Principal Component analysis of a local temperature field within the global circulation

Abstract

Some climatic characteristics of the mesoscale (territory of Croatia) temperature field and the macroscale (European Northern Atlantic region) relative topography (RT) 500/1 000 hPa and surface pressure fields, as well as their complexe relationships were considered in the present study. The average monthly surface temperature for 108 weather stations from the mesoscale territory as well as the average monthly RT 500/1 000 hPa and surface pressure for 12 × 19 grid points from the macroscale region were used. The Principal Components (PCs) method was applied to the data. The obtained results were divided into two groups: the first group is related to the average (climatological) annual courses of cited parameters and the second is related to their anomalies. In addition, a regionalization was established, and existence of six temperature anomaly types from mesoscale and the same number of RT and surface pressure anomaly types from macroscale. The first group of results is useful for description and better understanding of the climate of the considered regions and the second for an interpretation of mesoscale temperature field anomalies in terms of macrocirculation anomalies (RT 500/1 000 hPa and surface pressure).