Hölder Scales of Sea Level

الملخص EN

The statistics of sea level is essential in the field of geosciences, ranging from ocean dynamics to climates.

The fractal properties of sea level, such as long-range dependence (LRD) or long memory, 1/f noise behavior, and self-similarity (SS), are known.

However, the description of its multiscale behavior as well as local roughness with the Hölder exponent h(t) from a view of multifractional Brownian motion (mBm) is rarely reported, to the best of our knowledge.

In this research, we will exhibit that there is the multiscale property of sea level based on h(t)s of sea level data recorded by the National Data Buoy Center (NDBC) at six stations in the Florida and Eastern Gulf of Mexico.

The contributions of this paper are twofold as follows.

(i) Hölder exponent of sea level may not change with time considerably at small time scale, for example, daily time scale, but it varies significantly at large time scale, such as at monthly time scale.

(ii) The dispersion of the Hölder exponents of sea level may be different at different stations.

This implies that the Hölder roughness of sea level may be spatial dependent.