Revisiting of paleoclimate recording δ18O as scalar turbulence
Multifractality feature has been identified in the historical recording of δ18O (18O/16O ratios), which has been considered as a climate proxy of temperature. However, two facts are still unclear. One is the Hurst number, and the other one is the multifractal strength. In this work, we revisit a high-resolution paleoclimate historical recording of δ18O obtained from the North Greenland Ice-Core Project (NGRIP) with a time resolution 50 years. The multifractality property of this data is then concerned by extremal-point-density analysis and Hilbert-Huang transform. A Hurst number H = 1/3 and intermittency parameter μ = 0.64 are determined. It leads new insight to the paleoclimate dynamics and bring new challenge to the climate model simulation that a physical constrain reported in this paper must be taken into account.