During April-mid August (the long wet season) the TNA (TSA) becomes warmer
(colder) than normal indicating a northward movement of the ITCZ. Oceanic air rises
over the TNA warm water, easterly trade winds from the Atlantic Ocean are weakened
north of the equator and easterly trade winds south of the equator increase. The
southeasterly trade winds also bring the tropical heat sources of the Amazon to
Suriname. Evaporation increases over the TNA and as a result precipitation increases
over northern South America. During this period, the ITCZ has a rainfall belt that is
twice the rainfall belt during DJF and hardly covers the whole of Suriname. The
extension of this season compared to the small wet season is due to the fact that the
ITCZ collides with the relief of the country (near Tafelberg) as well with the south and
northeast trade winds, which causes its movement to become slower. This explains the
high rainfall in the center of Suriname (Figure 3b). During the beginning of the long wet
season (MAM), the Niño 1+2, TSA and the tropical Atlantic Niño SSTAs show all a
strong correlation with the rainfall anomalies in the same order of magnitude of about
clag 1 Nino1+2
= 0.59, clag 0 TSA = -0.52 and clag 0 Atlantic Nino
= -0.52, than with the TNA SSTAs
(clag 0 = 0.23) and the TA dipole SSTAs (clag 7 = 0.33) (Figure 6). During JJA, the SSTAs
in both the TA dipole and TSA region show a stronger correlation with the rainfall
anomalies than in the other regions of clag 10 = -0.49 and clag 0 = -0.52 respectively.