Fourier-Transform Frequency Comb Cavity Mode Spectroscopy at Hz Level for Trace Gas Measurements

Spectra of the atmosphere have been measured in the near-UV and visible spectral range for the first time with a Fourier transform spectrometer using direct and zenith scattered sunlight. The observations were performed in the Arctic at 79°N, 12°E in 1994. Spectra were recorded in the wavelength range 310 to 1100 nm up to a resolution of about 0.0008 nm. The use of the FT spectrometer allowed the study of atmospheric trace gas concentrations in the whole spectral region between 500 and 31,000 cm−1 (0.3–20 μm) with one instrument by only changing the beamsplitters and choosing different detectors. At a spectral resolution of 1.2 nm, the atmospheric absorptions of O3 around 505 nm and NO2 at 448 nm were analyzed. Results are compared with observations performed in the infrared with the same instrument, with TOMS data and with ozone balloon data.

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Recent trace gas measurements with mid-IR Fourier transform spectrometers

10.1117/12.196682 ◽

1994 ◽

Author(s):

Herbert Fischer

Keyword(s):

Fourier Transform ◽

Trace Gas ◽

Gas Measurements

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Validation of the IASI operational CH4 and N2O products using ground-based Fourier Transform Spectrometer: preliminary results at the Izaña Observatory (28ºN, 17ºW)

Annals of Geophysics ◽

10.4401/ag-6326 ◽

2014 ◽

Author(s):

Omaira García ◽

Matthias Schneider ◽

Frank Hase ◽

Thomas Blumenstock ◽

Andreas Wiegele ◽

...

Keyword(s):

Fourier Transform ◽

Atmospheric Composition ◽

Trace Gas ◽

Fourier Transform Spectrometer ◽

Gas Products ◽

Gas Measurements ◽

Ch4 And N2o ◽

Atmospheric Trace Gas ◽

Level 2 ◽

Made In

Within the project VALIASI (VALidation of IASI level 2 products) the validation of the IASI operational atmospheric trace gas products (total column amounts of H2O, O3, CH4, N2O, CO2 and CO as well H2O and O3 profiles) will be carried out. Ground-based FTS (Fourier Transform Spectrometer) trace gas measurements made in the framework of NDACC (Network for the Detection of Atmospheric Composition Change) serve as the validation reference. In this work, we will present the validation methodology developed for this project and show the first intercomparison results obtained for the Izaña Atmospheric Observatory between 2008 and 2012. As example, we will focus on two of the most important greenhouse gases, CH4 and N2O.

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Soil gas probes for monitoring trace gas messengers of microbial activity

Scientific Reports ◽

10.1038/s41598-021-86930-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Joseph R. Roscioli ◽

Laura K. Meredith ◽

Joanne H. Shorter ◽

Juliana Gil-Loaiza ◽

Till H. M. Volkmann

Keyword(s):

Microbial Activity ◽

Soil Heterogeneity ◽

Soil Gas ◽

Microbial Processes ◽

Trace Gas ◽

Soil Microbiome ◽

Sampling System ◽

Site Specific ◽

Gas Measurements ◽

Subsurface Monitoring

AbstractSoil microbes vigorously produce and consume gases that reflect active soil biogeochemical processes. Soil gas measurements are therefore a powerful tool to monitor microbial activity. Yet, the majority of soil gases lack non-disruptive subsurface measurement methods at spatiotemporal scales relevant to microbial processes and soil structure. To address this need, we developed a soil gas sampling system that uses novel diffusive soil probes and sample transfer approaches for high-resolution sampling from discrete subsurface regions. Probe sampling requires transferring soil gas samples to above-ground gas analyzers where concentrations and isotopologues are measured. Obtaining representative soil gas samples has historically required balancing disruption to soil gas composition with measurement frequency and analyzer volume demand. These considerations have limited attempts to quantify trace gas spatial concentration gradients and heterogeneity at scales relevant to the soil microbiome. Here, we describe our new flexible diffusive probe sampling system integrated with a modified, reduced volume trace gas analyzer and demonstrate its application for subsurface monitoring of biogeochemical cycling of nitrous oxide (N2O) and its site-specific isotopologues, methane, carbon dioxide, and nitric oxide in controlled soil columns. The sampling system observed reproducible responses of soil gas concentrations to manipulations of soil nutrients and redox state, providing a new window into the microbial response to these key environmental forcings. Using site-specific N2O isotopologues as indicators of microbial processes, we constrain the dynamics of in situ microbial activity. Unlocking trace gas messengers of microbial activity will complement -omics approaches, challenge subsurface models, and improve understanding of soil heterogeneity to disentangle interactive processes in the subsurface biome.

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Level 2 processing for the imaging Fourier transform spectrometer GLORIA: derivation and validation of temperature and trace gas volume mixing ratios from calibrated dynamics mode spectra

Atmospheric Measurement Techniques ◽

10.5194/amt-8-2473-2015 ◽

2015 ◽

Vol 8 (6) ◽

pp. 2473-2489 ◽

Cited By ~ 19

Author(s):

J. Ungermann ◽

J. Blank ◽

M. Dick ◽

A. Ebersoldt ◽

F. Friedl-Vallon ◽

...

Keyword(s):

Fourier Transform ◽

Horizontal Resolution ◽

Trace Gas ◽

Radiative Transfer Model ◽

Transfer Model ◽

Ionization Mass ◽

Fourier Transform Spectrometer ◽

Upper Troposphere ◽

Mixing Ratios

Abstract. The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) is an airborne infrared limb imager combining a two-dimensional infrared detector with a Fourier transform spectrometer. It was operated aboard the new German Gulfstream G550 High Altitude LOng Range (HALO) research aircraft during the Transport And Composition in the upper Troposphere/lowermost Stratosphere (TACTS) and Earth System Model Validation (ESMVAL) campaigns in summer 2012. This paper describes the retrieval of temperature and trace gas (H2O, O3, HNO3) volume mixing ratios from GLORIA dynamics mode spectra that are spectrally sampled every 0.625 cm−1. A total of 26 integrated spectral windows are employed in a joint fit to retrieve seven targets using consecutively a fast and an accurate tabulated radiative transfer model. Typical diagnostic quantities are provided including effects of uncertainties in the calibration and horizontal resolution along the line of sight. Simultaneous in situ observations by the Basic Halo Measurement and Sensor System (BAHAMAS), the Fast In-situ Stratospheric Hygrometer (FISH), an ozone detector named Fairo, and the Atmospheric chemical Ionization Mass Spectrometer (AIMS) allow a validation of retrieved values for three flights in the upper troposphere/lowermost stratosphere region spanning polar and sub-tropical latitudes. A high correlation is achieved between the remote sensing and the in situ trace gas data, and discrepancies can to a large extent be attributed to differences in the probed air masses caused by different sampling characteristics of the instruments. This 1-D processing of GLORIA dynamics mode spectra provides the basis for future tomographic inversions from circular and linear flight paths to better understand selected dynamical processes of the upper troposphere and lowermost stratosphere.

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An evaluation of the performance of chemistry transport models by comparison with research aircraft observations. Part 1: Concepts and overall model performance

Atmospheric Chemistry and Physics ◽

10.5194/acp-3-1609-2003 ◽

2003 ◽

Vol 3 (5) ◽

pp. 1609-1631 ◽

Cited By ~ 35

Author(s):

D. Brunner ◽

J. Staehelin ◽

H. L. Rogers ◽

M. O. Köhler ◽

J. A. Pyle ◽

...

Keyword(s):

Quantitative Methods ◽

Climate Models ◽

Model Performance ◽

Average Concentration ◽

Convective Transport ◽

Trace Gas ◽

Atmospheric Conditions ◽

Time Step ◽

Research Aircraft ◽

Gas Measurements

Abstract. A rigorous evaluation of five global Chemistry-Transport and two Chemistry-Climate Models operated by several different groups in Europe, was performed. Comparisons were made of the models with trace gas observations from a number of research aircraft measurement campaigns during the four-year period 1995-1998. Whenever possible the models were run over the same four-year period and at each simulation time step the instantaneous tracer fields were interpolated to all coinciding observation points. This approach allows for a very close comparison with observations and fully accounts for the specific meteorological conditions during the measurement flights. This is important considering the often limited availability and representativity of such trace gas measurements. A new extensive database including all major research and commercial aircraft measurements between 1995 and 1998, as well as ozone soundings, was established specifically to support this type of direct comparison. Quantitative methods were applied to judge model performance including the calculation of average concentration biases and the visualization of correlations and RMS errors in the form of so-called Taylor diagrams. We present the general concepts applied, the structure and content of the database, and an overall analysis of model skills over four distinct regions. These regions were selected to represent various atmospheric conditions and to cover large geographical domains such that sufficient observations are available for comparison. The comparison of model results with the observations revealed specific problems for each individual model. This study suggests the further improvements needed and serves as a benchmark for re-evaluations of such improvements. In general all models show deficiencies with respect to both mean concentrations and vertical gradients of important trace gases. These include ozone, CO and NOx at the tropopause. Too strong two-way mixing across the tropopause is suggested to be the main reason for differences between simulated and observed CO and ozone values. The generally poor correlations between simulated and measured NOx values suggest that in particular the NOx input by lightning and the convective transport from the polluted boundary layer are still not well described by current parameterizations, which may lead to significant differences in the spatial and seasonal distribution of NOx in the models. Simulated OH concentrations, on the other hand, were found to be in surprisingly good agreement with measured values.

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The high Arctic in extreme winters: vortex, temperature, and MLS and ACE-FTS trace gas evolution

Atmospheric Chemistry and Physics ◽

10.5194/acp-8-505-2008 ◽

2008 ◽

Vol 8 (3) ◽

pp. 505-522 ◽

Cited By ~ 62

Author(s):

G. L. Manney ◽

W. H. Daffer ◽

K. B. Strawbridge ◽

K. A. Walker ◽

C. D. Boone ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Lower Stratosphere ◽

High Arctic ◽

Trace Gas ◽

Satellite Measurements ◽

Broadband Emission ◽

Gas Measurements ◽

Chemistry Experiment ◽

Very High ◽

Good Agreement

Abstract. The first three Arctic winters of the ACE mission represented two extremes of winter variability: Stratospheric sudden warmings (SSWs) in 2004 and 2006 were among the strongest, most prolonged on record; 2005 was a record cold winter. Canadian Arctic Atmospheric Chemistry Experiment (ACE) Validation Campaigns were conducted at Eureka (80° N, 86° W) during each of these winters. New satellite measurements from ACE-Fourier Transform Spectrometer (ACE-FTS), Sounding of the Atmosphere using Broadband Emission Radiometry (SABER), and Aura Microwave Limb Sounder (MLS), along with meteorological analyses and Eureka lidar temperatures, are used to detail the meteorology in these winters, to demonstrate its influence on transport, and to provide a context for interpretation of ACE-FTS and validation campaign observations. During the 2004 and 2006 SSWs, the vortex broke down throughout the stratosphere, reformed quickly in the upper stratosphere, and remained weak in the middle and lower stratosphere. The stratopause reformed at very high altitude, near 75 km. ACE measurements covered both vortex and extra-vortex conditions in each winter, except in late-February through mid-March 2004 and 2006, when the strong, pole-centered vortex that reformed after the SSWs resulted in ACE sampling only inside the vortex in the middle through upper stratosphere. The 2004 and 2006 Eureka campaigns were during the recovery from the SSWs, with the redeveloping vortex over Eureka. 2005 was the coldest winter on record in the lower stratosphere, but with an early final warming in mid-March. The vortex was over Eureka at the start of the 2005 campaign, but moved away as it broke up. Disparate temperature profile structure and vortex evolution resulted in much lower (higher) temperatures in the upper (lower) stratosphere in 2004 and 2006 than in 2005. Satellite temperatures agree well with lidar data up to 50–60 km, and ACE-FTS, MLS and SABER show good agreement in high-latitude temperatures throughout the winters. Consistent with a strong, cold upper stratospheric vortex and enhanced radiative cooling after the SSWs, MLS and ACE-FTS trace gas measurements show strongly enhanced descent in the upper stratospheric vortex in late January through March 2006 compared to that in 2005.

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