Modes of tropical Atlantic climate variability observed by PIRATA

Servain, Jacques; Clauzet, Gabriel; Wainer, Ilana

doi:10.1029/2002gl015124

Cited by 19 publications

(10 citation statements)

References 18 publications

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“…The program, called PIRATA (Pilot Research Moored Array in the Tropical Atlantic) provides the time series measurements of upper ocean temperature used here. These same measurements are used in a companion paper Servain et al [submitted] to evaluate the two modes of variability in the tropical Atlantic.…”

Section: Introductionmentioning

confidence: 99%

Time scales of upper ocean temperature variability inferred from the PIRATA data (1997–2000)

Wainer

Clauzet

Servain³

et al. 2003

Geophysical Research Letters

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[1] Time series from the PIRATA 10-minute measurements are investigated in order to study the upper-ocean thermal field time-scales of variability using the serial covariance power spectra method and wavelet analysis. This is one of the few studies that analyze in time and space the PIRATA buoy data in the region. Analysis of the depth of the 20°C isotherm show distinct patterns for the northwestern Atlantic at 8N -38W and the southeastern Atlantic, at 10S-10W. In the west, warm surface waters are accompanied by a shallower thermocline while in the east warm surface waters are associated with its deepening, consistent with Houghton [1991]. At higher frequencies the dominant signals in sea surface temperature are the diurnal and semi-diurnal cycles. Spectral analysis of the depth of the 20°C isotherm show a predominance of the semi-diurnal period. In the eastern Atlantic there are two additional dominant bands in the spectra: 10-14 days, 25-27 days and for the depth of the 20°C isotherm there is also a lower frequency band at 20-40 days associated with tropical instability waves at the equator. The first band can be associated with atmospherically forced motions and the lower frequency band with barotropic instability waves.

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Section: Introductionmentioning

confidence: 99%

Time scales of upper ocean temperature variability inferred from the PIRATA data (1997–2000)

Wainer

Clauzet

Servain³

et al. 2003

Geophysical Research Letters

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“…With respect to sea surface temperature (SST), the tropical Atlantic ocean displays two dominant modes of interanual variability largely described in the literature [e.g. Servain , 1991; Wainer et al , 2002; Servain et al , 2002]. One represents an inter‐hemispheric SST gradient signature.…”

Section: Introductionmentioning

confidence: 99%

Equatorial currents transport changes for extreme warm and cold events in the Atlantic Ocean

Góes

Wainer

2003

Geophysical Research Letters

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[1] In this work the Equatorial Atlantic Ocean circulation dynamics for warm and cold composite events are analyzed. Warm and cold typical years were composited from the respective five warmest and the five coldest years of the available record. Equatorial currents velocity and transport are calculated. During a typical warm event, the circulation decreases in the upper ocean, while during the typical cold event there is intensification. The strengthening (weakening) of the circulation during cold (warm) events increases (decreases) the stress between the Equatorial Undercurrent (EUC) and the South Equatorial Current (SEC), associated with an increase (decrease) in entrainment of cold waters into the surface and their westward transport. The EUC showed striking differences between both composited events. For the cold (warm) event the EUC shows a greater (reduced) transport and core velocity, and a deeper (shallower) structure. INDEX TERMS: 4231

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“…However, the Atlantic Niño is much weaker than its Pacific counterpart (Zebiak 1993;Carton and Huang 1994;Latif and Grötzner 2000;Servain et al 2003). A relationship between the Atlantic Niño and Pacific variability has also been suggested by some studies (Servain and Merle 1993;Carton and Huang 1994).…”

Section: Introductionmentioning

confidence: 84%

Sea surface temperature patterns in the Tropical Atlantic: Principal component analysis and nonlinear principal component analysis

Kenfack-Sadem¹,

Mkankam²,

Alory³

et al. 2017

Terr. Atmos. Ocean. Sci.

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The tropical Atlantic Ocean exhibits several modes of interannual variability such as the equatorial (or Atlantic Niño) mode, and meridional (or Atlantic dipole) mode. Nonlinear principal component analysis (NLPCA) is applied on detrended monthly Sea Surface Temperature Anomaly (SSTA) data from the tropical Atlantic Ocean (30°W -20°E, 26°S -22°N) for the period 1950 to 2005. The objective is to compare the modes extracted through this statistical analysis to those previously extracted through simpler principal component analysis (PCA). It is shown that the first NLPCA mode explains 38% of the total SST variance compared to 36% by the first PCA while the second NLPCA mode explains 22% of the total SST variance compared to 16% by the second PCA. The first two NLPCA modes marginally explain more of the total data variance than the first two PCA modes. Our analysis confirms results from previous studies and, in addition, shows that the Atlantic El Niño structure is spatially more stable than the Atlantic dipole structure.

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Modes of tropical Atlantic climate variability observed by PIRATA

Cited by 19 publications

References 18 publications

Time scales of upper ocean temperature variability inferred from the PIRATA data (1997–2000)

Time scales of upper ocean temperature variability inferred from the PIRATA data (1997–2000)

Equatorial currents transport changes for extreme warm and cold events in the Atlantic Ocean

Sea surface temperature patterns in the Tropical Atlantic: Principal component analysis and nonlinear principal component analysis

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