Changes in the rainfall regime
of this state have been associated with ENSO (El Nino Southern Oscillation) events, which is reported as the greatest source of climatic variability in seasonal and interannual scales (Berlato & Fontana, 2003; Britto et al., 2008; Matzenauer et al., 2017).
Recently, 2 severe droughts occurred within a period of only 5 years, evidencing pronounced alterations in the Amazonian rainfall regime
. We propose a new methodology to evaluate the onset and length of the Brazilian Amazon rainy season during the last decades using cloudiness observations from geostationary satellites.
Thus, bimodal polyestry is closely related to a rainfall regime
that occurs twice a year (Wilson, 1979; Racey, 1982; Racey & Entwistle, 2000).
The district is within the moist semideciduous forest ecological zone with a major and a minor rainfall regime
. The major rainfall regimes
is from March to July while the minor is from September to November.
Experiments were also carried out during 2010 in a second region that has a quite different rainfall regime
: in the wine growing area of Kakheti where rainfall averages ~800 mm/year.
Due to lack of data monitoring, there is only a dearth of studies for the Amazon region on the rainfall regime
. This problem is partly due to the size of the region which increases costs in the establishment and operation of the network, as well as the costs of in logistics and transport of technical teams for measurements, data collection, analysis of the behavior of rainfall and flows, all highly crucial for hydrological studies.
The Acre State, which is located at the southwestern Amazon, is characterized by a seasonal rainfall regime
monsoon (7,16), with an annual rainfall approx.
Raziee and Azizi (2009), using principal components analysis and clustering methods, classified rainfall regime
in the west of Iran.
According to the rainfall regime
system, this area is classified to be under Mediterranean Sea seasonal rainfall system, which is characterized by winter rainfall due to the effect of the Westerlies and atmospheric depressions.
It is plausible that the lower air temperatures and distinct annual rainfall regime
found in the subtropical region could produce an activity pattern for anurans distinct from that found in the tropics.