Limits...
Spatial and temporal variability of rainfall in eastern Amazon during the rainy season.

Ferreira DB, de Souza EB, de Moraes BC, Meira Filho LG - ScientificWorldJournal (2015)

Bottom Line: Empirical orthogonal functions (EOF) and composites analysis were employed on pentad data in order to investigate the tropical atmospheric-ocean patterns over the Atlantic Ocean and the spatial-temporal characteristics of the rainfall in eastern Amazon during the peak of the rainy season (February to April).The EOF results evidenced that the Intertropical Convergence Zone (ITCZ) is the main rainfall-producing system in eastern Amazon during the rainy season.Conditions associated with the southward SST gradient in the intertropical Atlantic formed the dynamic patterns that favored the position of the ITCZ to south of the equator, thus explaining the predominance of positive precipitation anomalies in eastern Amazon, especially in the state of Maranhão and northeastern Pará during the February and April months.

View Article: PubMed Central - PubMed

Affiliation: Vale Institute of Technology, Boaventura da Silva Street 955, 66055-090 Belém, PA, Brazil ; Post-Graduate Program in Environmental Sciences, Federal University of Pará, Augusto Corrêa Street 1, 66075-110 Belém, PA, Brazil.

ABSTRACT
Empirical orthogonal functions (EOF) and composites analysis were employed on pentad data in order to investigate the tropical atmospheric-ocean patterns over the Atlantic Ocean and the spatial-temporal characteristics of the rainfall in eastern Amazon during the peak of the rainy season (February to April). The EOF results evidenced that the Intertropical Convergence Zone (ITCZ) is the main rainfall-producing system in eastern Amazon during the rainy season. Conditions associated with the southward SST gradient in the intertropical Atlantic formed the dynamic patterns that favored the position of the ITCZ to south of the equator, thus explaining the predominance of positive precipitation anomalies in eastern Amazon, especially in the state of Maranhão and northeastern Pará during the February and April months.

No MeSH data available.


Related in: MedlinePlus

Climatology (1981/2010) for the FMA period of the (a) rainfall (mm/day) in South America and (b) OLR (W/m2) in the Atlantic Ocean and eastern Amazon. (c) Time evolution from January to May of the daily climatological OLR (W/m2) averaged in ITCZ region (2.5S/2.5N and 40W/10W; see location in dashed box). Black dashed lines in (a) show the limits of the states of the Brazilian Amazon, emphasizing AP (Amapá), PA (Pará), and MA (Maranhão) in eastern Amazon.
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fig1: Climatology (1981/2010) for the FMA period of the (a) rainfall (mm/day) in South America and (b) OLR (W/m2) in the Atlantic Ocean and eastern Amazon. (c) Time evolution from January to May of the daily climatological OLR (W/m2) averaged in ITCZ region (2.5S/2.5N and 40W/10W; see location in dashed box). Black dashed lines in (a) show the limits of the states of the Brazilian Amazon, emphasizing AP (Amapá), PA (Pará), and MA (Maranhão) in eastern Amazon.

Mentions: The Amazon in South America and equatorial Africa and Indonesia form the three main centers of action of deep convection around the global tropical belt [1]. In particular, the Amazon exhibits a high spatial and temporal variability of rainfall with a very pronounced seasonality, such that the rainy and dry seasons typically occur during the months of summer/autumn and winter/spring, respectively [2]. The focus of the present paper is on the spatial distribution of rainfall in eastern Amazon (see location in Figure 1(a)) during the period in which the maximum (the peak of the rainy season) of the annual cycle is reached, that is, February to April (FMA). The climatological mean (1981–2010) for FMA (Figure 1(a)) clearly shows that the continental precipitation maximum is concentrated over the eastern Amazon, with values above 11 mm/day in most of the states of AP (Amapá), PA (Pará), and MA (Maranhão).


Spatial and temporal variability of rainfall in eastern Amazon during the rainy season.

Ferreira DB, de Souza EB, de Moraes BC, Meira Filho LG - ScientificWorldJournal (2015)

Climatology (1981/2010) for the FMA period of the (a) rainfall (mm/day) in South America and (b) OLR (W/m2) in the Atlantic Ocean and eastern Amazon. (c) Time evolution from January to May of the daily climatological OLR (W/m2) averaged in ITCZ region (2.5S/2.5N and 40W/10W; see location in dashed box). Black dashed lines in (a) show the limits of the states of the Brazilian Amazon, emphasizing AP (Amapá), PA (Pará), and MA (Maranhão) in eastern Amazon.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4352512&req=5

fig1: Climatology (1981/2010) for the FMA period of the (a) rainfall (mm/day) in South America and (b) OLR (W/m2) in the Atlantic Ocean and eastern Amazon. (c) Time evolution from January to May of the daily climatological OLR (W/m2) averaged in ITCZ region (2.5S/2.5N and 40W/10W; see location in dashed box). Black dashed lines in (a) show the limits of the states of the Brazilian Amazon, emphasizing AP (Amapá), PA (Pará), and MA (Maranhão) in eastern Amazon.
Mentions: The Amazon in South America and equatorial Africa and Indonesia form the three main centers of action of deep convection around the global tropical belt [1]. In particular, the Amazon exhibits a high spatial and temporal variability of rainfall with a very pronounced seasonality, such that the rainy and dry seasons typically occur during the months of summer/autumn and winter/spring, respectively [2]. The focus of the present paper is on the spatial distribution of rainfall in eastern Amazon (see location in Figure 1(a)) during the period in which the maximum (the peak of the rainy season) of the annual cycle is reached, that is, February to April (FMA). The climatological mean (1981–2010) for FMA (Figure 1(a)) clearly shows that the continental precipitation maximum is concentrated over the eastern Amazon, with values above 11 mm/day in most of the states of AP (Amapá), PA (Pará), and MA (Maranhão).

Bottom Line: Empirical orthogonal functions (EOF) and composites analysis were employed on pentad data in order to investigate the tropical atmospheric-ocean patterns over the Atlantic Ocean and the spatial-temporal characteristics of the rainfall in eastern Amazon during the peak of the rainy season (February to April).The EOF results evidenced that the Intertropical Convergence Zone (ITCZ) is the main rainfall-producing system in eastern Amazon during the rainy season.Conditions associated with the southward SST gradient in the intertropical Atlantic formed the dynamic patterns that favored the position of the ITCZ to south of the equator, thus explaining the predominance of positive precipitation anomalies in eastern Amazon, especially in the state of Maranhão and northeastern Pará during the February and April months.

View Article: PubMed Central - PubMed

Affiliation: Vale Institute of Technology, Boaventura da Silva Street 955, 66055-090 Belém, PA, Brazil ; Post-Graduate Program in Environmental Sciences, Federal University of Pará, Augusto Corrêa Street 1, 66075-110 Belém, PA, Brazil.

ABSTRACT
Empirical orthogonal functions (EOF) and composites analysis were employed on pentad data in order to investigate the tropical atmospheric-ocean patterns over the Atlantic Ocean and the spatial-temporal characteristics of the rainfall in eastern Amazon during the peak of the rainy season (February to April). The EOF results evidenced that the Intertropical Convergence Zone (ITCZ) is the main rainfall-producing system in eastern Amazon during the rainy season. Conditions associated with the southward SST gradient in the intertropical Atlantic formed the dynamic patterns that favored the position of the ITCZ to south of the equator, thus explaining the predominance of positive precipitation anomalies in eastern Amazon, especially in the state of Maranhão and northeastern Pará during the February and April months.

No MeSH data available.


Related in: MedlinePlus