LONG-RANGE POWER-LAW CORRELATIONS IN LOCAL DAILY TEMPERATURE-FLUCTUATIONS

We have studied long-time daily temperature records (between 56 and 21 8 years) obtained from 12 meteorological stations in Europe and North America from various climatological zones. To analyse the fluctuations of the daily temperatures around their average values, we have calcul ated directly the autocorrelation function C(l) between two days separ ated by l days, and applied also random-walk fluctuation analysis and wavelets methods, which can systematically overcome non-stationarities in the data. In addition, we have also analysed the distribution of t he daily temperature fluctuations, which in most cases is well approxi mated by a Gaussian. Our analysis suggests that the persistence, chara cterized by the autocorrelation function C(l), is long ranged and appr oximately decays with a power law C(l)similar or equal to l(-gamma), w ith roughly the same exponent gamma approximate to 2/3 for all station s considered. This universal persistence law seems to be valid at leas t for one decade of years, but we cannot exclude the possibility that the range of the power-law correlations even exceeds the range of the temperature series considered.