Multidecadal variability of summer temperature over Romania and its relation with Atlantic Multidecadal Oscillation

摘要

We investigate the multidecadal variability of summer temperature over Romania as measured at 14 meteorological stations with long term observational records. The dominant pattern of summer temperature variability has a monopolar structure and shows pronounced multidecadal variations. A correlation analysis reveals that these multidecadal variations are related with multidecadal variations in the frequency of four daily atmospheric circulation patterns from the North Atlantic region. It is found that, on multidecadal time scales, negative summer mean temperature (TT) anomalies are associated with positive sea level pressure (SLP) anomalies centered over the northern part of the Atlantic Ocean and Scandinavia and negative SLP anomalies centered over the northern part of Africa. It is speculated that a possible cause of multidecadal fluctuations in the frequency of these four patterns are the sea surface temperature anomalies associated to the Atlantic Multidecadal Oscillation. These results have implications for predicting the evolution of summer temperature over Romania on multidecadal time scales.