Contribution of mixing to the upward transport across the TTL
| Autor: | S. Viciani, Ralph Müller, F. H. S. dos Santos, Gebhard Günther, Martin Riese, Hans Schlager, A. Ulanovsky, Laura L. Pan, Daniel S. McKenna, Cornelius Schiller, C. M. Volk, Paul Konopka, Fabrizio Ravegnani |
|---|---|
| Přispěvatelé: | Institut für Chemie und Dynamik der Geosphäre - Stratosphäre (ICG-1), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, Istituto di Scienze dell'Atmosfera e del Clima [Bologna] (ISAC), Consiglio Nazionale delle Ricerche (CNR), CAO, DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Institut für Meteorologie und Geophysik [Frankfurt], Goethe-Universität Frankfurt am Main, INOA, National Center for Atmospheric Research [Boulder] (NCAR) |
| Rok vydání: | 2006 |
| Předmět: |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean
Atmosphere Convection 010504 meteorology & atmospheric sciences Meteorology Advection 0207 environmental engineering Mesoscale meteorology 02 engineering and technology Atmospheric sciences 01 natural sciences Troposphere 13. Climate action ddc:550 Potential temperature Environmental science Outflow Tropopause 020701 environmental engineering Stratosphere 0105 earth and related environmental sciences |
| Zdroj: | Atmospheric Chemistry and Physics Discussions Atmospheric Chemistry and Physics Discussions, European Geosciences Union, 2006, 6 (6), pp.12217-12266 Atmospheric chemistry and physics / Discussions 6, 12217-12266 (2006). doi:10.5194/acpd-6-12217-2006 Atmospheric chemistry and physics 7, 3285-3308 (2007). doi:10.5194/acp-7-3285-2007 |
| ISSN: | 1680-7367 1680-7375 |
| DOI: | 10.5194/acpd-6-12217-2006 |
| Popis: | International audience; During the second part of the TROCCINOX campaign that took place in Brazil in early 2005, chemical species were measured on-board of the high altitude research aircraft Geophysica (ozone, water vapor, NO, NOy, CH4 and CO) in the altitude range up to 20 km (or up to 450 K potential temperature), i.e. spanning the TTL region roughly extending between 350 and 420 K. Analysis of transport across TTL is performed using a new version of the Chemical Lagrangian Model of the Stratosphere (CLaMS). In this new version, the stratospheric model has been extended to the earth surface. Above the tropopause, the isentropic and cross-isentropic advection in CLaMS is driven by ECMWF winds and heating/cooling rates derived from a radiation calculation. Below the tropopause the model smoothly transforms from the isentropic to hybrid-pressure coordinate and, in this way, takes into account the effect of large-scale convective transport as implemented in the ECMWF vertical wind. As with other CLaMS simulations, the irreversible transport, i.e. mixing, is controlled by the local horizontal strain and vertical shear rates. Stratospheric and tropospheric signatures in the TTL can be seen both in the observation and in the model. The composition of air above ?350 K is mainly controlled by mixing on a time scale of weeks or even months. Based on CLaMS transport studies where mixing can be completely switched off, we deduce that vertical mixing, mainly driven by the vertical shear in the outflow regions of the large-scale convection and in the vicinity of the subtropical jets, is necessary to understand the upward transport of the tropospheric air from the main convective outflow around 350 K up to the tropical tropopause around 380 K. This mechanism is most effective if the outflow of the mesoscale convective systems interacts with the subtropical jets. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|