The Beginning of the Endeavour
In the early 1891, a traveler named S.M. Scott was staying near Talara in northwestern Peru when clouds started building on the horizon. He described the extraordinary season of torrential rains and a transformed landscape as “a low-hanging, densely clouded sky, intense heat … The rain fell in inconceivable torrents for weeks… If the sea was full of wonders, the land was even more so … the desert became a garden.” These were his vivid observations, and they captured a phenomenon known to locals for centuries: El Niño.
Since the 16th century, Spanish colonists in South America had written about these años de abundancia, when torrential rains made the desert bloom. Named after the Christ Child due to its tendency to occur around Christmas, it is a periodic warming of sea surface temperatures in the central and eastern Pacific Ocean. Yet, its impacts ripple globally, bringing torrential rains to the deserts of Peru, droughts to Asia, and altering weather patterns across continents! But El Niño and our understanding has evolved, shaped not just by scientists but also by everyday observers – a true testament to the power of citizen science.
Historical Roots of Citizen Science
Before modern meteorology, much of what we knew about climate came from the meticulous records kept by sailors. These 19th-century navigators documented sea temperatures, wind patterns, and unusual weather phenomena in their logbooks. Their observations, driven by necessity rather than scientific inquiry, laid the groundwork for understanding El Niño and its broader patterns.
These historical records have become invaluable for climate research. For instance, wind observations from ship logbooks between 1815 and 1854 have been used to reconstruct indices of the El Niño Southern Oscillation (ENSO), helping scientists understand its historical variability. The insights gained from these documents demonstrate the immense value of consistent and widespread data collection, even when conducted by non-specialists.
Critical Discovery by Gilbert Walker: The Southern Oscillation
Back then, the monsoon season was understood to deliver water that sustains crops, livestocks, and its people throughout much of Asia. However, a few times in a generation, as-of-yet unexplained and inconsistent weather patterns led to devastating famines that claimed millions of lives.
In 1903, Gilbert Walker, a mathematician and director general of the Indian Meteorological Department, set out to solve the puzzle of India’s monsoons. Predicting the monsoon failures became a pressing scientific challenge! Meteorologists at the time were still mostly observing local weather conditions and hazarding short-term limited forecasts. Thus, to grapple with a phenomenon the size of the monsoon, Walker needed to zoom way out, beyond the bounds of the science as it stood, to seek data and patterns on a much larger scale, across time as well as distance. To do so, Walker mobilized observers across the British Empire, using the telegraph to collect atmospheric pressure, rainfall, and temperature data from scattered stations.
Through years of systematic observation and statistical analysis, Walker identified a see-saw pattern in atmospheric pressure between the Indian Ocean and the Pacific, which he named the Southern Oscillation. He discovered that this oscillation had influenced rainfall patterns thousands of miles away, laying the foundation for our modern understanding of ENSO.
Creation of the Full Picture by Jacob Bjerknes
By 1957, El Niños in Peru were still thought to be a local quirk. However, Norwegian-American meteorologist Jacob Bjerknes went on and built on Walker’s work. With more sophisticated sampling techniques than Walker had in his prime, they found that the telltale slug of warm water wasn’t limited to the Peruvian coast. In fact, it extended thousands of miles into the middle of the Pacific. It was Bjerknes’s first hard clue that El Niños in Peru might be just one expression of a trans-Pacific phenomenon, and that the Southern Oscillation of atmospheric pressure might be associated with similar geographical shifts in sea surface temperature!
In essence, El Niño was not just a regional phenomenon but part of a global climate system, where an anomalously warm spot in the eastern Pacific can weaken the east-west temperature difference, disrupting trade winds, which push warm water to the west. The result is increasingly warm water toward the east, which in turn reinforces the weakening of the trade winds in a self-sustaining feedback loop. This interconnected dynamic profoundly impacts weather patterns across the globe, cementing El Niño as a cornerstone of our understanding of global climate systems.
Modern Citizen Science and El Niño
Today, the spirit of collaboration that marked Walker and Bjerknes’ work lives on in modern citizen science initiatives. Through the power of technology and public participation, modern projects aim to study El Niño and its impacts in extensive detail.
Today, as climate change accelerates, understanding El Niño has never been more critical. With El Niño in full force from mid-2023 to mid-2024, global temperatures have broken records for 12 months in a row. Furthermore, as one of the strongest El Niño events on record, it was likely the main culprit of unprecedented heat, floods and droughts worldwide. Scientists even predict that warming oceans may increase the frequency and intensity of El Niño events in the coming years, leading to more extreme weather patterns worldwide.
However, much of what we know of climate science is still deeply uncertain. To reconstruct our climate history, we implore you to join us at Monsoon Voyages, as we aim to illuminate Southeast Asia’s climate history through digitising ship’s logbooks, uncovering past historical rainfall patterns!
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