Diagnostics of the tropical tropopause layer from in-situ observations and CCM data

A suite of diagnostics is applied to in-situ aircraft measurements and one Chemistry-Climate Model (CCM) data to characterize the vertical structure of the Tropical Tropopause Layer (TTL). The diagnostics are based on th
A suite of diagnostics is applied to in-situ aircraft measurements and one Chemistry-Climate Model (CCM) data to characterize the vertical structure of the Tropical Tropopause Layer (TTL). The diagnostics are based on the vertical tracers profiles, relative vertical tracers gradients, and tracer-tracer relationships in the tropical Upper Troposphere/Lower Stratosphere (UT/LS), using tropopause coordinates.
Observations come from the four tropical campaigns performed from 1998 to 2006 with the research aircraft Geophysica and have been directly compared to the output of the ECHAM5/MESSy CCM. The model vertical resolution in the TTL allows for appropriate comparison with high-resolution aircraft observations and the diagnostics used highlight common TTL features between the model and the observational data.
The analysis of the vertical profiles of water vapour, ozone, and nitrous oxide, in both the observations and the model, shows that concentration mixing ratios exhibit a strong gradient change across the tropical tropopause, due to the role of this latter as a transport barrier and that transition between the tropospheric and stratospheric regimes occurs within a finite layer. The use of relative vertical ozone gradients, in addition to the vertical profiles, helps to highlight the region where this transition occurs and allows to give an estimate of its thickness. The analysis of the CO-O3 and H2O-O3 scatter plots and of the Probability Distribution Function (PDF) of the H2O-O3 pair completes this picture as it allows to better distinguish tropospheric and stratospheric regimes that can be identified, first, by their differing chemical composition. 
The joint analysis and comparison of observed and modelled data allows us to evaluate the capability of the model in reproducing the observed vertical structure of the TTL and its variability, and also to assess whether observations from particular regions on a monthly timescale can be representative of the fine scale mean structure of the Tropical Tropopause Layer.
show moreshow less

Download full text files

Export metadata

  • Export Bibtex
  • Export RIS

Additional Services

    Share in Twitter Search Google Scholar
Metadaten
Author:Elisa Palazzi, Federico Fierli, Francesco Cairo, Chiara Cagnazzo, Guido Di Donfrancesco, Elisa Manzini, Fabrizio Ravegnani, Cornelius Schiller, Francesco D'Amato, C.-Michael Volk
URN:urn:nbn:de:hebis:30:3-267487
URL:http://www.atmos-chem-phys-discuss.net/9/11659/2009/
DOI:http://dx.doi.org/10.5194/acpd-9-11659-2009
ISSN:1680-7375
ISSN:1680-7367
Parent Title (English):Atmospheric chemistry and physics / Discussions, 9.2009, S. 11659-11698
Publisher:European Geosciences Union
Place of publication:Katlenburg-Lindau
Document Type:Article
Language:English
Date of Publication (online):2009/05/12
Date of first Publication:2009/05/12
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2012/10/15
Volume:9
Pagenumber:40
First Page:11659
Last Page:11698
Note:
© Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License.
HeBIS PPN:358295211
Institutes:Geowissenschaften
Dewey Decimal Classification:550 Geowissenschaften
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - Namensnennung 3.0

$Rev: 11761 $