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

2013 ◽  
Vol 6 (4) ◽  
pp. 6567-6611 ◽  
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.

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

2014 ◽  
Vol 7 (2) ◽  
pp. 609-624 ◽  
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).

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

2014 ◽  
Vol 7 (2) ◽  
pp. 625-636 ◽  
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.

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

2013 ◽  
Vol 6 (4) ◽  
pp. 6613-6643 ◽  
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.

scholarly journals Operation of the Airborne 355-nm High Spectral Resolution and Doppler Lidar LNG

2020 ◽  
Vol 237 ◽  
pp. 06011
Author(s):  
D. Bruneau ◽  
J. Pelon ◽  
F. Blouzon ◽  
Q. Cazenave ◽  
H. Collomb ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
High Energy ◽  
High Spectral Resolution ◽  
Doppler Lidar ◽  
Backscatter Coefficient ◽  
Relative Precision ◽  
Airborne Measurements ◽  
Wind Measurements ◽  
High Spectral Resolution Lidar ◽  
Better Than

High spectral resolution lidar (HSRL) are known to offer capabilities of separating attenuated aerosol and molecular backscattering so that particle extinction and backscattering can be separately retrieved. UV operation provides high energy in eye-safety conditions. Further to that, it could be important for most meteorological or environmental studies to get wind measurements at the same time. LNG is now the only HSR Doppler Lidar (HSRDL) system capable of this. Results obtained during ground-based and airborne measurements show that the backscatter and extinction coefficients at 355 nm can be measured with a relative precision better than 10% (adjusting altitude and time resolution from 60 m to 240 m and 30s to 2mn, respectively) in aerosol layers of 0.5 10−6 m−1 sr−1 backscatter coefficient from ground and aircraft. The same relative precision is obtained in cirrus clouds of a 10−5 m−1 sr−1 backscatter coefficient. The capacity of the system to perform wind velocity measurements has also been demonstrated with precisions in the range of 1 to 2 ms−1 in same conditions. We present the main characteristics and illustrate observational capabilities from ground-based and airborne measurements.

Laser measurements of ozone absorption cross sections in the Chappuis Band

1992 ◽  
Vol 19 (9) ◽  
pp. 933-936 ◽  
Author(s):  
Stuart M. Anderson ◽  
Konrad Mauersberger
Keyword(s):  
Cross Sections ◽  
Absorption Cross ◽  
Ozone Absorption ◽  
Laser Measurements

scholarly journals On the relative absorption strengths of water vapour in the blue wavelength range

2015 ◽  
Vol 8 (6) ◽  
pp. 5895-5936 ◽  
Author(s):  
J. Lampel ◽  
D. Pöhler ◽  
J. Tschritter ◽  
U. Frieß ◽  
U. Platt
Keyword(s):  
Water Vapour ◽  
Cross Sections ◽  
Spectral Region ◽  
Field Measurements ◽  
Optical Absorption Spectroscopy ◽  
Absorption Cross ◽  
Absorption Bands ◽  
Blue Wavelength ◽  
Water Vapour Absorption ◽  
Density Ratios

Abstract. In recent updates of the HITRAN water vapour H2O spectroscopic compilation covering the blue spectral region (here: 394–480 nm) significant changes for the absorption bands at 416 and 426 nm were reported. In order to investigate the consistency of the different cross-sections calculated from these compilations, H2O vapour column density ratios for different spectral intervals were retrieved from Long-path and Multi-Axis – Differential Optical Absorption Spectroscopy (DOAS) measurements. We observed a significant improvement of the DOAS evaluation when using the updated HITRAN water vapour absorption cross-sections for the calculation of the reference spectra. In particular the magnitudes of the residual spectra as well as the fit errors were reduced. However we also found that the best match between measurement and model is reached when the absorption cross-section of groups of lines are scaled by factors ranging from 0.5 and 1.9, suggesting that the HITRAN water vapour absorption compilation still needs significant corrections. For this spectral region we present correction factors for HITRAN 2009, HITRAN 2012, HITEMP and BT2 derived from field measurements. Additionally, upper limits for water vapour absorption in the UV-A range from 330–390 nm are given.

scholarly journals The Ionisation Equilibrium for Heavy Elements

1968 ◽  
Vol 34 ◽  
pp. 205-208
Author(s):  
D.R. Flower
Keyword(s):  
Radiation Field ◽  
Optical Depth ◽  
Cross Sections ◽  
Ground State ◽  
Spectral Region ◽  
Heavy Elements ◽  
First Approximation ◽  
Initial Work ◽  
Far Ultraviolet ◽  
Better Than

Calculations are being made of the distribution of the ions of heavy elements in planetary nebulae. Initial work has been concentrated on the central or He2+ zone of planetaries. The optical depths of ions of C, N, O, and Ne have been computed using ground state ionisation cross-sections and using approximations which should be substantially better than hydrogenic. A comparison has been made between the combined optical depth of the heavy elements and the optical depth of He+ in the far ultraviolet. The optical depths of the heavy elements in this spectral region may become significant, but a reasonable first approximation to the radiation field may be obtained by neglecting the absorption of all ions except He+. The distribution of the ions of the heavy elements has been calculated on this assumption.

scholarly journals Mapping spectroscopic uncertainties into prospective methane retrieval errors from Sentinel-5 and its precursor

2015 ◽  
Vol 8 (1) ◽  
pp. 1333-1363
Author(s):  
R. Checa-Garcia ◽  
J. Landgraf ◽  
F. Hase ◽  
H. Tran ◽  
V. Boudon ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Global Scale ◽  
High Spectral Resolution ◽  
Spectroscopic Parameters ◽  
Infrared Spectral ◽  
Retrieval Errors ◽  
Shortwave Infrared ◽  
Very High ◽  
Better Than

Abstract. Sentinel-5 (S5) and its precursor (S5P) are future European satellite missions aiming at global monitoring of methane (CH4) column average dry air mole fractions (XCH4). The spectrometers to be deployed on-board the satellites record spectra of sunlight backscattered from the Earth's surface and atmosphere. In particular, they exploit CH4 absorption in the shortwave infrared spectral range around 1.65 μm (S5 only) and 2.35 μm (both, S5 and S5P) wavelength. Given an accuracy goal of better than 2% for XCH4 to be delivered on regional scales, assessment and reduction of potential sources of systematic error such as spectroscopic uncertainties is crucial. Here, we investigate how spectroscopic errors propagate into retrieval errors on the global scale. To this end, absorption spectra of a ground-based Fourier Transform Spectrometer (FTS) operating at very high spectral resolution serve as estimate for the quality of the spectroscopic parameters. Feeding the FTS fitting residuals as a perturbation into a global ensemble of simulated S5 and S5P-like spectra at relatively low spectral resolution, XCH4 retrieval errors exceed 1% in large parts of the world and show systematic correlations on regional scales, calling for improved spectroscopic parameters.

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

2014 ◽  
Vol 7 (8) ◽  
pp. 8067-8100 ◽  
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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