El Niño and our ships: the ocean is changing course

We hardly notice it here in the Netherlands, but at sea, El Niño is anything but an abstract concept. Ships sailing internationally, such as the Tecla and the Bark Europa, are currently experiencing the effects of this climate phenomenon in the Pacific Ocean.

El Niño is a natural climate system in which the seawater in the eastern part of the tropical Pacific Ocean temporarily warms up. According to the US National Oceanic and Atmospheric Administration (NOAA), this causes the trade winds to weaken and alters ocean currents and wave patterns worldwide. This leads not only to extreme weather on land, but also to noticeable changes at sea, such as unusual swell directions and unpredictable wind systems.

Experiences on board

On board both the Tecla and the Bark Europa, these changes become very real. In their logbooks, the crews describe how, near Rapa Nui (Easter Island), waves come from unusual directions, sometimes making it impossible to land for days on end. Small ‘windows’ of favourable weather must be exploited to get supplies or crew on and off the ship at all. As the Tecla notes: ‘The power of the waves’ makes it clear just how decisive ocean conditions are for every movement of the ship.

The Bark Europa confirms this picture in its logbook, which describes how conditions surrounding arrival and disembarkation are heavily influenced by the sea and swell. Such observations are consistent with scientific findings: during El Niño, wave patterns and wind systems shift, which can have a major local impact on navigation and coastal access (NOAA Climate.gov).

Polynesians and the discovery of Rapa Nui through El Niño?

It is interesting to note that these changing conditions also raise historical questions. Some researchers suggest that El Niño periods in the past may have contributed to the great Polynesian voyages of discovery. Changing wind directions may have made islands that were normally upwind — such as Rapa Nui — temporarily more accessible. The first inhabitants of Rapa Nui (Easter Island) almost certainly came from Polynesia. Archaeological and genetic research suggests that they reached the island around the year 1200 AD, following an immense ocean voyage of thousands of kilometres.

What makes this remarkable is that these were not accidental drifts. The Polynesians were master navigators. They deliberately sailed across the open ocean, without instruments, but using their knowledge of the stars, waves and wind patterns. Researchers believe that the expedition to Rapa Nui probably set out from islands in Eastern Polynesia, such as Mangareva. Experimental voyages — for example, using traditional canoes — have shown that this route is indeed feasible.  Rapa Nui is extremely remote, situated on the edge of the so-called ‘Polynesian Triangle’. It is precisely for this reason that the journey is regarded as one of the greatest achievements in maritime history: purposeful navigation to a tiny island in the middle of the ocean.

For seafarers, El Niño is therefore not a theoretical concept, but a direct factor influencing routes, planning and safety. As the phenomenon develops further, the coming months will reveal just how significant its impact on the Pacific Ocean will be this time.

Photo above: The anchorage as seen from the Europa
Photo on the right: Tecla at anchor
Chart: NOAA

Earlier in Windassist: Panama Canal dry due to El Niño 

Sources:
NOAA Climate.gov
Bark Europa logbook
Tecla logbook
Cambridge|
Science Direct