scholarly journals Changes in Western Pacific Tropical Cyclones Associated with the El Niño–Southern Oscillation Cycle

2012 ◽  
Vol 25 (17) ◽  
pp. 5864-5878 ◽  
Author(s):  
Richard C. Y. Li ◽  
Wen Zhou
Keyword(s):  
Tropical Cyclones ◽  
El Niño ◽  
Wind Shear ◽  
El Nino ◽  
Southern Oscillation ◽  
Vertical Wind Shear ◽  
Vertical Wind ◽  
La Niña ◽  
El Nino Southern Oscillation ◽  
La Nina

Abstract This study examines the interannual variability of three groups of tropical cyclones (TCs)—super typhoons (STYs), typhoons (TYs), and tropical storms and tropical depressions (TSTDs)—and their relationship with the El Niño–Southern Oscillation (ENSO). Both wavelet analysis and correlation studies of upper-ocean heat content reveal significant differences for the three types of TCs. In particular, an increase (decrease) in the frequency of STYs is usually associated with the mature phase of El Niño (La Niña) events, while the converse is true for TSTDs. In contrast, the frequency of TYs increases (decreases) during the transition period from La Niña to El Niño (El Niño to La Niña) events. The results suggest that the timing with which ENSO impacts STYs, TYs, and TSTDs varies and that their corresponding changes in frequency closely follow the evolution of the ENSO cycle. Empirical orthogonal function analysis is also conducted to investigate the impact of different environmental factors influenced by ENSO on TCs. The vertical wind shear and moist static energy associated with ENSO are identified as the dominant factors that control the frequency of STYs. In comparison, the frequency of TYs is found to be closely related to the relative vorticity and vertical wind shear associated with both the transition phase of ENSO and with other types of climate variability.

scholarly journals The Impact of Obliquity Change on El Niño Southern Oscillation (ENSO) and La Niña Climate Episodes

2022 ◽  
Author(s):  
Paul C. Rivera
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Global Climate ◽  
Global Climate Model ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
La Nina ◽  
The Impact

An alternative physical mechanism is proposed to describe the occurrence of the episodic El Nino Southern Oscillation (ENSO) and La Nina climatic phenomena. This is based on the earthquake-perturbed obliquity change (EPOCH) model previously discovered as a major cause of the global climate change problem. Massive quakes impart a very strong oceanic force that can move the moon which in turn pulls the earth’s axis and change the planetary obliquity. Analysis of the annual geomagnetic north-pole shift and global seismic data revealed this previously undiscovered force. Using a higher obliquity in the global climate model EdGCM and constant greenhouse gas forcing showed that the seismic-induced polar motion and associated enhanced obliquity could be the major mechanism governing the mysterious climate anomalies attributed to El Nino and La Nina cycles.

scholarly journals Response of regional climate and glacier ice proxies to El Niño-Southern Oscillation (ENSO) in the subtropical Andes

2008 ◽  
Vol 4 (1) ◽  
pp. 173-211
Author(s):  
E. Dietze ◽  
A. Kleber ◽  
M. Schwikowski
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Ice Core ◽  
La Niña ◽  
El Nino Southern Oscillation ◽  
Ion Concentrations ◽  
Major Ion ◽  
La Nina ◽  
Glacier Ice

Abstract. El Niño-Southern Oscillation (ENSO) is an important element of earth's ocean-climate system. To further understand its past variability, proxy records from climate archives need to be studied. Ice cores from high alpine glaciers may contain high resolution ENSO proxy information, given the glacier site is climatologically sensitive to ENSO. We investigated signals of ENSO in the climate of the subtropical Andes in the proximity of Cerro Tapado glacier (30°08' S, 69°55' W, 5550 m a.s.l.), where a 36 m long ice core was drilled in 1999 (Ginot, 2001). We used annual and semi-annual precipitation and temperature time series from regional meteorological stations and interpolated grids for correlation analyses with ENSO indices and ice core-derived proxies (net accumulation, stable isotope ratio δ18O, major ion concentrations). The total time period investigated here comprises 1900 to 2000, but varies with data sets. Only in the western, i.e. Mediterranean Andes precipitation is higher (lower) during El Niño (La Niña) events, especially at higher altitudes, due to the latitudinal shift of frontal activity during austral winters. However, the temperature response to ENSO is more stable in space and time, being higher (lower) during El Niño (La Niña) events in most of the subtropical Andes all year long. From a northwest to southeast teleconnection gradient, we suggest a regional water vapour feedback triggers temperature anomalies as a function of ENSO-related changes in regional pressure systems, Pacific sea surface temperature and tropical moisture input. Tapado glacier ice proxies are found to be predominantly connected to eastern Andean summer rain climate, which contradicts previous studies and the modern mean spatial boundary between subtropical summer and winter rain climate derived from the grid data. The only ice core proxy showing a response to ENSO is the major ion concentrations, via local temperature indicating reduced sublimation and mineral dust input during El Niño years.

scholarly journals Tropical Cyclone Activity in the Fiji Region: Spatial Patterns and Relationship to Large-Scale Circulation

2009 ◽  
Vol 22 (14) ◽  
pp. 3877-3893 ◽  
Author(s):  
Savin S. Chand ◽  
Kevin J. E. Walsh
Keyword(s):  
Tropical Cyclone ◽  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Southern Oscillation ◽  
Vertical Wind Shear ◽  
Relative Vorticity ◽  
La Niña ◽  
Factors Affecting ◽  
La Nina

Abstract This study examines the variations in tropical cyclone (TC) genesis positions and their subsequent tracks for different phases of the El Niño–Southern Oscillation (ENSO) phenomenon in the Fiji, Samoa, and Tonga region (FST region) using Joint Typhoon Warning Center best-track data. Over the 36-yr period from 1970/71 to 2005/06, 122 cyclones are observed in the FST region. A large spread in the genesis positions is noted. During El Niño years, genesis is enhanced east of the date line, extending from north of Fiji to over Samoa, with the highest density centered around 10°S, 180°. During neutral years, maximum genesis occurs immediately north of Fiji with enhanced genesis south of Samoa. In La Niña years, there are fewer cyclones forming in the region than during El Niño and neutral years. During La Niña years, the genesis positions are displaced poleward of 12°S, with maximum density centered around 15°S, 170°E and south of Fiji. The cyclone tracks over the FST region are also investigated using cluster analysis. Tracks during the period 1970/71–2005/06 are conveniently described using three separate clusters, with distinct characteristics associated with different ENSO phases. Finally, the role of large-scale environmental factors affecting interannual variability of TC genesis positions and their subsequent tracks in the FST region are investigated. Favorable genesis positions are observed where large-scale environments have the following seasonal average thresholds: (i) 850-hPa cyclonic relative vorticity between −16 and −4 (×10−6 s−1), (ii) 200-hPa divergence between 2 and 8 (×10−6 s−1), and (iii) environmental vertical wind shear between 0 and 8 m s−1. The subsequent TC tracks are observed to be steered by mean 700–500-hPa winds.

scholarly journals An Analysis of Anomalous Winter and Spring Tornado Frequency by Phase of the El Niño/Southern Oscillation, the Global Wind Oscillation, and the Madden-Julian Oscillation

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Todd W. Moore ◽  
Jennifer M. St. Clair ◽  
Tiffany A. DeBoer
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Madden Julian Oscillation ◽  
La Nina ◽  
Upper Level ◽  
Favorable Conditions

Winter and spring tornado activity tends to be heightened during the La Niña phase of the El Niño/Southern Oscillation and suppressed during the El Niño phase. Despite these tendencies, some La Niña seasons have fewer tornadoes than expected and some El Niño seasons have more than expected. To gain insight into such anomalous seasons, the two La Niña winters and springs with the fewest tornadoes and the two El Niño winters and springs with the most tornadoes between 1979 and 2016 are identified and analyzed in this study. The relationships between daily tornado count and the Global Wind Oscillation and Madden-Julian Oscillation in these anomalous seasons are also explored. Lastly, seasonal and daily composites of upper-level flow, low-level flow and humidity, and atmospheric instability are generated to describe the environmental conditions in the anomalous seasons. The results of this study highlight the potential for large numbers of tornadoes to occur in a season if favorable conditions emerge in association with individual synoptic-scale events, even during phases of the El Niño/Southern Oscillation, Global Wind Oscillation, and Madden-Julian Oscillation that seem to be unfavorable for tornadoes. They also highlight the potential for anomalously few tornadoes in a season even when the oscillations are in favorable phases.

scholarly journals El Niño Southern Oscillation (1896 to 2016): Quantifying Effects on Winter Precipitation and Temperature in Southwest Ohio, USA

2021 ◽  
Vol 121 (2) ◽  
pp. 64-77
Author(s):  
Robert W. Ritzi ◽  
Lauren M. Roberson ◽  
Michael Bottomley
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Winter Precipitation ◽  
Winter Temperature ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
La Nina ◽  
Precipitation And Temperature

Continental-scale studies of North America suggest that the El Niño Southern Oscillation (ENSO) can cause winters to be warmer, with less precipitation, during El Niño conditions and colder, with more precipitation, during La Niña conditions in the Midwest United States. Two sources of historical records of precipitation and temperature in southwest Ohio from 1896 to 2016 were analyzed. Three statistical methodologies were used to test the hypothesis that anomalies in winter temperature and precipitation occurred in relation to ENSO phases. Eighty percent of El Niño winters had below-average winter precipitation; the average anomaly was −5 cm. Precipitation decreased with increase in El Niño strength as measured by the Multivariate ENSO Index (MEI). These results were statistically significant beyond the 95% level. However, variation in MEI only accounted for 3% of the overall variability in winter precipitation. Many of the drier winters on record, including the extrema, occurred during neutral winters. During La Niña winters precipitation was not statistically significantly different from that in neutral winters. Winter temperature was not statistically significantly different during El Niño and La Niña winters within the century of record. The results were consistent between separate analyses of data from the 2 different sources.

The impact of El Niño Southern Oscillation on seasonal drought in the southern Australian grainbelt

2010 ◽  
Vol 61 (7) ◽  
pp. 528 ◽  
Author(s):  
P. T. Hayman ◽  
A. M. Whitbread ◽  
D. L. Gobbett
Keyword(s):  
Cluster Analysis ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Moisture Stress ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
High Rainfall ◽  
La Nina

The cropping simulation model APSIM (Agricultural Production Systems Simulator) was used to investigate the pattern of seasonal moisture stress during the growing season for four medium- to high-rainfall regions and four low-rainfall regions in the southern Australian grains belt over the period 1906–2007. Cluster analysis of the pattern of crop water stress experienced by each simulated crop was used to devise season types for the study sites. Average crop moisture stress for two periods up to grain filling, i.e. germination to 600°C days of thermal accumulation (~Zadoks 0–32) and from 600 to 1200 days of thermal accumulation (~Zadoks 32–71), was used to devise a classification of season type: low moisture stress early and late (L-L), low early and high late (L-H), high early and low late (H-L) and high early and late (H-H). Using regional rainfall we found that El Niño events are associated with double the risk of the season being in the lowest tercile from 33 to 67% and La Niña events increase the chance of being in the top tercile to 50%. Although there was a wide range of simulated yields in El Niño and La Niña years, for most sites the average yields were lower in El Niño years and higher in La Niña years. For most sites in the study 6 or 7 of the worst 10 years were El Niño, 3 Neutral and 1 or nil cases were La Niña events. This contrasts with a pattern assuming no El Niño Southern Oscillation (ENSO) influence of 2 El Niño, 6 Neutral and 2 La Niña events. Analysis of the relationship of season types identified by the cluster analysis to ENSO showed significant results for high-rainfall sites but not for low-rainfall sites. One of the reasons for this is that in low-rainfall sites, moisture stress occurs in most seasons. We conclude that there is good reason for farmers and advisers in South Australia to pay attention to a forecast of ENSO for the coming season as one part of their risk management strategy. We conclude on the need to think clearly about drought and aridity in these low-rainfall environments and comment on how this analysis further questions canopy management as a means of dealing with drought risk.

scholarly journals KORELASI MULTIVARIABEL ENSO, MONSUN DAN DIPOLEMODE TERHADAP VARIABILITAS CURAH HUJAN DI MALUKU

2018 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Alexander Y. Elake ◽  
Merlin Talahatu ◽  
Pieldrie Nanlohy
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Dipole Mode ◽  
La Nina

Analisis korelasi multivariabel antara curah hujan diMaluku (Ambon, Tual, dan Saumlaki) dengan anomali suhu the El Niño Southern Oscillation (ENSO) di daerah Niño 3.4 Samudera Pasifik, angin Monsun di wilayah Maluku serta anomali suhu Dipole Mode Event (DME) di Samudera Hindia telah dilakukan dengan analisa korelasi parsial dan berganda. Analisis tersebut dilakukan untuk data selama 10 tahun kalender yaitu dari Januari 2005 – Desember 2014 yang meliputi dua periode kejadian El Niño (tahun 2006/07 dan 2009/10), dua tahun fasa ENSO Normal (2005 dan 2013), dan tiga periode La Niña (2007/08, 2010/11, dan 2011/12). Pengaruh interaksi ENSO, Monsun dan Dipole Mode terhadap curah hujan Maluku ditunjukkan oleh nilai koefisien korelasi berganda (rb1) yang berkisar antara 0,748 – 0,999 dan nilai koefisien penentu berganda (rpb1) dengan kisaran 55,9–99,8% pada fasa El Niño. Sedangkan untuk fasa ENSO Normal nilainya berturut-turut rb2 = 0,807–0,905 dan rpb2 = 64,6 – 81,9%, dan untuk fasa fasa La Niña adalah rb3 = 0,674–0,964 dan rpb3 = 45,4– 92,9%. Pengaruh ENSO yang dominan terhadap curah hujan Ambon terlihat pada fasa El Niño dan fasa La Niña, sedangkan Monsun lebih dominan pada ENSO Normal. Untuk Tual, pengaruh ENSO, Monsun, dan Dipole Mode sama-sama terlihat pada fasa El Niño dan fasa La Niña, sedangkan Monsun lebih dominan dari Dipole Mode pada ENSO Normal. Sementara pengaruh Dipole Mode sangat dominan terhadap curah hujan Saumlaki.

scholarly journals PERGERAKAN ZONA KONVERGENSI DI SAMUDERA PASIFIK BAGIAN BARAT BERDASARKAN DATA INSITU DAN SATELIT

2015 ◽  
Vol 10 (2) ◽  
pp. 75
Author(s):  
Faisal Hamzah ◽  
Eko Susilo ◽  
Iis Triyulianti ◽  
Agus Setiawan
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
La Nina

Samudera Pasifik berperan penting dalam siklus El-Nino Southern Oscillation (ENSO) dan berpengaruh signifikan pada kegiatan penangkapan tuna di Indonesia, khususnya ikan Cakalang. Penelitian ini bertujuan mengetahui pola pergerakan zona konvergensi di Samudera Pasifik bagian Barat dengan mengamati pergerakan parameter oseanografi seperti suhu, salinitas, klorofil-a, dan produktivitas primer. Data parameter oseanografi tersebut terdiri dari data insitu, data satelit maupun hasil pemodelan. Hasil analisis menunjukan adanya pergerakan zona konvergensi di Barat Pasifik yang dicirikan variabel proksi yaitu isotermal 29°C, isohalin 34,6 psu, konsenrasi klorofil-a sebesar 0,1 mg/m3 dan NPP 300 mgC/m2/day. Pola pergerakan zona konvergensi baik secara horisontal maupun vertikal dipengaruhi oleh ENSO. Pada saat terjadi La-Nina massa air dengan suhu yang hangat bergeser ke arah Barat yang diikuti dengan meningkatnya kesuburan perairan. Pergerakan vertikal massa air hangat terjadi pada kedalaman 25-75 m (suhu) dan 50 m (salinitas). Namun pada saat El-Nino massa air hangat bergerak ke arah Timur Samudera Pasifik. Fluktuasi produksi tangkapan ikan Cakalang di perairan Indonesia Timur mengikuti pola pergerakan zona konvergensi tersebut. Peningkatan jumlah produksi ikan Cakalang di Kota Sorong meningkat seiring dengan keberadaan zona konvergensi di bagian Barat (La-Nina), namun di Propinsi Papua menunjukan pola sebaliknya.

scholarly journals The Impact of Different Phases of the El Niño-Southern Oscillation Phenomenon on Goiás State Rainfalls and Temperature Characteristics Across Three Decades

2021 ◽  
Author(s):  
David Henriques da Matta ◽  
Caio Augusto dos Santos Coelho ◽  
Leydson Lara dos Santos ◽  
Luis Fernando Stone ◽  
Alexandre Bryan Heinemann
Keyword(s):  
El Niño ◽  
Minimum Temperature ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
Maximum Temperature ◽  
El Nino Southern Oscillation ◽  
La Nina ◽  
The Impact

Abstract Rainfall and temperature are the two key parameters of crop development. Studying the characteristics of these parameters under El Niño-Southern Oscillation (ENSO) conditions is important to better understand the impacts of the different phases of this phenomenon (El Niño, Neutral, and La Niña conditions) on agriculture. This study analyzes 32 years (1980–2011) of climatic data from 128 weather stations across Goiás State in Brazil to determine the behavior of temperature and rainfall time series over three periods (1980–1989; 1990–1999 and 2000–2011) under El Niño, Neutral, and La Niña conditions. The analysis revealed no major impacts of ENSO conditions on accumulated rainfall characteristics, a feature particularly marked in the most recent period (2000–2011). ENSO impacting temperature was identified but presented considerable variability across the periods investigated. These impacts were marked in the first two periods as for maximum temperature and increased from the first to the last period as for minimum temperature. These features were noticed in both analyses in the entire Goiás State and most of the investigated mega-regions, except for the East and Northeast mega-regions as for minimum temperature. There were increases in maximum temperature values throughout the rainfed season (October to March) for all ENSO conditions and investigated periods. Minimum temperature also increased across the three investigated periods, and this was marked in the beginning of the rainfed season (October) under El Niño and Neutral conditions.

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