On the role of tropopause folds in summertime tropospheric ozone over the eastern Mediterranean and the Middle East
We study the contribution of tropopause folds in the summertime pool of tropospheric ozone over the eastern Mediterranean and the Middle East (EMME) with the aid of the ECHAM5/MESSy Atmospheric Chemistry (EMAC) model. Tropopause fold events in EMAC simulations were identified with a 3-D labeling...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-11-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/16/14025/2016/acp-16-14025-2016.pdf |
| Summary: | We study the contribution of tropopause folds in the
summertime pool of tropospheric ozone over the eastern Mediterranean and the
Middle East (EMME) with the aid of the ECHAM5/MESSy Atmospheric Chemistry (EMAC) model. Tropopause fold events in EMAC simulations were
identified with a 3-D labeling algorithm that detects folds at grid points
where multiple crossings of the dynamical tropopause are computed.
Subsequently the events featuring the largest horizontal and vertical extent
were selected for further study. For the selection of these events we
identified a significant contribution of the stratospheric ozone reservoir to
the high concentrations of ozone in the middle and lower free troposphere over
the EMME. A distinct increase of ozone is found over the EMME in the middle
troposphere during summer as a result of the fold activity, shifting towards
the southeast and decreasing altitude. We find that the interannual
variability of near-surface ozone over the eastern Mediterranean (EM) during
summer is related to that of both tropopause folds and ozone in the free
troposphere. |
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| ISSN: | 1680-7316 1680-7324 |