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

Spatial pattern of (a) EOF1 for February, (b) EOF2 for March, and (c) EOF1 for April performed on pentad OLR anomalies (1983–2012).
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4352512&req=5

fig2: Spatial pattern of (a) EOF1 for February, (b) EOF2 for March, and (c) EOF1 for April performed on pentad OLR anomalies (1983–2012).

Mentions: Figure 2 illustrates the dominant modes of OLR variability for February, March, and April with an explained variance of 16.5%, 9.2%, and 16.1%, respectively. All modes are statistically independent of the other modes according to North [17] criterion. Contours shaded in gray represent eigenvectors at a confidence level of 95% by Student's t-test. The spatial patterns obtained from the first mode (EOF1) for February (Figure 2(a)), second mode (EOF2) for March (Figure 2(b)), and first mode (EOF1) for April (Figure 2(c)) resemble the well-known ITCZ-related OLR band along the equatorial Atlantic and eastern Amazon. For February and April the respective significant positive and negative OLR areas show the ITCZ band influencing eastern Amazon and equatorial Atlantic, while in March the positive OLR pattern is over the south Atlantic.


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)

Spatial pattern of (a) EOF1 for February, (b) EOF2 for March, and (c) EOF1 for April performed on pentad OLR anomalies (1983–2012).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig2: Spatial pattern of (a) EOF1 for February, (b) EOF2 for March, and (c) EOF1 for April performed on pentad OLR anomalies (1983–2012).
Mentions: Figure 2 illustrates the dominant modes of OLR variability for February, March, and April with an explained variance of 16.5%, 9.2%, and 16.1%, respectively. All modes are statistically independent of the other modes according to North [17] criterion. Contours shaded in gray represent eigenvectors at a confidence level of 95% by Student's t-test. The spatial patterns obtained from the first mode (EOF1) for February (Figure 2(a)), second mode (EOF2) for March (Figure 2(b)), and first mode (EOF1) for April (Figure 2(c)) resemble the well-known ITCZ-related OLR band along the equatorial Atlantic and eastern Amazon. For February and April the respective significant positive and negative OLR areas show the ITCZ band influencing eastern Amazon and equatorial Atlantic, while in March the positive OLR pattern is over the south Atlantic.

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