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 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 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 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 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 Validation of IASI FORLI carbon monoxide retrievals using FTIR data from NDACC

2012 ◽  
Vol 5 (11) ◽  
pp. 2751-2761 ◽  
Author(s):  
T. Kerzenmacher ◽  
B. Dils ◽  
N. Kumps ◽  
T. Blumenstock ◽  
C. Clerbaux ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Atmospheric Composition ◽  
Satellite Measurements ◽  
Solar Absorption ◽  
Mean Values ◽  
Significant Bias ◽  
Ftir Spectrometer ◽  
The Mean ◽  
The Individual ◽  
Total Column

Abstract. Carbon monoxide (CO) is retrieved daily and globally from space-borne IASI radiance spectra using the Fast Optimal Retrievals on Layers for IASI (FORLI) software developed at the Université Libre de Bruxelles (ULB). The IASI CO total column product for 2008 from the most recent FORLI retrieval version (20100815) is evaluated using correlative CO profile products retrieved from ground-based solar absorption Fourier transform infrared (FTIR) observations at the following FTIR spectrometer sites from the Network for the Detection of Atmospheric Composition Change (NDACC): Ny-Ålesund, Kiruna, Bremen, Jungfraujoch, Izaña and Wollongong. In order to have good statistics for the comparisons, we included all IASI data from the same day, within a 100 km radius around the ground-based stations. The individual ground-based data were adjusted to the lowest altitude of the co-located IASI CO profiles. To account for the different vertical resolutions and sensitivities of the ground-based and satellite measurements, the averaging kernels associated with the various retrieved products have been used to properly smooth coincident data products. It has been found that the IASI CO total column products compare well on average with the co-located ground-based FTIR total columns at the selected NDACC sites and that there is no significant bias for the mean values at all stations.

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 Validation of IASI FORLI carbon monoxide retrievals using FTIR data from NDACC

2012 ◽  
Vol 5 (3) ◽  
pp. 3973-4002 ◽  
Author(s):  
T. Kerzenmacher ◽  
B. Dils ◽  
N. Kumps ◽  
T. Blumenstock ◽  
C. Clerbaux ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Atmospheric Composition ◽  
Satellite Measurements ◽  
Solar Absorption ◽  
Mean Values ◽  
Significant Bias ◽  
Ftir Spectrometer ◽  
The Mean ◽  
The Individual ◽  
Total Column

Abstract. Carbon monoxide (CO) is retrieved daily and globally from space-borne IASI radiance spectra using the Fast Optimal Retrievals on Layers for IASI (FORLI) software developed at the Université Libre de Bruxelles (ULB). The IASI CO total column product for 2008 from the most recent FORLI retrieval version (20100815) is evaluated using correlative CO profile products retrieved from ground-based solar absorption Fourier transform infrared (FTIR) observations at the following FTIR spectrometer sites from the Network for the Detection of Atmospheric Composition Change (NDACC): Ny Ålesund, Kiruna, Bremen, Jungfraujoch, Izaña and Wollongong. In order to have good statistics for the comparisons, we included all IASI data from the same day, within a 100 km radius around the ground-based stations. The individual ground-based data were adjusted to the lowest altitude of the co-located IASI CO profiles. To account for the different vertical resolutions and sensitivities of the ground-based and satellite measurements, the averaging kernels associated with the various retrieved products have been used to properly smooth coincident data products. It has been found that the IASI CO total column products compare well on average with the co-located ground-based FTIR total columns at the selected NDACC sites and that there is no significant bias for the mean values at all stations.

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 Validation and update of OMI Total Column Water Vapor product

2016 ◽  
Vol 16 (17) ◽  
pp. 11379-11393 ◽  
Author(s):  
Huiqun Wang ◽  
Gonzalo Gonzalez Abad ◽  
Xiong Liu ◽  
Kelly Chance
Keyword(s):  
Water Vapor ◽  
Liquid Water ◽  
Retrieval Algorithm ◽  
Ozone Monitoring Instrument ◽  
Validation Data ◽  
Data Set ◽  
Wide Range ◽  
Key Factor ◽  
The Mean ◽  
Total Column

Abstract. The collection 3 Ozone Monitoring Instrument (OMI) Total Column Water Vapor (TCWV) data generated by the Smithsonian Astrophysical Observatory's (SAO) algorithm version 1.0 and archived at the Aura Validation Data Center (AVDC) are compared with NCAR's ground-based GPS data, AERONET's sun-photometer data, and Remote Sensing System's (RSS) SSMIS data. Results show that the OMI data track the seasonal and interannual variability of TCWV for a wide range of climate regimes. During the period from 2005 to 2009, the mean OMI−GPS over land is −0.3 mm and the mean OMI−AERONET over land is 0 mm. For July 2005, the mean OMI−SSMIS over the ocean is −4.3 mm. The better agreement over land than over the ocean is corroborated by the smaller fitting residuals over land and suggests that liquid water is a key factor for the fitting quality over the ocean in the version 1.0 retrieval algorithm. We find that the influence of liquid water is reduced using a shorter optimized retrieval window of 427.7–465 nm. As a result, the TCWV retrieved with the new algorithm increases significantly over the ocean and only slightly over land. We have also made several updates to the air mass factor (AMF) calculation. The updated version 2.1 retrieval algorithm improves the land/ocean consistency and the overall quality of the OMI TCWV data set. The version 2.1 OMI data largely eliminate the low bias of the version 1.0 OMI data over the ocean and are 1.5 mm higher than RSS's “clear” sky SSMIS data in July 2005. Over the ocean, the mean of version 2.1 OMI−GlobVapour is 1 mm for July 2005 and 0 mm for January 2005. Over land, the version 2.1 OMI data are about 1 mm higher than GlobVapour when TCWV  <  15 mm and about 1 mm lower when TCWV  >  15 mm.

scholarly journals Validation of SCIAMACHY HDO/H<sub>2</sub>O measurements using the TCCON and NDACC-MUSICA networks

2015 ◽  
Vol 8 (4) ◽  
pp. 1799-1818 ◽  
Author(s):  
R. A. Scheepmaker ◽  
C. Frankenberg ◽  
N. M. Deutscher ◽  
M. Schneider ◽  
S. Barthlott ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Hydrological Cycle ◽  
Source Region ◽  
Total Carbon ◽  
Atmospheric Composition ◽  
The Tibetan Plateau ◽  
Wet Season ◽  
Data Set ◽  
The Mean ◽  
The Impact

Abstract. Measurements of the atmospheric HDO/H2O ratio help us to better understand the hydrological cycle and improve models to correctly simulate tropospheric humidity and therefore climate change. We present an updated version of the column-averaged HDO/H2O ratio data set from the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). The data set is extended with 2 additional years, now covering 2003–2007, and is validated against co-located ground-based total column δD measurements from Fourier transform spectrometers (FTS) of the Total Carbon Column Observing Network (TCCON) and the Network for the Detection of Atmospheric Composition Change (NDACC, produced within the framework of the MUSICA project). Even though the time overlap among the available data is not yet ideal, we determined a mean negative bias in SCIAMACHY δD of −35 ± 30‰ compared to TCCON and −69 ± 15‰ compared to MUSICA (the uncertainty indicating the station-to-station standard deviation). The bias shows a latitudinal dependency, being largest (∼ −60 to −80‰) at the highest latitudes and smallest (∼ −20 to −30‰) at the lowest latitudes. We have tested the impact of an offset correction to the SCIAMACHY HDO and H2O columns. This correction leads to a humidity- and latitude-dependent shift in δD and an improvement of the bias by 27‰, although it does not lead to an improved correlation with the FTS measurements nor to a strong reduction of the latitudinal dependency of the bias. The correction might be an improvement for dry, high-altitude areas, such as the Tibetan Plateau and the Andes region. For these areas, however, validation is currently impossible due to a lack of ground stations. The mean standard deviation of single-sounding SCIAMACHY–FTS differences is ∼ 115‰, which is reduced by a factor ∼ 2 when we consider monthly means. When we relax the strict matching of individual measurements and focus on the mean seasonalities using all available FTS data, we find that the correlation coefficients between SCIAMACHY and the FTS networks improve from 0.2 to 0.7–0.8. Certain ground stations show a clear asymmetry in δD during the transition from the dry to the wet season and back, which is also detected by SCIAMACHY. This asymmetry points to a transition in the source region temperature or location of the water vapour and shows the added information that HDO/H2O measurements provide when used in combination with variations in humidity.

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