utilities (MICRU) algorithm. Cloud fraction (CF) data is used to study the distribution of clouds in general. Furthermore, CF is a crucial input parameter for retrievals of tropospheric trace gases from satellite measurements in the UV/vis spectral region because CF errors may even dominate vertical column density (VCD) retrieval errors of tropospheric trace gases. The MICRU algorithm has been specifically developed to retrieve small cloud fractions (CF<20%) at high accuracy in order to improve retrievals of tropospheric trace gases. Here, MICRU is applied to TROPOMI data offering a more than 100 times higher spatial resolution compared to GOME-2 (Global Ozone Monitoring Experiment-2), on which it was previously applied. Hence, MICRU CF can be used as an alternative to the operational CF product. The most important feature of MICRU is the derivation of the minimum reflectance map from the measurements themselves. The algorithm builds on the assumption that the surface is dark compared to clouds, and it is therefore limited to regions not permanently covered by clouds, ice or snow. In particular, the MICRU algorithm applies four parameters to constrain interferences with surface BRDF effects like sun glitter and shadowing. Our approach features a lower threshold map parameterised by time, viewing zenith angle, scattering angle, and reflection angle. We demonstrate that MICRU, compared to the operational cloud fraction algorithms OCRA and FRESCO, interferences less with viewing angle, solar glitter, and shore lines and, hence, significantly improves the determination of cloud fractions. Furthermore, CF features made visible by the unprecedented spatial resolution of TROPOMI are discussed.</pre>

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Observations of the Martian atmosphere by NOMAD on ExoMars Trace Gas Orbiter

10.5194/egusphere-egu2020-8812 ◽

2020 ◽

Author(s):

Ann Carine Vandaele ◽

Arianna Piccialli ◽

Ian R. Thomas ◽

Frank Daerden ◽

Shohei Aoki ◽

...

Keyword(s):

Spectral Range ◽

Dust Storm ◽

Trace Gases ◽

Martian Atmosphere ◽

Trace Gas ◽

Ice Clouds ◽

Mars Atmosphere ◽

Solar Occultation ◽

Composition And Structure

The NOMAD (&#8220;Nadir and Occultation for MArs Discovery&#8221;) spectrometer suite on board the ExoMars Trace Gas Orbiter has been designed to investigate the composition of Mars' atmosphere, with a particular focus on trace gases, clouds and dust probing the ultraviolet and infrared regions covering large parts of the 0.2-4.3 &#181;m spectral range [1,2].Since its arrival at Mars in April 2018, NOMAD performed solar occultation, nadir and limb observations dedicated to the determination of the composition and structure of the atmosphere. Here we report on the different discoveries highlighted by the instrument: investigation of the 2018 Global dust storm and its impact on the water uplifting and escape, its impact on temperature increases within the atmosphere as inferred by GCM modeling and observations, the dust and ice clouds distribution during the event, ozone measurements, dayglow observations and in general advances in the analysis of the spectra recorded by the three channels of NOMAD.References[1] Vandaele, A.C., et al., 2015. Planet. Space Sci. 119, 233-249.[2] Vandaele et al., 2018. Space Sci. Rev., 214:80, doi.org/10.1007/s11214-11018-10517-11212.

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Determination of hydrogen sulfide in air. Assessment of impregnated paper tape methods

Analytical Chemistry ◽

10.1021/ac60339a001 ◽

1974 ◽

Vol 46 (3) ◽

pp. 410-415 ◽

Cited By ~ 30

Author(s):

D. F. S. Natusch ◽

J. R. Sewell ◽

R. L. Tanner

Keyword(s):

Hydrogen Sulfide ◽

Paper Tape

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Air Quality over China

Remote Sensing ◽

10.3390/rs13173542 ◽

2021 ◽

Vol 13 (17) ◽

pp. 3542

Author(s):

Gerrit de Leeuw ◽

Ronald van der A ◽

Jianhui Bai ◽

Yong Xue ◽

Costas Varotsos ◽

...

Keyword(s):

Air Pollution ◽

Air Quality ◽

Trace Gases ◽

Satellite Observations ◽

Air Pollution Control ◽

Trace Gas Emissions ◽

Temporal And Spatial Variability ◽

Quality Modeling ◽

Underlying Processes

The strong economic growth in China in recent decades, together with meteorological factors, has resulted in serious air pollution problems, in particular over large industrialized areas with high population density. To reduce the concentrations of pollutants, air pollution control policies have been successfully implemented, resulting in the gradual decrease of air pollution in China during the last decade, as evidenced from both satellite and ground-based measurements. The aims of the Dragon 4 project “Air quality over China” were the determination of trends in the concentrations of aerosols and trace gases, quantification of emissions using a top-down approach and gain a better understanding of the sources, transport and underlying processes contributing to air pollution. This was achieved through (a) satellite observations of trace gases and aerosols to study the temporal and spatial variability of air pollutants; (b) derivation of trace gas emissions from satellite observations to study sources of air pollution and improve air quality modeling; and (c) study effects of haze on air quality. In these studies, the satellite observations are complemented with ground-based observations and modeling.

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Strategies for measuring canonical tracer relationships in the stratosphere

Atmospheric Chemistry and Physics ◽

10.5194/acp-3-259-2003 ◽

2003 ◽

Vol 3 (1) ◽

pp. 259-266 ◽

Cited By ~ 1

Author(s):

O. Morgenstern ◽

J. A. Pyle

Keyword(s):

High Resolution ◽

Satellite Data ◽

Trace Gases ◽

Accurate Determination ◽

Mixing Processes ◽

Resolution Simulation

Abstract. A high-resolution simulation of stratospheric long-lived trace gases is subsampled in ways resembling various commonly used measurement platforms. The resulting measurements are analyzed with respect to whether they allow an accurate determination of stratospheric tracer relationships, as a prerequisite for a quantification of mixing processes from them. By varying the simulated locations, frequencies, and, in the case of satellite data, accuracies of the measurements we determine minimal requirements that the measurements need to satisfy in order to be suitable for a derivation of tracer relationships.

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The effect of desiccation on the emission of volatile bromocarbons from two common temperate macroalgae

Biogeosciences ◽

10.5194/bg-12-387-2015 ◽

2015 ◽

Vol 12 (2) ◽

pp. 387-398 ◽

Cited By ~ 7

Author(s):

E. C. Leedham Elvidge ◽

S.-M. Phang ◽

W. T. Sturges ◽

G. Malin

Keyword(s):

Photosynthetic Capacity ◽

Trace Gases ◽

Antioxidant Response ◽

Fucus Vesiculosus ◽

Physiological Processes ◽

Ulva Intestinalis ◽

Inorganic Iodine ◽

The Impact

Abstract. Exposure of intertidal macroalgae during low tide has been linked to the emission of a variety of atmospherically-important trace gases into the coastal atmosphere. In recent years, several studies have investigated the role of inorganic iodine and organoiodides as antioxidants and their emission during exposure to combat oxidative stress, yet the role of organic bromine species during desiccation is less well understood. In this study the emission of dibromomethane (CH2Br2) and bromoform (CHBr3) during exposure and desiccation of two common temperate macroalgae, Fucus vesiculosus and Ulva intestinalis, is reported. Determination of the impact exposure may have on algal physiological processes is difficult as intertidal species are adapted to desiccation and may undergo varying degrees of desiccation before their physiology is affected. For this reason we include comparisons between photosynthetic capacity (Fv/Fm) and halocarbon emissions during a desiccation time series. In addition, the role of rewetting with freshwater to simulate exposure to rain was also investigated. Our results show that an immediate flux of bromocarbons occurs upon exposure, followed by a decline in bromocarbon emissions. We suggest that this immediate bromocarbon pulse may be linked to volatilisation or emissions of existing bromocarbon stores from the algal surface rather than the production of bromocarbons as an antioxidant response.

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Fast Detection of Nitrite with a Test Paper Tape

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.538-541.2181 ◽

2012 ◽

Vol 538-541 ◽

pp. 2181-2183

Author(s):

Bao Shan He ◽

Fang Wei ◽

Na Gao ◽

Qi Yu Lu

Keyword(s):

Sulfanilic Acid ◽

Paper Tape ◽

Testing Time ◽

Dependent Manner ◽

Test Paper ◽

Concentration Dependent Manner ◽

Fast Detection ◽

System A ◽

Ethylenediamine Dihydrochloride

A test paper tape on the determination of nitrite in food was designed, which is based on the diazotization of nitrite with sulfanilic acid under weakly acidic conditions then coupled with N-(1-Naphthyl)-ethylenediamine dihydrochloride in forming the colour-producing response. Then the reaction membrane turned to purple-red. The deeper purple-red film was obtained in an increased nitrite concentration-dependent manner. Experimental results showed that nitrite concentrations were proportional to a values of the L a b color system. A favorable linearity was presented in the range of 25 to 5000 μg/mL. The correlation coefficient(r) was 0.984 and the whole testing time needed was about 1.5 min at room temperature.

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