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| Titel |
Characterization of Mediterranean hail-bearing storms using an operational polarimetric X-band radar |
| VerfasserIn |
G. Vulpiani, L. Baldini, N. Roberto |
| 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 ; 8, no. 11 ; Nr. 8, no. 11 (2015-11-06), S.4681-4698 |
| Datensatznummer |
250116678
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| Publikation (Nr.) |
 copernicus.org/amt-8-4681-2015.pdf |
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| Zusammenfassung |
| This work documents the effective use of X-band radar observations for
monitoring severe storms in an operational framework.
Two severe hail-bearing Mediterranean storms that
occurred in 2013 in southern Italy, flooding two important Sicilian cities, are described in terms of their polarimetric radar
signatures and retrieved rainfall fields. The X-band
dual-polarization radar operating inside the Catania airport
(Sicily, Italy), managed by the Italian Department of Civil
Protection, is considered here. A suitable processing is applied to X-band radar
measurements. The crucial procedural step relies on the differential phase processing, being preparatory for attenuation correction and rainfall estimation.
It is based on an iterative approach that uses a very
short-length (1 km) moving window, allowing proper capture of the
observed high radial gradients of the differential phase. The
parameterization of the attenuation correction algorithm, which uses
the reconstructed differential phase shift, is derived from
electromagnetic simulations based on 3 years of drop size distribution (DSD) observations
collected in Rome (Italy). A fuzzy logic hydrometeor classification
algorithm was also adopted to support the analysis of the storm
characteristics. The precipitation field amounts were reconstructed
using a combined polarimetric rainfall algorithm based on
reflectivity and specific differential phase. The first
storm was observed on 21 February when a winter convective
system that originated in the Tyrrhenian Sea, marginally hit the
central-eastern coastline of Sicily, causing a flash flood in
Catania. Due to an optimal location (the system is located
a few kilometers from the city center), it was possible to
retrieve the storm characteristics fairly well, including the amount of
rainfall field at the ground. Extemporaneous signal extinction, caused
by close-range hail core causing significant differential phase
shift in a very short-range path, is documented. The second storm,
on 21 August 2013, was a summer mesoscale convective
system that originated from a Mediterranean low pressure system lasting a few hours that eventually flooded the city of
Syracuse. The undergoing physical process, including the storm
dynamics, is inferred by analyzing the vertical sections of the
polarimetric radar measurements. The high registered
amount of precipitation was fairly well reconstructed, although with a trend toward
underestimation at increasing distances. Several episodes of signal
extinction were clearly manifested during the mature stage of the
observed supercells. |
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