Traceable total ozone column retrievals from direct solar spectral irradiance measurements in the ultraviolet

Abstract. Total column ozone (TCO) is commonly measured by Brewer and Dobson spectroradiometers. Both types of instruments are using four wavelengths in the ultraviolet radiation range to derive TCO. For the calibration and quality assurance of the measured TCO both instrument types require periodic field comparisons with a reference instrument. This study presents traceable TCO retrievals from direct solar spectral irradiance measurements with the portable UV reference instrument QASUME. TCO is retrieved by a spectral fitting technique derived by a minimal least square fit algorithm using spectral measurements in the wavelength range between 305 nm and 345 nm. The retrieval is based on an atmospheric model accounting for different atmospheric parameters such as effective ozone temperature, aerosol optical depth, Rayleigh scattering, SO2, ground air pressure, ozone absorption cross sections and top-of-atmosphere solar spectrum. Traceability means, that the QASUME instrument is fully characterized and calibrated in the laboratory to SI standards (International System of Units). The TCO retrieval method from this instrument is independent from any reference instrument and does not require periodic in situ field calibration. The results show that TCO from QASUME can be retrieved with a relative standard uncertainty of less than 0.8 %, when accounting for all possible uncertainties from the measurements and the retrieval model, such as different cross sections, different reference solar spectra, uncertainties from effective ozone temperature or other atmospheric parameters. The long-term comparison of QASUME TCO with a Brewer and a Dobson in Davos, Switzerland, reveals, that all three instruments are consistent within 1 % when using the ozone absorption cross section from the University of Bremen. From the results and method presented here, other absolute SI calibrated cost effective solar spectroradiometers, such as array spectroradiometers, may be applied for traceable TCO monitoring.

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Consistency of total column ozone measurements between the Brewer and Dobson spectroradiometers of the LKO Arosa and PMOD/WRC Davos

10.5194/amt-2020-497 ◽

2021 ◽

Author(s):

Julian Gröbner ◽

Herbert Schill ◽

Luca Egli ◽

René Stübi

Keyword(s):

Time Series ◽

Cross Sections ◽

Rayleigh Scattering ◽

Absorption Cross ◽

Ozone Absorption ◽

Total Column Ozone ◽

Measured Line ◽

Column Ozone ◽

Scattering Cross Sections ◽

Total Column

Abstract. Total column ozone measured by Brewer and Dobson spectroradiometers at Arosa and Davos, Switzerland, have systematic seasonal variations of around 1.5 % using the standard operational data processing. Most of this variability can be attributed to the temperature sensitivity of approx. +0.1 %/K of the ozone absorption coefficient of the Dobson spectroradiometer (in this study D101). While the currently used Bass&Paur ozone absorption cross-sections produce inconsistent results for Dobson and Brewer, the use of the ozone absorption cross-sections from Serdyuchenko et al. (2013) in conjunction with an effective ozone temperature dataset produces excellent agreement between the investigated four Brewers (of which two double Brewers), and Dobson D101. Even though other ozone absorption cross-sections available in the literature are able to reduce the seasonal variability, all of those investigated produce systematic biases in total column ozone between Brewer and Dobson of 1.1 % to 3.1 %. The highest consistency of total column ozone from Brewers and Dobson D101 at Arosa/Davos of 0.1 % is obtained by applying the Rayleigh scattering cross-sections from Bodhaine et al. (1999), the ozone absorption cross-sections from Serdyuchenko et al. (2013), the effective ozone temperature from either ozonesondes or ECMWF, and the measured line-spread functions of Brewer and Dobson. The variability between Brewer and Dobson for single measurements of 0.9 % can be reduced to less than 0.5 % for monthly means and 0.3 % on yearly means. As show here, the proposed methodology produces consistent total column ozone datasets between Brewer and Dobson spectroradiometers of better than 1 %. For colocated Brewer and Dobson spectroradiometers, as is the case for the Arosa/Davos total column ozone times series, this allows the merging of these two distinct datasets to produce a homogeneous time series of total column ozone measurements. Furthermore, it guarantees the long-term future of this longest total column ozone time-series, by proposing a methodology how to eventually replace the ageing Dobson spectroradiometer with the state-of-the art Brewer spectroradiometer.

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Laser measurements of ozone absorption cross sections in the Chappuis Band

Geophysical Research Letters ◽

10.1029/92gl00780 ◽

1992 ◽

Vol 19 (9) ◽

pp. 933-936 ◽

Cited By ~ 60

Author(s):

Stuart M. Anderson ◽

Konrad Mauersberger

Keyword(s):

Cross Sections ◽

Absorption Cross ◽

Ozone Absorption ◽

Laser Measurements

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Monte Carlo method for determining uncertainty of total ozone derived from direct solar irradiance spectra: Application to Izaña results

10.5194/amt-2017-403 ◽

2018 ◽

Cited By ~ 1

Author(s):

Anna Vaskuri ◽

Petri Kärhä ◽

Luca Egli ◽

Julian Gröbner ◽

Erkki Ikonen

Keyword(s):

Monte Carlo ◽

Total Ozone ◽

Monte Carlo Model ◽

Spectral Irradiance ◽

Total Column Ozone ◽

Solar Spectral Irradiance ◽

Irradiance Data ◽

Column Ozone ◽

Ozone Column ◽

Total Column

Abstract. We demonstrate a Monte Carlo model to calculate the uncertainties of total ozone column, TOC, derived from ground-based directional solar spectral irradiance measurements. The model takes into account effects that correlations in the spectral irradiance data may have on the results. The model is tested with spectral data measured with three different spectroradiometers at an intercomparison campaign of the research project Traceability for atmospheric total column ozone at Izaña, Tenerife on 17 September 2016. The TOC values derived at noon have expanded uncertainties of 1.3 % for a high-end scanning spectroradiometer, 1.3 % for a high-end array spectroradiometer, and 3.3 % for a roughly adopted instrument based on commercially available components and an array spectroradiometer. The level of TOC measured with reference Brewer spectrophotometer #183 is of the order of 282 DU during the analysed day and in agreement with the results of the two former instruments.

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High spectral resolution ozone absorption cross-sections – Part 2: Temperature dependence

Atmospheric Measurement Techniques ◽

10.5194/amt-7-625-2014 ◽

2014 ◽

Vol 7 (2) ◽

pp. 625-636 ◽

Cited By ~ 143

Author(s):

A. Serdyuchenko ◽

V. Gorshelev ◽

M. Weber ◽

W. Chehade ◽

J. P. Burrows

Keyword(s):

Temperature Dependence ◽

Spectral Range ◽

Cross Sections ◽

Spectral Resolution ◽

Uncertainty Budget ◽

Companion Paper ◽

High Spectral Resolution ◽

Absorption Cross ◽

Ozone Absorption ◽

Section Data

Abstract. We report on the temperature dependence of ozone absorption cross-sections measured in our laboratory in the broad spectral range 213–1100 nm with a spectral resolution of 0.02–0.24 nm (full width at half maximum, FWHM) in the atmospherically relevant temperature range from 193 K to 293 K. The temperature dependence of ozone absorption cross-sections was established using measurements at eleven temperatures. This investigation is superior in terms of spectral range and number of considered temperatures compared to the previous studies. The methodology of the absolute broadband measurements, experimental procedures and spectra processing were described in our companion paper together with the associated uncertainty budget. In this paper, we report in detail on our data below room temperature and compare them with literature data using direct comparisons as well as the standard approach using a quadratic polynomial in temperature fitted to the cross-section data.

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Accurate laser measurements of ozone absorption cross-sections in the Hartley band

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-7-8067-2014 ◽

2014 ◽

Vol 7 (8) ◽

pp. 8067-8100 ◽

Cited By ~ 1

Author(s):

J. Viallon ◽

S. Lee ◽

P. Moussay ◽

K. Tworek ◽

M. Petersen ◽

...

Keyword(s):

Gas Phase ◽

Cross Section ◽

Cross Sections ◽

Radiative Forcing ◽

Nitrogen Monoxide ◽

Air Pollutant ◽

Tropospheric Chemistry ◽

Absorption Cross ◽

Ozone Absorption ◽

Hartley Band

Abstract. Ozone plays a crucial role in tropospheric chemistry, is the third largest contributor to greenhouse radiative forcing after carbon dioxide and methane and also a toxic air pollutant affecting human health and agriculture. Long-term measurements of tropospheric ozone have been performed globally for more than 30 years with UV photometers, all relying on the absorption of ozone at the 253.65 nm line of mercury. We have re-determined this cross-section and report a value of 11.27 × 10−18 cm2 molecule−1 with an expanded relative uncertainty of 0.84 %. This is lower than the conventional value currently in use and measured by Hearn in 1961 with a relative difference of 1.8%, with the consequence that historically reported ozone concentrations should be increased by 1.8%. In order to perform the new measurements of cross sections with reduced uncertainties, a system to generate pure ozone in the gas phase together with an optical system based on a UV laser with lines in the Hartley band, including accurate path length measurement of the absorption cell and a careful evaluation of possible impurities in the ozone sample by mass spectrometry and Fourier Transform Infrared spectroscopy was setup. This resulted in new measurements of absolute values of ozone absorption cross sections of 9.48 × 10−18, 10.44 × 10−18, and 11.07 × 10−18 cm2 molecule−1, with relative expanded uncertainties better than 0.6%, for the wavelengths (in vacuum) of 244.062, 248.32, and 257.34 nm respectively. The cross-section at the 253.65 nm line of mercury was determined by comparisons using a Standard Reference Photometer equipped with a mercury lamp as the light source. The newly reported value should be used in the future to obtain the most accurate measurements of ozone concentration, which are in closer agreement with non UV photometry based methods such as the gas phase titration of ozone with nitrogen monoxide.

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Revised temperature dependent ozone absorption cross section spectra (Bogumil et al.) measured with the sciamachy satellite spectrometer

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-6-2449-2013 ◽

2013 ◽

Vol 6 (2) ◽

pp. 2449-2481 ◽

Cited By ~ 3

Author(s):

W. Chehade ◽

V. Gorshelev ◽

A. Serdyuchenko ◽

J. P. Burrows ◽

M. Weber

Keyword(s):

Cross Section ◽

Cross Sections ◽

Absorption Cross Section ◽

Total Ozone ◽

Published Data ◽

Absorption Cross ◽

Atmospheric Conditions ◽

Cross Section Data ◽

Ozone Absorption ◽

Section Data

Abstract. Ozone absorption cross section spectra and other trace gases had been measured using the Scanning Imaging Absorption spectroMeter for Atmospheric ChartograpHY (SCIAMACHY) satellite instrument at relevant atmospheric conditions. The measured cross sections were relative cross sections and were converted to absolute values using published data. Using the SCIAMACHY's FM cross sections as published by Bogumil et al. (2003) in the SCIAMACHY retrievals of total ozone leads to an overestimation in the total ozone by 5% compared to collocated GOME data. This work presents the procedures followed to correct the ozone cross section data as published in Bogumil et al. (2003) starting from original raw data (optical density spectra) from the original measurements. The revised data agrees well within 3% with other published ozone cross-sections and preserves the correct temperature dependence in the Hartley, Huggins, Chappuis and Wolf bands. SCIAMACHY's total ozone columns retrieved using the revised cross section data are shown to be within 1% compared to the ozone amounts retrieved routinely from SCIAMACHY.

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High spectral resolution ozone absorption cross-sections – Part 2: Temperature dependence

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-6-6613-2013 ◽

2013 ◽

Vol 6 (4) ◽

pp. 6613-6643 ◽

Cited By ~ 8

Author(s):

A. Serdyuchenko ◽

V. Gorshelev ◽

M. Weber ◽

W. Chehade ◽

J. P. Burrows

Keyword(s):

Temperature Dependence ◽

Cross Sections ◽

Spectral Resolution ◽

Full Width Half Maximum ◽

Companion Paper ◽

High Spectral Resolution ◽

Absorption Cross ◽

Ozone Absorption ◽

Section Data ◽

Spectra Processing

Abstract. We report on the temperature dependence of ozone absorption cross-sections measured in our laboratory in the spectral range 213–1100 nm with a spectral resolution of 0.02–0.24 nm (Full Width Half Maximum, FWHM) in the atmospherically relevant temperature range from 193 to 293 K. The temperature dependence of ozone absorption cross-sections was established using measurements at eleven temperatures. The methodology of the absolute broadband measurements, experimental procedures and spectra processing were described in our companion paper together with the associated error budget. In this paper, we report in detail on our data below room temperature and compare them with literature data using direct comparisons as well as the standard approach using a quadratic polynomial in temperature fitted to the cross-section data.

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High spectral resolution ozone absorption cross-sections – Part 1: Measurements, data analysis and comparison with previous measurements around 293 K

Atmospheric Measurement Techniques ◽

10.5194/amt-7-609-2014 ◽

2014 ◽

Vol 7 (2) ◽

pp. 609-624 ◽

Cited By ~ 79

Author(s):

V. Gorshelev ◽

A. Serdyuchenko ◽

M. Weber ◽

W. Chehade ◽

J. P. Burrows

Keyword(s):

Data Analysis ◽

Cross Section ◽

Cross Sections ◽

Spectral Resolution ◽

Spectral Region ◽

Uncertainty Budget ◽

High Spectral Resolution ◽

Absorption Cross ◽

Ozone Absorption ◽

Better Than

Abstract. In this paper we discuss the methodology of taking broadband relative and absolute measurements of ozone cross-sections including uncertainty budget, experimental set-ups, and methods for data analysis. We report on new ozone absorption cross-section measurements in the solar spectral region using a combination of Fourier transform and echelle spectrometers. The new cross-sections cover the spectral range 213–1100 nm at a spectral resolution of 0.02–0.06 nm in the UV–visible and 0.12–0.24 nm in the IR at eleven temperatures from 193 to 293 K in steps of 10 K. The absolute accuracy is better than three percent for most parts of the spectral region and wavelength calibration accuracy is better than 0.005 nm. The new room temperature cross-section data are compared in detail with previously available literature data. The temperature dependence of our cross-sections is described in a companion paper (Serdyuchenko et al., 2014).

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High spectral resolution ozone absorption cross-sections – Part 1: Measurements, data analysis and comparison with previous measurements around 293 K

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-6-6567-2013 ◽

2013 ◽

Vol 6 (4) ◽

pp. 6567-6611 ◽

Cited By ~ 10

Author(s):

V. Gorshelev ◽

A. Serdyuchenko ◽

M. Weber ◽

W. Chehade ◽

J. P. Burrows

Keyword(s):

Data Analysis ◽

Cross Sections ◽

Spectral Resolution ◽

Spectral Region ◽

Uncertainty Budget ◽

Companion Paper ◽

High Spectral Resolution ◽

Absorption Cross ◽

Ozone Absorption ◽

Better Than

Abstract. In this paper we discuss the methodology of taking broadband relative and absolute measurements of ozone cross-sections including uncertainty budget, experimental set-ups, and methods for data analysis. We report on new ozone absorption cross-section measurements in the solar spectral region using a combination of Fourier transform and echelle spectrometers. The new cross-sections cover the spectral range 213–1100 nm at a spectral resolution of 0.02–0.06 nm in the UV-vis and 0.12–0.24 nm in the IR at eleven temperatures from 193 to 293 K in steps of 10 K. The absolute accuracy is better than three percent for most parts of the spectral region and wavelength calibration accuracy is better than 0.005 nm. The new room temperature cross-sections data are compared in detail with previously available literature data. The temperature dependence of our cross-sections is described in a companion paper.

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Revised temperature-dependent ozone absorption cross-section spectra (Bogumil et al.) measured with the SCIAMACHY satellite spectrometer

Atmospheric Measurement Techniques ◽

10.5194/amt-6-3055-2013 ◽

2013 ◽

Vol 6 (11) ◽

pp. 3055-3065 ◽

Cited By ~ 8

Author(s):

W. Chehade ◽

V. Gorshelev ◽

A. Serdyuchenko ◽

J. P. Burrows ◽

M. Weber

Keyword(s):

Cross Section ◽

Cross Sections ◽

Absorption Cross Section ◽

Total Ozone ◽

Published Data ◽

Absorption Cross ◽

Cross Section Data ◽

Temperature Dependent ◽

Ozone Absorption ◽

Section Data

Abstract. Absorption cross-section spectra for ozone and other trace gases had been measured using the Scanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) satellite instrument at relevant atmospheric conditions. The measured cross sections were relative cross sections and were converted to absolute values using published data. Using SCIAMACHY's FM cross sections as published by Bogumil et al. (2003) in the SCIAMACHY retrievals of total ozone leads to an overestimation in the total ozone by 5% compared to collocated GOME data. This work presents the procedures followed to correct the ozone cross-section data starting from original raw data (optical density spectra). The quality of the revised temperature-dependent ozone absorption cross sections is investigated over SCIAMACHY's entire spectral range. The revised data agree well within 3% with other published ozone cross sections and preserve the correct temperature dependence in the Hartley, Huggins, Chappuis and Wulf bands as displayed by the literature data. SCIAMACHY's total ozone columns retrieved using the revised cross-section data are shown to be within 1% compared to the ozone amounts retrieved routinely from SCIAMACHY, which uses Bogumil et al. (2003) data but adjusted with a scaling factor of 5.3% and a wavelength shift of 0.08 nm.

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