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Climate cycles responsible for 1-2 degrees Celsius temperature variability

Irregular cycles with various periods have been observed in the changing Earth climate. While the El-Nino phenomenon occurring with the period about 3-6 years is well known, the cycle with the period about 7-8 years detected in the climate-related data is still a subject of interest for a narrow circle of researchers. The amplitude of the 7-8-year cycle is relatively low and the cycle is hidden in complex, noise-like climate variability. Consequently this cycle was not yet considered in climate change studies, nor in comprehensive climate models. In a recent study of long-term records of air temperature from various European locations, M. Palus from the Institute of Computer Science of the Academy of Sciences of the Czech Republic has uncovered a causal relation between the phase of slow irregular oscillations, mainly with the period about 7-8 years, and the amplitude of faster temperature fluctuations occurring on time scales from a few months to 2-3 years. As a consequence of these cross-scale interactions, the overall effect of the slow oscillations on the inter-annual temperature variability can reach the range of 1-2 degrees Celsius. This new physical phenomenon of cross-scale information transfer in atmospheric dynamics is described in a paper published in Physical Review Letters .

Figure: Statistically significant effect (color-coded in degrees Celsius) of the 7-8yr cycle on air temperature variability in Europe.

© Milan Palus 2014