Stratosphere Troposphere exchange (STE) is important to study as
it controls the chemical composition of the upper
troposphere/lower stratosphere (UTLS) and thus the radiative
balance of this region. STE also controls the transport of
chemicals into the stratosphere which are vital to ozone
depletion. The troposphere and the stratosphere have specific
chemical characteristics and the transition region between these
regions displays characteristics of both. Ozone and water vapour
concentrations can be used as tracers for the characteristics of
the troposphere and stratosphere. This thesis develops measures
in tracer space, which allow the determination of the strength
and depth of atmospheric mixing between the troposphere and the
stratosphere in extratropical regions.
The application of entropy as a measure of atmospheric mixing as
introduced by Patmore and Toumi [2006], is improved in this
study. This is a measure of how the ozone and water vapour mixing
ratios vary as a result of mixing. An additional metric to give
further information on the form of the mixing line in tracer
space is also developed. This measure uses the ozone and water
vapour mixing ratios at the boundaries of the transition region
(BO3 and BH2O). This study uses data from ozonesondes and
hygrometers, along with satellite data from the Atmospheric
Infrared Sounder (AIRS). The ozone product from AIRS is also
validated as part of this study.
The entropy, BO3 and BH2O measures from this study, are
successfully shown to detect regions of enhanced mixing in
comparison studies. A key comparison shows that the measures
developed in this study are able to produce comparable
conclusions to higher resolution aircraft data, with regards to
mixing. The separation of entropy, BO3 and BH2O, into different
categories allows mixing processes to be assigned to some of the
categories. Mixing is shown to have geographic preference, with
some regions having significantly more mixing. Some categories
have preference with regards to their location either poleward or
equatorward of the jet stream. In addition, some information as
to the direction of the vertical transport, whether stratosphere
to troposphere or vice versa, is obtained.
| Identifer | oai:union.ndltd.org:canterbury.ac.nz/oai:ir.canterbury.ac.nz:10092/2573 |
| Date | January 2008 |
| Creators | Monahan, Kathleen Patricia |
| Publisher | University of Canterbury. Physics and Astronomy |
| Source Sets | University of Canterbury |
| Language | English |
| Detected Language | English |
| Type | Text, Electronic thesis or dissertation |
| Rights | Copyright Kathleen Patricia Monahan, http://library.canterbury.ac.nz/thesis/etheses_copyright.shtml |
| Relation | NZCU |
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