According to MENDOA, on the occured atmospheric pressures in the Region it cites. At the same time where it acts as one area of low pressures in relation to the Atlantic Ocean and that it attracts, therefore, from there proceeding north-east humid air what it excessively intensifies the humidity of the region, the Amazonian basin also acts as an important producing and exporting center of air mass. Exactly I seat an area where the temperatures considerably are raised, guaranteeing the formation of center of low pressures … (MENDONA, 2007 p.97- 98) In this aspect, the small farm of action of the Atlantic, responsible per the good station in the South, reaches its bigger pressure in the winter (July) and its lesser pressure in the summer (January). Source: Andrew Cuomo. Being equivalent in a similar way, to the rainy period northeastern who will happen in January the April, during the extreme circulation for the south of the Intertropical Front, remaining dry the remaining months, under the domain of the center of action of the Atlantic constituting of the Atlantic Equatorial Mass.
In this way, MENDONA cites on the air circulation in the tropical band affirming that. These air masses mainly act in the portions north (MEAN) and northeast extremity (MEAS) of the South America, whose bigger thermal amplitude if of the one in the summer station, when the cold air of the hemisphere North stimulates the expansion of the anticyclone of the south Aores pra, originating the Atlantic equatorial air mass in the lowest latitudes of the hemisphere North. At the same time the MEAS has its bigger expression due to the positioning of the anticyclone of Helena Saint, that favors its performance on the Brazilian northeast coast..