The Pacific high and the Brazilian low regulate the weather over the land portion of this eclipse. The Atlantic high, lying closer to the African coast, has little influence over South America, but is the dominating system over the Atlantic portion of track. In the southern hemisphere, winds circulate in a counterclockwise direction around the high pressure cells. On the Pacific side this brings a stubborn southerly wind onto the Peruvian coast. This wind is further strengthened by local sea breezes that build the largest sand dunes in the world.
Sea breezes are onshore winds caused by the heating of the land along the coast.
The heated air rises upward and cooler ocean air then moves inland to replace it. The influence of the highs extends beyond directing wind flow. Air inside anticyclones descends from higher levels in the atmosphere. Air which is descending is warmed and dried. At the ocean surface is the cold Peruvian Current, bringing water northward from the sub polar regions off Antarctica.