Climatology and long-term variability of the annual cycle of air temperature over Europe

Climatology and long-term variations of characteristics of the annual cycle of air temperature over Europe are studied in terms of amplitudes and phases on the basis of data for 1901–2000. It is shown that the spatial amplitude distribution of the annual cycle of air temperature well reflects a decrease in the influence of the Atlantic and an increase in the continentality of the European climate from west to east. It is found that positive (negative) anomalies of annual mean air temperature are accompanied mainly by negative (positive) anomalies of amplitudes and phases of the annual cycle air temperature. In other words, abnormally warm years are characterized by smaller amplitudes of the annual cycle, and the maximum in the annual cycle of air temperature is observed earlier than usual. The first empirical orthogonal function (EOF) mode of temperature amplitudes is connected with the North Atlantic Oscillation (NAO). It means that at a high NAO index one observes small (large) amplitudes of the annual cycle of air temperature over Europe.