scholarly journals Role of El Niño Southern Oscillation (ENSO) Events on Temperature and Salinity Variability in the Agulhas Leakage Region

2018 ◽  
Vol 10 (1) ◽  
pp. 127 ◽  
Author(s):  
◽  
1994 ◽  
Vol 6 (4) ◽  
pp. 473-478 ◽  
Author(s):  
C. Guinet ◽  
P. Jouventin ◽  
J-Y. Georges

The population trend over the last decade for subantarctic fur seals (Arctocephalus tropicalis) on Amsterdam and St. Paul islands and on Possession Island (Crozet Archipelago) and Antarctic fur seals (A. gazella) on Possession Island are analysed. At Amsterdam Island, based on pup counts, the subantarctic fur seal population appears to have stabilized after a period of rapid growth. At Possession Island subantarctic fur seal and Antarctic fur seal, with respective annual growth rates of 19.2 and 17.4%, are reaching the maximum growth rate for the genus Arctocephalus. Annual pup censuses at Possession Island since 1978 indicate important variations from year to year with pup production for A. gazella significantly lower the year after an El Niño Southern Oscillation (ENSO) event, but with no such relationship for A. tropicalis. Several other long term demographic studies of seabirds and marine mammals at different breeding locations in the Southern Ocean indicate that the breeding success of several of these predators appears to be widely affected in years which appear to be related to the ENSO events. To clarify this, it is necessary to analyse in more detail the demographic data obtained for the different subantarctic and Antarctic locations where long term monitoring programmes are conducted.


2016 ◽  
Vol 2016 (1) ◽  
Author(s):  
Sutyajeet Soneja* ◽  
Chengsheng Jiang ◽  
Jared Fisher ◽  
David Blythe ◽  
Clifford Mitchell ◽  
...  

2007 ◽  
Vol 20 (5) ◽  
pp. 788-800 ◽  
Author(s):  
Andrew B. G. Bush

Abstract A sequence of numerical simulations with a coupled atmosphere–ocean general circulation model configured for particular times during the late Quaternary shows that simulated El Niño–Southern Oscillation (ENSO) events decrease in frequency from the Last Glacial Maximum (LGM) to today, in accord with linear stability theory, but increase in amplitude. Diagnostic analyses indicate that altered momentum fluxes from midlatitude eddy activity caused by changes in orbital forcing (in the Holocene) and topographic forcing (at the LGM) regulate the strength of climatological easterlies and therefore affect both the tropical mean state and the characteristics of interannual variability. The fact that climatic teleconnections associated with paleo-ENSO are fundamentally different during these times suggests a way in which to reconcile some of the existing discrepancies amongst interpretations of proxy records and numerical paleoclimate simulations.


2010 ◽  
Vol 7 (5) ◽  
pp. 8521-8543 ◽  
Author(s):  
A. Lü ◽  
S. Jia ◽  
H. Yan ◽  
S. Wang

Abstract. Many studies have examined that El Niño-Southern Oscillation (ENSO) could result in the variation of rainfall and runoff of different rivers across the world. In this paper, we will look specifically at the Headwaters Region of the Yellow River (HRYR) to explore the rainfall-ENSO and runoff-ENSO relationships and discuss the potential for water resources forecasting using these relationships. Cross-correlation analyses were performed to determine the significant correlation between rainfall, runoff and ENSO indicators (e.g. SOI, Niño 1.2, Niño 3, Niño 4, and Niño 3.4) and the lag period for each relationship. Main result include: (1) there are significant correlation at 95% confidence level during three periods, i.e. January and March, from September to November; (2) there were significant correlations between monthly streamflow and monthly ENSO indictors during three periods, i.e. JFM, June, and OND, with lag periods between one and twelve months. As ENSO events can be accurately predicted one to two years in advances using physical model of coupled ocean-atmosphere system, the lead time for forecasting runoff using ENSO indicator in the HRYR can be extent to one to thirty-six months. Therefore, ENSO may have potential as a powerful forecast tool for water resource in headwater regions of Yellow River.


Gaia Scientia ◽  
2019 ◽  
Vol 13 (4) ◽  
Author(s):  
Robson de Sousa Nascimento ◽  
José Ivaldo Barbosa de Brito ◽  
Valéria Peixoto Borges

The goal of the present study it was to know the behavior of the Net Primary Production (NPP) in years that have occurred El Niño Southern Oscillation (ENSO) and during the temperature anomalies of the surface of the Sea (SST) in the Tropical Atlantic, that is Atlantic Dipole. The results showed that the Amazon Rainforest, Atlantic Forest, and the Cerrado were not enough affected by the occurrence of El Niño Southern Oscillation and Atlantic Dipole. However, the Caatinga biome has shown to be quite sensitive to these events and patterns, especially in years of occurrence of El Niño, which contributed to a reduction in NPP; while in years of El Niña and negative dipole, the NPP achieved the highest values. The amount of rainfall in the previous year to the El Niño Southern Oscillation episodes showed influence on the amount of carbon sequestered by biomes in the year of study.


2000 ◽  
Vol 15 (4) ◽  
pp. 465-470 ◽  
Author(s):  
Thierry Corrège ◽  
Thierry Delcroix ◽  
Jacques Récy ◽  
Warren Beck ◽  
Guy Cabioch ◽  
...  

2011 ◽  
Vol 29 (3) ◽  
pp. 529-540 ◽  
Author(s):  
J. Zhu ◽  
G. Zhou ◽  
R.-H. Zhang ◽  
Z. Sun

Abstract. The role of decadal changes in ocean thermal structure in modulating El Niño/Southern Oscillation (ENSO) properties was examined using a hybrid coupled model (HCM), consisting of a statistical atmospheric model and an oceanic general circulation model (OGCM) with an explicitly embedded empirical parameterization for the temperature of subsurface water entrained into the mixed layer (Te), which was constructed via an EOF analysis of model-based historical data. Using the empirical Te models constructed from two subperiods, 1963–1979 (Te63−79) and 1980–1996 (Te80−96), the coupled system exhibits striking different properties of interannual variability, including oscillation periods and the propagation characteristic of sea surface temperature anomalies (SSTAs) along the equator. In the Te63−79 run, the model features a 2–3 yr oscillation and a westward propagation of SSTAs along the equator, while in the Te80−96 run, it is characterized by a 4–5 yr oscillation and an eastward propagation. Furthermore, a Lag Covariance Analysis (LCOA) was utilized to illustrate the leading physical processes responsible for decadal change in SST. It is shown that the change in the structure of Te acts to modulate the relative strength of the zonal advective and thermocline feedbacks in the coupled system, leading to changes in ENSO properties. Two additional sensitive experiments were conducted to further illustrate the respective roles of the changes in ocean mean states and in Te in modulating ENSO behaviors. These decadal changes in the simulated ENSO properties are consistent with the observed shift occurred in the late 1970s and a previous simulation performed with an intermediate coupled model (ICM) described in Zhang and Busalacchi (2005), indicating a dominant role Te plays in decadal ENSO changes.


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