Intercomparison of ultraviolet photometry and gas‐phase titration techniques for ozone reference standards at ambient levels

Tanimoto, Hiroshi; Mukai, Hirofumi; Hashimoto, Shigeru; Norris, James E

doi:10.1029/2005jd006983

Cited by 18 publications

(22 citation statements)

References 29 publications

(38 reference statements)

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“…Sediment concentrations are usually high, much higher than what is predicted from the water levels (Jurado et al 2007;Dueri et al 2008). In open oceans, sediments can be considered as a final sink, and the deep ocean is together with atmospheric degradation one of the two main sinks of POPs Lohmann et al 2006). However, even though coastal sediments are an important reservoir of POPs globally (Jonsson et al 2003), they are not a final sink of POPs.…”

Section: Cycle Of Organic Pollutants In Transitional and Coastal Watersmentioning

confidence: 98%

Organic Pollutants in Coastal Waters, Sediments, and Biota: A Relevant Driver for Ecosystems During the Anthropocene?

Dachs

Méjanelle

2010

Estuaries and Coasts

101

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The total number of synthetic organic chemicals introduced to the environment by humans has never been quantified, but it is not lower than thousands. A fraction of these chemicals have toxic effects to coastal organisms and presumably affect ecosystems structure and function. During the last decades, some of the processes affecting the transport, degradation, and fate of a limited number of chemicals have been studied, and the rising concern for environmental risk of organic chemical has lead to the regulation of a few of them by national and international organisms. However, the environmental inventory of organic pollutants is far from being quantified, and current methodologies used in most toxicological tests only allow to determine effects of individual chemicals to organisms. There are major limitations on appropriate methodologies to assess the effects of organic pollutants at population and ecosystem levels and the effects induced by complex mixtures of organic pollutants present in natural environments. The modification of the composition of the biosphere by a myriad of organic pollutants at ultra-trace levels is not yet regarded as another vector of environmental change which is irreversible due to the persistent character of many of these chemicals and due to its global coverage. Here, we claim that the modification of the atmosphere, water, sediments, and biota composition is a factor to be taken into account in coastal ecosystems, and that its pressure on the environment has been exponentially increasing during the last six decades of the anthropocene.

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Section: Cycle Of Organic Pollutants In Transitional and Coastal Watersmentioning

confidence: 98%

Organic Pollutants in Coastal Waters, Sediments, and Biota: A Relevant Driver for Ecosystems During the Anthropocene?

Dachs

Méjanelle

2010

Estuaries and Coasts

101

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“…A second ozone standard is gas phase titration of ozone against nitric oxide gas standards. Differences between GPT and standard UV photometry have been investigated by Tanimoto et al (2006) and Viallon et al (2006bViallon et al ( , 2016 and found to be very small (~0.3%) when the newer values of the ozone absorption cross-sections (see Section 2.2.1) are used . Thus GPT supports the proposed decrease in the ozone absorption cross-section at 253.65 nm.…”

Section: Standards For the Measurement Of Ozone In The Atmospherementioning

confidence: 99%

Tropospheric Ozone Assessment Report: Tropospheric ozone from 1877 to 2016, observed levels, trends and uncertainties

Tarasick

Galbally

Cooper

et al. 2019

Elementa: Science of the Anthropocene

158

168

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From the earliest observations of ozone in the lower atmosphere in the 19th century, both measurement methods and the portion of the globe observed have evolved and changed. These methods have different uncertainties and biases, and the data records differ with respect to coverage (space and time), information content, and representativeness. In this study, various ozone measurement methods and ozone datasets are reviewed and selected for inclusion in the historical record of background ozone levels, based on relationship of the measurement technique to the modern UV absorption standard, absence of interfering pollutants, representativeness of the well-mixed boundary layer and expert judgement of their credibility. There are significant uncertainties with the 19th and early 20th-century measurements related to interference of other gases. Spectroscopic methods applied before 1960 have likely underestimated ozone by as much as 11% at the surface and by about 24% in the free troposphere, due to the use of differing ozone absorption coefficients.There is no unambiguous evidence in the measurement record back to 1896 that typical mid-latitude background surface ozone values were below about 20 nmol mol -1 , but there is robust evidence for increases in the temperate and polar regions of the northern hemisphere of 30-70%, with large uncertainty, between the period of historic observations, 1896-1975, and the modern period (1990-2014). Independent historical observations from balloons and aircraft indicate similar changes in the free troposphere. Changes in the southern hemisphere are much less. Regional representativeness of the available observations remains a potential source of large errors, which are difficult to quantify.The great majority of validation and intercomparison studies of free tropospheric ozone measurement methods use ECC ozonesondes as reference. Compared to UV-absorption measurements they show a modest (~1-5% ±5%) high bias in the troposphere, but no evidence of a change with time. Umkehr, lidar, and FTIR methods all show modest low biases relative to ECCs, and so, using ECC sondes as a transfer standard, all appear to agree to within one standard deviation with the modern UV-absorption standard. Other sonde types show an increase of 5-20% in sensitivity to tropospheric ozone from 1970-1995. Biases and standard deviations of satellite retrieval comparisons are often 2-3 times larger than those of other free tropospheric measurements. The lack of information on temporal changes of bias for satellite measurements of tropospheric ozone is an area of concern for long-term trend studies.

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“…The operating principle of the laser photometer and the SRP are briefly described in this section. More details of the SRP's principle and its capabilities have been presented by Paur et al [2003]. The major changes made to obtain the laser ozone photometer, which are in its optical setup, are further described.…”

Section: Measurement Setupmentioning

confidence: 99%

Relative measurements of ozone absorption cross‐sections at three wavelengths in the Hartley band using a well‐defined UV laser beam

et al. 2012

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[1] New measurements of absorption cross sections of ozone are reported using a photometer with a well-defined UV laser beam at three different wavelengths in the Hartley band, by comparison with the conventional cross-section value at the mercury line wavelength of 253.65 nm. Reported measurement results and uncertainties are dependent on the value of the cross section used at 253.65 nm. Using the value determined by Hearn (1961), ozone absorption cross-section values of 9.64 Â 10 À18 , 10.61 Â 10 À18 , and 11.26 Â 10 À18 cm 2 molecule À1 are reported at wavelengths of 244.06, 248.32, and 257.34 nm, respectively; whereas, use of the Malicet (1995) value leads to ozone absorption cross-section values of 9.50 Â 10 À18 , 10.45 Â 10 À18 , and 11.12 Â 10 À18 cm 2 molecule À1 , respectively. In all cases, the uncertainty of the results is dominated by the contribution from the cross-section value at 253.65 nm. The experimental setup described in this article not only provides a minor contribution to the entire reported measurement uncertainties but also confirms the internal consistency of previously published ozone absorption cross-section data sets and demonstrates the biases that can be introduced by changing data sets. The results are important for the accurate measurement of ozone concentrations in the troposphere by UV absorption methods and also for all measurements of ozone concentration in the atmosphere by spectroscopic methods for which the values of the absorption cross sections have been scaled to measured values in the Hartley band.Citation: Petersen, M., J. Viallon, P. Moussay, and R. I. Wielgosz (2012), Relative measurements of ozone absorption cross-sections at three wavelengths in the Hartley band using a well-defined UV laser beam,

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Intercomparison of ultraviolet photometry and gas‐phase titration techniques for ozone reference standards at ambient levels

Cited by 18 publications

References 29 publications

Organic Pollutants in Coastal Waters, Sediments, and Biota: A Relevant Driver for Ecosystems During the Anthropocene?

Organic Pollutants in Coastal Waters, Sediments, and Biota: A Relevant Driver for Ecosystems During the Anthropocene?

Tropospheric Ozone Assessment Report: Tropospheric ozone from 1877 to 2016, observed levels, trends and uncertainties

Relative measurements of ozone absorption cross‐sections at three wavelengths in the Hartley band using a well‐defined UV laser beam

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