The lack of hurricanes in the South Atlantic and eastern South Pacific is due to a variety of factors. One of the main factors is the presence of strong vertical wind shear, which is the change in wind speed and direction with height. This wind shear can disrupt the formation and intensification of tropical storms and hurricanes. In addition, the sea surface temperatures in these regions are generally too cool to support the development of tropical cyclones. Finally, the lack of large-scale weather patterns, such as the Intertropical Convergence Zone, can also contribute to the absence of hurricanes in these regions. Overall, the combination of these factors makes it difficult for hurricanes to form and intensify in the South Atlantic and eastern South Pacific.