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Ahn, J. H., and H. S. Kim. "Nonlinear Modeling of El Nino/Southern Oscillation Index." Journal of Hydrologic Engineering 10, no. 1 (January 2005): 8–15. http://dx.doi.org/10.1061/(asce)1084-0699(2005)10:1(8).
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Lou, Ying Jun, Li Na Lu, and Li Jie Zhu. "The Effect of ENSO on Wheat Futures Based on EMD and GARCH Model." Applied Mechanics and Materials 40-41 (November 2010): 866–72. http://dx.doi.org/10.4028/www.scientific.net/amm.40-41.866.
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At present, most of the studies on the relationship between El Nino Southern Oscillation and agricultural futures focus on perceptual analyses and directly data analysis, and these discussions are usually limited to futures price. This article uses EMD algorithm to decompose Wheat futures prices and denoised ENSO index, and finally gets the negative relationship between El Nino Southern Oscillation and wheat Futures prices. Then, this article conducts the comparative analysis of operation performance based on El Niño Southern Oscillation, finding that this mode of operation can greatly increase yields, which further explains the practical significance of ENSO. In order to explore the impact of El Nino Southern Oscillation on wheat futures yields, use classic GARCH models, transform ENSO index into virtual variables, respectively introduce them into the mean value equation and conditional variance equation. After analysis, the conclusion shows that the impact is mainly on the volatility of return rate, which reminds traders of considering risk management first.
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Yananto, Ardila, and Rini Mariana Sibarani. "ANALISIS KEJADIAN EL NINO DAN PENGARUHNYA TERHADAP INTENSITAS CURAH HUJAN DI WILAYAH JABODETABEK (Studi Kasus : Periode Puncak Musim Hujan Tahun 2015/2016)." Jurnal Sains & Teknologi Modifikasi Cuaca 17, no. 2 (December 27, 2016): 65. http://dx.doi.org/10.29122/jstmc.v17i2.541.
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IntisariBeberapa lembaga riset dunia dan badan-badan meteorologi beberapa negara di dunia menyatakan adanya kejadian El Nino Tahun 2015 terus berlanjut hingga tahun 2016. Adanya kejadian El Nino tersebut secara umum akan mempengarui intensitas curah hujan di sebagian besar wilayah Indonesia termasuk wilayah Jabodetabek. Analisis kejadian El Nino Tahun 2015/2016 dilakukan dengan menganalisis nilai NINO 3.4 SST Index, Southern Oscillation Index (SOI), Indian Ocean Dipole (IOD), pola sebaran suhu permukaan laut (Sea Surface Temperature) dan juga gradient wind di Samudra Pasifik Tropis. Sedangkan Analisis Curah Hujan dilakukan dengan menggunakan data TRMM (Tropical Rainfall Measuring Mission). Dari penelitian ini dapat diketahui bahwa berdasarkan parameter NINO 3.4 SST Index dan Southern Oscillation Index (SOI) pada pertengahan Tahun 2015 hingga awal Tahun 2016 telah terjadi fenomana El Nino pada level kuat, adanya peningkatan suhu permukaan laut di sebagian besar wilayah Indonesia sejak Bulan November 2015 yang diikuti dengan penurunan indeks Dipole Mode hingga menjadi bernilai negatif (-) sejak awal Tahun 2016 serta dengan adanya peralihan Angin Muson Timur ke Angin Muson Barat di wilayah Indonesia telah menyebabkan peningkatan curah hujan yang cukup signifikan dalam batas normal di wilayah Jabodetabek pada puncak musim hujan Tahun 2015/2016 (November 2015 - Februari 2016) walaupun pada Bulan November 2015 hingga Februari 2016 tersebut masih berada pada level El Nino kuat. AbstractVarious research institutions in the world that work in the field of Meteorology and Climatology predicted an El Nino events in 2015 continued into 2016. The El Nino events phenomenon in general will affect to intensity of the rainfall in most parts of Indonesia, including the Greater Jakarta area. El Nino events phenomenon Analysis by Nino 3.4 SST index, Southern Oscillation Index (SOI), Indian Ocean Dipole (IOD), Sea Surface Temperature (SST) and gradient wind in the Tropical Pacific Ocean. While rainfall intensity analysis using TRMM (Tropical Rainfall Measuring Mission) data. From this research it is known that based on the parameters NINO 3.4 SST index and the Southern Oscillation Index (SOI), it is known that there was a strong El Nino event occurred in mid-2015 to early 2016, the increase of sea surface temperature in most parts of Indonesia since November 2015 followed by declines Dipole Mode Index to be negative (-) since the beginning 2016 as well as the shift East monsoon to West monsoon in Indonesia has led to significant rainfall increased within normal limits in the Greater Jakarta area at the peak period of the rainy season 2015/2016 (November 2015 - February 2016) although in November 2015 until February 2016 El Nino event is still at the strong level.
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Koem, S., R. J. Lahay, and S. K. Nasib. "The sensitivity of meteorological drought index towards El Nino-Southern Oscillation." IOP Conference Series: Earth and Environmental Science 1089, no. 1 (November 1, 2022): 012005. http://dx.doi.org/10.1088/1755-1315/1089/1/012005.
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Abstract El Nino-Southern Oscillation (ENSO) contributes to the regional climates, such as precipitation and droughts. The objectives of the present work were to: (1) identify the severity index; (2) analyze the correlation of SPI and RDI, and; (3) identify the response of SPI and RDI towards ENSO. SPI and RDI were calculated for time scales (3, 6, and 12 months), and these represented the seasonal and annual drought. The identification of the responses of the drought severity index, based on ENSO, consisted of several thresholds, namely weak, moderate, and strong. The correlational value and RMSE only represented the performance of SPI and RDI on different time scales. The drought severity index would decline along with an increase in the time scales. The strong El Nino phase could be significant to the seasonal and annual drought. In other words, ENSO was impactful on the precipitation and dynamics of drought. Drought periods were due to the moderate and strong El Nino phase, while the weak phase led to a normal condition. For this reason, ENSO could be functioned as an indicator to predict drought.
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Aprilia, Bunga, Marzuki Marzuki, and Imam Taufiq. "Prediksi El Nino Southern Oscillation (ENSO) Menggunakan Jaringan Saraf Tiruan (JST)-Backpropagation." Jurnal Fisika Unand 9, no. 4 (January 25, 2021): 421–27. http://dx.doi.org/10.25077/jfu.9.4.421-427.2020.
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Penelitian ini bertujuan untuk memprediksi nilai indeks ENSO yaitu Sea Surface Temperature (Nino 1.2, Nino 3, Nino 3.4 dan Nino 4), Southern Oscillation Index (SOI) dan Multivariate ENSO Index versi 2 (MEI.v2) yang diambil dari tahun 1979-2018. Prediksi dilakukan dengan menggunakan metode JST-backpropagation dengan memvariasikan learning rate dan momentum. Semua indeks menghasilkan nilai akurasi prediksi ENSO yang tinggi, namun indeks Nino 4 merupakan indeks yang memiliki akurasi tertinggi karena nilai Mean Square Error (MSE) pelatihan dan pengujiannya yang relatif lebih kecil dibandingkan dengan indeks lainnya. Indeks Nino 4 memiliki MSE pelatihan 0,0072739 yang berhenti pada epoch ke-69 dan MSE pengujian 0,0085917 dengan akurasi prediksi 99,9989%. Hasil ini diperoleh dari arsitektur JST-backpropagation 12-10-1 dengan nilai learning rate 0,10 dan momentum 0,40. Prediksi ENSO berdasarkan indeks Nino 4 untuk tahun 2021 menunjukkan keadaan iklim dunia dalam kondisi normal. This study aims to predict ENSO index using Sea Surface Temperature (Nino 1.2, Nino 3, Nino 3.4 and Nino 4 indexes), Southern Oscillation Index (SOI), and Multivariate ENSO Index version 2 (MEI.v2) during 1979 - 2018. The prediction was carried out using the ANN-backpropagation method by varying the learning rate and momentum. All indices produce high ENSO prediction accuracy values, but the Nino 4 index is the best one because the Mean Square Error (MSE) for training and testing steps are relatively smaller than other indexes. The Nino 4 index has a training MSE of 0.0072739 which stops at the 69th epoch and a testing MSE of 0.0085917 with a predictive accuracy of 99.9989%. These results were obtained from the back-propagation architecture ANN 12-10-1 with a learning rate of 0.10 and a momentum of 0.40. The prediction of ENSO in 2021 based on the Nino 4 index shows that the world climate condition is under normal conditions.
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Tongkukut, Seni Herlina J. "El-NINO DAN PENGARUHNYA TERHADAP CURAH HUJAN DI MANADO SULAWESI UTARA." JURNAL ILMIAH SAINS 11, no. 1 (April 1, 2011): 102. http://dx.doi.org/10.35799/jis.11.1.2011.51.
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Telah dilakukan analisis El-Nino dan pengaruhnya terhadap curah hujan di Manado Sulut dengan menggunakan data curah hujan bulanan dan Southern Oscillation Index SOI selama thn 1999-2009. Data curah hujan diperoleh dari BMKG Kayuwatu Manado Sulut dan data SOI diunduh dari website Biro Meteorologi Australia BoM. Analisis dilakukan dengan analisis regresi linear sederhana. Diperoleh hasil bahwa curah hujan kota Manado secara umum dari thn 1999-2008 dipengaruhi oleh SOI namun pada thn 2009 ketika terjadi El-nino, curah hujan bulanan Manado tidak dipengaruhi oleh efek El-nino. Hal ini karena pada saat yang sama suhu muka laut perairan Indonesia juga menghangat. EL-NINO AND ITS EFFECT ON RAINFALL IN MANADONORTH SULAWESIABSTRACTAnalysis of El-Nino and its effect on rainfall in Manado, North Sulawesi, using monthly rainfall data and the Southern Oscillation Index SOI during the years 1999-2009 has been carried out. Rainfall data obtained from BMKG Kayuwatu Manado and SOI data downloaded from the website of Australian Bureau of Meteorology (BoM). The analysis was performed with simple linear regression analysis. The results obtained indicate that rainfall in Manado , in general, was influenced by SOI from the years 1999-2008, but when there is an El-Nino in 2009, monthly rainfall in Manado is not affected by the El-Nino effect. This is due to, at the same time, sea surface temperature in Indonesian territory are also warm.
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Mahmud, Mastura, and Nur Hidayah Ahmad. "Peristiwa El Nino, keragaman hujan dan potensi Southern Oscillation Index untuk peramalan kualiti udara di Malaysia." Malaysian Journal of Society and Space 14, no. 2 (May 29, 2018): 13–25. http://dx.doi.org/10.17576/geo-2018-1402-02.
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Hashidu, U. S., and S. I. Badaru. "Relationship between El-Niño southern oscillation and rainfall in Sudano-Sahelian Region of Northern Nigeria." JOURNAL OF AGRICULTURAL ECONOMICS, ENVIRONMENT AND SOCIAL SCIENCES 7, no. 2 (November 28, 2021): 211–16. http://dx.doi.org/10.56160/jaeess202172019.
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El Nino Southern-Oscillation (ENSO) refers to the cycle of coherent and sometimes very strong variations in the sea surface temperature (SST), convective rainfall, surface pressure and atmospheric circulation across the equatorial Pacific Ocean. The research investigated the relationship between ENSO and rainfall across the Sudano-Sahelian region of northern Nigeria. Rainfall data for seven (7) locations were sourced from the Nigerian Meteorological Agency (NIMET) covering the period from 1950 to 2019 and El-Nino Southern Oscillation (ENSO) data which comprised of Southern Oscillation Index (SOI) covering the same period. The Southern Oscillation Index (SOI) data was obtained from National Oceanographic Atmospheric Administration (NOAA) Climate Prediction Centre. A bivariate correlation analysis between rainfall and SOI were computed for all the seven locations to determine the relationship between ENSO and Sudano-Sahelian rainfall. The result shows a significant relationship for Potiskum, Maiduguri and Katsina with correlation coefficient (r) values of 0.25, 0.26 and 0.27 respectively while Kano Gusau Nguru and Sokoto show no significant relationship. It is therefore concluded that there is no strong relationship between rainfall and ENSO in Sudano-Sahelian part of northern Nigeria. It is recommended that further research could be carried out to investigate the influence of ENSO on other climate parameters such as temperature, humidity and evapotranspiration in the study area.
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Dwipayana, Made, I. Gede Putu Eka Suryana, and I. Gede Yudi Wisnawa. "The Impact of El Nino on Rainfall Variability in Buleleng Regency (Case Study: Period 1995-2004)." Tunas Geografi 12, no. 1 (July 31, 2023): 47. http://dx.doi.org/10.24114/tgeo.v12i1.46586.
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The climate in Indonesia usually runs yearly; there are times when a decrease in rainfall results in drought, and at other times, the rainfall increases resulting in flooding. One of the causes of changes in precipitation in Indonesia, including in most parts of the world, is ENSO (El Nino-Southern Oscillation), often called El Nino. This study aimed to determine the relationship between ENSO index data (SST Nino 3.4 anomaly) and monthly rainfall data in Buleleng Regency. This study uses secondary data, namely monthly rainfall data at 16 rain posts in Buleleng Regency and ENSO Index data from BMKG Region III Denpasar. Data were collected through observation, document recording and analyzed using statistical correlation methods. Furthermore, the results are processed spatially, namely by the Isohyet method. The research results show that the impact of El Nino on rainfall in Buleleng varies spatially and depends on the intensity of El Nino. In June-July-August (JJA/dry season) and September-October-November (SON/transition season), the impact of El Nino on rainfall variability in Buleleng Regency is more significant than other months, strong El Nino causes a decrease in rainfall in the majority of the Buleleng region with the characteristic of Below Normal rain (30% decrease in precipitation from the average), El Nino of weak - moderate intensity causes a reduction in rainfall in a small part of the Buleleng area with the dominant rain characteristic of Below Normal.Keywords: El Nino, Precipitation Variability, and Correlation Index.
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Utami, Arini Wahyu, Jamhari Jamhari, and Suhatmini Hardyastuti. "EL NINO, LA NINA, DAN PENAWARAN PANGAN DI JAWA, INDONESIA." Jurnal Ekonomi Pembangunan: Kajian Masalah Ekonomi dan Pembangunan 12, no. 2 (December 1, 2011): 257. http://dx.doi.org/10.23917/jep.v12i2.197.
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Paddy and maize are two important food crops in Indonesia and mainly produced in Java Island. This research aimed to know the impact of El Nino and La Nina on paddy and maize farmer’s supply in Java. Cross sectional data from four provinces in Java was combined with time series data during 1987-2006. Paddy supply was estimated using log model, while maize supply used autoregressive model; each was estimated using two types of regression function. First, it included dummy variable of El Nino and La Nina to know their influence into paddy and maize supply. Second, Southern Oscillation Index was used to analyze the supply changing when El Nino or La Nina occur. The result showed that El Nino and La Nina did not influence paddy supply, while La Nina influenced maize supply in Java. Maize supply increased when La Nina occurred.
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Sukresno, Bambang, Denarika Jatisworo, and Denny Wijaya Kusuma. "ANALISIS MULTILAYER VARIABILITAS UPWELLING DI PERAIRAN SELATAN JAWA." Jurnal Kelautan Nasional 13, no. 1 (April 2, 2018): 15. http://dx.doi.org/10.15578/jkn.v1i1.6619.
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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.
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Bolius, David, Margit Schwikowski, Theo Jenk, Heinz W. Gäggeler, Gino Casassa, and Andrés Rivera. "A first shallow firn-core record from Glaciar La Ollada, Cerro Mercedario, central Argentine Andes." Annals of Glaciology 43 (2006): 14–22. http://dx.doi.org/10.3189/172756406781812474.
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AbstractIn January 2003, shallow firn cores were recovered from Glaciar Esmeralda on Cerro del Plomo (33°14’S, 70°13’W; 5300 ma.s.l.), central Chile, and from Glaciar La Ollada on Cerro Mercedario (31°58’S, 70°07’W; 6070 ma.s.l.), Argentina, in order to find a suitable archive for paleoclimate reconstruction in a region strongly influenced by the El Nino-Southern Oscillation. In the area between 28°S and 35°S, the amount of winter precipitation is significantly correlated to the Southern Oscillation Index, with higher values during El Nino years. Glaciochemical analysis indicates that the paleo-record at Glaciar La Ollada is well preserved, whereas at Glaciar Esmeralda the record is strongly influenced by meltwater formation and percolation. A preliminary dating of the Mercedario core by annual-layer counting results in a time-span of 17 years (1986-2002), yielding an average annual net accumulation of 0.45 m w.e.
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Hsieh, WW, and BV Hamon. "The El Nino-Southern Oscillation in south-eastern Australian waters." Marine and Freshwater Research 42, no. 3 (1991): 263. http://dx.doi.org/10.1071/mf9910263.
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Using four decades of hydrographic data collected off the coast near Sydney, New South Wales, and sea-level data at Sydney, we studied the interannual variability in south-eastern Australian shelf waters. The first two empirical orthogonal function (EOF) modes of the band-pass-filtered 50-m-depth hydrographic data (temperature, T; salinity, S; nitrate, N; inorganic phosphate, P; and oxygen, O) and the sea level (SL) and adjusted sea level (ASL) data accounted respectively for 51 and 27% of the total variance. Both modes were significantly correlated with the Southern Oscillation Index (SOI). The first mode, with T, S, O and ASL varying in opposition to N and P, represented the internal or baroclinic response, associated with vertical displacements of the isopycnals. The second mode, with large in-phase fluctuations in SL and ASL but small changes in the hydrographic variables, represented mainly the external or barotropic response during the El Niiio-Southern Oscillation (ENSO). Three-year composites centred around seven ENSO warm episodes revealed that T, S, O and ASL were generally low and N, P, SL and SO1 were high in the year before each ENSO warm episode, but the former group rose while the latter group dropped in the year of the warm episode. The changes in the hydrographic variables at 50 m depth were consistent with relatively shallow isopycnals in the year before the ENSO warm episode, followed by a deepening of the isopycnals during the warm episode. Estimates of this downward displacement of isopycnals, as determined from T, N, P and O, were in the range 7-10 m. The geostrophic wind arising from the pressure fluctuations during ENSO is proposed as a probable cause for the vertical displacement of the isopycnals. In the year before the warm episode, the low air pressure over Australia would produce a clockwise geostrophic wind around south-eastern Australia, generating offshore Ekman transport and coastal upwelling. During the warm episode, air pressure over Australia rises, the geostrophic wind reverses, and downward movement of the isopycnals would occur off south-eastern Australia.
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Oladejo, K. M. "RELATIONSHIP OF EL NINO/SOUTHERN OSCILLATION TO RAINFALL PATTERNS IN NIGERIA." Open Journal of Environmental Research (ISSN: 2734-2085) 1, no. 1 (March 10, 2020): 1–20. http://dx.doi.org/10.52417/ojer.v1i1.68.
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This paper examines the relationship between El Nino/Southern Oscillation (ENSO) and rainfall patterns in Nigeria. Annual rainfall totals, growing season rainfall totals and annual raindays of 27 Nigerian meteorological stations with varying lengths of records from 1903 to 2012 were collected from the Nigerian Meteorological Agency (NIMET). Monthly Sea Surface Temperatures (SSTs) anomalies data over Atlantic and Pacific Oceans and Southern Oscillation Index (SOI) were obtained from Climatic Prediction Centre (CPC). Kendall tau statistics and Step-Wise Multiple Regression model were used for data analyses. Results from this study showed that annual rainfall totals, growing season rainfall and annual raindays series exhibited a significant downward trend at most of the stations over the period of the study. It was observed that annual rainfall pattern changed from a positive pattern within 1931- 1960 period to a negative pattern within 1961-1990 period and then, to a positive pattern within 1991-2012 period. It was concluded that he alternating wet and dry patterns in inter-annual rainfall fluctuations and by extension, the droughts and floods over Nigeria within the study period, were caused by sea surface temperature anomalies over the Atlantic and Pacific Oceans. The paper therefore concludes that SSTs should be integrated in the seasonal rainfall prediction models in Nigeria for an improved forecast.
Oladejo, K. M. | Department of Geography, Usmanu Danfodiyo University, Sokoto, Nigeria
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Hidayat, Anistia Malinda, Usman Efendi, Lisa Agustina, and Paulus Agus Winarso. "KORELASI INDEKS NINO 3.4 DAN SOUTHERN OSCILLATION INDEX (SOI) DENGAN VARIASI CURAH HUJAN DI SEMARANG." Jurnal Sains & Teknologi Modifikasi Cuaca 19, no. 2 (December 31, 2018): 75. http://dx.doi.org/10.29122/jstmc.v19i2.3143.
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Semarang merupakan salah satu wilayah di Indonesia yang rawan terdampak bencana hidrometeorologi. Sejumlah wilayah di Semarang merupakan daerah rawan kekeringan, sementara di wilayah lainnya merupakan daerah langganan banjir tiap tahunnya. Salah satu parameter yang memiliki keterkaitan erat dengan fenomena hidrometeorologi adalah El Nino Southern Oscillation (ENSO). Sebagai sirkulasi tropis non musiman, ENSO memiliki peran penting terhadap variasi curah hujan yang diamati. Penelitian terkait ENSO telah banyak dilakukan sebelumnya, namun belum ada penelitian tekait yang dilakukan di Semarang yang notabene merupakan daerah rawan bencana hidrometeorologi, sehingga fluktuasi ENSO menarik untuk dikaji di wilayah ini. Penelitian ini bertujuan untuk menganalisis korelasi fenomena global laut atmosfer terhadap distribusi curah hujan di wilayah Semarang. Dalam jangka waktu 15 tahun (2001-2015), pengaruh dari ENSO dianalisis menggunakan korelasi temporal untuk menentukan dampak dari ENSO pada curah hujan yang diamati di enam pos pengamatan hujan di Semarang. Analisis tersebut menunjukkan bahwa korelasi antara anomali Suhu Permukaan Laut (SPL) di wilayah Nino 3.4 dengan curah hujan diamati secara signifikan pada lima pos pengamatan hujan selama periode September Oktober November (SON) dengan rentang nilai korelasi antara -0.598 sampai dengan -0.679. Sementara itu, korelasi variabilitas curah hujan dengan Southern Oscillation Index (SOI) menunjukan nilai yang berkisar antara 0.561 sampai dengan 0.780. Curah hujan yang diamati umumnya selalu berkurang pada tahun-tahun dimana nilai indeks Nino 3.4 positif dan nilai SOI negatif, sedangkan curah hujan diamati meningkat pada tahun-tahun dimana nilai indeks Nino 3.4 negatif dan nilai SOI yang positif.
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Dewi, Sri Mai, and Marzuki Marzuki. "Analisis Pengaruh Pergeseran Lokasi ENSO terhadap Curah Hujan di Indonesia." Jurnal Fisika Unand 9, no. 2 (November 9, 2020): 176–82. http://dx.doi.org/10.25077/jfu.9.2.176-182.2020.
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ENSO (El Nino Southern Oscillation) merupakan gejala penyimpangan suhu permukaan laut di Samudera Pasifik bagian timur dari kondisi normal. Penelitian ini menganalisis dampak dari perbedaan posisi pusat ENSO terhadap curah hujan di Indonesia. Posisi pusat ENSO ditentukan berdasarkan indeks terbesar dari empat indeks Nino selama tahun 1982-2016. Posisi pusat ENSO didefinisikan jauh, menengah dan dekat dari Indonesia ketika indek Nino yang terbesar berturut-turut adalah Nino 1+2, Nino 3 dan Nino 3,4, serta Nino 4. Intensitas curah hujan di setiap posisi ENSO diamati menggunakan data Global Precipitation Climatology Centre (GPCC). Rata-rata curah hujan bulanan pada saat pusat El Nino jauh dari Indonesia lebih tinggi di kawasan Indonesia bagian timur. Selain itu, selama pusat El Nino jauh dari Indonesia, kondisi yang lebih kering teramati di sebagian besar wilayah Indonesia bagian barat dan tengah. Pada sisi lain, rata-rata intensitas curah hujan bulanan pada saat La Nina menengah lebih tinggi dibandingkan La Nina jauh. Perbedaan intensitas curah hujan dari setiap posisi ENSO ini selaras dengan perbedaan pergerakan udara ke atas yang tergambar dari nilai omega dari data reanalisis NCEP dan NCAR. Dengan demikian, posisi ENSO mempengaruhi curah hujan di Indonesia walaupun dampaknya tidak seragam. ENSO (El Nino Southern Oscillation) is a periodic fluctuation in sea surface temperature and other meteorological parameters across the equatorial Pacific Ocean. This study investigates the impact of ENSO's central position on rainfall pattern in Indonesia. The location of the ENSO was determined by the largest index of four Nino indexes during 1982-2016 and itis defined far, medium and close to Indonesia when the largest Nino indexes are Nino 1+2, Nino 3 and Nino 3.4, and Nino 4. Rainfall intensity at each ENSO position was observed using Global Precipitation Climatology Centre (GPCC) data. Average monthly rainfall when the El Nino central position is far from Indonesia is higher in the eastern part of Indonesia. In addition, when the El Nino central position is far from Indonesia, drier conditions are observed in large parts of western and central Indonesia. On the other hand, the average intensity of monthly rainfall during medium position of La Nina is higher than that for La Nina cases with the central position being far from Indonesia. The difference in rainfall intensity from each ENSO position coincides with the difference in upward air movement which is reflected by the omega values from the NCEP and NCAR. reanalysis data. Thus, the position of ENSO influences rainfall in Indonesia even though the impact is not uniform.
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RAJEEVAN, M. "Post monsoon tropical cyclone activity in the north Indian Ocean in relation to the El Nion / southern Oscillation phenomenon." MAUSAM 40, no. 1 (April 28, 2022): 55–58. http://dx.doi.org/10.54302/mausam.v40i1.1934.
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In this paper the relationship between post monsoon (Oct-Dec) tropical cyclone activity in the north Indian Ocean and El Nino Southern Oscillation (ENSO) is discussed. The study uses a 83-year {1901-1983) time series or number of storm days for preliminary analysis. On an average the number of storm days during El Nina year is not departed from the normal. Usin9 the 48-year. (1935-1982) time series of number of storm days correlations were calculated with southern oscillation index (mean sea level pressure difference between Tahiti and Darwin) before, during and after the season: A weak negative correlation is seen between the storm activity and SOI before the season. Stability of correlations is examined by recalculating correlations using four 12-year data subsets. Magnitude of correlations is found to vary significantly in the subsets.
There is no appreciable difference between the strike rate (number of storm crossing the coast/total number of storms) per El Nina year and strike rate per non El Nina year. There is no marked shift in the area of formation of storms during El Nino years from the climatologically favourable area:
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Voskresenskaya, E. N., and V. N. Maslova. "Winter-spring cyclonic variability in the Mediterranean-Black Sea region associated with global processes in the ocean-atmosphere system." Advances in Science and Research 6, no. 1 (August 30, 2011): 237–43. http://dx.doi.org/10.5194/asr-6-237-2011.
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Abstract. Using global NCEP/NCAR reanalysis data set on 1000 hPa geopotential height (1948–2006), cyclones in the Mediterranean and Black Sea regions were detected and their main characteristics (frequency, depth, integrated area) were calculated. Analysis of their interannual-multidecadal variability in January-March associated with global processes in the ocean-atmosphere system was done. It was shown that North Atlantic Oscillation (NAO) manifests in the Black Sea region mainly in the variability of frequency of cyclones while in the Mediterranean – in the interannual anomalies of cyclones' depth and area. Joint NAO and El Nino – Southern Oscillation (ENSO) influence is responsible for about 20–45% of cyclones' frequency variance in the Black Sea region, and in the Mediterranean region for up to 10–25 and 20–30% of the depth and area variance, accordingly. As a result of using a new approach to study ENSO manifestations based on El Nino classification, correlation coefficients between characteristics of cyclones and Southern Oscillation index (SOI) increase at least twice. The influence of the Pacific Decadal and Atlantic Multidecadal Oscillations on variability of cyclonic activity in the Mediterranean-Black Sea region manifests in considerable differences of cyclones' characteristics and their typical location.
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Yananto, Ardila, and Saraswati Dewi. "ANALISIS KEJADIAN EL NINO TAHUN 2015 DAN PENGARUHNYA TERHADAP PENINGKATAN TITIK API DI WILAYAH SUMATERA DAN KALIMANTAN." Jurnal Sains & Teknologi Modifikasi Cuaca 17, no. 1 (June 15, 2016): 11. http://dx.doi.org/10.29122/jstmc.v17i1.544.
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IntisariKejadian El Nino yang berdampak pada sebagian besar wilayah Indonesia akan selalu berasosiasi dengan kekeringan akibat dari berkurangnya intensitas curah hujan. Lebih jauh akibat dari kekeringan tersebut telah menimbulkan meningkatnya titik api secara signifikan dibandingkan dengan tahun-tahun sebelumnya khususnya di wilayah Sumatera dan Kalimantan, dimana hal tersebut telah mengakibatkan terjadinya bencana asap pada tahun 2015. Tujuan utama penulisan karya tulis ini adalah untuk menganalisis kejadian El Nino pada tahun 2015 dan pengaruhnya terhadap peningkatan titik api di wilayah Sumatera dan Kalimantan baik dalam skala temporal maupun spasial. Dari hasil penelitian ini dapat diketahui bahwa berdasarkan parameter NINO 3.4 SST Indeks dan Southern Oscillation Index (SOI) pada tahun 2015 telah terjadi fenomana El Nino pada level kuat yang ditandai dengan adanya pelemahan sirkulasi walker sehingga pusat tekanan rendah perpindah dari Samudera Pasifik bagian Barat ke Samudera Pasifik bagian Timur, dimana hal ini telah menyebabkan adanya penurunan intensitas curah hujan (anomali negatif) disebagian besar wilayah Indonesia terutama pada bulan Juli hingga Oktober 2015 dan oleh karena itulah pada bulan Juli hingga Oktober 2015 tersebut terjadi peningkatan jumlah titik api yang sangat tajam di wilayah Indonesia dimana persebaran titik api tersebut sebagian besar terkonsentrasi di Provinsi Sumatera Selatan dan Kalimantan Tengah. AbstractEl Nino that impact most areas of Indonesia will always be associated in drought due to reduced rainfall intensity. Drought, in further, has resulted in increasing titik apis significantly compared to previous years, especially in the Sumatra and Kalimantan, that was creating smog disaster in 2015. The main objective of this research was to analyze the occurrence of El Nino in 2015 and its influence on increase of titik api in Sumatera and Kalimantan both in temporal and spatial scale. From this research it is known that based on the NINO 3.4 SST index and the Southern Oscillation Index (SOI) it is known there was a strong El Niño event occurred in 2015 showed there was a weakening Walker circulation so that the low pressure center moved from Western part of the Pacific Ocean to the Eastern Pacific Ocean, where this has led to a decrease rainfall intensity (negative anomaly) in most parts of Indonesia, especially from July to October 2015 and because of that from July to October 2015 there was very hight increasing number of titik apis in Indonesia where the spread of titik api the mostly concentrated in the province of South Sumatera and Central Kalimantan.
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Chung, Christine T. Y., and Scott B. Power. "The non-linear impact of El Nino, La Nina and the Southern Oscillation on seasonal and regional Australian precipitation." Journal of Southern Hemisphere Earth Systems Science 67, no. 1 (2017): 25. http://dx.doi.org/10.1071/es17004.
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The relationship between El Niño-Southern Oscillation (ENSO) indices and precipitation (P) in some parts of Australia has previously been shown to be non-linear on annual and seasonal time scales. Here we examine the relationship between P and the Southern Oscillation Index (SOI) at all Australian locations and in all seasons. We show that in many Australian regions, there is more-than-expected P during strong La Niña years (SOI>13), but less-than-expected drying during strong El Niño years (SOI
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Lin, Jen-Yang, Ming-Chung Tang, and Febrianto Wijaya. "Satellite Oceanographic Data Processing and Analysis: Correlation Between Nino 3.4 Sea Surface Temperature & Sea Surface High and Wind." Indonesian Journal of Earth Sciences 2, no. 2 (December 26, 2022): 157–76. http://dx.doi.org/10.52562/injoes.v2i2.428.
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El Nino Southern Oscillation (ENSO) is an irregular climate oscillation induced by sea surface temperature anomalies (SSTA) in the Equatorial Pacific Ocean. An anomalous warming in this area is known as El Nino, while an anomalous cooling bears the name of La Nina. The objectives of this study are to: reproduce Oceanic Nino Index (ONI) based on MW OISST; produce Nino Region 3.4 wind and Sea Surface High (SSH); analyze the correlation between SST and Wind & SSH; discuss Typhoon Soudelor based on SST, Wind, and SSH; and analyze the correlation of El Nino and Precipitation in specific area. MWOI-SST was used to produce monthly mean SST over Nino 3.4 region from January 1998 – May 2020. Monthly wind data was obtained from QuickScat. Daily Sea Surface High (SSH) was obtained from Copernicus Marine Environment Monitoring Service (CMEMS). Daily precipitation from TRMM 3B42 over Bandung City (Indonesia) was used to assess the correlation between El Nino and precipitation in specific area. The results show that in Nino 3.4 region, 2015 is the hottest year during 1998-2020 period with average SST of 28.5oC, and 1999 is the coldest year with average SST of 25.7oC. The result shows that the MWOI-SST Ocean Nino Index has very strong correlation with ERSST.v5 with coefficient of correlation is 0.92 and RMSE is 0.36oC. the wind speed of Nino 3.4 region is range from 5.23 m/s to 7.97 m/s. Unlike Sea Surface Temperature (SST), annual average wind speed is more stable with monthly variation. The wind speed is observed high in the beginning and the end of years. Sea Surface Height (SSH) over Nino 3.4 region varied from 65.8 cm to 106.8 cm. 2015 is the highest SSH with annual average of 96 cm, whereas 1999 is the lowest SSH with annual average of 71.4 cm. It is observed that Sea Surface Temperature (SST) has negative correlation with wind speed with coefficient of correlation of 0.28. Conversely, Sea Surface Temperature (SST) over Nino 3.4 region has positive correlation with Sea Surface High (SSH) with coefficient of correlation of 0.30. which mean the higher temperature, the higher Sea Surface Height. During the passage of Typhoon Soudelor, there is evident cool trail along its track with rightward bias. We can assume that the decreasing precipitation in Bandung City might be affected by strong El Nino occurrence in 2015.
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Atmadipoera, Agus S., Agitha Saverti Jasmine, Mulia Purba, and Anastasia R. T. D. Kuswardani. "UPWELLING CHARACTERISTICS IN THE SOUTHERN JAVA WATERS DURING STRONG LA NINA 2010 AND SUPER EL NINO 2015." Jurnal Ilmu dan Teknologi Kelautan Tropis 12, no. 1 (April 27, 2020): 257–76. http://dx.doi.org/10.29244/jitkt.v12i1.28977.
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Seasonal coastal upwelling in the Southern Java waters is considered to be modulated by interannual ocean-atmosphere variability of El Nino Southern Oscillation (ENSO). This study aims to investigate a contrast in seasonal upwelling characteristics during the La Nina 2010 and El Nino 2015 events, by using multi-datasets from INDESO model output and satellite-derived datasets. Distinct characteristics of seasonal upwelling was clearly seen. In La Nina, surface ocean-atmosphere variables were much lower than that observed in El Nino, except for precipitation rate, sea surface temperature, and sea surface height. In La Nina, warmer (27-28°C) and a very freshwater (<33.80psu) were predominant in the upper 45m depth, concealing upwelling cooler water at subsurface. In contrast, in the El Nino, a drastic upwelled subsurface water of isotherms of 25-26°C and isohalines of 34.24-34.44psu were outcropped at the sea surface. Temperature-based upwelling index is -2°C and +4°C, demonstrating the ENSO has strongly modulated the upwelling intensity. A strong eastward South Java Coastal Current (SJCC) was found only in La Nina event. Persistent westward Indonesian Throughflow south of 9.5°S were visible both in different ENSO events. Estimate of Ekman transport derived from model meridional current was intervened strongly by the presence of the SJCC and the ITF.
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Malau, Leo Rio Ependi, Khoiru Rizqy Rambe, Nur Arifatul Ulya, and Arly Getha Purba. "Dampak perubahan iklim terhadap produksi tanaman pangan di indonesia." Jurnal Penelitian Pertanian Terapan 23, no. 1 (March 30, 2023): 34–46. http://dx.doi.org/10.25181/jppt.v23i1.2418.
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Perubahan iklim menjadi salah satu tantangan serius yang dihadapi oleh Indonesia dalam pemenuhan kebutuhan pangan. Salah satu fenomena perubahan iklim yang berpengaruh terhadap sektor pertanian khususnya tanaman pangan adalah El Nino Southern Oscillation (ENSO) yang terdiri dari El Nino dan La Nina. ENSO menyebabkan variabilitas curah hujan sehingga berdampak buruk bagi produksi tanaman pangan seperti padi, jagung dan kedelai. Penelitian ini bertujuan untuk (1) mengidentifikasi provinsi terdampak ENSO di Indonesia dan (2) menganalisis dampak ENSO dan determinan lainnya terhadap produksi tanaman pangan (padi, jagung, kedelai) di provinsi yang terdampak. Penelitian ini menggunakan panel data sekunder tahun 2010-2017 dari 16 provinsi terdampak ENSO. Korelasi Pearson dan regresi panel statis digunakan untuk menjawab tujuan penelitian. Fenomena ENSO diproksi melalui curah hujan. Hasil penelitian menunjukkan sebagian besar provinsi di Indonesia terdampak ENSO, yang terlihat dari korelasi negatif dan signifikan antara Oceanic Nino Index (ONI) dan curah hujan. Regresi panel statis menunjukkan ENSO berpengaruh signifikan terhadap produksi padi dan kedelai melalui indikator curah hujan. El Nino yang disertai penurunan curah hujan signifikan berdampak lebih besar terhadap produksi padi dan kedelai, sedangkan La Nina yang disertai peningkatan curah hujan signifikan memiliki dampak lebih besar terhadap produksi kedelai. Secara umum, El Nino memiliki pengaruh yang lebih besar terhadap produksi tanaman pangan.
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Li, H. J., J. E. Gao, H. C. Zhang, Y. X. Zhang, and Y. Y. Zhang. "Response of Extreme Precipitation to Solar Activity and El Nino Events in Typical Regions of the Loess Plateau." Advances in Meteorology 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/9823865.
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Extreme climatic oscillation has been the subject of global attention. The purpose of this study is to explore the response of extreme precipitation to solar activity and El Nino events in typical regions of the Loess Plateau—a case study in the Yan’an area. The precipitation data was from nine weather stations in Yan’an and the sunspot number and the Southern Oscillation Index (SOI) were from 1951 to 2015. The results show that maximum precipitation occurred mainly at the peak sunspot number or 2a near it and the sunspot number minimum and valley values were not significantly correlated. The results of Morlet wavelet showed that a 41-year period of precipitation was the most obvious within the 64-year scale. Similarly, sunspot number showed a 16-year periodic variability. Correlation analyses of the 16-year and 41-year scales demonstrated that the relationships between precipitation and sunspot number were close. In addition, extreme precipitation often occurred in the year following El Nino events. According to 10-year moving average curves, precipitation generally showed a downward trend when SOI was negative. The results indicate that solar activity and El Nino events had significant impacts on precipitation in typical regions of the Loess Plateau.
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KANE, R. P. "Trends, periodicities and ENSO relationships of the annual precipitation over the contiguous United States and Southern Canada." MAUSAM 52, no. 4 (January 11, 2022): 659–68. http://dx.doi.org/10.54302/mausam.v52i4.1738.
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The century-long (1891-1990) time series of Groisman and Easterling (1994a,b) representing estimates of annual precipitation amounts over five homogeneous regions of the United States and Southern Canada (south of 55° N) were examined for trends, periodicities and ENSO relationships. The trends were not uniformly up or down during the 100-year interval, for any region. From 1891 to about 1930, the trends were downward or negligible. Thereafter, the trends were mostly upward, with cyclic variations superposed. A spectral analysis revealed significant periodicities in the QBO and QTO regions (2-3 years and 3-4 years) as also higher periodicities, some common to all regions and hence seen in the series for the entire region. To study the ENSO relationship, a finer classification of El Nino events was used. Each year was examined to check whether it had an El Nino (EN) and/or a Southern Oscillation Index SOI minimum (SO) and/or warm (W) or cold (C) equatorial eastern Pacific sea surface temperatures SST. Several years were ENSOW, which were further subdivided into two groups viz. Unambiguous ENSOW where El Nino existed and SOI minima and SST maxima were in the middle of the calendar year (May-Aug) and, Ambiguous ENSOW where El Nino existed but the SOI minima and SST maxima were in the early or late part of the calendar year, not in the middle. Other El Nino events were of the type ENSO, ENW, ENC, EN. For the All India summer monsoon rainfall, Unambiguous ENSOW were overwhelmingly associated with droughts. For the rainfall in USA and Canada, relationships were not clear-cut except in the Gulf-Mexico region and some other parts. For these regions, excess rains were associated better with the Unambiguous ENSOW.
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VALE, Roseilson Souza do, Ana Carla dos Santos GOMES, Raoni Aquino Silva de SANTANA, Júlio TÓTA, Scott Dennis MILLER, and Rodrigo Augusto Ferreira de SOUSA. "Hydroclimatic variables associated with El Nino and La Nina events at the Curuá-Una hydroelectric reservoir, Central Amazonia." Acta Amazonica 46, no. 3 (September 2016): 303–8. http://dx.doi.org/10.1590/1809-4392201600083.
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ABSTRACT The anomalies of Sea Surface Temperature (SST) influence rainfall and therefore the regime of the rise and fall in the level of the rivers in the Amazon region. The aim of this study was to investigate the influence of the El Nino-Southern Oscillation (ENSO) on hydroclimatic variables and identify the existence of trends on these variables in the Curuá-Una hydroelectric reservoir in the West of the State of Pará. It was used 27 years of monthly precipitation and water flow data to identify possible trends using a non-parametric test (Mann Kendall, p<0.05), and the standardized precipitation index (SPI) was also calculated. The results indicate a positive tendency of the influence of the ENSO on hydroclimatic variables, although it was observed that the rainfall did not increase over the period of 1977 to 2004. The SPI indicates that extreme events of precipitation are related to El Nino and La Nina and that lower precipitation periods were more intense in the decades of the 80´s and 90's. The results show that El Nino events can directly affect the water balance at the micro-watershed of Curuá-Una, as was observed in 2015.
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Diatta, Samo, Cheikh Waly Diedhiou, Didier Maria Dione, and Soussou Sambou. "Spatial Variation and Trend of Extreme Precipitation in West Africa and Teleconnections with Remote Indices." Atmosphere 11, no. 9 (September 18, 2020): 999. http://dx.doi.org/10.3390/atmos11090999.
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Extreme precipitation is a great concern for West Africa country, as it has serious consequence on key socio-economic activities. We use high resolution data from the Climate Hazards Group InfraRed Precipitation Stations (CHIRPS) to determine the spatial variability, trend of 8 extreme precipitation indices in West Africa and their relationship to remote indices. Spatial variability of extreme is characterized by maximum precipitation over the orographic regions, and in southern Sahel. The trend analysis shows a decrease of dry condition in Sahel and Sahara, and an increase tendency of wet indices over western Sahel and southern Sahel. The correlation analysis reveals that extreme precipitation in Sahel is strongly teleconnected to the Eastern Mediterranean Sea (EMS), whereas western and western-north Sahel is associated with both Atlantic Meridional Mode (AMM), Maiden Julian Oscillation phase 8 (MJO8), El Niño 3.4 index (NINO.3.4), and Trans-Atlantic-Pacific Ocean Dipole Index (TAPODI) but with different characteristics or directions. Guinean coast extreme precipitation is highly associated with Atlantic zone 3 SST anomaly (ATL3), Northern Cold Tongue Index (NCTI), TAPODI but also with an opposite sign with NINO.3.4 and in somewhat with the MJO8.
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Chandler, Elise. "Seasonal climate summary southern hemisphere (winter 2015): Mild winter over most of Australia as El Nino strengthens." Journal of Southern Hemisphere Earth Systems Science 66, no. 1 (2016): 68. http://dx.doi.org/10.1071/es16007.
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The climate is summarised for the austral winter season of 2015 with emphasis on the tropical Pacific region as well as rainfall and temperature over Australia. In the tropical Pacific, winter was dominated by a developing El Niño event; by June the Southern Oscillation Index had already exceeded El Niño thresholds for the second month running and sea surface temperatures had also passed key threshold levels as the tropical Pacific Ocean warmed rapidly. Several compo-site indices of El Niño such as the 5VAR and Multivariate ENSO Index (MEI) continued to rise as the winter months progressed, indicating an atmosphere and ocean that was building towards a strong event, with index values by August being comparable to the previously strong El Niño events of 1982–83 and 1997–98.August saw the start of the strongest positive Indian Ocean Dipole event since 2006 while the Southern Annular Mode was consistently positive throughout winter. Australian rainfall was lower than average during winter, most notably over the southern regions, with daytime temperatures above normal in northern and western parts of Australia. Night-time temperatures were overall warmer than normal with the main exception being Tasmania, parts of the southeast and Northern Territory.
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JHA, T. N., and R. D. RAM. "Study of rainfall departure over catchments of Bihar plains." MAUSAM 61, no. 2 (November 27, 2021): 187–96. http://dx.doi.org/10.54302/mausam.v61i2.800.
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Station wise daily rainfall data of sixty years is used to study rainfall departure and variability in Kosi, Kamala/Bagmati/Adhwara and Gandak/Burhi Gandak catchments during monsoon season. Station and catchment wise rainfall time series have been made to compute rainfall departure and Coefficient of Variation (CV). Southern Oscillation Index (SOI), Multivariate ENSO Index (MEI) and ENSO strength based on percentile analysis are used to ascertain their impact on rainfall distribution in the category as excess, normal, deficient and scanty. Results indicate that the variability is greater over Kosi as compared to the other catchments. Probability of normal rainfall is found 0.75 and there is no possibility of scanty rain over the catchments during El Nino and La Nina year. Similarly probabilities of normal, deficient, excess rainfall are found as 0.67, 0.18 and 0.15 respectively during mixed year. SOI has emerged as principal parameter which modifies the departure during El Nino and La Nina year. MEI along with ENSO strength are more prominent during mixed year particularly to ascertain deficient and excess rain in weak and strong- moderate La Nina respectively .
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Puspasari, R., P. F. Rahmawati, and E. Prianto. "The Effect of ENSO (El Nino Southern Oscillation) phenomenon on Fishing Season of Small Pelagic Fishes in Indonesia Waters." IOP Conference Series: Earth and Environmental Science 934, no. 1 (November 1, 2021): 012018. http://dx.doi.org/10.1088/1755-1315/934/1/012018.
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Abstract The El Nino Southern Oscillation (ENSO) phenomenon causes changes in environmental conditions such as water temperature, salinity, and rainfall. In fisheries sector, the changing environment has affected the fishing seasons and Catch per Unit Effort (CPUE) of some pelagic species. This research was conducted by calculating CPUE and fishing season index for several small pelagic fishes in Makassar Strait, Bali Strait, and Aceh waters, then comparing the index value with the fishing season pattern in two extreme periods that are 2010-2011 and 2016 - 2017. An ANOVA test was conducted to assess the significant difference between normal and extreme conditions. The results of the analysis showed that there was a significant different in CPUE between average normal condition and ENSO period. Every single species showed different response to ENSO event, mostly decreased in CPUE relate to El Nino event, except for sardine in Bali and Makassar Strait and scad in Makassar Strait. ENSO affects shift in the fishing season of big-eye scad, scad, sardine, and neritic tuna in Makassar Strait, Bali Strait, and around Aceh waters. Indian mackerel in Makassar Strait showed no change in fishing season but the CPUE showed lower than normal condition. This study shows that ENSO was significantly affected fisheries in Indonesia waters.
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Ogutu, J., R. Reid, H.-P. Piepho, H. Dublin, and Nina Bhola. "El Nino-southern oscillation, rainfall, temperature and normalized difference vegetation index fluctuations in the Mara-Serengeti ecosystem." IOP Conference Series: Earth and Environmental Science 6, no. 2 (January 1, 2009): 022012. http://dx.doi.org/10.1088/1755-1307/6/2/022012.
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Saputra, Candra, I. Wayan Arthana, and I. Gede Hendrawan. "THE VULNERABILITY STUDY OF LEMURU (SARDINELLA LEMURU) FISH RESOURCES SUSTAINABILITY IN BALI STRAIT IN CORELLATION WITH ENSO AND IOD." ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) 11, no. 2 (November 30, 2017): 140. http://dx.doi.org/10.24843/ejes.2017.v11.i02.p02.
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The aim of this research is to know the relationship between lemuru fish catch to Sea Surface Temperature (SST), El-Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) phenomenon in Bali Strait. The results showed, that in the period 2007 – 2016. fluctuations of catches lemuru tends to decline. Sea Surface Temperature (SST) distribution with the lowest temperature 25,28oC at 24,53oC - 27,16oC and the highest temperature is 29,31oC in the range of 28,730C – 30,490C. The lowest temperature occurred in July - September while the highest temperature occurred in January - April. Based on the calculation there is a linkage and relationship between catch and SST as shown on the value of determination and correlation reached 50,0% and 70,73%. Most of the catches occurred in the west season and then the transition II, transition I and East Season. The relationship of ENSO phenomenon to the catch during the El-Nino phase of lemuru catch will increase while in the phase of La-Nina the catch of lemuru will decrease, because time of El-Nino phase of the sea surface temperature (SST) relative low which results in the chlorophyll-a mean case which is a food sources of lemuru fish. Based on Trenberth's theory, (1997), the rise and fall of the ENSO Index of less than six months is not stated in ENSO. From the calculation results during the research of 2007 - 2016 happened three times ENSO phenomenon that is in 2009, 2010 and 2015. At the time of the IOD phenomenon, the IOD (+) phase will result in a decrease in catch while the normal IOD phase and (-) will increase the catch. From the results of this study can also be observed, in the year 2007 - 2011 phenomenon ENSO and IOD have a strong influence on the catch while in the year 2012 - 2016 the influence of the phenomenon of ENSO and IOD has no strong influence caused by the quantity of lemuru fish that have been over exploitation that resulted in the current Bali Strait on Over Fishing status.
Keywords : Fish Catch; El-Nino Southern Oscillation (ENSO); Indian Ocean
Dipole (IOD)
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Firdaus, Alfian, Donny Harisuseno, and Ery Suhartanto. "Studi Analisa Kekeringan Metode Standardized Precipitation Index (SPI) dan Palmer Drought Severity Index (PDSI) di DAS Kemuning Kabupaten Sampang." Jurnal Teknologi dan Rekayasa Sumber Daya Air 1, no. 2 (July 31, 2021): 535–48. http://dx.doi.org/10.21776/ub.jtresda.2021.001.02.17.
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Kekeringan ialah bencana alam yang terjadi secara perlahan dan berdampak buruk untuk kelangsungan hidup penduduk Kabupaten Sampang. Mengingat hal tersebut, perlu dilakukan analisa indeks kekeringan serta pemetaan sebarannya sebagai upaya mitigasi bencana kekeringan. Studi ini bertujuan untuk mengetahui tingkat keparahan kekeringan dengan metode Standardized Precipitation Index (SPI) dan Palmer Drought Severity Index (PDSI), serta kesesuaiannya dengan data Southern Oscillation Index (SOI) yang mampu mempresentasikan kejadian El Nino Southern Oscillation (ENSO). Setelah itu, Indeks kekeringan yang lebih sesuai dengan pola SOI dipetakan dengan metode Inverse Distance Weighting (IDW) untuk mengetahui sebaran kekeringan. Metode SPI menghasilkan indeks kekeringan terparah di bulan April 2004 sebesar -3,651 pada periode defisit 1 bulanan. Metode PDSI menghasilkan indeks kekeringan terparah di bulan September 2001 sebesar - 20,628. Berdasarkan hasil analisa rerata PDSI periode 1998-2017, diketahui bahwa bencana kekeringan umumnya bermula sejak bulan Juli dan berakhir di bulan Oktober, sedangkan puncak kekeringan terjadi pada bulan September. Metode PDSI juga memiliki kesesuaian sebesar 60% terhadap nilai SOI berdasarkan penggambaran grafik surplus dan defisit indeks rerata tahunan, lebih baik daripada metode SPI yang hanya bernilai 53%. Penggambaran peta sebaran kekeringan berdasarkan indeks kekeringan PDSI menunjukkan bahwa Kecamatan Sampang, Torjun, dan Camplong perlu diprioritaskan dalam upaya mitigasi bencana kekeringan di masa mendatang karena memiliki potensi bencana kekeringan lebih besar jika dibandingan kecamatan lainnya.
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Chandrasekara, Sewwandhi, Venkatraman Prasanna, and Hyun-Han Kwon. "Monitoring Water Resources over the Kotmale Reservoir in Sri Lanka Using ENSO Phases." Advances in Meteorology 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/4025964.
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In this study, the El Nino Southern Oscillation (ENSO) phase index is used for water management over the Kotmale reservoir in Sri Lanka. Daily rainfall data of 9 stations over the Kotmale catchment during 1960–2005 June-September (JJAS) season is investigated over the Kotmale catchment. The ENSO phases are identified based on the 0.5°C sea surface temperature (SST) anomaly over Nino 3 region. The study has brought out few stations showing increasing and a few decreasing seasonal rainfall trends for JJAS season, while there is no change in the annual rainfall for the catchment. Monthly and seasonal rainfall of all the selected stations showed negative correlation with the sea surface temperature (SST) over the Nino-3 region index during JJAS season with varying magnitudes. During the warm phase of ENSO, below average rainfall is prominent for JJAS season over many stations. The rainfall especially during early September showed a significant below average rainfall during the warm ENSO phase. The seasonal rainfall during neutral and cold ENSO phases does not experience similar significant changes as seen during warm ENSO phase. Inflow of the Kotmale reservoir shows decreasing trend for the period of 1960–2005 in the observation from all stations collectively.
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Restitiasih, Wayan Mita, I. Ketut Sukarasa, and I. Wayan Andi Yuda. "The Correlation of Southern Oscillation Index (SOI) with the Rainfall at Rainy and Dry Season Peak in Kintamani-Bangli Region period 1986-2015." BULETIN FISIKA 20, no. 2 (September 1, 2019): 6. http://dx.doi.org/10.24843/bf.2019.v20.i02.p02.
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A correlation study of the Southern Oscillation Index (SOI) on rainfall at the peak of the wet and dry season in the Kintamani-Bangli region has been carried out by taking SOI values and rainfall data for the period 1986-2015. The rainfall data used were recorded at 2 rain posts, namely Kembangsari and Kintamani. The research aimed to determine the relationship of fluctuations in the value of SOI with the intensity of rainfall, so that it can be used as a regional management plan when El Nino occurs. The method used in this study is correlation. The results obtained from the correlation that is the relationship between SOI value and rainfall in February were quite strong in the Kembangsari post with correlation coefficient of 0.409. Whereas for the Kintamani post the correlation obtained was weak with a correlation coefficient of 0.308. Then in August a weak correlation occurred in the Kembangsari post with a correlation coefficient of 0.2398 and was quite strong in the Kintamani post with a correlation coefficient of 0.4662. So that the influence of El Nino in the Kintamani area in February was more dominant in the Kembangsari post and in August at the Kintamani post.
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Kumar, Vinay. "Development of Precise Indices for Assessing the Potential Impacts of Climate Change." Atmosphere 11, no. 11 (November 15, 2020): 1231. http://dx.doi.org/10.3390/atmos11111231.
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The Special Issue on climate indices and climate change deals with various kinds of indices exits to assess weather and climate over a region. These indices might be based on local, regional, remote variables, which may affect and define the weather and climate of a region. Climate indices are the time series used to monitor the state of the climate and its relationship with other possible causes. With indices being myriad, it is challenging to choose which one is appropriate for a region of interest. However, the relationship between the indices and the climate of a region varies. El-Nino Southern Oscillation (Southern Oscillation Index, SOI/ENSO) is one of the most robust climate signals that stimulate rainfall, temperature, and hurricanes via teleconnections. SOI has a correlation of 0.5 over the Indonesian archipelago. Here, some of the well-known indices Holiday Climate Index (HCI), Tourism Climate Index (TCI), and Simple Diversity Index (SDI) are being reconnoitered to understand the holiday-tourism, end-of-the-day (EOD) judgment. The intrusion of dry air in the middle troposphere can create unstable weather, leading to heavy precipitation. The Special Issue seeks to encourage researchers to discover new indices in multidisciplinary department of atmospheric and physical sciences.
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Nadolnyak, Denis, and Dmitry Vedenov. "Information Value of Climate Forecasts for Rainfall Index Insurance for Pasture, Rangeland, and Forage in the Southeast United States." Journal of Agricultural and Applied Economics 45, no. 1 (February 2013): 109–24. http://dx.doi.org/10.1017/s1074070800004612.
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In this article, possible use of climate forecasts in rainfall index insurance of hay and forage production is considered in a geographical area (southeast United States) relatively heavily impacted by the El Nino Southern Oscillation (ENSO). Analysis of the stochastic properties of rainfall, yields, and the ENSO forecasts using the copula technique shows that the forecast impact depends on the proximity to the Gulf Coast where the impact of the ENSO is more pronounced and earlier in the year. Stochastic modeling shows that the use of skillful long-term climate forecasts by the insured producers creates intertemporal adverse selection that can be precluded by offering forecast conditional premiums. The impacts on the efficiency of the rainfall index insurance and results of sensitivity analysis with respect to model parameters are discussed.
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KANE, R. P. "Relation of El Niño characteristics and timings with rainfall extremes in India and Australia." MAUSAM 55, no. 2 (January 19, 2022): 257–68. http://dx.doi.org/10.54302/mausam.v55i2.1081.
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Whereas some El Nino years are known to be associated with droughts in some parts of the globe, notably India and south-east Australia, the El Niño effects are probabilistic, affecting only some regions and, not all El Niños are equally effective. Recently, it was observed that Unambiguous ENSOW (El Niño years, in which the Southern Oscillation Index minima and Pacific sea surface temperature maxima occurred in the middle of the calendar year) were better associated with droughts. In this communication, it is checked whether the effectiveness of El Niños was in any way related to suitable timings of the El Niño events (coincident with main rainy seasons) in India and Australia. In general, El Niños active during the main rainy season were associated better with droughts. But some events did not fit this pattern. Also, many years not having El Niños or La Niñas were associated with droughts or floods. Thus, the El Niño/rainfall relationship is rather loose.
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Sugiarto, Yon, and Dori Kurniawan. "ANALISIS DAMPAK ENSO (EL-NINO SOUTHERN OSCILLATION) TERHADAP TINGKAT KEKERINGAN UNTUK TANAMAN PANGAN DAN PALAWIJA (STUDI KASUS : SULAWESI SELATAN)." Agromet 23, no. 2 (December 18, 2009): 182. http://dx.doi.org/10.29244/j.agromet.23.2.182-198.
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<p>Weather and climate variability is a long-term weather changes that are characterized by fluctuations and deviations from normal conditions. One possible cause is the ENSO (El-Nino Southern Oscillation) which affected in drought events. This research was conducted to determine and analyze the level of drought in South Sulawesi due to the influence of ENSO and compare the production of food crops and secondary food crops in normal years and ENSO.<br />Drought index is calculated based on the Palmer method by using data of rainfall, air temperature and soil moisture as input. Based on the calculations using the method of Palmer drought index, the regions with monsoon rain patterns have a range of values between -22.71 drought until 18:23, Equatorial patterns ranging from -4.03 to 5:07, and on local patterns ranged<br />from -8.57 until 10:07. Verification test results on the drought index of crop production data showed that each ENSO event is always followed by a decline in rice production, especially of rice fields. Food crop production generally tends to increase at each ENSO event because most crops are plants that are resistant to drought, particularly local varieties that have adapted well to their environment. Thus, the drought caused by the influence of ENSO can affect the production of food crops and secondary food crops.</p>
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Maryanaji, Zohreh, Leili Tapak, and Omid Hamidi. "Climatic and atmospheric indices teleconnection impact on the characteristics of frost season in western Iran." Journal of Water and Climate Change 10, no. 2 (December 18, 2017): 391–401. http://dx.doi.org/10.2166/wcc.2017.114.
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Abstract The large-scale variability of atmospheric and ocean circulation patterns cause seasonal climate changes in the Earth. In other words, climate elements are affected by phenomena like El Niño Southern Oscillation (ENSO), El Niño (NINO), and Northern Atlantic Oscillation (NAO). In this study the characteristics of the frost season over a 20-year period (1996–2015) from seven synoptic stations in western Iran were evaluated using support vector machine and random forest regression. Comparing determination coefficients obtained by these models between atmospheric and ocean circulation indices and the characteristics of the frost season showed a positive effect. Thus, the onset and the end of the frost season in this region were highly correlated with the Southern Oscillation Index (SOI) and NAO, respectively. In regions with lower correlations (central areas and some regions of Alvand Mountain), the role of the geographical factors, altitude and topography becomes more pronounced and the impact of the global indices is reduced. Cluster analysis was also conducted to detect patterns and to identify regions according to the effect of the atmospheric and oceanic indices on frost season, and three regions were identified. The largest correlations with global indices (in both models) belonged to the first and third classes, respectively. The results of this study could be applied for planning environmental and agricultural activities.
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Kasim, Kamaluddin, Agustinus Anung Widodo, and Andhika Prima Prasetyo. "PENGARUH EPISODE LA NINA DAN EL NINO TERHADAP PRODUKSI BEBERAPA PELAGIS KECIL YANG DIDARATKAN DI PANTAI UTARA JAWA." Jurnal Penelitian Perikanan Indonesia 17, no. 4 (January 30, 2017): 257. http://dx.doi.org/10.15578/jppi.17.4.2011.257-264.
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Sumberdaya ikan pelagis di Laut Jawa telah dimanfaatkan secara intensif sejak dekade tahun 1980-an danmerupakan kegiatan perikanan utama di Indonesia. Beberapa famili ikan pelagis dominan yang tertangkap diantaranya dari famili Clupeidae, Carangidae dan Scombridae. Penelitian bertujuan untuk mengetahui pengaruh periode La Nina dan El Nino terhadap produksi beberapa jenis ikan yang dominan tertangkap di Pantai Utara Jawa. Penelitian dilakukan selama bulan April sampai dengan September 2010 dengan mengumpulkan data pendaratan ikan melalui enumerator di beberapa lokasi pendaratan ikan yakni PPN Pekalongan; PPI Bajomulyo II dan Bajomulyo I – Juwana; serta PPIRembang. Data SouthernOscilation Indiex (SOI) diperoleh dari situs resmi BadanMetereologi pemerintah Australia. Hasil penelitian menunjukkan bahwa puncak produksi ikan layang, banyar dan tongkol yang didaratkan di Pantai Utara Jawa relatif lebih panjang pada periode La Nina dibandingkan pada periode El Nino. Rata-rata produksi ikan selar berbeda nyata (P<0,05) antara periode El Nino dan Periode La Nina sedangkan jenis layang, banyar dan tongkol tidak berbeda nyata (P>0,05). Pelagic fish resources in the Northern Coast of Java has been exploited since early 1980’s as themost intensive fishery in Indonesia. Several families of pelagic fish that commonly exploited in Java Sea are Clupeidae, Carangidae, and Scombridae. The study was conducted from March to September 2010 by compiling fish landing data from field enumerators in the several fish landing locations such as PPN Pekalongan, PPI bajomulyo I and Bajomulyo II at Juwana, and PPI Rembang. The Current work aims to determine the production of small pelagic fishery affected by El Nino or La Nina evidence. Southern Oscillation Index (SOI) parameter was used as an indicator of climate change parameter. The results show that the peak of season production of russel’s scad (Decapterus russelli), indianmackerel (Rastrelliger kanagurta), and frigate mackerel (Auxis thazard) weremore longer during the periode of La Nina than those of the periode of El Nino. Average production values of yellowstrip trevally (Selaroides leptolepis) were significantly different during La Nina periodes compared to El Nino periodes (P<0,05) while russel’s scad, indian mackerel, and frigate mackerel did not show significantly different.
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Wang, Huaijun, Yingping Pan, and Yaning Chen. "Impacts of regional climate and teleconnection on hydrological change in the Bosten Lake Basin, arid region of northwestern China." Journal of Water and Climate Change 9, no. 1 (October 25, 2017): 74–88. http://dx.doi.org/10.2166/wcc.2017.140.
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Abstract This investigation examined effects of climate change, measured as annual, seasonal, and monthly air temperature and precipitation from 1958 to 2010, on water resources (i.e., runoff) in the Bosten Lake Basin. Additionally, teleconnections of hydrological changes to large-scale circulation indices including El Nino Southern Oscillation (ENSO), Arctic Oscillation (AO), North Atlantic Oscillation (NAO), Tibetan High (XZH), westerly circulation index (WI), and northern hemisphere polar vortex area index (VPA) were analyzed in our study. The results showed the following. (1) Annual and seasonal air temperature increased significantly in the Bosten Lake Basin. Precipitation exhibited an increasing trend, while the significance was less than that of temperature. Abrupt changes were observed in 1996 in mountain temperature and in 1985 in plain temperature. (2) Runoff varied in three stages, decreasing before 1986, increasing from 1987 to 2003, and decreasing after 2003. (3) Precipitation and air temperature have significant impacts on runoff. The hydrological processes in the Bosten Lake Basin were (statistically) significantly affected by the northern hemisphere polar vortex area index (VPA) and the Tibetan High (XZH). The results of this study are good indicators of local climate change, which can enhance human mitigation of climate warming in the Bosten Lake Basin.
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Wijaya, Thomas. "The Rainfall Variability at Gunung Kidul Regency, Indonesia and Farmer Knowledge on Climate Change." European Journal of Environment and Earth Sciences 4, no. 1 (February 11, 2023): 62–68. http://dx.doi.org/10.24018/ejgeo.2023.4.1.372.
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The survey was carried out to analyze rainfall variability, to gather information of farmer practise on cropping pattern and farmer knowledge of climate change. The survey was conducted from on 21 September to 1 October 2022 in Ngoro oro and Watu Gajah sub villages, at Gunung Kidul Regency, about 30 km Southern of Yogyakarta city, Indonesia. Field visit and the group discussion were conducted to explore farmer knowledge on climate change. Rainfall was correlated with previous monthly Southern Oscillation Index to enabale rainfall prediction. The main finding of the survey were the farmers had local knowledge that was good enough to anticipate of climate change such as observing the nature sign i.e. the growth of the gadung tree (Dioscorea hispida) and suweg plant (Amorphophallus sp), the use of Javanese calendar for agriculture and also checking the soil wetness were used to decide the first season of planting after dry season. However, the information from meteorology agency (BMKG) regarding the La Nina was not reaching the farmers. The analysis of rainfall revealed that rainfall at Gunung Kidul was closely related to El Nino and La Nina, and this affected the the time of first planting season after dry season. Also, SOI could be useful for prediction of fortcoming rainfall. The scientific aspect of climatic anomaly such as La Nina and El Nino was reasonably understood and it could be predicted by scientists, and this valuable information needed to be delivered by mediators to assist farmers in farming management. As the occurrence of El Nino and La Nina was known in advance, this information from BMKG needed to be delivered by mediators in simple words so that farmer would get the benefit of climate change to manage their farm.
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Mulyanti, Heri. "Keterkaitan Antara El Niño-Southern Oscillation (ENSO) Dengan Variabilitas Curah Hujan Bojonegoro." Berkala Ilmiah Pertanian 6, no. 1 (February 28, 2023): 35. http://dx.doi.org/10.19184/bip.v6i1.37221.
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Indonesian climate, especially Java Island have been associated with El Niño-Southern Oscillation (ENSO). The research using rainfall station at Bojonegoro District from 1979 – 2009 to detect rainfall variability and its linkages with ENSO phenomenom. ENSO’s indexes then used to predict rainfall in Bojonegoro. Rainfall station was clustered using cluster analysis and then Mann-Kendall test used to predict rainfall trend of each cluster. There are 16 rainfall station that passed the rainfall test that can be conduct in the rainfall anomaly analysis. All stations have experienced both dry and wet anomalies during observation. Positive ENSO years have associated with more stations experienced dry anomalies; in other hand wet anomalies occurred more when negative ENSO. The stronger ENSO caused more extrem anomalies. There are obtained 5 clusters rainfall area over Bojonegoro District used HCA Ward method. Largest rainfall variations was experienced by cluster 5, Gondang and Jatiblimbing. Trend in rainfall only experienced by cluster 2 (Sumberejo and Mekuris) for December – January but another clusters didn’t experience such significant rainfall pattern change. October and November have been the most influenced month caused by ENSO; and positive ENSO anomaly caused prolonged dry season up to November. October and November’s rainfall can be predicted using SSTA Nino 3.4 index 3 months before.
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Ziemke, J. R., S. Chandra, L. D. Oman, and P. K. Bhartia. "A new ENSO index derived from satellite measurements of column ozone." Atmospheric Chemistry and Physics 10, no. 8 (April 21, 2010): 3711–21. http://dx.doi.org/10.5194/acp-10-3711-2010.
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Abstract. Column Ozone measured in tropical latitudes from Nimbus 7 total ozone mapping spectrometer (TOMS), Earth Probe TOMS, solar backscatter ultraviolet (SBUV), and Aura ozone monitoring instrument (OMI) are used to derive an El Nino-Southern Oscillation (ENSO) index. This index, which covers a time period from 1979 to the present, is defined as the "Ozone ENSO Index" (OEI) and is the first developed from atmospheric trace gas measurements. The OEI is constructed by first averaging monthly mean column ozone over two broad regions in the western and eastern Pacific and then taking their difference. This differencing yields a self-calibrating ENSO index which is independent of individual instrument calibration offsets and drifts in measurements over the long record. The combined Aura OMI and MLS ozone data confirm that zonal variability in total column ozone in the tropics caused by ENSO events lies almost entirely in the troposphere. As a result, the OEI can be derived directly from total column ozone instead of tropospheric column ozone. For clear-sky ozone measurements a +1 K change in Nino 3.4 index corresponds to +2.9 Dobson Unit (DU) change in the OEI, while a +1 hPa change in SOI coincides with a −1.7 DU change in the OEI. For ozone measurements under all cloud conditions these numbers are +2.4 DU and −1.4 DU, respectively. As an ENSO index based upon ozone, it is potentially useful in evaluating climate models predicting long term changes in ozone and other trace gases.
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Zhang, Kexin, Jiajia Luo, Jiaoting Peng, Hongchang Zhang, Yan Ji, and Hong Wang. "Analysis of Extreme Temperature Variations on the Yunnan-Guizhou Plateau in Southwestern China over the Past 60 Years." Sustainability 14, no. 14 (July 6, 2022): 8291. http://dx.doi.org/10.3390/su14148291.
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Analysis of variations in 12 extreme temperature indices at 68 meteorological stations on the Yunnan-Guizhou Plateau (YGP) in southwestern China during 1960–2019 revealed widespread significant changes in all temperature indices. The temperature of the hottest days and coldest nights show significantly increasing trends, and the frequencies of the warm days and nights also present similar trends. The temperature of the coldest night has a significant and strong warming trend (0.38 °C/decade), whereas the frequency of frost days shows the fastest decrease (1.5 days/decade). Increases in the summer days are statistically significant, while a decreasing trend for the diurnal temperature range is not significant. Furthermore, there were significant differences in the changes of temperature indices between 1960–1989 and 1990–2019. Most parts of the YGP underwent significant warning, manifesting that the mountainous regions are relatively sensitive and vulnerable to climate change. The correlation coefficients between the temperature indices and various geographical factors (latitude, longitude, and height) reflect the complexity of regional temperature variability and indicate enhanced sensitivity of extreme temperatures to geographical factors on the YGP. It was also found that extreme temperatures generally had weaker correlations with the El Nino-Southern Oscillation, North Pacific Index, Southern Oscillation Index, North Atlantic Oscillation, and East Asian Summer Monsoon Index than with the South Asian summer monsoon index, Nino4 indices and Arctic Oscillation, and there were more insignificant correlations. Regional trends of the extreme temperature indices reflect the non-uniform temperature change over the YGP, which is due to the complex interaction between atmospheric circulation patterns and local topography. The results of this study have important practical significance for mitigating the adverse effects of extreme climatic changes, in particular for the YGP with its typical karst geomorphology and fragile ecological environment.
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Salman, Afan Galih, and Yen Lina Prasetio. "Implementasi Jaringan Syaraf Tiruan Recurrent Dengan Metode Pembelajaran Gradient Descent Adaptive Learning Rate Untuk Pendugaan Curah Hujan Berdasarkan Peubah Enso." ComTech: Computer, Mathematics and Engineering Applications 1, no. 2 (December 1, 2010): 418. http://dx.doi.org/10.21512/comtech.v1i2.2384.
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The use of technology of technology Artificial Neural Network (ANN) in prediction of rainfall can be done using the learning approach. ANN prediction accuracy measured by the coefficient of determination (R2) and Root Mean Square Error (RMSE).This research employ a recurrent optimized heuristic Artificial Neural Network (ANN) Recurrent Elman gradient descent adaptive learning rate approach using El-Nino Southern Oscilation (ENSO) variable, namely Wind, Southern Oscillation Index (SOI), Sea Surface Temperatur (SST) dan Outgoing Long Wave Radiation (OLR) to forecast regional monthly rainfall. The patterns of input data affect the performance of Recurrent Elman neural network in estimation process. The first data group that is 75% training data and 25% testing data produce the maximum R2 69.2% at leap 0 while the second data group that is 50% training data & 50% testing data produce the maximum R2 53.6%.at leap 0 Our result on leap 0 is better than leap 1,2 or 3.
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Salman, Afan Galih, and Yen Lina Prasetio. "Implementasi Jaringan Syaraf Tiruan Recurrent Menggunakan Gradient Descent Adaptive Learning Rate and Momentum Untuk Pendugaan Curah Hujan." ComTech: Computer, Mathematics and Engineering Applications 2, no. 1 (June 1, 2011): 23. http://dx.doi.org/10.21512/comtech.v2i1.2707.
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The artificial neural network (ANN) technology in rainfall prediction can be done using the learning approach. The ANN prediction accuracy is measured by the determination coefficient (R2) and root mean square error (RMSE). This research implements Elman’s Recurrent ANN which is heuristically optimized based on el-nino southern oscilation (ENSO) variables: wind, southern oscillation index (SOI), sea surface temperatur (SST) dan outgoing long wave radiation (OLR) to forecast regional monthly rainfall in Bongan Bali. The heuristic learning optimization done is basically a performance development of standard gradient descent learning algorithm into training algorithms: gradient descent momentum and adaptive learning rate. The patterns of input data affect the performance of Recurrent Elman neural network in estimation process. The first data group that is 75% training data and 25% testing data produce the maximum R2 leap 74,6% while the second data group that is 50% training data and 50% testing data produce the maximum R2 leap 49,8%.
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CHAN, J. Y. C., H. L. LIN, and L. W. TIAN. "Meteorological factors and El Nino Southern Oscillation are associated with paediatric varicella infections in Hong Kong, 2004–2010." Epidemiology and Infection 142, no. 7 (September 27, 2013): 1384–92. http://dx.doi.org/10.1017/s0950268813002306.
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SUMMARYVaricella accounts for substantial morbidities and remains a public health issue worldwide, especially in children. Little is known about the effect of meteorological variables on varicella infection risk for children. This study described the epidemiology of paediatric varicella notifications in Hong Kong from 2004 to 2010, and explored the association between paediatric varicella notifications in children aged <18 years and various meteorological factors using a time-stratified case-crossover model, with adjustment of potential confounding factors. The analysis found that daily mean temperature, atmospheric pressure and Southern Oscillation Index (SOI) were positively associated with paediatric varicella notifications. We found that an interquartile range (IQR) increase in temperature (8·38°C) at lag 1 day, a 9·50 hPa increase in atmospheric pressure for the current day, and a 21·91 unit increase in SOI for the current day may lead to an increase in daily cases of 5·19% [95% confidence interval (CI) 1·90–8·58], 5·77% (95% CI 3·01–8·61), and 4·32% (95% CI 2·98–5·68), respectively. An IQR increase in daily relative humidity (by 11·96%) was associated with a decrease in daily paediatric varicella (−2·79%, 95% CI −3·84 to −1·73). These findings suggest that meteorological factors might be important predictors of paediatric varicella infection in Hong Kong.
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Liu, Haibo, Xiaogu Zheng, Jing Yuan, and Carsten S. Frederiksen. "Potential Predictability of Seasonal Global Precipitation Associated with ENSO and MJO." Atmosphere 14, no. 4 (April 7, 2023): 695. http://dx.doi.org/10.3390/atmos14040695.
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A covariance decomposition method is applied to a monthly global precipitation dataset to decompose the interannual variability in the seasonal mean time series into an unpredictable component related to “weather noise” and to a potentially predictable component related to slowly varying boundary forcing and low-frequency internal dynamics. The “potential predictability” is then defined as the fraction of the total interannual variance accounted for by the latter component. In tropical oceans (30° E–0° W, 30° S–30° N), the consensus is that the El Nino-Southern Oscillation (ENSO, with 4–8 year cycles) is a dominant driver of the potentially predictable component, while the Madden-Julian Oscillation (MJO, with 30–90 days cycles) is a dominant driver of the unpredictable component. In this study, the consensus is verified by using the Nino3-4 SST index and a popular MJO index. It is confirmed that Nino3-4 SST does indeed explain a significant part of the potential predictable component, but only limited variability of the unpredictable component is explained by the MJO index. This raises the question of whether the MJO is dominant in the variability of the unpredictable component of the precipitation, or the current MJO indexes do not represent MJO variability well.