scholarly journals RESPONS SUHU PERMUKAAN LAUT DAN KLOROFIL-A TERHADAP KEJADIAN ENSO DAN IODM DI WILAYAH INDO-PASIFIK TROPIS

2020 ◽  
Vol 12 (1) ◽  
pp. 167-182
Author(s):  
Andry Purnama Putra ◽  
Agus S. Atmadipoera ◽  
John I. Pariwono
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Dipole Mode ◽  
Indian Ocean Dipole Mode ◽  
Chl A ◽  
Orthogonal Function ◽  
Mode 2 ◽  
Explained Variance

Fenomena anomali laut-atmosfer antar-tahunan dari El Nino Southern Oscillation (ENSO) dan Indian Ocean Dipole Mode (IODM) di wilayah Indo-Pasifik Tropis memberikan dampak pada ekosistem laut, hidrologi dan variabilitas iklim. Penelitian ini bertujuan untuk menganalisis pola spasial dan variabilitas temporal suhu permukaan laut (SPL) dan klorofil-a permukaan (Chl-a) terkait dengan ENSO dan IODM di Indo-Pasifik Tropis. Data deret waktu bulanan dari tahun 1980-2017 (37 tahun) diperoleh dari pusat data global, dan dianalisis menggunakan metode empirical orthogonal function (EOF). Hasil penelitian menunjukkan nilai tiga terbesar pertama dari SPL (Chl-a) menjelaskan 81,7% (76%) dari total explained variance. Struktur spasial SPL mode-1 (56%) membentuk seperti dua kutub asimetris antara timur dan barat Pasifik Tropis dengan pola yang berbeda di lepas Pantai Peru. Pola ini diduga berhubungan dengan tahun normal atau La Nina. Selanjutnya, kondisi EL Nino dan IODM diduga tergambarkan oleh SPL mode-2 (19%), dengan fase negatif dominan di atas ekuator Pasifik dan menghilangnya area upwelling di lepas Pantai Peru.

scholarly journals EFFECTS OF DIPOLE MODE AND EL-NINO EVENTS ON CATCHES OF YELLOWFIN TUNA (Thunnus albacares) IN THE EASTERN INDIAN OCEAN OFF WEST JAVA

2015 ◽  
Vol 21 (2) ◽  
pp. 75 ◽  
Author(s):  
Khairul Amri ◽  
Ali Suman ◽  
Hari Eko Irianto ◽  
Wudianto Wudianto
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
El Nino ◽  
Yellowfin Tuna ◽  
Environmental Data ◽  
Thunnus Albacares ◽  
Dipole Mode ◽  
Indian Ocean Dipole Mode ◽  
El Niño Events ◽  
El Nino Events

The effects of Indian Ocean Dipole Mode and El Niño–Southern Oscillation events on catches of YellowfinTuna (<em>Thunnus albacares</em>) in the Eastern Indian Ocean (EIO) off Java were evaluated through the use of remotely sensed environmental data (sea surface temperature/SST and chlorophyll-a concentration/SSC) and Yellowfin Tuna catch data. Analyses were conducted for the period of 2003–2012, which included the strong positive dipole mode event in association with weak El-Nino 2006.Yellowfin Tuna catch data were taken from Palabuhanratu landing place and remotely sensed environmental data were taken from MODIS-Aqua sensor.The result showed that regional climate anomaly Indian Ocean Dipole Mode influenced Yellowfin Tuna catch and its composition. The catches per unit effort (CPUE) of Thunnus alabacares in the strong positive dipole mode event in 2006 and weak El-Nino events in 2011 and 2012 was higher. The increase patern of CPUE followed the upwelling process, started from May-June achieved the peak between September-October.Very high increase in CPUE when strong positive dipole mode event (2006) and a weak El-Nino events (2011 and 2012) had a relation with the increase in the distribution of chlorophyll-a indicating an increase in the abundance of phytoplankton (primary productivity) due to upwelling. In contrast, yellowfin tuna CPUE is very low at the La-Nina event (2005), though as the dominant catch when compared to others.

A Diagnostic Study of the Indian Ocean Dipole Mode in El Niño and Non–El Niño Years

2007 ◽  
Vol 20 (13) ◽  
pp. 2961-2977 ◽  
Author(s):  
Hae-Kyung Lee Drbohlav ◽  
Silvio Gualdi ◽  
Antonio Navarra
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
Indian Ocean Dipole ◽  
El Nino ◽  
Western Indian Ocean ◽  
Wind Flow ◽  
Dipole Mode ◽  
Indian Ocean Dipole Mode ◽  
Anticyclonic Circulation ◽  
The Indian Ocean

Abstract The Indian Ocean dipole mode (IODM) is examined by comparing the characteristics of oceanic and atmospheric circulations, heat budgets, and possible mechanisms of IODM between El Niño and non–El Niño years. Forty-year ECMWF Re-Analysis (ERA-40) data, Reynolds SST data, and ocean assimilation data from the Modular Ocean Model are used to form composites of the IODM that occur during El Niño (1972, 1982, and 1997) and non–El Niño (1961, 1967, and 1994) years. In El Niño years, two off-equatorial, anticyclonic circulations develop, associated with the increased pressure over the eastern Indian Ocean. The anticyclonic circulation over the Northern Hemisphere enhances the easterly component of the winds in the northwestern Indian Ocean. This enhanced easterly component increases the mixed layer temperature by inducing an anomalous westward ocean current that advects the warm mean mixed layer from the central to the western Indian Ocean. Meanwhile, the anticyclonic circulation over the southeastern Indian Ocean strengthens southeasterlies, thereby causing oceanic meridional and vertical advection of the cold mean temperature. Consequently, the IODM in El Niño years is characterized by the warming in the northwestern and the cooling in the southeastern Indian Ocean. In non–El Niño years, a monsoonlike wind flow increases the westerly and southeasterly components of the wind over the northwestern and southeastern Indian Ocean, respectively. Oceanic currents induced by these winds result in anomalous cold advection in both of these regions. In addition, the monsoonlike wind flow over the southeastern Indian Ocean enhances the anomalous latent and sensible heat fluxes in non–El Niño years. Hence, the cooling of the eastern tropical Indian Ocean, rather than the warming of the western Indian Ocean, becomes the major feature of the IODM during non–El Niño years.

scholarly journals ANALISIS MULTILAYER VARIABILITAS UPWELLING DI PERAIRAN SELATAN JAWA

2018 ◽  
Vol 13 (1) ◽  
pp. 15 ◽  
Author(s):  
Bambang Sukresno ◽  
Denarika Jatisworo ◽  
Denny Wijaya Kusuma
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
Indian Ocean Dipole ◽  
El Nino ◽  
Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Dipole Mode ◽  
Argo Float ◽  
Dipole Mode Index ◽  
Mode Index

 Variabilitas upwelling di perairan selatan Jawa telah diidentifikasi. Analisis multilayer dilakukan dengan menggunakan data ARGO Float. Variabilitas suhu permukaan laut (SPL) dan klorofil-a (klor-a) dianalisis dengan menggunakan data satelit MODIS Aqua. Pengaruh El Nino Southern Oscillation (ENSO) terhadap upwelling dilakukan dengan menggunakan indeks Oceanic Nino Index (ONI), sedangkan pengaruh Indian Ocean Dipole (IOD) direpresentasikan dengan menggunakan indeks Dipole Mode Index (DMI). Dari hasil penelitian diketahui bahwa ENSO mempengaruhi intensitas upwelling. Pada periode el nino intensitas upwelling mengalami peningkatan yang diikuti oleh penurunan SPL dan naiknya konsentrasi klor-a, sebaliknya pada periode la nina terjadi penurunan intensitas upwelling yang diikuti naiknya SPL dan turunnya konsentrasi klor-a. Peningkatan intensitas upwelling juga terdeteksi pada saat terjadi periode IOD positif, sedangkan penurunan intensitas upwelling terjadi pada periode IOD negatif. 

scholarly journals Indian Ocean impact on ENSO evolution 2014–2016 in a set of seasonal forecasting experiments

2021 ◽  
Author(s):  
Michael Mayer ◽  
Magdalena Alonso Balmaseda
Keyword(s):  
Pacific Ocean ◽  
Indian Ocean ◽  
El Niño ◽  
Initial Conditions ◽  
El Nino ◽  
Southern Oscillation ◽  
Heat Content ◽  
Tropical Pacific ◽  
Decadal Variations ◽  
The Indian Ocean

AbstractThis study investigates the influence of the anomalously warm Indian Ocean state on the unprecedentedly weak Indonesian Throughflow (ITF) and the unexpected evolution of El Niño-Southern Oscillation (ENSO) during 2014–2016. It uses 25-month-long coupled twin forecast experiments with modified Indian Ocean initial conditions sampling observed decadal variations. An unperturbed experiment initialized in Feb 2014 forecasts moderately warm ENSO conditions in year 1 and year 2 and an anomalously weak ITF throughout, which acts to keep tropical Pacific ocean heat content (OHC) anomalously high. Changing only the Indian Ocean to cooler 1997 conditions substantially alters the 2-year forecast of Tropical Pacific conditions. Differences include (i) increased probability of strong El Niño in 2014 and La Niña in 2015, (ii) significantly increased ITF transports and (iii), as a consequence, stronger Pacific ocean heat divergence and thus a reduction of Pacific OHC over the two years. The Indian Ocean’s impact in year 1 is via the atmospheric bridge arising from altered Indian Ocean Dipole conditions. Effects of altered ITF and associated ocean heat divergence (oceanic tunnel) become apparent by year 2, including modified ENSO probabilities and Tropical Pacific OHC. A mirrored twin experiment starting from unperturbed 1997 conditions and several sensitivity experiments corroborate these findings. This work demonstrates the importance of the Indian Ocean’s decadal variations on ENSO and highlights the previously underappreciated role of the oceanic tunnel. Results also indicate that, given the physical links between year-to-year ENSO variations, 2-year-long forecasts can provide additional guidance for interpretation of forecasted year-1 ENSO probabilities.

scholarly journals Indo-Western Pacific Climate Variability: ENSO Forcing and Internal Dynamics in a Tropical Pacific Pacemaker Simulation

2018 ◽  
Vol 31 (24) ◽  
pp. 10123-10139 ◽  
Author(s):  
Chuan-Yang Wang ◽  
Shang-Ping Xie ◽  
Yu Kosaka
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
General Circulation ◽  
El Nino ◽  
Southern Oscillation ◽  
Internal Variability ◽  
Tropical Pacific ◽  
Western Pacific ◽  
Ocean Atmosphere ◽  
Sst Anomalies

El Niño–Southern Oscillation (ENSO) peaks in boreal winter but its impact on Indo-western Pacific climate persists for another two seasons. Key ocean–atmosphere interaction processes for the ENSO effect are investigated using the Pacific Ocean–Global Atmosphere (POGA) experiment with a coupled general circulation model, where tropical Pacific sea surface temperature (SST) anomalies are restored to follow observations while the atmosphere and oceans are fully coupled elsewhere. The POGA shows skills in simulating the ENSO-forced warming of the tropical Indian Ocean and an anomalous anticyclonic circulation pattern over the northwestern tropical Pacific in the post–El Niño spring and summer. The 10-member POGA ensemble allows decomposing Indo-western Pacific variability into the ENSO forced and ENSO-unrelated (internal) components. Internal variability is comparable to the ENSO forcing in magnitude and independent of ENSO amplitude and phase. Random internal variability causes apparent decadal modulations of ENSO correlations over the Indo-western Pacific, which are high during epochs of high ENSO variance. This is broadly consistent with instrumental observations over the past 130 years as documented in recent studies. Internal variability features a sea level pressure pattern that extends into the north Indian Ocean and is associated with coherent SST anomalies from the Arabian Sea to the western Pacific, suggestive of ocean–atmosphere coupling.

scholarly journals Effects of El Niño–Southern Oscillation events on catches of Bigeye Tuna (Thunnus obesus) in the eastern Indian Ocean off Java

2013 ◽  
Vol 111 (2) ◽  
pp. 175-188 ◽  
Author(s):  
Mega L. Syamsuddin ◽  
Sei-Ichi Saitoh ◽  
Toru Hirawake ◽  
Samsul Bachri ◽  
Agung B. Harto
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Eastern Indian Ocean ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Bigeye Tuna ◽  
Thunnus Obesus

scholarly journals KAJIAN STATISTIK UKURAN BESAR BUTIR SEDIMEN DAN KAITANNYA DENGAN VARIABILITAS IKLIM MUSIMAN DAN TAHUNAN DI MUARA GEMBONG, TELUK JAKARTA

2019 ◽  
Vol 11 (3) ◽  
pp. 683-695 ◽  
Author(s):  
Taufik R. Syachputra ◽  
Ivonne M. Radjawane ◽  
Rina Zuraida
Keyword(s):  
El Niño ◽  
Southern Oscillation Index ◽  
El Nino ◽  
Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Dipole Mode ◽  
Australian Monsoon ◽  
Dipole Mode Index ◽  
Monsoon Index ◽  
Mode Index

Variabilitas iklim dapat mempengaruhi sifat sedimen yang terendapkan di dasar laut. Salah satu sifat sedimen yang dipengaruhi oleh iklim adalah besar butir. Penelitian ini bertujuan untuk menguji hubungan antara besar butir dengan variabilitas iklim menggunakan sampel core GM01-2010-TJ22 dari Muara Gembong, Teluk Jakarta, muara sungai Citarum. Sampel core diambil pada tahun 2010 dengan menggunakan Kapal Riset Geomarin I oleh Pusat Penelitian dan Pengembangan Geologi Kelautan (P3GL). Pengukuran besar butir dilakukan dengan menggunakan Mastersizer 2000. Hasil pengukuran ditampilkan dalam seri waktu dari tahun 2001 sampai 2010. Hasil analisis besar butir sampel sedimen dikorelasikan secara statistik dengan fenomena musiman (monsun), tahunan dan antar tahun (El Niño/La Niña dan Dipole Mode). Verifikasi data dilakukan dengan menggunakan data sekunder temperatur permukaan laut dari citra satelit di sekitar lokasi sampel dan data curah hujan di Bekasi. Hasil verifikasi menunjukkan bahwa peningkatan curah hujan di sekitar daerah hilir Sungai Citarum diikuti dengan penurunan temperatur permukaan laut dan peningkatan ukuran rata-rata besar butir. Hasil yang didapat dalam uji statistika menunjukkan bahwa perubahan ukuran besar butir sampel sedimen di Muara Gembong memiliki korelasi signifikan dengan Multivariate ENSO (El Niño Southern Oscillation) Index (MEI), Ocean Niño Index (ONI), Dipole Mode Index (DMI) dan Australian Monsoon Index (AUSMI). Hasil tersebut menunjukkan bahwa besar butir sedimen dasar laut potensial digunakan untuk mengetahui variabilitas iklim di sekitar Teluk Jakarta.

scholarly journals Isolated Effects of Indian Ocean Basin-Wide and El Niño–Southern Oscillation on Austral Winter Rainfall over South America

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1605
Author(s):  
Mary T. Kayano ◽  
Wilmar L. Cerón ◽  
Rita V. Andreoli ◽  
Rodrigo A. F. Souza ◽  
Itamara P. Souza
Keyword(s):  
Indian Ocean ◽  
South America ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Tropical Indian Ocean ◽  
Ocean Basin ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Partial Correlations

Contrasting effects of the tropical Indian and Pacific Oceans on the atmospheric circulation and rainfall interannual variations over South America during southern winter are assessed considering the effects of the warm Indian Ocean basin-wide (IOBW) and El Niño (EN) events, and of the cold IOBW and La Niña events, which are represented by sea surface temperature-based indices. Analyses are undertaken using total and partial correlations. When the effects of the two warm events are isolated from each other, the contrasts between the associated rainfall anomalies in most of South America become accentuated. In particular, EN relates to anomalous wet conditions, and the warm IOBW event to opposite conditions in extensive areas of the 5° S–25° S band. These effects in the 5° S–15° S sector are due to the anomalous regional Hadley cells, with rising motions in this band for the EN and sinking motions for the warm IOBW event. Meanwhile, in subtropical South America, the opposite effects of the EN and warm IOBW seem to be due to the presence of anomalous anticyclone and cyclone and associated moisture transport, respectively. These opposite effects of the warm IOBW and EN events on the rainfall in part of central South America might explain the weak rainfall relation in this region to the El Niño–Southern Oscillation (ENSO). Our results emphasize the important role of the tropical Indian Ocean in the South American climate and environment during southern winter.

scholarly journals El Niño-Southern Oscillation and Indian Ocean Dipole Modes: Their Effects on South American Rainfall during Austral Spring

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1437
Author(s):  
Mary T. Kayano ◽  
Wilmar L. Cerón ◽  
Rita V. Andreoli ◽  
Rodrigo A. F. Souza ◽  
Itamara P. Souza ◽  
...  
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
Indian Ocean Dipole ◽  
El Nino ◽  
Southern Oscillation ◽  
Tropical Indian Ocean ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Austral Spring ◽  
Precipitation Anomalies

This paper examines the effects of the tropical Pacific Ocean (TPO) and Indian Ocean Dipole (IOD) modes in the interannual variations of austral spring rainfall over South America (SA). The TPO mode refers to the El Niño-Southern Oscillation (ENSO). The isolated effects between IOD and TPO were estimated, events were chosen from the residual TPO (R-TPO) or residual IOD (R-IOD), and the IOD (TPO) effects for the R-TPO (R-IOD) composites were removed from the variables. One relevant result was the nonlinear precipitation response to R-TPO and R-IOD. This feature was accentuated for the R-IOD composites. The positive R-IOD composite showed significant negative precipitation anomalies along equatorial SA east of 55° W and in subtropical western SA, and showed positive anomalies in northwestern SA and central Brazil. The negative R-IOD composite indicated significant positive precipitation anomalies in northwestern Amazon, central–eastern Brazil north of 20° S, and western subtropical SA, and negative anomalies were found in western SA south of 30° S. This nonlinearity was likely due to the distinct atmospheric circulation responses to the anomalous heating sources located in longitudinally distinct regions: the western tropical Indian Ocean and areas neighboring Indonesia. The results obtained in this study might be relevant for climate monitoring and modeling studies.

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