MULTIFRACTAL ANALYSIS OF THE GREENLAND ICE-CORE PROJECT CLIMATE DATA

Recent climatic records from the Greenland ice-core project (GRIP) ice core show that the cliInate proxy temperatures delta(18)O (O-18/(16) O ratios) display sharp gradients and large fluctuations over all obse rved scales. We show that a these variations are scale invariant over the range approximate to 400 yr to approximate to 40 kyr. The fluctuat ions corresponding to these scales are studied using multifractal anal ysis techniques. We estimate universal multifractal indices which char acterize all the fluctuations for all the scales in this range and whi ch are close to those obtained for turbulent temperatures at much shor ter time scales. We speculate briefly on the origin of these common fe atures intervening all over the observed range from seconds to kyr.