scholarly journals XCO<sub>2</sub>-measurements with a tabletop FTS using solar absorption spectroscopy

2012 ◽  
Vol 5 (4) ◽  
pp. 5691-5724 ◽  
Author(s):  
M. Gisi ◽  
F. Hase ◽  
S. Dohe ◽  
T. Blumenstock ◽  
A. Simon ◽  
...  
Keyword(s):  
Low Cost ◽  
Total Carbon ◽  
Fourier Transform Spectrometer ◽  
Promising Candidate ◽  
Solar Absorption ◽  
Solar Tracker ◽  
Ftir Spectrometer ◽  
Field Campaigns ◽  
Total Column ◽  
Comparison Period

Abstract. A commercial low-resolution (0.5 cm−1) Fourier-Transform-Spectrometer (FTS) has been modified and is used for determining the total column XCO2 of the atmosphere by analyzing direct solar radiation. The spectrometer has a small home-built solar tracker attached, so that it is a ready-to-use instrument. The results are validated with temporally coinciding on-site measurements taken with a high-resolution Total Carbon Column Observing Network (TCCON) FTIR-spectrometer. For the whole comparison period of 5 months (26 measurement days) an agreement with TCCON-results of (0.12 ± 0.08)% is achieved. This makes the spectrometer a promising candidate for a low-cost addition to the TCCON core FTIR sites, especially suitable for locations with limited infrastructure. An impressive mechanical and thermal stability is proved, enabling the spectrometer for use in field campaigns and for the monitoring of local sources.

scholarly journals XCO<sub>2</sub>-measurements with a tabletop FTS using solar absorption spectroscopy

2012 ◽  
Vol 5 (11) ◽  
pp. 2969-2980 ◽  
Author(s):  
M. Gisi ◽  
F. Hase ◽  
S. Dohe ◽  
T. Blumenstock ◽  
A. Simon ◽  
...  
Keyword(s):  
Low Cost ◽  
Total Carbon ◽  
Fourier Transform Spectrometer ◽  
Promising Candidate ◽  
Solar Absorption ◽  
Solar Tracker ◽  
Ftir Spectrometer ◽  
Field Campaigns ◽  
Total Column ◽  
Comparison Period

Abstract. A commercial low-resolution (0.5 cm−1) Fourier Transform Spectrometer (FTS) has been modified and is used for determining the total column XCO2 of the atmosphere by analysing direct solar radiation. The spectrometer has a small home-built solar tracker attached, so that it is a ready-to-use instrument. The results are validated with temporally coinciding on-site measurements taken with a high-resolution Total Carbon Column Observing Network (TCCON) FTIR spectrometer. For the whole comparison period of 5 months (26 measurement days) an agreement with TCCON results of (0.12 ± 0.08)% is achieved. This makes the spectrometer a promising candidate for a low-cost addition to the TCCON core FTIR sites, especially suitable for locations with limited infrastructure. An impressive mechanical and thermal stability is proved, enabling the spectrometer for use in field campaigns and for the monitoring of local sources.

scholarly journals Retrieval of xCO<sub>2</sub> from ground-based mid-infrared (NDACC) solar absorption spectra and comparison to TCCON

2016 ◽  
Vol 9 (2) ◽  
pp. 577-585 ◽  
Author(s):  
Matthias Buschmann ◽  
Nicholas M. Deutscher ◽  
Vanessa Sherlock ◽  
Mathias Palm ◽  
Thorsten Warneke ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Seasonal Cycle ◽  
Total Carbon ◽  
Atmospheric Composition ◽  
Composition Change ◽  
Solar Absorption ◽  
Mid Infrared ◽  
Infrared Spectral ◽  
Ftir Spectrometer ◽  
Total Column

Abstract. High-resolution solar absorption spectra, taken within the Network for the Detection of Atmospheric Composition Change Infrared Working Group (NDACC-IRWG) in the mid-infrared spectral region, are used to infer partial or total column abundances of many gases. In this paper we present the retrieval of a column-averaged mole fraction of carbon dioxide from NDACC-IRWG spectra taken with a Fourier transform infrared (FTIR) spectrometer at the site in Ny-Ålesund, Spitsbergen. The retrieved time series is compared to colocated standard TCCON (Total Carbon Column Observing Network) measurements of column-averaged dry-air mole fractions of CO2 (denoted by xCO2). Comparing the NDACC and TCCON retrievals, we find that the sensitivity of the NDACC retrieval is lower in the troposphere (by a factor of 2) and higher in the stratosphere, compared to TCCON. Thus, the NDACC retrieval is less sensitive to tropospheric changes (e.g., the seasonal cycle) in the column average.

scholarly journals Background CO<sub>2</sub> levels and error analysis from ground-based solar absorption IR measurements in central Mexico

2017 ◽  
Author(s):  
Jorge L. Baylon ◽  
Wolfgang Stremme ◽  
Michel Grutter ◽  
Frank Hase ◽  
Thomas Blumenstock
Keyword(s):  
Total Carbon ◽  
Central Mexico ◽  
Independent Data ◽  
Data Set ◽  
Solar Absorption ◽  
Diurnal Cycles ◽  
Ftir Spectrometer ◽  
The Mean ◽  
Main Component ◽  
Total Column

Abstract. In this investigation we analyze two common optical configurations to retrieve CO2 total column amounts from solar absorption infrared spectra. The noise errors using either a KBr or a CaF2 beamsplitter, a main component of a Fourier transform infrared (FTIR) spectrometer, are quantified in order to assess the relative precisions of the measurements. The configuration using a CaF2 beamsplitter, as deployed by the instruments which contribute to the Total Carbon Column Observing Network (TCCON), shows a slightly better precision. However, we show that the precisions in XCO2 retrieved from > 96 % of the spectra measured with a KBr beamsplitter, fall well below 0.2 %. A small bias in XCO2 (KBr – CaF2) of +0.56 ± 0.25 ppm was found when using an independent data set as reference. This value, which corresponds to +0.14 ± 0.064 %, is slightly larger than the mean precisions obtained and could be taken into account when homogenizing or comparing data from both beamsplitters. A 3-year XCO2 time series from FTIR measurements at the high-altitude site of Altzomoni in central Mexico presents clear annual and diurnal cycles and a trend of +2.2 ppm/yr could be determined.

scholarly journals Ground-based Measurements of Atmospheric Trace Gases in Beijing during the Olympic Games

Sci ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 6
Author(s):  
Jie Cheng
Keyword(s):  
Olympic Games ◽  
Trace Gases ◽  
Fourier Transform Spectrometer ◽  
Atmospheric Trace Gases ◽  
Validation Data ◽  
Solar Absorption ◽  
The Mean ◽  
The City ◽  
Total Column ◽  
The Olympic Games

A portable Fourier Transform Spectrometer (B3M-IR) is built and used to measure atmospheric trace gases in the city of Beijing during Olympic Games in 2008. A short description of the instrument is first provided in this paper. A detailed spectral analysis is then presented. The total columns of ozone (O3), carbon monoxide (CO), methane (CH4) and nitrous oxide (N2O) are retrieved from the ground-based solar absorption spectra recorded by the B3M-IR during the Olympic Games. Lacking validation data, only the retrieved total column of O3 is compared with that retrieved by MAX-DOAS, which is deployed at the same station. The mean difference between the two methods of measurement is 6.5%, demonstrating the performance and reliability of B3M-IR.

scholarly journals Retrieval of atmospheric CH<sub>4</sub> vertical information from ground-based FTS near-infrared spectra

2019 ◽  
Vol 12 (11) ◽  
pp. 6125-6141 ◽  
Author(s):  
Minqiang Zhou ◽  
Bavo Langerock ◽  
Mahesh Kumar Sha ◽  
Nicolas Kumps ◽  
Christian Hermans ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Mole Fraction ◽  
Atmospheric Chemistry ◽  
Near Infrared ◽  
Satellite Observations ◽  
Total Carbon ◽  
Fourier Transform Spectrometer ◽  
Aircraft Measurements ◽  
Retrieval Software ◽  
Total Column

Abstract. The Total Carbon Column Observing Network (TCCON) column-averaged dry air mole fraction of CH4 (XCH4) measurements have been widely used to validate satellite observations and to estimate model simulations. The GGG2014 code is the standard TCCON retrieval software used in performing a profile scaling retrieval. In order to obtain several vertical pieces of information in addition to the total column, in this study, the SFIT4 retrieval code is applied to retrieve the CH4 mole fraction vertical profile from the Fourier transform spectrometer (FTS) spectrum at six sites (Ny-Ålesund, Sodankylä, Bialystok, Bremen, Orléans and St Denis) during the time period of 2016–2017. The retrieval strategy of the CH4 profile retrieval from ground-based FTS near-infrared (NIR) spectra using the SFIT4 code (SFIT4NIR) is investigated. The degree of freedom for signal (DOFS) of the SFIT4NIR retrieval is about 2.4, with two distinct pieces of information in the troposphere and in the stratosphere. The averaging kernel and error budget of the SFIT4NIR retrieval are presented. The data accuracy and precision of the SFIT4NIR retrievals, including the total column and two partial columns (in the troposphere and stratosphere), are estimated by TCCON standard retrievals, ground-based in situ measurements, Atmospheric Chemistry Experiment – Fourier Transform Spectrometer (ACE-FTS) satellite observations, TCCON proxy data and AirCore and aircraft measurements. By comparison against TCCON standard retrievals, it is found that the retrieval uncertainty of SFIT4NIR XCH4 is similar to that of TCCON standard retrievals with systematic uncertainty within 0.35 % and random uncertainty of about 0.5 %. The tropospheric and stratospheric XCH4 from SFIT4NIR retrievals are assessed by comparison with AirCore and aircraft measurements, and there is a 1.0 ± 0.3 % overestimation in the SFIT4NIR tropospheric XCH4 and a 4.0 ± 2.0 % underestimation in the SFIT4NIR stratospheric XCH4, which are within the systematic uncertainties of SFIT4NIR-retrieved partial columns in the troposphere and stratosphere respectively.

scholarly journals Background CO<sub>2</sub> levels and error analysis from ground-based solar absorption IR measurements in central Mexico

2017 ◽  
Vol 10 (7) ◽  
pp. 2425-2434 ◽  
Author(s):  
Jorge L. Baylon ◽  
Wolfgang Stremme ◽  
Michel Grutter ◽  
Frank Hase ◽  
Thomas Blumenstock
Keyword(s):  
Beam Splitter ◽  
Total Carbon ◽  
Central Mexico ◽  
Data Set ◽  
Solar Absorption ◽  
Diurnal Cycles ◽  
Infrared Spectrometer ◽  
The Mean ◽  
Main Component ◽  
Total Column

Abstract. In this investigation we analyze two common optical configurations to retrieve CO2 total column amounts from solar absorption infrared spectra. The noise errors using either a KBr or a CaF2 beam splitter, a main component of a Fourier transform infrared spectrometer (FTIR), are quantified in order to assess the relative precisions of the measurements. The configuration using a CaF2 beam splitter, as deployed by the instruments which contribute to the Total Carbon Column Observing Network (TCCON), shows a slightly better precision. However, we show that the precisions in XCO2 ( =  0.2095  ⋅  Total Column CO2Total Column O2) retrieved from  >  96 % of the spectra measured with a KBr beam splitter fall well below 0.2 %. A bias in XCO2 (KBr − CaF2) of +0.56 ± 0.25 ppm was found when using an independent data set as reference. This value, which corresponds to +0.14 ± 0.064 %, is slightly larger than the mean precisions obtained. A 3-year XCO2 time series from FTIR measurements at the high-altitude site of Altzomoni in central Mexico presents clear annual and diurnal cycles, and a trend of +2.2 ppm yr−1 could be determined.

scholarly journals Retrieval of tropospheric column-averaged CH<sub>4</sub> mole fraction by solar absorption FTIR-spectrometry using N<sub>2</sub>O as a proxy

2014 ◽  
Vol 7 (10) ◽  
pp. 3295-3305 ◽  
Author(s):  
Z. Wang ◽  
N. M. Deutscher ◽  
T. Warneke ◽  
J. Notholt ◽  
B. Dils ◽  
...  
Keyword(s):  
Total Carbon ◽  
Relative Uncertainty ◽  
Solar Absorption ◽  
Seasonal Behavior ◽  
Ftir Spectrometry ◽  
Ch4 Concentration ◽  
The Mean ◽  
The Tropics ◽  
Total Column ◽  
Absorption Measurements

Abstract. Tropospheric column-averaged CH4 mole fractions were derived from ground-based column absorption measurements. The method uses stratospheric N2O columns to correct for the stratospheric contribution to the CH4 total column. The method was applied to four Total Carbon Column Observing Network (TCCON) sites covering locations from the Northern Arctic to the tropics. It performs well for all sites. The derived tropospheric CH4 concentrations were compared with profiles measured by aircraft at three sites. The results indicate an inter-site consistency within 6 ppb (~0.3%). With aircraft profiles up to 3 km, the seasonal behavior of the derived tropospheric CH4 concentration was also checked, revealing a difference of around 20 ppb. The mean relative uncertainty of the four sites, as estimated from the daily standard deviations, is 0.23%.

scholarly journals Camtracker: a new camera controlled high precision solar tracker system for FTIR-spectrometers

2011 ◽  
Vol 4 (1) ◽  
pp. 47-54 ◽  
Author(s):  
M. Gisi ◽  
F. Hase ◽  
S. Dohe ◽  
T. Blumenstock
Keyword(s):  
Fourier Transform ◽  
Digital Camera ◽  
Disk Center ◽  
Variable Intensity ◽  
Solar Absorption ◽  
Pointing Errors ◽  
Solar Tracker ◽  
Ftir Spectrometer ◽  
New System ◽  
Better Than

Abstract. A new system to very precisely couple radiation of a moving source into a Fourier Transform Infrared (FTIR) Spectrometer is presented. The Camtracker consists of a homemade altazimuthal solar tracker, a digital camera and a homemade program to process the camera data and to control the motion of the tracker. The key idea is to evaluate the image of the radiation source on the entrance field stop of the spectrometer. We prove that the system reaches tracking accuracies of about 10 arc s for a ground-based solar absorption FTIR spectrometer, which is significantly better than current solar trackers. Moreover, due to the incorporation of a camera, the new system allows to document residual pointing errors and to point onto the solar disk center even in case of variable intensity distributions across the source due to cirrus or haze.

scholarly journals Ship-borne measurements of XCO<sub>2</sub>, XCH<sub>4</sub>, and XCO above the Pacific Ocean and comparison to CAMS atmospheric analyses and S5P/TROPOMI

2020 ◽  
Author(s):  
Marvin Knapp ◽  
Ralph Kleinschek ◽  
Frank Hase ◽  
Anna Agustí-Panareda ◽  
Antje Inness ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Excellent Agreement ◽  
Total Carbon ◽  
Solar Absorption ◽  
The Pacific ◽  
Before And After ◽  
Infrared Spectral ◽  
Solar Tracker ◽  
The Pacific Ocean ◽  
Shortwave Infrared

Abstract. Measurements of atmospheric column-averaged dry-air mole fractions of carbon dioxide (XCO2), methane (XCH4), and carbon monoxide (XCO) have been collected across the Pacific ocean during the Measuring Ocean REferences 2 (MORE-2) campaign in June 2019. We deployed a ship-borne variant of the EM27/SUN Fourier Transform Spectrometer (FTS) on board the German research vessel Sonne which, during MORE-2, crossed the Pacific ocean from Vancouver, Canada, to Singapore. Equipped with a specially manufactured fast solar tracker, the FTS operated in direct-sun viewing geometry during the ship cruise reliably delivering solar absorption spectra in the shortwave infrared spectral range (4000 to 11 000 1/cm). After filtering and bias correcting the dataset, we report on XCO2, XCH4, and XCO measurements for 22 days along a trajectory that largely aligns with 30° N of latitude between 140° W and 120° E of longitude. The dataset has been scaled to the Total Carbon Column Observing Network (TCCON) station in Karlsruhe, Germany, before and after the MORE-2 campaign through side-by-side measurements. The precision for hourly means of XCO2, XCH4, and XCO during the campaign is found 0.24 ppm, 1.1 ppb, and 0.75 ppb, respectively. Comparing concentration fields analysed by the Copernicus Atmosphere Monitoring Service (CAMS) to our data, we find excellent agreement of 0.52 ± 0.31 ppm for XCO2, 0.9 ± 4.1 ppb for XCH4, and 3.2 ± 3.4 ppb for XCO (mean difference ± standard deviation of differences for entire record). Likewise, we find excellent agreement to within 2.2 ± 6.6 ppb with the XCO observations of the TROPOspheric MOnitoring Instrument (TROPOMI) on the Sentinel-5 Precursor satellite (S5P). The ship-borne measurements are accessible at https://doi.org/10.1594/PANGAEA.917240 (Knapp et al., 2020).

scholarly journals Quality assessment of ozone total column amounts as monitored by ground-based solar absorption spectrometry in the near infrared (> 3000 cm<sup>−1</sup>)

2014 ◽  
Vol 7 (3) ◽  
pp. 2071-2106
Author(s):  
O. E. García ◽  
M. Schneider ◽  
F. Hase ◽  
T. Blumenstock ◽  
E. Sepúlveda ◽  
...  
Keyword(s):  
Near Infrared ◽  
Absorption Spectrometry ◽  
Systematic Difference ◽  
Total Carbon ◽  
Atmospheric Composition ◽  
Solar Absorption ◽  
Annual Cycles ◽  
Long Term Stability ◽  
Total Column

Abstract. This study examines the possibility of ground-based remote sensing ozone total column amounts (OTC) from spectral signatures at 3040 and 4030 cm−1. These spectral regions are routinely measured by the NDACC (Network for the Detection of Atmospheric Composition Change) ground-based FTIR (Fourier Transform InfraRed) experiments. In addition, they are potentially detectable by the TCCON (Total Carbon Column Observing Network) FTIR instruments. The ozone retrieval strategy presented here estimates the OTC from NDACC FTIR high resolution spectra with a theoretical precision of about 2% and 5% in the 3040 cm−1 and 4030 cm−1 regions, respectively. Empirically, these OTC products are validated by inter-comparison to FTIR OTC reference retrievals in the 1000 cm−1 spectral region (standard reference for NDACC ozone products), using a 8 year FTIR time series (2005–2012) taken at the subtropical ozone super-site of the Izaña Observatory (Tenerife, Spain). Associated with the weaker ozone signatures at the higher wavenumber regions, the 3040 cm−1 and 4030 cm−1 retrievals show lower vertical sensitivity than the 1000 cm−1 retrievals. Nevertheless, we observe that the rather consistent variations are detected: the variances of the 3040 cm−1 and the 4030 cm−1 retrievals agree within 90% and 75%, respectively, with the variance of the 1000 cm−1 standard retrieval. Furthermore, all three retrievals show very similar annual cycles. However, we observe a large systematic difference of about 7% between the OTC obtained at 1000 cm−1 and 3040 cm−1, indicating a significant inconsistency between the spectroscopic ozone parameters (HITRAN 2012) of both regions. Between the 1000 cm−1 and the 4030 cm−1 retrieval the systematic difference is only 2–3%. Finally, the long-term stability of the OTC retrievals has also been examined, observing that both near infrared retrievals can monitor the long-term OTC evolution in consistency to the 1000 cm−1reference data.

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