Wave Climate from Spectra and its Connections with Local and Remote Wind Climate

TL;DR

This study analyzes the spectral wave climate in the tropical Eastern Pacific, revealing how local and remote wind patterns influence wave spectra and demonstrating the potential to reconstruct wave climate from global wind data.

Contribution

It introduces a method to link wave spectra with basin-scale wind fields, showing remote wind influence on local wave climate and enabling wave climate reconstruction from wind observations.

Findings

Wave spectra exhibit distinct climate systems with seasonal and long-term variability.

Remote wind fields significantly influence local wave spectra across large distances.

Wave spectra can be used to infer basin-scale wind climate patterns.

Abstract

Because wind-generated waves can propagate over large distances, wave spectra from a fixed point can record information about air-sea interactions in distant areas. In this study, the spectral wave climate is computed for a specific location in the tropical Eastern Pacific Ocean. Several well-defined partitions independent of each other, referred to as wave-climate systems, are observed in the annual mean wave spectrum. Significant seasonal cycling, long-term trends, and correlations with climate indices are observed in the local wave spectra, showing the abundant climatic information they contain. The projections of the wind vector on the direction pointing to the target location are used to link the spectral wave climate and basin-scale wind climate. The origins of all the identified wave climate systems are clearly shown in the wind projection maps and some are thousands of kilometers away from the target point, demonstrating the validity of this connection. Comparisons are made between wave spectra and the corresponding local and remote wind fields with respect to seasonal and interannual variability, as well as the long-term trends. The results show that each frequency and direction of ocean wave spectra at a certain location can be linked to the wind field for a geographical area from a climatological point of view, implying that it is feasible to reconstruct a spectral wave climate from global observational wind field data and wind climate monitoring using observations of wave spectrum geographically far away.