scholarly journals A Continuum Approach to Understanding Changes in the ENSO-Indian Monsoon Relationship

2020 ◽  
pp. 1-49
Author(s):  
Justin Schulte ◽  
Fredrick Policielli ◽  
Benjamin Zaitchik
Keyword(s):  
Southern Oscillation ◽  
Monsoon Season ◽  
Rainfall Variability ◽  
Strongly Correlated ◽  
Sea Surface Temperature Anomalies ◽  
Indian Rainfall ◽  
The 1960S ◽  
June July ◽  
Work Supports ◽  
The Relationship

AbstractIt is well-documented that the relationship between the El Niño/Southern Oscillation (ENSO) and the Indian summer monsoon changes on interdecadal timescales, yet an explanation for the variations is still a subject of debate. Here, using a continuum framework based on one-point partial correlation maps, we show that the ENSO-Indian rainfall relationship is influenced by the gradient of sea surface temperature anomalies (SSTA) across the Niño 3 region. Based on this identified SSTA pattern, a simple trans Niño 3 (TN3) index is created that explains up to 50% of All-India rainfall variability during the mid to late monsoon season after the 1960s. It is also shown that the influence of the TN3 pattern on the relationship between common ENSO metrics and All-India rainfall is strongest during the August-September (AS) monsoon sub-season and weakest during the June-July sub-season. The TN3 pattern accounts for up to 80% of the change and sign reversal in the AS Niño 1+2-All-India rainfall relationship in recent decades. The 1940s coincides with the intensification of the TN3 pattern and its influence. As the TN3 index is nearly orthogonal to the Niño 3 index, and both are strongly correlated with All-India rainfall, the strengthening TN3 influence must be systematically associated with the weakening Niño 3-All-India relationship in recent decades. This work supports arguments that recent changes in the ENSO-Indian rainfall relationship are not solely related to noise.

scholarly journals Interannual variability of isotopic composition in water vapor over western Africa and its relationship to ENSO

2015 ◽  
Vol 15 (6) ◽  
pp. 3193-3204 ◽  
Author(s):  
A. Okazaki ◽  
Y. Satoh ◽  
G. Tremoy ◽  
F. Vimeux ◽  
R. Scheepmaker ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Southern Oscillation ◽  
Monsoon Season ◽  
Precipitation Amount ◽  
Isotopic Signature ◽  
Atmospheric Environment ◽  
Global Spectral Model ◽  
Near Surface ◽  
Western Africa ◽  
The Relationship

Abstract. This study was performed to examine the relationship between isotopic composition in near-surface vapor (δ18Ov) over western Africa during the monsoon season and El Niño–Southern Oscillation (ENSO) activity using the Isotope-incorporated Global Spectral Model. The model was evaluated using a satellite and in situ observations at daily to interannual timescales. The model provided an accurate simulation of the spatial pattern and seasonal and interannual variations of isotopic composition in column and surface vapor and precipitation over western Africa. Encouraged by this result, we conducted a simulation stretching 34 years (1979–2012) to investigate the relationship between atmospheric environment and isotopic signature on an interannual timescale. The simulation indicated that the depletion in the monsoon season does not appear every year at Niamey. The major difference between the composite fields with and without depletion was in the amount of precipitation in the upstream area of Niamey. As the interannual variation of the precipitation amount is influenced by the ENSO, we regressed the monsoon season averaged δ18Ov from the model and annually averaged NINO3 index and found a statistically significant correlation (R = 0.56, P < 0.01) at Niamey. This relationship suggests that there is a possibility of reconstructing past western African monsoon activity and ENSO using climate proxies.

Monitoring Agricultural Drought in Australia

2005 ◽  
Author(s):  
Kenneth A. Day ◽  
Kenwyn G. Rickert
Keyword(s):  
Agricultural Production ◽  
Southern Oscillation ◽  
Rainfall Variability ◽  
Government Policies ◽  
Primary Producers ◽  
The Past ◽  
North East ◽  
The North ◽  
Eastern Australia ◽  
The 1960S

Since European settlement of Australia began in 1788, drought has been viewed as a major natural threat. Despite warnings by scientists (e.g., Ratcliffe, 1947) and many public inquiries, government policies have, in the past, encouraged closer land settlement and intensification of cropping and grazing during wetter periods. Not surprisingly, drought forms part of the Australian psyche and has been well described in poetry, literature (e.g., Ker Conway, 1993), art, and the contemporary media (newspapers and television). Droughts have resulted in social, economic, and environmental losses. Attitudes toward drought in Australia are changing. Government policies now consider drought to be part of the natural variability of rainfall and acknowledge that drought should be better managed both by governments and by primary producers. Nonetheless, each drought serves as a reminder of the difficult challenges facing primary producers during such times. We begin this chapter with a brief overview of drought in Australia and its impacts on agricultural production, the environment, rural communities, and the national economy. We outline some of the ways governments and primary producers plan for and respond to drought and describe in detail an operational national drought alert system. Australia has mainly an arid or semiarid climate. Only 22% of the country has rainfall in excess of 600mmper annum, confined to coastal areas to the north, east, southeast, and far southwest of the country (http://www.bom.gov.au/climate/ahead/soirain.shtml). Australia also has high year-to-year and decade-to-decade variation in rainfall due, in part, to the influence of the El Niño/Southern Oscillation (ENSO) phenomenon (http://www.bom.gov.au/climate/ahead/soirain.shtml). The Interdecadal Pacific Oscillation (IPO) also contributes to the rainfall variability at annual and decadal scales and modulates ENSO impacts on rainfall (Power et al., 1999). The current geographic boundaries of agricultural production were reached in the late 19th century, and the entire agricultural region has experienced drought, in some form, over the past 100 years. Protracted dry periods occurred during the period from late 1890s to 1902 in eastern Australia, during the mid to late 1920s and 1930s over most of the continent, during the 1940s in eastern Australia, during the 1960s over central and eastern Australia, and during 1991–95 in parts of central and northeastern Australia.

Climatic variability and change over southern Africa: a reflection on underlying processes

1997 ◽  
Vol 21 (1) ◽  
pp. 23-50 ◽  
Author(s):  
S.J. Mason ◽  
M.R. Jury
Keyword(s):  
Southern Africa ◽  
Southern Oscillation ◽  
Rainfall Variability ◽  
Climatic Variability ◽  
Sea Surface ◽  
Annual Rainfall ◽  
Eastern Equatorial Pacific ◽  
Moisture Fluxes ◽  
Sea Surface Temperature Anomalies

Quasi-periodicities in annual rainfall totals over southern Africa have been identified; in particular, an approximately 18-year cycle may be related to interdecadal variability in sea-surface temperatures in the eastern equatorial Pacific and central Indian Oceans. A 10-year cycle along the south coast is related to variability in standing wave 3. Atmospheric anomalies associated with wet and dry years can be related to changes in the frequency, intensity and persistence of important rainfall-producing weather systems and highlight the significance of the strength of the continental heat low and the preferred locations and amplitudes of the westerly troughs. El Niño Southern Oscillation events and sea-surface temperature anomalies in the Indian and South Atlantic Oceans can influence both the tropical and the temperate atmospheric circulation and moisture fluxes over the subcontinent and thus are significant influences on rainfall variability. Evidence for long-term climatic change is not as definitive as in the Sahel, although there are indications of desiccation in some areas since the late-1970s. Increases in temperatures are of approximately the same magnitude as the hemispheric trends and may be attributable to the enhanced greenhouse effect.

scholarly journals A re-examination of ENSO/ anti-ENSO events and simultaneous performance of the Indian summer monsoon

MAUSAM ◽  
2021 ◽  
Vol 47 (1) ◽  
pp. 59-66
Author(s):  
J. CHATTOPADHYAY ◽  
R. BHATLA
Keyword(s):  
Monsoon Rainfall ◽  
Southern Oscillation ◽  
Monsoon Season ◽  
Strong Association ◽  
Enso Events ◽  
The Pacific ◽  
Degree Of Confidence ◽  
High Degree ◽  
The Relationship ◽  
Very High

The relationship between ENSO/anti-ENSO events in the Pacific basin and simultaneous all India monsoon has been re-examined for the period 1901-1990 using Southern Oscillation Index (SOI). The result shows that there is fairly strong association between ENSO events and dry monsoon years. There exists a weak teleconnection between anti-ENSO events and wet monsoon indicating that anti-ENSO events have only a moderate impact on the Indian monsoon rainfall. Developing ENSO (anti-ENSO) episodes during the monsoon season indicates non-occurrence of simultaneous floods (droughts) with a very high degree of confidence 70 (50) percent of the droughts (floods) during the above period have occurred during ENSO (anti-ENSO) events indicating that extreme monsoon activities in the form of droughts (floods) might be important factors for the occurrence of simultaneous ENSO/anti-ENSO events.

scholarly journals The Role of the Dominant Modes of Precipitation Variability over Eastern Africa in Modulating the Hydrology of Lake Victoria

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Kara A. Smith ◽  
Fredrick H. M. Semazzi
Keyword(s):  
East Africa ◽  
Southern Oscillation ◽  
Lake Victoria ◽  
Rainfall Variability ◽  
Precipitation Variability ◽  
Eastern Africa ◽  
Annual Rainfall ◽  
Lake Victoria Basin ◽  
The Relationship

Previous water budget studies over Lake Victoria basin have shown that there is near balance between rainfall and evaporation and that the variability of Lake Victoria levels is determined virtually entirely by changes in rainfall since evaporation is nearly constant. The variability of rainfall over East Africa is dominated by El Niño-Southern Oscillation (ENSO); however, the second and third most dominant rainfall climate modes also account for significant variability across the region. The relationship between ENSO and other significant modes of precipitation variability with Lake Victoria levels is nonlinear. This relationship should be studied to determine which modes need to be accurately modeled in order to accurately model Lake Victoria levels, which are important to the hydroelectric industry in East Africa. The objective of this analysis is to estimate the relative contributions of the dominant modes of annual precipitation variability to the modulation of Lake Victoria levels for the present day (1950–2012). The first mode of annual rainfall variability accounts for most of the variability in Lake Victoria levels, while the effects of the second and third modes are negligible even though these modes are also significant over the region.

scholarly journals Rainfall variability related to sea surface temperature anomalies in a Pacific–Andean basin into Ecuador and Peru

2013 ◽  
Vol 33 ◽  
pp. 53-62 ◽  
Author(s):  
L. Pineda ◽  
V. Ntegeka ◽  
P. Willems
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Coastal Plain ◽  
Southern Oscillation ◽  
Rainfall Variability ◽  
Sea Surface ◽  
Atmospheric Forcing ◽  
Temperature Anomalies ◽  
Sea Surface Temperature Anomalies ◽  
Instrumental Records

Abstract. The spatiotemporal modes of seasonal rainfall variability and their relation with sea surface temperature anomalies (SSTA 1.2 indices) are examined in the transition from the coastal plain towards the western Andes cordillera in southern Ecuador/northwestern Peru using instrumental records (1970–2000) collected from the Catamayo–Chira basin. A multi-criteria data analysis is conducted within different elevation ranges. The criteria involve rotated principal components, cross correlations and temporal changes of anomalies in rainfall quantiles. The results confirm that SSTA 1.2 indices influence rainfall variability over the coastal plain (< 510 m a.s.l.) where forcing is dominant within December–May. The El Niño Southern Oscillation also plays a role inland of the coastal plain where a region of ENSO-like rainfall variability is found on the southeastern part of the basin (4°30'–5° S/79°15'–80° W) within March–May (MAM). This suggests that inland distance and elevation are only partial controls of ocean–atmospheric forcing up to ~ 1300 m a.s.l. Our analysis also provides evidence of the SSTA 1.2 indices influence in a large altitudinal range ~ 1400–2700 m a.s.l. confined to the southeastern basin. This region is found consistently perturbed by ENSO within MAM. We conclude that geo-morphological features of the southwestern Ecuadorian Andean ridges play a twofold role in the control of ocean–atmospheric forcing. They can modulate the atmospheric circulation, leading to a dissipation of the signal, or they might favor meteorological processes, leading to enhancement of orographic precipitation. This would explain the observed ENSO signals in instrumental records at locations as high as 2700 m a.s.l.

Klein with Lacan: A Study on the Reception of Lacanian Ideas in Uruguay and Its Effects on Clinical Practices (1955–82)

2020 ◽  
Vol 22 (3) ◽  
pp. 341-361
Author(s):  
Gonzalo Grau-Pérez ◽  
J. Guillermo Milán
Keyword(s):  
Clinical Practice ◽  
Clinical Material ◽  
Clinical Practices ◽  
Before And After ◽  
The Difference ◽  
The 1960S ◽  
The Relationship ◽  
Discursive Approach ◽  
The Way ◽  
Clinical Cases

In Uruguay, Lacanian ideas arrived in the 1960s, into a context of Kleinian hegemony. Adopting a discursive approach, this study researched the initial reception of these ideas and its effects on clinical practices. We gathered a corpus of discursive data from clinical cases and theoretical-doctrinal articles (from the 1960s, 1970s and 1980s). In order to examine the effects of Lacanian ideas, we analysed the difference in the way of interpreting the clinical material before and after Lacan's reception. The results of this research illuminate some epistemological problems of psychoanalysis, especially the relationship between theory and clinical practice.

The Fragmentation of the Palestinian Political Field

2018 ◽  
Vol 11 (1-2) ◽  
pp. 189-216
Author(s):  
Jamil Hilal
Keyword(s):  
Women Workers ◽  
Political Leadership ◽  
The Political ◽  
Political Field ◽  
Cultural Field ◽  
National Representation ◽  
1960S And 1970S ◽  
The 1960S ◽  
Palestinian National Movement ◽  
The Relationship

The mid-1960s saw the beginnings of the construction of a Palestinian political field after it collapsed in 1948, when, with the British government’s support of the Zionist movement, which succeeded in establishing the state of Israel, the Palestinian national movement was crushed. This article focuses mainly on the Palestinian political field as it developed in the 1960s and 1970s, the beginnings of its fragmentation in the 1990s, and its almost complete collapse in the first decade of this century. It was developed on a structure characterized by the dominance of a center where the political leadership functioned. The center, however, was established outside historic Palestine. This paper examines the components and dynamics of the relationship between the center and the peripheries, and the causes of the decline of this center and its eventual disappearance, leaving the constituents of the Palestinian people under local political leadership following the collapse of the national representation institutions, that is, the political, organizational, military, cultural institutions and sectorial organizations (women, workers, students, etc.) that made up the PLO and its frameworks. The paper suggests that the decline of the political field as a national field does not mean the disintegration of the cultural field. There are, in fact, indications that the cultural field has a new vitality that deserves much more attention than it is currently assigned.

Rendimento de grãos de soja e de milho, no Rio Grande do Sul, não difere entre eventos El Niño Oscilação Sul

Agrometeoros ◽  
2018 ◽  
Vol 26 (1) ◽  
Author(s):  
Ronaldo Matzenauer ◽  
Bernadete Radin ◽  
Alberto Cargnelutti Filho
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Rio Grande ◽  
La Niña ◽  
Rio Grande Do Sul ◽  
La Nina ◽  
Significant Difference ◽  
Income Data ◽  
The Relationship

O objetivo deste trabalho foi avaliar a relação entre o fenômeno El Niño Oscilação Sul - ENOS e o rendimento de grãos de soja e de milho no Rio Grande do Sul e verificar a hipótese de que os eventos El Niño são favoráveis e os eventos La Niña são prejudiciais ao rendimento de grãos das culturas. Foram utilizados dados de rendimento de grãos dos anos agrícolas de 1974/75 a 2016/17, e relacionados com as ocorrências de eventos ENOS. Foram analisados os dados de rendimento observados na colheita e os dados estimados com a remoção da tendência tecnológica. Os resultados mostraram que não houve diferença significativa do rendimento médio de grãos de soja e de milho na comparação entre os eventos ENOS. Palavras-chave: El Niño, La Niña, safras agrícolas. Abstract – The objective of this work was to evaluate the relationship between the El Niño Southern Oscillation (ENSO) phenomenon with the grain yield of soybean and maize in Rio Grande do Sul state, Brazil and to verify the hypothesis that the El Niño events are favorable and the La Niña events are harmful to the culture’s grain yields. Were used data from the agricultural years of 1974/75 to 2016/17, and related to the occurrence of ENOS events. We analyzed income data observed at harvest and estimated data with technological tendency was removed. The results showed that there was no significant difference in the average yield of soybeans and corn in the comparison between events.

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