In early March, the strongest wave of tropical convection ever measured (known as the Madden Julian Oscillation) by modern meteorology moved into the western Pacific from Indonesian waters bringing an outbreak of 3 tropical cyclones, including deadly category 5 Pam which ravaged the south Pacific islands of Vanuatu. This extreme outburst of tropical storms and organized thunderstorms pulled strong westerly winds across the equator, unleashing a huge surge of warm water below the ocean surface. Normally, trade winds blow warm water across the Pacific from the Americas to Australia and Indonesia, pushing up sea level in the west Pacific. When the trade winds suddenly reversed to strong westerlies, it was as if a dam burst, but on the scale of the earth’s largest ocean, the Pacific. The front edge of that massive equatorial wave, called a Kelvin wave, is now coming ashore on the Americas.
Last year the largest Kelvin wave ever seen in the Pacific ocean developed in February. After it came ashore and the surge of warm water moved up the Pacific coast, the upwelling of nutrient rich cold water dramatically slowed, and marine life began starving up and down the coast of north America. As the warm water moved north from the equator it merged with an enormous mass of warm stagnant water dubbed “the blob” which had built up in the central north Pacific ocean under the mound of high barometric pressure known as the Pacific high. Because the Pacific high had expanded north of its normal position, possibly because of climate change, warm, stagnant low nutrient water covered a large percentage of the surface of the north Pacific ocean. That stagnant water came ashore on the coast of the Pacific northwest and Alaska as the surge of warm water from the Kelvin wave moved up the California coast. The warm stagnant water lacked nutrients to support the growth of krill and copepods which are at the bottom of the food chain. Species that fed on krill and copepods had little to eat. Juvenile birds were the first to be affected by the lack of food. The west coast marine die off is already a crisis but it’s likely to get much worse this summer and fall as the surge of warm water moves up the coast from the huge Kelvin wave now coming ashore.