MAXDOAS formaldehyde slant column measurements during CINDI: intercomparison and analysis improvement

Abstract. We present intercomparison results for formaldehyde (HCHO) slant column measurements performed during the Cabauw Intercomparison Campaign of Nitrogen Dioxide measuring Instruments (CINDI) that took place in Cabauw, the Netherlands, in summer 2009. During two months, nine atmospheric research groups simultaneously operated MAXDOAS instruments of various designs to record UV-visible spectra of scattered sunlight at different elevation angles that were analysed using common retrieval settings. The resulting HCHO dataset was found to be highly consistent, the mean difference between instruments generally not exceeding 15% or 7.5 × 1015 molec cm2, for all viewing elevation angles. Furthermore, a sensitivity analysis was performed to investigate the uncertainties in the HCHO slant column retrieval when varying key input parameters such as the molecular absorption cross-sections, correction terms for the Ring effect or the width and position of the fitting interval. This study led to the identification of potentially important sources of errors associated with cross-correlation effects involving the Ring effect, O4, HCHO and BrO cross-sections and the DOAS closure polynomial. As a result, a set of updated recommendations was formulated for HCHO slant column retrieval in the 336.5–359 nm wavelength range. To conclude, an error budget is proposed which distinguishes between systematic and random uncertainties. The total systematic error is estimated to be of the order of 20% and is dominated by uncertainties in absorption cross-sections and related spectral cross-correlation effects. For a typical integration time of one minute, random uncertainties range between 5% and 30%, depending on the noise level of individual instruments.

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MAX-DOAS formaldehyde slant column measurements during CINDI: intercomparison and analysis improvement

Atmospheric Measurement Techniques ◽

10.5194/amt-6-167-2013 ◽

2013 ◽

Vol 6 (1) ◽

pp. 167-185 ◽

Cited By ~ 60

Author(s):

G. Pinardi ◽

M. Van Roozendael ◽

N. Abuhassan ◽

C. Adams ◽

A. Cede ◽

...

Keyword(s):

Cross Sections ◽

Cross Correlation ◽

Optical Absorption Spectroscopy ◽

Integration Time ◽

Measuring Instruments ◽

Absorption Cross ◽

Correlation Effects ◽

Data Set ◽

Random Uncertainties ◽

Ring Effect

Abstract. We present intercomparison results for formaldehyde (HCHO) slant column measurements performed during the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI) that took place in Cabauw, the Netherlands, in summer 2009. During two months, nine atmospheric research groups simultaneously operated MAX-DOAS (MultiAXis Differential Optical Absorption Spectroscopy) instruments of various designs to record UV-visible spectra of scattered sunlight at different elevation angles that were analysed using common retrieval settings. The resulting HCHO data set was found to be highly consistent, the mean difference between instruments generally not exceeding 15% or 7.5 × 1015 molec cm−2, for all viewing elevation angles. Furthermore, a sensitivity analysis was performed to investigate the uncertainties in the HCHO slant column retrieval when varying key input parameters such as the molecular absorption cross sections, correction terms for the Ring effect or the width and position of the fitting interval. This study led to the identification of potentially important sources of errors associated with cross-correlation effects involving the Ring effect, O4, HCHO and BrO cross sections and the DOAS closure polynomial. As a result, a set of updated recommendations was formulated for HCHO slant column retrieval in the 336.5–359 nm wavelength range. To conclude, an error budget is proposed which distinguishes between systematic and random uncertainties. The total systematic error is estimated to be of the order of 20% and is dominated by uncertainties in absorption cross sections and related spectral cross-correlation effects. For a typical integration time of one minute, random uncertainties range between 5 and 30%, depending on the noise level of individual instruments.

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An IBBCEAS system for atmospheric measurements of glyoxal and methylglyoxal in the presence of high NO<sub>2</sub> concentrations

10.5194/amt-2019-40 ◽

2019 ◽

Cited By ~ 1

Author(s):

Jingwei Liu ◽

Xin Li ◽

Yiming Yang ◽

Haichao Wang ◽

Yusheng Wu ◽

...

Keyword(s):

Cross Sections ◽

Integration Time ◽

Absorption Cross ◽

Measurement Sensitivity ◽

Atmospheric Measurements ◽

Enhanced Absorption ◽

Cavity Enhanced Absorption Spectroscopy ◽

Spectrally Resolved ◽

Spectra Fitting

Abstract. A system based on incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) has been developed for simultaneous measurement of nitrogen dioxide (NO2), glyoxal (GLY) and methylglyoxal (MGLY). On this system, the absorption of light around 460 nm is spectrally resolved. The concentration of absorbers is determined from a multi-component fit. At an integration time of 100 s, the measurement sensitivity (2σ) for NO2, GLY, and MGLY can reach 18 ppt, 30 ppt, and 100 ppt, respectively. The measurement uncertainty which mainly originates from path length calibration, sampling loss, and uncertainty of absorption cross sections is estimated to be 8 % for NO2, 8 % for GLY, and 16 % for MGLY. When applying the instrument during field observations, we found significant influence of NO2 on spectra fitting for retrieving GLY and MGLY concentration, which is caused by the fact that NO2 has higher absorption cross section and higher ambient concentration. In order to minimize such an effect, a NO2 photolytic convertor (NPC) which removes sampled NO2 at an efficiency of 76 % was integrated on the IBBCEAS system. Since sampled GLY and MGLY are mostly conserved (≥ 95 %) after passing through the NPC, the quality of the spectra fitting and the measurement accuracy of ambient GLY and MGLY were largely improved.

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An IBBCEAS system for atmospheric measurements of glyoxal and methylglyoxal in the presence of high NO<sub>2</sub> concentrations

Atmospheric Measurement Techniques ◽

10.5194/amt-12-4439-2019 ◽

2019 ◽

Vol 12 (8) ◽

pp. 4439-4453 ◽

Cited By ~ 4

Author(s):

Jingwei Liu ◽

Xin Li ◽

Yiming Yang ◽

Haichao Wang ◽

Yusheng Wu ◽

...

Keyword(s):

Cross Sections ◽

Integration Time ◽

Absorption Cross ◽

Measurement Sensitivity ◽

Atmospheric Measurements ◽

Enhanced Absorption ◽

Cavity Enhanced Absorption Spectroscopy ◽

Spectrally Resolved ◽

Spectra Fitting

Abstract. A system based on incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) has been developed for simultaneous measurement of nitrogen dioxide (NO2), glyoxal (GLY), and methylglyoxal (MGLY). In this system, the measured light absorption at around 460 nm is spectrally resolved. The concentration of absorbers is determined from a multicomponent fit. At an integration time of 100 s, the measurement sensitivity (2σ) for NO2, GLY, and MGLY is 18, 30, and 100 ppt, respectively. The measurement uncertainty, which mainly originates from path length calibration, sampling loss, and uncertainty of absorption cross sections is estimated to be 8 % for NO2, 8 % for GLY, and 16 % for MGLY. When deploying the instrument during field observations, we found significant influence of NO2 on the spectra fitting for retrieving GLY and MGLY concentrations, which is caused by the fact that NO2 has a higher absorption cross section and higher ambient concentration. In order to minimize such an effect, a NO2 photolytic convertor (NPC), which removes sampled NO2 at an efficiency of 76 %, was integrated on the IBBCEAS system. Since sampled GLY and MGLY are mostly (≥95 %) conserved after passing through the NPC, the quality of the spectra fitting and the measurement accuracy of ambient GLY and MGLY under NO2-rich environments could be improved.

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Test Statistic Auto- and Cross-correlation Effects on Monitor False Alert and Missed Detection Probabilities

Proceedings of the 2017 International Technical Meeting of The Institute of Navigation ◽

10.33012/2017.14874 ◽

2017 ◽

Cited By ~ 5

Author(s):

Boris Pervan ◽

Samer Khanafseh ◽

Jaymin Patel

Keyword(s):

Cross Correlation ◽

Correlation Effects ◽

Test Statistic ◽

Detection Probabilities

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ABSORPTION CROSS-SECTIONS IN HITRAN2016: MAJOR DATABASE UPDATE FOR ATMOSPHERIC, INDUSTRIAL, AND CLIMATE APPLICATIONS

Proceedings of the 72nd International Symposium on Molecular Spectroscopy ◽

10.15278/isms.2017.tj10 ◽

2017 ◽

Author(s):

Roman Kochanov ◽

Christian Hill ◽

Georg Wagner ◽

Manfred Birk ◽

Timothy Wallington ◽

...

Keyword(s):

Cross Sections ◽

Absorption Cross

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Spectroscopy Fundamentals

10.1093/oso/9780199662104.003.0005 ◽

2017 ◽

Author(s):

Kelly Chance ◽

Randall V. Martin

Keyword(s):

Vibrational Spectroscopy ◽

Cross Sections ◽

Nuclear Spin ◽

Electronic Spectroscopy ◽

Rotational Spectroscopy ◽

Absorption Cross ◽

Transfer Processes ◽

Atmospheric Spectroscopy ◽

Quantitative Spectroscopy ◽

Broad Overview

This chapter provides a broad overview of the spectroscopic principles required in order to perform quantitative spectroscopy of atmospheres. It couples the details of atmospheric spectroscopy with the radiative transfer processes and also with the assessment of rotational, vibrational, and electronic spectroscopic measurements of atmospheres. The principles apply from line-resolved measurements (chiefly microwave through infrared) through ultraviolet and visible measurements employing absorption cross sections developed from individual transitions. The chapter introduces Einstein coefficients before in turn discussing rotational spectroscopy, vibrational spectroscopy, nuclear spin, and electronic spectroscopy.

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Black carbon and dust in the Third Pole glaciers: revaluated concentrations, mass absorption cross-sections and contributions to glacier ablation

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.147746 ◽

2021 ◽

pp. 147746

Author(s):

Yang Li ◽

Shichang Kang ◽

Xuelei Zhang ◽

Jizu Chen ◽

Julia Schmale ◽

...

Keyword(s):

Black Carbon ◽

Cross Sections ◽

Absorption Cross ◽

The Third ◽

Mass Absorption ◽

Glacier Ablation

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Ultraviolet Absorption Cross-Sections of Ammonia at Elevated Temperatures for Nonintrusive Quantitative Detection in Combustion Environments

Applied Spectroscopy ◽

10.1177/0003702821990445 ◽

2021 ◽

pp. 000370282199044

Author(s):

Wubin Weng ◽

Shen Li ◽

Marcus Aldén ◽

Zhongshan Li

Keyword(s):

Cross Section ◽

Cross Sections ◽

Absorption Cross Section ◽

Elevated Temperatures ◽

Uv Absorption ◽

Energy Utilization ◽

Quantitative Detection ◽

Absorption Cross ◽

Hot Gas

Ammonia (NH3) is regarded as an important nitrogen oxides (NOx) precursor and also as an effective reductant for NOx removal in energy utilization through combustion, and it has recently become an attractive non-carbon alternative fuel. To have a better understanding of thermochemical properties of NH3, accurate in situ detection of NH3 in high temperature environments is desirable. Ultraviolet (UV) absorption spectroscopy is a feasible technique. To achieve quantitative measurements, spectrally resolved UV absorption cross-sections of NH3 in hot gas environments at different temperatures from 295 K to 590 K were experimentally measured for the first time. Based on the experimental results, vibrational constants of NH3 were determined and used for the calculation of the absorption cross-section of NH3 at high temperatures above 590 K using the PGOPHER software. The investigated UV spectra covered the range of wavelengths from 190 nm to 230 nm, where spectral structures of the [Formula: see text] transition of NH3 in the umbrella bending mode, v2, were recognized. The absorption cross-section was found to decrease at higher temperatures. For example, the absorption cross-section peak of the (6, 0) vibrational band of NH3 decreases from ∼2 × 10−17 to ∼0.5 × 10−17 cm2/molecule with the increase of temperature from 295 K to 1570 K. Using the obtained absorption cross-section, in situ nonintrusive quantification of NH3 in different hot gas environments was achieved with a detection limit varying from below 10 parts per million (ppm) to around 200 ppm as temperature increased from 295 K to 1570 K. The quantitative measurement was applied to an experimental investigation of NH3 combustion process. The concentrations of NH3 and nitric oxide (NO) in the post flame zone of NH3–methane (CH4)–air premixed flames at different equivalence ratios were measured.

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