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| Titel |
Characteristics of tropopause parameters as observed with GPS radio occultation |
| VerfasserIn |
T. Rieckh, B. Scherllin-Pirscher, F. Ladstädter, U. Foelsche |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 7, no. 11 ; Nr. 7, no. 11 (2014-11-26), S.3947-3958 |
| Datensatznummer |
250115964
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| Publikation (Nr.) |
 copernicus.org/amt-7-3947-2014.pdf |
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| Zusammenfassung |
| Characteristics of the lapse rate tropopause are analyzed globally for
tropopause altitude and temperature using global positioning system (GPS)
radio occultation (RO) data from late 2001 to the end of 2013. RO
profiles feature high vertical resolution and excellent quality in the
upper troposphere and lower stratosphere, which are key factors for
tropopause determination, including multiple ones. RO data provide
measurements globally and allow examination of both temporal and spatial
tropopause characteristics based entirely on observational measurements.
To investigate latitudinal and longitudinal tropopause characteristics,
the mean annual cycle, and inter-annual variability, we use tropopauses
from individual profiles as well as their statistical measures for zonal
bands and 5° × 10° bins. The latitudinal
structure of first tropopauses shows the well-known distribution with
high (cold) tropical tropopauses and low (warm) extra-tropical
tropopauses. In the transition zones (20 to
40° N/S), individual profiles reveal varying tropopause
altitudes from less than 7 km to more than 17 km due to variability in
the subtropical tropopause break. In this region, we also find multiple
tropopauses throughout the year. Longitudinal variability is strongest
at northern hemispheric mid latitudes and in the Asian monsoon region.
The mean annual cycle features changes in amplitude and phase, depending
on latitude. This is caused by different underlying physical processes
(such as the Brewer–Dobson circulation – BDC) and atmospheric dynamics (such as
the strong polar vortex in the southern hemispheric winter). Inter-annual
anomalies of tropopause parameters show signatures of El Niño–Southern
Oscillation (ENSO), the quasi–biennial oscillation (QBO), and the varying strength of
the polar vortex, including sudden stratospheric warming (SSW) events. These
results are in good agreement with previous studies and underpin the high
utility of the entire RO record for investigating latitudinal,
longitudinal, and temporal tropopause characteristics globally. |
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