Winter synoptic weather types in Catalonia (NE Spain) and their linkage with minimum temperature anomalies

Autor: C. Serra, G. Fernández Mills, Xavier Lana, M. C. Periago
Rok vydání: 1999
Předmět:
Zdroj: International Journal of Climatology. 19:1675-1695
ISSN: 1097-0088
0899-8418
Popis: An objective classification of winter synoptic weather types in Catalonia (NE Spain) is obtained by means of the principal component analysis of daily variables followed by cluster analysis based on Average Linkage and K-Means methods. The period analysed includes days belonging to December, January and February, from 1976 to 1980. The data list consists of thermal, pressure, cloud cover, humidity, wind and precipitation values recorded at four different stations in Catalonia. The classification includes 14 clusters which accurately explain the winter synoptic variety of the country. All cluster features are discussed in detail and a study concerning transitions between these clusters is presented. Three groups (1, 3 and 7) are related to high pressure weather types, clusters 4, 5 and 8 to cold sectors of mid-latitude depressions and clusters 2 and 9 can be associated with cyclonic conditions with western circulation. The weather types related to extended precipitation are included in clusters 6 and 10 which are linked to eastern surface circulation. The obtained classification is then applied in a study concerning daily minimum temperature anomalies. The spatial distribution of these anomalies are analysed for each significant weather type. The clusters related to widely extended frost risk are finally identified (groups 4, 8 and 14).
Databáze: OpenAIRE
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