Three‐dimensional climatological distribution of tropospheric OH: Update and evaluation

Spivakovsky, C. M.; Logan, Jennifer A.; Montzka, S. A.; Balkanski, Yves; Foreman-Fowler, Michael S.; Jones, Dylan B. A.; Horowitz, Larry W.; Fusco, Andrew C.; Brenninkmeijer, C. A. M.; Prather, Michael J.; Wofsy, Steven C.; Chen, Xinyu

doi:10.1029/1999jd901006

Cited by 819 publications

(927 citation statements)

References 171 publications

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“…The lesser concentration of •OH was selected to account for concentrations of •OH likely to occur in more remote regions and at higher latitudes, for example in Canada. Global concentrations of •OH have been compiled and a concentration of 0.9 × 10 6 •OH molecules cm -3 was reported for April in the Central Valley of California and increasing to 1.46 × 10 6 in July and decreasing to 0.63 × 10 6 in October (Spivakovsky et al 2000). At the latitude of Iowa, USA, concentrations of •OH in summer were approximately 80-85% of the concentrations observed in California.…”

Section: Physical-chemical Properties Of Chlorpyrifos and Chlorpyrifomentioning

confidence: 99%

Fate in the Environment and Long-Range Atmospheric Transport of the Organophosphorus Insecticide, Chlorpyrifos and Its Oxon

Mackay

Giesy

Solomon

2014

Ecological Risk Assessment for Chlorpyrifos in Terrestrial and Aquatic Systems in the United States

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Section: Physical-chemical Properties Of Chlorpyrifos and Chlorpyrifomentioning

confidence: 99%

Fate in the Environment and Long-Range Atmospheric Transport of the Organophosphorus Insecticide, Chlorpyrifos and Its Oxon

Mackay

Giesy

Solomon

2014

Ecological Risk Assessment for Chlorpyrifos in Terrestrial and Aquatic Systems in the United States

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“…Monthly average temperature, rainfall, and wind speed for the region were from Environment Canada's online repository of climate normals for Fort McMurray from 1971 to 2000 (35). Monthly OH radical concentrations were estimated based on Spivakovsky et al (36). A complete list of the values used for environmental parameters and their respective sources, can be found in the SI Appendix, Table S1.…”

Section: Methodsmentioning

confidence: 99%

Evaluating officially reported polycyclic aromatic hydrocarbon emissions in the Athabasca oil sands region with a multimedia fate model

Parajulee

Wania

2014

Proc. Natl. Acad. Sci. U.S.A.

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Significance Our study shows that emissions of polycyclic aromatic hydrocarbons estimated in environmental impact assessments conducted to approve developments in the Athabasca oil sands region are likely too low. This finding implies that environmental concentrations in exposure-relevant media, such as air, water, and food, estimated using those emissions may also be too low. The potential therefore exists that estimation of future risk to humans and wildlife because of surface mining activity in the Athabasca oil sands region has been underestimated.

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“…A 12-box model of atmospheric transport and chemistry was used to simulate baseline mole fractions, which assumed that the atmosphere was divided into four zonal bands (90-30 • N, 30-0 • N, 0-30 • S and 30-90 • S) and at 500 and 200 hPa vertically (Cunnold et al, 1994;Rigby et al, 2013). The model uses an annually repeating, monthly varying hydroxyl radical (OH) field from Spivakovsky et al (2000), which has been adjusted to match the observed trend in methyl chloroform (e.g. Rigby et al, 2013).…”

Section: Global Atmospheric Modelmentioning

confidence: 99%

Recent increases in the atmospheric growth rate and emissions of HFC-23 (CHF<sub>3</sub>) and the link to HCFC-22 (CHClF<sub>2</sub>) production

et al. 2018

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Abstract. High frequency measurements of trifluoromethane (HFC-23, CHF 3 ), a potent hydrofluorocarbon greenhouse gas, largely emitted to the atmosphere as a by-product of the production of the hydrochlorofluorocarbon HCFC-22 (CHClF 2 ), at five core stations of the Advanced Global Atmospheric Gases Experiment (AGAGE) network, combined with measurements on firn air, old Northern Hemisphere air samples and Cape Grim Air Archive (CGAA) air samples, are used to explore the current and historic changes in the atmospheric abundance of HFC-23. These measurements are used in combination with the AGAGE 2-D atmospheric 12-box model and a Bayesian inversion methodology to determine model atmospheric mole fractions and the history of global HFC-23 emissions. The global modelled annual mole fraction of HFC-23 in the background atmosphere was 28.9 ± 0.6 pmol mol −1 at the end of 2016, representing a 28 % increase from 22.6 ± 0.4 pmol mol −1 in 2009. Over the same time frame, the modelled mole fraction of HCFC-22 increased by 19 % from 199 ± 2 to 237 ± 2 pmol mol −1 . However, unlike HFC-23, the annual average HCFC-22 growth rate slowed from 2009 to 2016 at an annual average rate of −0.5 pmol mol −1 yr −2 . This slowing atmospheric growth is consistent with HCFC-22 moving from dispersive (high fractional emissions) to feedstock (low fractional emissions) uses, with HFC-23 emissions remaining as a consequence of incomplete mitigation from all HCFC-22 production.Our results demonstrate that, following a minimum in HFC-23 global emissions in 2009 of 9.6 ± 0.6, emissions increased to a maximum in 2014 of 14.5 ± 0.6 Gg yr −1 and then declined to 12.7 ± 0.6 Gg yr −1 (157 Mt CO 2 eq. yr −1 ) in 2016. The 2009 emissions minimum is consistent with estimates based on national reports and is likely a response to the implementation of the Clean Development Mechanism (CDM) to mitigate HFC-23 emissions by incineration in developing (non-Annex 1) countries under the Kyoto Protocol. Our derived cumulative emissions of HFC-23 during 2010-2016 were 89 ± 2 Gg (1.1 ± 0.2 Gt CO 2 eq.), which led to an increase in radiative forcing of 1.0 ± 0.1 mW m −2 over the same period. Although the CDM had reduced global HFC-23 emissions, it cannot now offset the higher emissions from increasing HCFC-22 production in non-Annex 1 countries, as the CDM was closed to new entrants in 2009. We also find that the cumulative European HFC-23 emissions from 2010 to 2016 were ∼ 1.3 Gg, corresponding to just 1.5 % ofPublished by Copernicus Publications on behalf of the European Geosciences Union. The majority of the increase in global HFC-23 emissions since 2010 is attributed to a delay in the adoption of mitigation technologies, predominantly in China and East Asia. However, a reduction in emissions is anticipated, when the Kigali 2016 amendment to the Montreal Protocol, requiring HCFC and HFC production facilities to introduce destruction of HFC-23, is fully implemented.

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Three‐dimensional climatological distribution of tropospheric OH: Update and evaluation

Cited by 819 publications

References 171 publications

Fate in the Environment and Long-Range Atmospheric Transport of the Organophosphorus Insecticide, Chlorpyrifos and Its Oxon

Fate in the Environment and Long-Range Atmospheric Transport of the Organophosphorus Insecticide, Chlorpyrifos and Its Oxon

Evaluating officially reported polycyclic aromatic hydrocarbon emissions in the Athabasca oil sands region with a multimedia fate model

Recent increases in the atmospheric growth rate and emissions of HFC-23 (CHF<sub>3</sub>) and the link to HCFC-22 (CHClF<sub>2</sub>) production

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Three‐dimensional climatological distribution of tropospheric OH: Update and evaluation

Cited by 819 publications

References 171 publications

Fate in the Environment and Long-Range Atmospheric Transport of the Organophosphorus Insecticide, Chlorpyrifos and Its Oxon

Fate in the Environment and Long-Range Atmospheric Transport of the Organophosphorus Insecticide, Chlorpyrifos and Its Oxon

Evaluating officially reported polycyclic aromatic hydrocarbon emissions in the Athabasca oil sands region with a multimedia fate model

Recent increases in the atmospheric growth rate and emissions of HFC-23 (CHF&lt;sub&gt;3&lt;/sub&gt;) and the link to HCFC-22 (CHClF&lt;sub&gt;2&lt;/sub&gt;) production

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Recent increases in the atmospheric growth rate and emissions of HFC-23 (CHF<sub>3</sub>) and the link to HCFC-22 (CHClF<sub>2</sub>) production