A Comparison Between the Generalized Digital Environmental Model and Levitus climatologies

TLDR

The study compares the Generalized Digital Environmental Model (GDEM) with the Climatological Atlas of the World Ocean. Dynamic height fields for the North Atlantic, North Pacific, and Indian oceans were computed seasonally on a 1° grid from each climatology, mapped, and compared, while the construction methodology of GDEM was detailed. Both climatologies similarly represent large‑scale oceanographic features, but GDEM provides superior seasonal variability and high‑shear region representation, such as the Gulf Stream, due to its finer grid and distinct smoothing.

Abstract

Two ocean climatologies of temperature and salinity, the Generalized Digital Environmental Model (GDEM) and the Climatological Atlas of the World Ocean, are compared. Dynamic height fields are computed by season from each climatology for the North Atlantic, North Pacific, and Indian oceans and are compared on a 1° latitude‐longitude grid. Large‐scale oceanographic features are generally found to be similarly represented in both climatologies. GDEM appears to render better representations of seasonal variability and regions of high current shear, such as the Gulf Stream, because of a different smoothing method and a finer grid spacing. Maps of dynamic heights from both climatologies are presented, and their similarities and differences are discussed. The methodology for the construction of GDEM is also described in detail.