Dissertation / PhD Thesis/Book

PreJuSER-62637

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Hydratation und Dehydratation in der tropischen Tropopausenschicht

Silva dos Santos, F. H. (Corresponding author)FZJ*

2008
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/3223

Report No.: Juel-4267

Abstract: The topic of this PhD thesis is the abundance of water vapour at the tropical tropopause. For this purpose measurements were made with the hygrometer FISH of ICG-1 from the Research Centre J¨ulich onboard the hight altitude aircraft Geophysica. This experimental work was carried out during two field campaigns in 2005 in Brazil (TROCCINOX) and Australia (SCOUT-O3). Additional data from two other tropical campaigns in Africa (AMMA) and over the Indian Ocean (APE-THESEO) were also analysed. A seasonal cycle of the tropopause height was confirmed by the observed vertical profiles of water vapour (hygropause), saturation over ice and temperature (cold point tropopause). The data collected during the transfer flights show a seasonal motion of the tropical tropopause. The water mixing ratio in the UT/LS region is controlled by two different regimes: local processes below about 410 K potential temperature and large scale processes above this level. A propagation of water vapour in the stratosphere consistent with the tape recorder theory is shown. Particles were measured during the flights at the upper boundary of convection. These particles evaporate before they sediment again below the tropopause. Futhermore the data show that a significant quantity of water — more than previously thought — is transported into the stratosphere by means of convection. Isolated profiles over Africa show increased water vapour in unsaturated air masses in clear sky. Analysis of backward trajectories in conjunction with satellite data show that it originates from areas with overshooting convection. The background of the measured water concentration over Africa during the measurements was affected by asian monsoon regions.

Note: Record converted from VDB: 12.11.2012
Note: Wuppertal, Univ., Diss., 2008

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Research Program(s):

1. Atmosphäre und Klima (P22)

Appears in the scientific report 2008

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Database coverage:

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