Quantification of topographic venting of boundary layer air to the free troposphere
Net vertical air mass export by thermally driven flows from the atmospheric boundary layer (ABL) to the free troposphere (FT) above deep Alpine valleys was investigated. The vertical export of pollutants above mountainous terrain is presently poorly represented in global chemistry transport models (...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2004-01-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/4/497/2004/acp-4-497-2004.pdf |
| _version_ | 1819077253125898240 |
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| author | S. Henne M. Furger S. Nyeki S. Nyeki M. Steinbacher B. Neininger S. F. J. de Wekker S. F. J. de Wekker J. Dommen N. Spichtinger A. Stohl A. Stohl A. S. H. Prévôt |
| author_facet | S. Henne M. Furger S. Nyeki S. Nyeki M. Steinbacher B. Neininger S. F. J. de Wekker S. F. J. de Wekker J. Dommen N. Spichtinger A. Stohl A. Stohl A. S. H. Prévôt |
| author_sort | S. Henne |
| collection | DOAJ |
| description | Net vertical air mass export by thermally driven flows from the atmospheric boundary layer (ABL) to the free troposphere (FT) above deep Alpine valleys was investigated. The vertical export of pollutants above mountainous terrain is presently poorly represented in global chemistry transport models (GCTMs) and needs to be quantified. Air mass budgets were calculated using aircraft observations obtained in deep Alpine valleys. The results show that on average 3 times the valley air mass is exported vertically per day under fair weather conditions. During daytime the type of valleys investigated in this study can act as an efficient 'air pump' that transports pollutants upward. The slope wind system within the valley plays an important role in redistributing pollutants. Nitrogen oxide emissions in mountainous regions are efficiently injected into the FT. This could enhance their ozone (O<sub>3</sub>) production efficiency and thus influences tropospheric pollution budgets. Once lifted to the FT above the Alps pollutants are transported horizontally by the synoptic flow and are subject to European pollution export. Forward trajectory studies show that under fair weather conditions two major pathways for air masses above the Alps dominate. Air masses moving north are mixed throughout the whole tropospheric column and further transported eastward towards Asia. Air masses moving south descend within the subtropical high pressure system above the Mediterranean. |
| first_indexed | 2024-12-21T18:54:15Z |
| format | Article |
| id | doaj.art-c617c875bafe4f37bbdc420800637d41 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-21T18:54:15Z |
| publishDate | 2004-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-c617c875bafe4f37bbdc420800637d412022-12-21T18:53:39ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242004-01-0142497509Quantification of topographic venting of boundary layer air to the free troposphereS. HenneM. FurgerS. NyekiS. NyekiM. SteinbacherB. NeiningerS. F. J. de WekkerS. F. J. de WekkerJ. DommenN. SpichtingerA. StohlA. StohlA. S. H. PrévôtNet vertical air mass export by thermally driven flows from the atmospheric boundary layer (ABL) to the free troposphere (FT) above deep Alpine valleys was investigated. The vertical export of pollutants above mountainous terrain is presently poorly represented in global chemistry transport models (GCTMs) and needs to be quantified. Air mass budgets were calculated using aircraft observations obtained in deep Alpine valleys. The results show that on average 3 times the valley air mass is exported vertically per day under fair weather conditions. During daytime the type of valleys investigated in this study can act as an efficient 'air pump' that transports pollutants upward. The slope wind system within the valley plays an important role in redistributing pollutants. Nitrogen oxide emissions in mountainous regions are efficiently injected into the FT. This could enhance their ozone (O<sub>3</sub>) production efficiency and thus influences tropospheric pollution budgets. Once lifted to the FT above the Alps pollutants are transported horizontally by the synoptic flow and are subject to European pollution export. Forward trajectory studies show that under fair weather conditions two major pathways for air masses above the Alps dominate. Air masses moving north are mixed throughout the whole tropospheric column and further transported eastward towards Asia. Air masses moving south descend within the subtropical high pressure system above the Mediterranean.http://www.atmos-chem-phys.net/4/497/2004/acp-4-497-2004.pdf |
| spellingShingle | S. Henne M. Furger S. Nyeki S. Nyeki M. Steinbacher B. Neininger S. F. J. de Wekker S. F. J. de Wekker J. Dommen N. Spichtinger A. Stohl A. Stohl A. S. H. Prévôt Quantification of topographic venting of boundary layer air to the free troposphere Atmospheric Chemistry and Physics |
| title | Quantification of topographic venting of boundary layer air to the free troposphere |
| title_full | Quantification of topographic venting of boundary layer air to the free troposphere |
| title_fullStr | Quantification of topographic venting of boundary layer air to the free troposphere |
| title_full_unstemmed | Quantification of topographic venting of boundary layer air to the free troposphere |
| title_short | Quantification of topographic venting of boundary layer air to the free troposphere |
| title_sort | quantification of topographic venting of boundary layer air to the free troposphere |
| url | http://www.atmos-chem-phys.net/4/497/2004/acp-4-497-2004.pdf |
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