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| Titel |
Variability of the upper troposphere and lower stratosphere observed with GPS radio occultation bending angles and temperatures |
| VerfasserIn |
Torsten Schmidt, Jens Wickert, Antonia Haser, Stefan Heise |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250035002
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| Zusammenfassung |
| Recently, Lewis (2009) introduced a new method for the identification of tropopause heights
(TPHs) from GPS radio occultation (RO) bending angles (α). The method uses a covariance
transform to identify transitions in a ln(α) profile. In this study we apply the new method to
the RO data sets from CHAMP/GRACE (2001–2009) and FORMOSAT-3/COSMIC
(2006–2009). These results are the basis for TPH trend estimations for the time period
between May 2001 and August 2009 (100Â months) based on zonal monthly mean GPS RO
data from CHAMP (2001–2008), GRACE (since 2006) and FORMOSAT-3/COSMIC (since
2006). Further, we compare the α based TPH trends with lapse rate tropopause height trends
and discuss the differences, which are largest in the subtropical regions (20-–40-) on
both the northern and southern hemisphere. A global increase of the TPH between
5–9Â m/yr is found for both methods and different data sets (CHAMP/GRACE alone and
CHAMP/GRACE plus FORMOSAT-3/COSMIC). The results for the TPH trends
are linked with bending angle and temperature trends in the upper troposphere
and lower stratosphere region. Generally, an upper tropospheric warming (bending
angle decrease) and a lower stratospheric cooling (bending angle increase) is noted. |
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