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| Titel |
Detection of convective initiation using Meteosat SEVIRI: implementation in and verification with the tracking and nowcasting algorithm Cb-TRAM |
| VerfasserIn |
D. Merk, T. Zinner |
| 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 ; 6, no. 8 ; Nr. 6, no. 8 (2013-08-06), S.1903-1918 |
| Datensatznummer |
250085030
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| Publikation (Nr.) |
 copernicus.org/amt-6-1903-2013.pdf |
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| Zusammenfassung |
| In this paper a new detection scheme for convective initiation (CI) under day
and night conditions is presented. The new algorithm combines the strengths
of two existing methods for detecting CI with geostationary satellite data.
It uses the channels of the Spinning Enhanced Visible and Infrared Imager
(SEVIRI) onboard Meteosat Second Generation (MSG). For the new algorithm five
infrared (IR) criteria from the Satellite Convection Analysis and Tracking
algorithm (SATCAST) and one high-resolution visible channel (HRV) criteria
from Cb-TRAM were adapted. This set of criteria aims to identify the typical
development of quickly developing convective cells in an early stage. The
different criteria include time trends of the 10.8 IR channel, and IR channel
differences, as well as their time trends. To provide the trend fields an
optical-flow-based method is used: the pyramidal matching algorithm, which is
part of Cb-TRAM. The new detection scheme is implemented in Cb-TRAM, and is
verified for seven days which comprise different weather situations in
central Europe. Contrasted with the original early-stage detection scheme of
Cb-TRAM, skill scores are provided. From the comparison against detections of
later thunderstorm stages, which are also provided by Cb-TRAM, a decrease in
false prior warnings (false alarm ratio) from 91 to 81% is presented, an
increase of the critical success index from 7.4 to 12.7%, and a decrease
of the BIAS from 320 to 146% for normal scan mode. Similar trends are
found for rapid scan mode. Most obvious is the decline of false alarms found
for the synoptic class "cold air" masses. |
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