 |
| Titel |
Mesoscale numerical analysis of the historical November 1982 heavy precipitation event over Andorra (Eastern Pyrenees) |
| VerfasserIn |
L. Trapero, J. Bech, F. Duffourg, P. Esteban, J. Lorente |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1561-8633
|
| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 13, no. 11 ; Nr. 13, no. 11 (2013-11-22), S.2969-2990 |
| Datensatznummer |
250085564
|
| Publikation (Nr.) |
 copernicus.org/nhess-13-2969-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| From 6 to 8 November 1982 one of the most catastrophic flash-flood
events was recorded in the Eastern Pyrenees affecting Andorra and also
France and Spain with rainfall accumulations exceeding 400 mm in 24 h, 44
fatalities and widespread damage. This paper aims to exhaustively document
this heavy precipitation event and examines mesoscale
simulations performed by the French Meso-NH non-hydrostatic atmospheric
model. Large-scale simulations show the slow-evolving synoptic environment
favourable for the development of a deep Atlantic cyclone which induced a
strong southerly flow over the Eastern Pyrenees. From the evolution of the
synoptic pattern four distinct phases have been identified during the event.
The mesoscale analysis presents the second and the third phase as the most
intense in terms of rainfall accumulations and highlights the interaction of
the moist and conditionally unstable flows with the mountains. The presence
of a SW low level jet (30 m s−1) around 1500 m also had a crucial role on
focusing the precipitation over the exposed south slopes of the Eastern Pyrenees. Backward trajectories based on Eulerian on-line passive tracers
indicate that the orographic uplift was the main forcing mechanism which
triggered and maintained the precipitating systems more than 30 h over
the Pyrenees. The moisture of the feeding flow mainly came from the Atlantic
Ocean (7–9 g kg−1) and the role of the Mediterranean as a local moisture
source was very limited (2–3 g kg−1) due to the high initial water vapour
content of the parcels and the rapid passage over the basin along the
Spanish Mediterranean coast (less than 12 h). |
| |
|
| Teil von |
|
|
|
|
|
|
|
|