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El Niño Ready Nations and Disaster Risk Reduction

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Introduction

The Lessons Learned Portal Project is a recommendation by participants of the February 2015 Expert Forum in Antalya, Turkey, a gathering of more than 90 participants that focused on “Lessons Learned about Lessons Learned about Hydro-meteorological Disaster Risk Reduction in a Changing Climate.”

The initial objective of the Portal Project, which began in the Fall of 2015, was to assess the value of establishing an international, open-access, web-based platform -- a clearing house – for countries to share their hydrometeorological disaster risk reduction (DRR) experiences and lessons identified as well as learned.

At the very beginning of the Portal Project, the onset of an El Niño of “Godzilla proportion” was forecast by various international meteorological centers to emerge by late 2015 and continue into 2016. The 2015-16 El Niño forecast came with strong statistical support, a probability hovering around the 90 percent level. It was shaping up to be an extraordinary event, popularized in the media as a “Godzilla El Niño” to rival the 1997-98 “El Niño of the Century.”

The “Godzilla” forecast had followed a previous forecast of a major El Niño that appeared to be developing but failed to become a full-blown event in mid-Spring 2014. Rather than announce that the expected 2014 El Niño failed, forecasters referred to it in retrospect as a “borderline weak El Niño.” CCB took advantage of the opportunity to combine two research activities by making the 2015-16 El Niño review an integral part of the Portal Project.

A team of researchers came together to focus on the real-time responses to the forecasts and the impacts of El Niño in 15 countries in Asia, Latin America and SubSaharan Africa, countries affected to some degree during the 2015-16 event. The combined activity was renamed “Lessons Learned Portal Project for El Niño Ready Nations (ENRNs): A Stepping Stone toward ENSO-related DRR Lessons Learning.” To an attentive public, the following story about El Niño is likely known. They’ve read about it, track its progress in news clips, videos, etc.

"ENSO" refers to the El Niño/Southern Oscillation, the interaction between the atmosphere and ocean in the tropical Pacific that results in a somewhat periodic variation between below-normal and above-normal sea surface temperatures and dry and wet conditions over the course of a few years. While the tropical ocean affects the atmosphere above it, so too does the atmosphere influence the ocean below it. One layer of the Pacific Ocean that is influenced by ENSO is the thermocline.

The thermocline marks the transition between the warm upper water and the cold deep water in the Pacific Ocean. The upward currents along the equator (or upwelling) are strongest across this transition zone. The depth of the thermocline has a direct relationship with water surface temperatures. When the thermocline is closer to the water surface, upwelling of cold, nutrient rich deep-water is transported up from the bottom layers, leading to cooler temperatures at the water surface. The interaction of the atmosphere and ocean is an essential part of El Niño and La Niña events (the term coupled system is often used to describe the mutual interaction between the ocean and atmosphere).

During an El Niño, sea level pressure tends to be lower in the eastern Pacific and higher in the western Pacific while the opposite tends to occur during a La Niña.

This see-saw in atmospheric pressure between the eastern and western tropical Pacific is called the Southern Oscillation, often abbreviated as simply the SO.

Since El Niño and the Southern Oscillation are related, the two terms are often combined into a single phrase, the El Niño-Southern Oscillation, or ENSO.

Often the term ENSO Warm Phase is used to describe El Niño and ENSO Cold Phase to describe La Niña.

Meta-Observations

In the 400 or so pages in the full study document, CCB identified many factors meriting more discussion, eight of which are briefly described below. These factors influence one’s perceptions and thoughts about hydro-meteorological forecast credibility and accuracy and can in turn adversely affect timely preparedness. They present obstacles to effective disaster risk reduction. Each factor was encountered in the Project’s country, region and city studies about the 2015-16 El Niño event.