Temperature and Precipitation Variability and Trends in Northern Spain
271
5 Precipitation Analysis
5.1 EOF Patterns
Figs. 7a and b show the significant seasonal and patterns of the (Varimax) rotated
EOFs of Spanish precipitation anomalies by drawing the isolines of the loading
factors values. Table 2 shows the percentage of variance explained by each EOF.
The first rotated EOF pattern is centred on principally Andalusia and the interior
part of Spain. In this region, precipitation is associated with the westerly circulation,
common to polar maritime (mP) and tropical maritime (mT) air masses. According
to Capel Molina (1981), the most frequent flows are from the SW, followed by W
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Fig. 73. The significant principal components of the winter and spring precipitation anomalies in
mm for the twentieth century