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| Titel |
Understanding the unexpectedly high increase of observed (sub-)hourly precipitation extremes with temperature |
| VerfasserIn |
J. M. Loriaux, G. Lenderink, A. P. Siebesma, S. R. de Roode |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250063882
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| Zusammenfassung |
| Events of extreme precipitation are highly disruptive to society, and are likely to intensify
with global warming. When sufficient moisture is available, precipitation extremes are
expected to be related to temperature through the Clausius-Clapeyron (CC) relation of a
~7%/Ë C increase. However, several processes may influence precipitation intensity leading
to deviations from CC scaling. Recently, Lenderink & van Meijgaard (2008) found an
intensity increase consistent with two times CC (2CC) scaling for temperatures above
approximately 12Ë C, using hourly precipitation extremes in De Bilt, The Netherlands. At
lower temperatures CC scaling applied.
To study this, we first distinguish between convective and frontal precipitation based
on the different time-scales of these regimes using observations from 27 weather
stations in the Netherlands. By analyzing sub-hourly precipitation, convective extreme
events are selected from the dataset, leading to a 2CC trend over the entire range of
dewpoint temperatures. This places previous scaling relations of hourly extremes into
context, showing that 2CC scaling is a robust relation for convective precipitation
extremes.
To understand the origin of this 2CC relationship, we use a conceptual model based on
idealized deep convective profiles based on soundings at De Bilt. The results of this
conceptual model indeed provide support for a 2CC trend for extreme precipitation
intensities.
Lenderink, G. & van Meijgaard, E., Increase in hourly precipitation extremes
beyond expectations from temperature changes. Nature Geosci. 1, 511-514 (2008). |
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