Freak Ocean Wave Across the Pacific
However, climate oscillations, even small ones, have a deeper impact on the oceans. They can influence oceanic conditions a mile below. The Telegraph UK calls one newly revealed mechanism a "freak" ocean wave because it travels underwater, with little or no surface expression. This was such a good spin I had to promote it to main title.
In reality, these are periodic Kelvin waves travelling eastward along the equator at the submerged boundary between warm surface water and colder deep water. The forcing mechanism is a small climate oscillation called Madden-Julian Oscillation (MJO). The MJO is El Nino- Southern Oscillation's (ENSO's) little brother. It's a trigger for ENSO that drives the tumultuous weather in the Coral Triangle region around the Philippines and Indonesia.
The MJO is a one to two month cycle of high and low precipitation with associated winds that force a train of equatorial Kelvin waves. The waves cause periodic changes in temperature down to at least 600m, sometimes as deep as 1300m. The lag time between surface flux and deep temperature response is 1-2 weeks. The amplitude of the temperature change in the deep-ocean wave is 3-6 times that of the annual cycle. Currents are also intensified, roughly doubled.
Upon reaching the eastern coastline of the Pacific, these deep ocean waves propagate north and south along the coastline of the Americas. Which leads me to wonder... how do we surf a deep-ocean wave?
