Evolution of the intensity and duration of the Southern Hemisphere stratospheric polar vortex edge for the period 1979–2020
<p>The intensity and position of the Southern Hemisphere stratospheric polar vortex edge is evaluated as a function of equivalent latitude over the period 1979–2020 on three isentropic levels (475, 550, and 675 K) from ECMWF ERA-Interim reanalysis. The study also includes an analysis of the on...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-03-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/22/4187/2022/acp-22-4187-2022.pdf |
| _version_ | 1818393724716056576 |
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| author | A. Lecouffe S. Godin-Beekmann A. Pazmiño A. Hauchecorne |
| author_facet | A. Lecouffe S. Godin-Beekmann A. Pazmiño A. Hauchecorne |
| author_sort | A. Lecouffe |
| collection | DOAJ |
| description | <p>The intensity and position of the Southern Hemisphere stratospheric polar vortex edge is evaluated as a function of equivalent latitude over the period 1979–2020 on three isentropic levels (475, 550, and 675 K) from ECMWF ERA-Interim reanalysis. The study also includes an analysis of the onset and breakup dates of the polar vortex, which are determined from wind thresholds (e.g., 15.2, 20, and 25 m s<span class="inline-formula"><sup>−1</sup></span>) along the vortex edge. The vortex edge is stronger in late winter, during September–October–November, with the period of strongest intensity occurring later at the lowermost level. During the same period, we observe a lower variability of the edge position. A long-term increase in the vortex edge intensity and break-up date is observed during 1979–1999, linked to the increase in the ozone hole. A long-term decrease in the vortex onset date related to the 25 m s<span class="inline-formula"><sup>−1</sup></span> wind threshold is also observed at 475 K during this period. The solar cycle and to a lower extent the quasi-biennial oscillation (QBO) and El Niño–Southern Oscillation (ENSO) modulate the interannual evolution of the strength of the vortex edge and the vortex breakup dates. A stronger vortex edge and longer vortex duration are observed in solar minimum (minSC) years, with the QBO and ENSO further modulating the solar cycle influence, especially at 475 and 550 K: during west QBO (wQBO) phases, the difference between vortex edge intensity for minSC and maxSC years is smaller than during east QBO (eQBO) phases. The polar vortex edge is stronger and lasts longer for maxSC/wQBO years than for maxSC/eQBO years. ENSO has a weaker impact but the vortex edge is somewhat stronger during cold ENSO phases for both minSC and maxSC years.</p> |
| first_indexed | 2024-12-14T05:49:52Z |
| format | Article |
| id | doaj.art-f1f0db0881b7428882a61e3ad2729a4e |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-14T05:49:52Z |
| publishDate | 2022-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-f1f0db0881b7428882a61e3ad2729a4e2022-12-21T23:14:46ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242022-03-01224187420010.5194/acp-22-4187-2022Evolution of the intensity and duration of the Southern Hemisphere stratospheric polar vortex edge for the period 1979–2020A. LecouffeS. Godin-BeekmannA. PazmiñoA. Hauchecorne<p>The intensity and position of the Southern Hemisphere stratospheric polar vortex edge is evaluated as a function of equivalent latitude over the period 1979–2020 on three isentropic levels (475, 550, and 675 K) from ECMWF ERA-Interim reanalysis. The study also includes an analysis of the onset and breakup dates of the polar vortex, which are determined from wind thresholds (e.g., 15.2, 20, and 25 m s<span class="inline-formula"><sup>−1</sup></span>) along the vortex edge. The vortex edge is stronger in late winter, during September–October–November, with the period of strongest intensity occurring later at the lowermost level. During the same period, we observe a lower variability of the edge position. A long-term increase in the vortex edge intensity and break-up date is observed during 1979–1999, linked to the increase in the ozone hole. A long-term decrease in the vortex onset date related to the 25 m s<span class="inline-formula"><sup>−1</sup></span> wind threshold is also observed at 475 K during this period. The solar cycle and to a lower extent the quasi-biennial oscillation (QBO) and El Niño–Southern Oscillation (ENSO) modulate the interannual evolution of the strength of the vortex edge and the vortex breakup dates. A stronger vortex edge and longer vortex duration are observed in solar minimum (minSC) years, with the QBO and ENSO further modulating the solar cycle influence, especially at 475 and 550 K: during west QBO (wQBO) phases, the difference between vortex edge intensity for minSC and maxSC years is smaller than during east QBO (eQBO) phases. The polar vortex edge is stronger and lasts longer for maxSC/wQBO years than for maxSC/eQBO years. ENSO has a weaker impact but the vortex edge is somewhat stronger during cold ENSO phases for both minSC and maxSC years.</p>https://acp.copernicus.org/articles/22/4187/2022/acp-22-4187-2022.pdf |
| spellingShingle | A. Lecouffe S. Godin-Beekmann A. Pazmiño A. Hauchecorne Evolution of the intensity and duration of the Southern Hemisphere stratospheric polar vortex edge for the period 1979–2020 Atmospheric Chemistry and Physics |
| title | Evolution of the intensity and duration of the Southern Hemisphere stratospheric polar vortex edge for the period 1979–2020 |
| title_full | Evolution of the intensity and duration of the Southern Hemisphere stratospheric polar vortex edge for the period 1979–2020 |
| title_fullStr | Evolution of the intensity and duration of the Southern Hemisphere stratospheric polar vortex edge for the period 1979–2020 |
| title_full_unstemmed | Evolution of the intensity and duration of the Southern Hemisphere stratospheric polar vortex edge for the period 1979–2020 |
| title_short | Evolution of the intensity and duration of the Southern Hemisphere stratospheric polar vortex edge for the period 1979–2020 |
| title_sort | evolution of the intensity and duration of the southern hemisphere stratospheric polar vortex edge for the period 1979 2020 |
| url | https://acp.copernicus.org/articles/22/4187/2022/acp-22-4187-2022.pdf |
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