Air temperature variations in Greece. Part 1. Persistence, trend, and fluctuations

Abstract This paper considers annual and seasonal variations of temperatures at three stations in Greece with at least 80 years of records. The extent and nature of non‐random changes, such as persistence, trend and fluctuations, are investigated. There is statistical evidence of both Markov linear and non‐linear persistence in the data depending on stations and season. The trend analysis showed little of significance, probably because of the time periods chosen. The data were subjected to a ‘lowpass filter’ of a Gaussian type and the series of fluctuations which resulted are discussed. Finally the data for all three stations were combined and filtered in order to show changes that have occurred in the Greek region during the twentieth century.