<div style="text-align:justify">El Ni&ntilde;o events are large climate disturbances which are originated within the equatorial Pacific, and occur in every 2 to eight years. The developed phase of El Ni&ntilde;o is characterized by unusual warm waters at the ocean surface, from the coasts of Peru and Ecuador to the middle of the equatorial Pacific. This phenomenon is caused by strange weakening of the trade winds blowing westward, which allows warm surface waters to reverse their direction eastward. The climatic impacts of El Ni&ntilde;o are amplifying throughout the planet which may show several effects on regional weather. it&rsquo;s related with wide-ranging changes within the climate system and may cause prominent socio-economic impacts affecting infrastructure, agriculture, health and energy sectors. albeit El Ni&ntilde;o appears within the region of tropical Pacific; it&rsquo;s impact on the worldwide climate and weather phenomena like drought/flooding and tropical storms. the traditional status within the equatorial Pacific is modified due to the raise in greenhouse gases which in turn leads to El Ni&ntilde;o Southern Oscillation (ENSO) changes. we are able to assure that ENSO variations will endure and influence the worldwide climate within the coming decades and centuries. Hence, forecasting and interpreting ENSO conditions are essential to both the scientists and therefore the public. during this paper, the occurrence of El Ni&ntilde;o and its impact on global climate and socio-economic status has been studied and reviewed from literature.</div>

ENSO - A Review

Background:&nbsp;The Long Xuyen Quadrangle (LXQ) serves as a critical cornerstone of rice production within the Vietnamese Mekong Delta, yet a paradox currently exists where traditional monotonic statistical tests classify the region&rsquo;s rainfall as &ldquo;stable,&rdquo; contradicting farmers&rsquo; reports of intensifying water scarcity due to climate change. 
 
Methods:&nbsp;This study resolves this discrepancy by investigating the spatiotemporal evolution of rainfall (1984-2022) using the Advanced Innovative Trend Analysis (ITA) method, contrasted with the standard Mann-Kendall (MK) test and analyzing teleconnections to identify asymmetric ENSO modulation on local hydrology. 
 
Result:&nbsp;While MK tests showed no significant trends for inland stations (p&gt;0.05), ITA successfully unmasked a critical &ldquo;hidden&rdquo; drying trend in the lower rainfall quantiles, implying that &ldquo;dry years are becoming drier&rdquo; Spatially, coastal stations (Ha Tien, Rach Gia) exhibit accelerated drying trends driven by weakening Southwest Monsoon circulation. Teleconnection analysis reveals a robust, asymmetric ENSO modulation: El-Ni&ntilde;o phases reduce dry-season rainfall by up to 41.2%, whereas La-Ni&ntilde;a phases fail to provide an equivalent compensatory surplus (increasing only by 20.1%). 
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Asymmetric ENSO Modulation on Hidden Drying Trends in the Vietnamese Mekong Delta: Implications for Rice Security and Scarcity-based Adaptation