Multifractality of global sea level heights in the satellite altimeter-era

Abstract

Sea level rise is the major concern of climate change research. Beside the positive trends, global sea levels also demonstrate a complex scaling behavior. In this study, multifractal analyses based on the multifractal detrended fluctuation analysis (MFDFA) method are conducted to the global sea level anomaly (SLA) time series in the altimeter-era since 1993. By eliminating the multifractality caused by finite-size effect, the effective multifractality is estimated as the degree of multifractality of SLA time series. The results of show that global SLA time series are multifractals rather than monofractals. Long range dependence was also heuristically demonstrated by both autocorrelation functions and multifractal spectrums, respectively. The complex spatial patterns of sea level changes and multifractality could be partly explained by different mechanisms such as thermal expansion, the shift of ocean currents, and river injections, which are all associated with global climate change.