<i>Letter to the Editor</i> <br>Seasonal variations and vertical movement of the tropopause in the UTLS region
Based on the tracking of the movement of the tropopause over the whole year, the extent/depth of stratosphere-troposphere exchange (STE) events and their seasonal variations is investigated. It is found that a stratospheric signature can be observed at pressures as high as 400 hPa in a hemis...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2002-06-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/20/871/2002/angeo-20-871-2002.pdf |
| Summary: | Based on the tracking of
the movement of the tropopause over the whole year, the extent/depth of
stratosphere-troposphere exchange (STE) events and their seasonal variations is
investigated. It is found that a stratospheric signature can be observed at
pressures as high as 400 hPa in a hemisphere during its winter to spring
period, while a tropospheric signature can be observed at pressures as low as
190 hPa during the hemispheric summer to autumn months. The major implication
for such a pronounced vertical movement is that the downward penetration of air
from the stratosphere is likely to deposit elevated levels of O<sub>3</sub>
into the upper troposphere. Though the analysis at 250 hPa reveals that the
values of the stratosphere-troposphere index are similar all year round, a
result which is consistent with other studies, it is found that an intrusion
from the stratosphere to the troposphere is more likely to occur during the
hemispheric winter to spring period than other seasons.<br><br><b>Key words. </b>Atmospheric composition
and structure (pressure, density, and temperature; troposphere–composition
and chemistry) |
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| ISSN: | 0992-7689 1432-0576 |