“Easterly Wave Disturbances” Over the Tropical South Atlantic: A Review and Discussion About Terminology

Abstract

This article provides an overview about the disturbances in the trade winds that propagate over the south Atlantic Ocean, as well as a discussion about this weather system, according to the literature. Most authors suggest that these disturbances have their main processes found at low levels of the troposphere. These studies indicate that this system is austral fall and winter typical and can be associated to most of the annual precipitation observed over the eastern area of the Brazil Northeast region. A practical guide for the identification of the disturbances in the trade winds is presented, and a new terminology is proposed to resolve misunderstandings in operational practice due the use of the same terminology to refer to different systems. The new nomenclature suggested is “Wave Disturbances in the Trade Winds”, since the analyzed system presents its main activity at low levels, differentiating itself from other systems that flow from the east or are stationary and are not directly linked to the trade winds, presenting their main processes at higher levels.

Keywords
trade winds; disturbances; south Atlantic; practical guide; terminology