Publication Abstracts

Parrish et al. 2021

Parrish, D.D., R.G. Derwent, S.T. Turnock, F.M. O'Connor, J. Staehelin, S.E. Bauer, M. Deushi, N. Oshima, K. Tsigaridis, T. Wu, and J. Zhang, 2021: Anthropogenic reversal of the natural ozone gradient between northern and southern mid-latitudes. Atmos. Chem. Phys., 21, no. 12, 9669-9679, doi:10.5194/acp-21-9669-2021.

Our quantitative understanding of natural tropospheric ozone concentrations is limited by the paucity of reliable measurements before the 1980s. We utilize the existing measurements to compare the long-term ozone changes that occurred within the marine boundary layer at northern and southern mid-latitudes. Since 1950 ozone concentrations have increased by a factor of 2.1±0.2 in the northern hemisphere (NH) and are presently larger than in the southern hemisphere (SH), where only a much smaller increase has occurred. These changes are attributed to increased ozone production driven by anthropogenic emissions of photochemical ozone precursors that increased with industrial development. The greater ozone concentrations and increases in the NH are consistent with the predominant location of anthropogenic emission sources in that hemisphere. The available measurements indicate that this interhemispheric gradient was much smaller, and was likely reversed in the natural troposphere with higher concentrations in the SH. Six Earth System Model (ESM) simulations indicate similar total NH increases (1.9 with a standard deviation of 0.3), but they occurred more slowly over a longer time period, and the ESMs do not find higher pre-industrial ozone in the SH. Several uncertainties in the ESMs may cause these model-measurement disagreements: the assumed natural nitrogen oxide emissions may be too large, the relatively greater fraction of ozone injected by stratosphere-troposphere exchange to the NH may be overestimated, ozone surface deposition to ocean and land surfaces may not be accurately simulated, and model treatment of emissions of biogenic hydrocarbons and their photochemistry may not be adequate.

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BibTeX Citation

  author={Parrish, D. D. and Derwent, R. G. and Turnock, S. T. and O'Connor, F. M. and Staehelin, J. and Bauer, S. E. and Deushi, M. and Oshima, N. and Tsigaridis, K. and Wu, T. and Zhang, J.},
  title={Anthropogenic reversal of the natural ozone gradient between northern and southern mid-latitudes},
  journal={Atmos. Chem. Phys.},

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RIS Citation

ID  - pa09600r
AU  - Parrish, D. D.
AU  - Derwent, R. G.
AU  - Turnock, S. T.
AU  - O'Connor, F. M.
AU  - Staehelin, J.
AU  - Bauer, S. E.
AU  - Deushi, M.
AU  - Oshima, N.
AU  - Tsigaridis, K.
AU  - Wu, T.
AU  - Zhang, J.
PY  - 2021
TI  - Anthropogenic reversal of the natural ozone gradient between northern and southern mid-latitudes
JA  - Atmos. Chem. Phys.
VL  - 21
IS  - 12
SP  - 9669
EP  - 9679
DO  - 10.5194/acp-21-9669-2021
ER  -

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