Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter
A long-term climatology of air mass transport through the tropical tropopause layer (TTL) is presented, covering the period from 1962–2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic traje...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2008-02-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/8/813/2008/acp-8-813-2008.pdf |
| _version_ | 1818487599674687488 |
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| author | K. Krüger S. Tegtmeier M. Rex |
| author_facet | K. Krüger S. Tegtmeier M. Rex |
| author_sort | K. Krüger |
| collection | DOAJ |
| description | A long-term climatology of air mass transport through the tropical tropopause layer (TTL) is presented, covering the period from 1962–2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. We demonstrate the improved performance of such an approach compared to previous studies using vertical winds from meteorological analyses. Within the upper part of the TTL, the averaged diabatic ascent is 0.5 K/day during Northern Hemisphere (NH) winters 1992–2001. Climatological maps show a cooling and strengthening of this part of the residual circulation during the 1990s and early 2000s compared to the long-term mean. Lagrangian cold point (LCP) fields show systematic differences for varying time periods and natural forcing components. The interannual variability of LCP temperature and density fields is found to be influenced by volcanic eruptions, El Niño Southern Oscillation (ENSO), Quasi-Biennial Oscillation (QBO) and the solar cycle. The coldest and driest TTL is reached during QBO easterly phase and La Niña over the western Pacific, whereas during volcanic eruptions, El Niño and QBO westerly phase it is warmer and less dry. |
| first_indexed | 2024-12-10T16:40:07Z |
| format | Article |
| id | doaj.art-33d1eea7390046238fbd6d87ae1c4560 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-10T16:40:07Z |
| publishDate | 2008-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-33d1eea7390046238fbd6d87ae1c45602022-12-22T01:41:16ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242008-02-0184813823Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winterK. KrügerS. TegtmeierM. RexA long-term climatology of air mass transport through the tropical tropopause layer (TTL) is presented, covering the period from 1962–2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. We demonstrate the improved performance of such an approach compared to previous studies using vertical winds from meteorological analyses. Within the upper part of the TTL, the averaged diabatic ascent is 0.5 K/day during Northern Hemisphere (NH) winters 1992–2001. Climatological maps show a cooling and strengthening of this part of the residual circulation during the 1990s and early 2000s compared to the long-term mean. Lagrangian cold point (LCP) fields show systematic differences for varying time periods and natural forcing components. The interannual variability of LCP temperature and density fields is found to be influenced by volcanic eruptions, El Niño Southern Oscillation (ENSO), Quasi-Biennial Oscillation (QBO) and the solar cycle. The coldest and driest TTL is reached during QBO easterly phase and La Niña over the western Pacific, whereas during volcanic eruptions, El Niño and QBO westerly phase it is warmer and less dry.http://www.atmos-chem-phys.net/8/813/2008/acp-8-813-2008.pdf |
| spellingShingle | K. Krüger S. Tegtmeier M. Rex Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter Atmospheric Chemistry and Physics |
| title | Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter |
| title_full | Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter |
| title_fullStr | Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter |
| title_full_unstemmed | Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter |
| title_short | Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter |
| title_sort | long term climatology of air mass transport through the tropical tropopause layer ttl during nh winter |
| url | http://www.atmos-chem-phys.net/8/813/2008/acp-8-813-2008.pdf |
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