scholarly journals Pengaruh Central Pacific dan eastern Pacific El Nino terhadap variabilitas curah hujan di Sulawesi

2018 ◽  
Vol 15 (2) ◽  
pp. 73
Author(s):  
Budi Prasetyo ◽  
Nikita Pusparini
Keyword(s):  
Data Assimilation ◽  
El Niño ◽  
El Nino ◽  
Climate Prediction ◽  
Eastern Pacific ◽  
Central Pacific ◽  
Eastern Pacific El Niño ◽  
Ocean Data Assimilation ◽  
Ep El Niño ◽  
Climate Prediction Center

Pulau Sulawesi dipengaruhi oleh fenomena Central Pacific (CP) dan Eastern Pacific (EP) El Niño. Curah hujan Sulawesi mencakup ketiga pola hujan yang ada di Indonesia yaitu Monsunal, equatorial, dan lokal. Variabilitas ketiga pola curah hujan tersebut akan memberikan respon yang berbeda terhadap pengaruh dari kedua tipe El Niño tersebut. Maka, Kajian ini akan membahas pengaruh dari kedua tipe El Niño  terhadap curah hujan Sulawesi. Penelitian ini Menggunakan data curah hujan bulanan berasal dari Climate Prediction Center (CPC) National Oceanic and Atmospheric Administration (NOAA), Suhu Permukaan Laut (SPL) bulanan dari System Ocean Data Assimilation (SODA) versi 2.2.4 dan oceanic Niño Indeks (ONI) dengan periode  Januari 1950 hingga Desember 2010 (60 tahun). Perhitungan statistik sederhana berupa perata-rataan, korelasi, dan analisa komposit digunakan dalam kajian ini. Penentuan tipe El Niño menggunakan tiga buah indeks yang berbeda. Hasilnya diperoleh bahwa Curah hujan Sulawesi berkurang saat kedua tipe El Niño. Penurunan curah hujan akibat EP El Niño berkisar antara 5 – 20 mm sedangkan akibat CP El Niño berkisar antara 2-12 mm. Wilayah Sulawesi dengan pola curah hujan monsunal merupakan wilayah yang mengalami penurunan curah hujan terbesar akibat kedua tipe El Niño tersebut, kemudian diikuti dengan pola curah hujan equatorial dan terakhir Lokal.

scholarly journals Intraseasonal Tropical Atmospheric Variability Associated with the Two Flavors of El Niño

2012 ◽  
Vol 140 (11) ◽  
pp. 3669-3681 ◽  
Author(s):  
Daria Gushchina ◽  
Boris Dewitte
Keyword(s):  
El Niño ◽  
El Nino ◽  
Wave Activity ◽  
Kelvin Wave ◽  
Atmospheric Variability ◽  
Central Pacific ◽  
Cp El Niño ◽  
Ocean Data Assimilation ◽  
Double Space ◽  
Ep El Niño

ABSTRACT The characteristics of intraseasonal tropical variability (ITV) associated with the two flavors of El Niño [i.e., the canonical or eastern Pacific (EP) El Niño and the Modoki or central Pacific (CP) El Niño] are documented using composite and regression analysis. Double space–time Fourier analysis is applied to the NCEP–NCAR zonal wind at 850 hPa (U850) to separate the different components of the ITV in the tropical troposphere, which is then used to define indices of wave activity, and document the spatial pattern of the waves. It is shown that the ITV characteristics are altered during CP El Niño compared to the typical seasonal dependence of the ITV–ENSO relationship. In particular, while EP El Niño is characterized by enhanced MJO and equatorial Rossby (ER) wave activity during spring–summer prior to the ENSO peak, during CP El Niño, the ITV activity is increased during the mature and decaying phases. It is suggested that ITV is more propitious to the triggering of the EP event; while during the CP event, it contributes mostly to the persistence of positive SST anomalies. The oceanic response of these ITV anomalous patterns is further investigated in the Simple Ocean Data Assimilation (SODA) reanalysis by documenting the seasonal evolution of the intraseasonal equatorial oceanic Kelvin wave (IEKW) activity during the two flavors of El Niño. It is shown that anomalous westerlies associated with ITV may generate the corresponding response in the ocean in the form of anomalous IEKW activity.

Causes of the El Niño and La Niña Amplitude Asymmetry in the Equatorial Eastern Pacific

2010 ◽  
Vol 23 (3) ◽  
pp. 605-617 ◽  
Author(s):  
Jingzhi Su ◽  
Renhe Zhang ◽  
Tim Li ◽  
Xinyao Rong ◽  
J-S. Kug ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Mixed Layer ◽  
El Niño ◽  
El Nino ◽  
La Niña ◽  
Eastern Pacific ◽  
Ocean Data Assimilation ◽  
La Nina ◽  
Nonlinear Advection ◽  
Far Eastern

Abstract The amplitude asymmetry between El Niño and La Niña is investigated by diagnosing the mixed-layer heat budget during the ENSO developing phase by using the three ocean assimilation products: Simple Ocean Data Assimilation (SODA) 2.0.2, SODA 1.4.2, and the Global Ocean Data Assimilation System (GODAS). It is found that the nonlinear zonal and meridional ocean temperature advections are essential to cause the asymmetry in the far eastern Pacific, whereas the vertical nonlinear advection has the opposite effect. The zonal current anomaly is dominated by the geostrophic current in association with the thermocline depth variation. The meridional current anomaly is primarily attributed to the Ekman current driven by wind stress forcing. The resulting induced anomalous horizontal currents lead to warm nonlinear advection during both El Niño and La Niña episodes and thus strengthen (weaken) the El Niño (La Niña) amplitude. The convergence (divergence) of the anomalous geostrophic mixed-layer currents during El Niño (La Niña) results in anomalous downwelling (upwelling) in the far eastern equatorial Pacific, which leads to a cold nonlinear vertical advection in both warm and cold episodes.

scholarly journals Contrasting Effects of Central Pacific and Eastern Pacific El Niño on stratospheric water vapor

2013 ◽  
Vol 40 (15) ◽  
pp. 4115-4120 ◽  
Author(s):  
Chaim I. Garfinkel ◽  
Margaret M. Hurwitz ◽  
Luke D. Oman ◽  
Darryn W. Waugh
Keyword(s):  
Water Vapor ◽  
El Niño ◽  
El Nino ◽  
Eastern Pacific ◽  
Central Pacific ◽  
Stratospheric Water Vapor ◽  
Eastern Pacific El Niño

Are the teleconnections of Central Pacific and Eastern Pacific El Niño distinct in boreal wintertime?

2012 ◽  
Vol 41 (7-8) ◽  
pp. 1835-1852 ◽  
Author(s):  
C. I. Garfinkel ◽  
M. M. Hurwitz ◽  
D. W. Waugh ◽  
A. H. Butler
Keyword(s):  
El Niño ◽  
El Nino ◽  
Eastern Pacific ◽  
Central Pacific ◽  
Eastern Pacific El Niño

scholarly journals A Comparative Analysis of the Impacts of Two Types of El Niño on the Central and Eastern Pacific ITCZ

Atmosphere ◽  
2018 ◽  
Vol 9 (7) ◽  
pp. 266
Author(s):  
Jinshuang Zhu ◽  
Yudi Liu ◽  
Ruiqing Xie ◽  
Haijie Chang
Keyword(s):  
Rossby Wave ◽  
El Niño ◽  
El Nino ◽  
Eastern Pacific ◽  
Wave Response ◽  
Mature Period ◽  
Rossby Wave Response ◽  
Sst Anomaly ◽  
Ep El Niño ◽  
Meridional Mode

The precipitation data from the Global Precipitation Climatology Project (GPCP) and CPC Merged Analysis of Precipitation (CMAP) were used to investigate the discrepancy of Centre and Eastern Pacific ITCZ (CEP-ITCZ) during two types of El Niño years. Two models of the heat source distribution during two types of El Niño events were constructed, and the causes of different CEP-ITCZ anomalies for two types of El Niño events were analyzed through the Gill model. The results show that the CEP-ITCZ precipitation is approximately 4.0° southward, and the intensity is enhanced by 3.6 mm/day during the mature period of Eastern Pacific El Niño (EP-El Niño), while during the mature period of Central Pacific El Niño (CP-El Niño), it is only 0.8° southward, and the intensity is enhanced by 3.2 mm/day. The meridional mode of the SST anomaly by means of EOF (Empirical Orthogonal Function) can indirectly affect the CEP-ITCZ by influencing the atmospheric Rossby wave response. In CP-El Niño years, the meridional mode of the SST anomaly is weak, and the atmospheric Rossby wave response enhances the northern and southern trade-wind zones at the same time. The anomaly of cross-equatorial flow is weak and the CEP-ITCZ moves southward a little. At the same time, the wind convergence zone is enhanced, and it is more conducive to the vertical transport of water vapor. In EP-El Niño years, the meridional mode of the SST anomaly is strong, and the atmospheric Rossby wave response strengthens the meridional wind on the northern side of the equator, leading to the southward shift of the CEP-ITCZ. At the same time, the wind convergence zone is weakened and widened, and to a certain extent, it suppresses the vertical transport increase of water vapor caused by the sea surface evaporation.

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