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| Titel |
A statistical analysis of the influence of deep convection on water vapor variability in the tropical upper troposphere |
| VerfasserIn |
J. S. Wright, R. Fu, A. J. Heymsfield |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 15 ; Nr. 9, no. 15 (2009-08-12), S.5847-5864 |
| Datensatznummer |
250007573
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| Publikation (Nr.) |
 copernicus.org/acp-9-5847-2009.pdf |
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| Zusammenfassung |
| The factors that control the influence of deep convective detrainment
on water vapor in the tropical upper troposphere are examined using
observations from multiple satellites in conjunction with a trajectory
model. Deep convection is confirmed to act primarily as a moisture
source to the upper troposphere, modulated by the ambient relative
humidity (RH). Convective detrainment provides strong moistening at
low RH and offsets drying due to subsidence across a wide range of
RH. Strong day-to-day moistening and drying takes place most
frequently in relatively dry transition zones, where between 0.01%
and 0.1% of Tropical Rainfall Measuring Mission Precipitation Radar
observations indicate active convection. Many of these strong
moistening events in the tropics can be directly attributed to
detrainment from recent tropical convection, while others in the
subtropics appear to be related to stratosphere-troposphere
exchange. The temporal and spatial limits of the convective source are
estimated to be about 36–48 h and 600–1500 km, respectively,
consistent with the lifetimes of detrainment cirrus clouds. Larger
amounts of detrained ice are associated with enhanced upper
tropospheric moistening in both absolute and relative terms. In
particular, an increase in ice water content of approximately 400%
corresponds to a 10–90% increase in the likelihood of moistening and
a 30–50% increase in the magnitude of moistening. |
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