The timing could not have been more perfect for this expedition. Kelvin Richards, oceanographer at the University of Hawaiʻi at Mānoa, and his team took full advantage of the strong El Niño conditions during the three-week research cruise in the central equatorial Pacific completed yesterday. The expedition aboard Schmidt Ocean Institute’s research vessel (R/V) Falkor left Majuro, Marshall Islands in late July and completed an 11-day time-series at the equator, giving these researchers their first view of the water profile in this region.
The science team, led by Richards, has completed similar water profiling in the western equatorial Pacific region. However, this is Richards’ first time moving to the central Pacific.
Turbulence moves heat–fuel for the climate engine
Recent research suggests that small-scale turbulence in the ocean plays a critical—and to a certain extent overlooked—role in large ocean processes like El Niño. Accurately modeling how the ocean absorbs and moves heat, via turbulence, for example, is among the greatest challenges for climate change modeling and forecasting of El Niño Southern Oscillations (ENSOs).
The ocean helps to regulate Earth’s temperature with the movement of heat through vertical mixing of the ocean layers. However, ENSO alters typical ocean temperatures with anomalously warm or cold water bands that develop off the western coast of South America, causing climatic changes across the tropics and subtropics. The movement of ocean heat is especially important in understanding ENSO, which spawn weather shifts such as flooding in relatively dry regions of the western U.S., droughts in typically wetter regions in the western Pacific, and the lessening of trades and warmer temperatures in Hawaiʻi.
Equatorial ocean “a special place”
“We are seeing small vertical scale features in the shear present here and perhaps even stronger than in the west, giving an indication that these features are important in turbulent mixing,” Richards explains.
The features that Richards alludes to are produced by a combination of factors including wind blowing across the surface of the ocean. “We are seeing that the equatorial region is a special place for the production of these small vertical scale velocity structures and mixing.”
“Schmidt Ocean Institute is delighted to support this important research with significant implications for our understanding of how small scale mixing processes in the ocean are interconnected with the global climate change,” says Victor Zykov, director of research for Schmidt Ocean Institute.
This expedition comes after six successful collaborative research cruises with the Schmidt Ocean Institute and UH. Several projects completed in 2014 have had meaningful impact, including extensive mapping cruises in the Papahānaumokuākea Marine National Monument and the discovery of several new fish species.
For more information about this and future expeditions, visit the Schmidt Ocean Institute website.
—By Marcie Grabowski