Eddies Team Up to Give Life to Ocean

Ocean Storm Chilico

For the first time in history Double Eddies have proven to exist. A new study revealed that they can transport vast amounts of water as well as move fish and other species a great distance. They have been measured to last as much as 6 months, travel the distance and take on great speeds.

Newsweek reported on December 27 that double whirlpools have been found “spinning across hundreds of miles in the ocean”.

In the ocean as well as in lakes and other bodies of water -whirlpools or eddies are a well documented phenomenon. However, double whirlpools where only matter of theory for oceanographers and mathematicians. On paper physics said double whirlpools could exists but they had not been spotted nor documented until now.

In the Ocean, the movement of water is everything...ocean currents, tides, swells, changes of temperature, thermoclines, mixing of nutrients, the list goes on and on. Ocean movement is the chain reaction to life in the ocean in all forms.

“For the first time, the phenomenon of a double whirlpool has been observed. The discovery was made by a team of scientists at the University of Liverpool, and serves as a confirmation of an occurrence that was only theoretically possible for decades,” Newsweek reported

Chris Hughes -Oceanographer from the University of Liverpool and lead author of the speaks...

“Ocean eddies almost always head to the west, but by pairing up they can move to the east and travel ten times as fast as a normal eddy, so they carry water in unusual directions across the ocean.”

Hughes used satellite data to register for the first time in history double whirlpools -also known as Modons. With a strong focus on Australia and the Tasman Sea the study released soon picked up the attention of the International Scientific Press.

In an interview with Popular Science, Hughes elaborated on his find.

“I happened to notice one little feature down in the Tasman Sea that was behaving very strangely compared to everywhere else…Almost all these eddies drift slowly westwards, but this little feature was going quickly eastwards.”

Hughes assures that double whirlpools are not as rare nor as strange either. They managed to capture image and data from several of them streaming across the ocean in a short period of time.

The discovery was documented in a paper in Geophysical Research Letters in December. The paper is co-authored by Peter Miller, of Plymouth Marine Laboratory in the UK.

Authors believe that the whirlpools travelling in pairs are capable of transporting microorganisms, small marine creatures and even fish through great distances in space and time. This could in fact lead to even larger marine organisms to feel attracted to this forward speed movement.  

“It’s quite possible there are shoals of particular types of fish following these eddies for their special conditions,” Hughes adds.“Fish would actually actively follow the eddies by choice because of what’s in them.”

The Paper titled “Rapid Water Transport by Long-Lasting Modon Eddy Pairs in the Southern Mid Latitude Oceans,” takes to detail to water flow in the ocean and double whirlpool´s importance.

“Water in the ocean is generally carried with the mean flow, mixed by eddies, or transported westward by coherent eddies at speeds close to the long baroclinic Rossby wave speed. Modons -dipoleeddy pairs are a theoretically predicted exception to this behavior, which can carry water to the east or west at speeds much larger than the Rossby wave speed, leading to unusual transports of heat, nutrients, and carbon,” the paper reads.

“We provide the first observational evidence of such rapidly moving modons propagating over large distances. These modons are found in the midlatitude oceans around Australia, with one also seen in the South Atlantic west of the Agulhas region. They can travel at more than 10 times the Rossby wave speed of 1–2cms-1 and typically persist for about 6 months carrying their unusual water mass properties with them,before splitting into individual vortices, which can persist for many months longer…” they kick it.

Rotating masses of water -underwater tornadoes are very common in the ocean but unlike these double whirlpools have the power to travel ten times faster due to the interconnected behaviour.

Connected underwater by a U-shaped vortex they are physically capable of slurping up marine animals and ferry them great distances. Questions such as how do they form, and why they behave as they do begin to rise.

Water inside double whirlpools such as in eddies carry different temperatures and nutrient content that the surrounding water through which they glide. Much like upwellings they can be seen as a vital influx of abiotic factors of life.

“Eddies which form the double whirlpool are rich in nutrients,” Huges says.

Huges today still is in doubt on areas where these double whirlpools team up. "I’ve looked at other areas of other oceans but I’ve only seen them in the oceans around Australia, plus one in the South Atlantic," Hughes told the press.

In this the first time recorded in history, double whirlpools where registered to last as much as 6 months moving over 1 thousand kilometers in different directions.

“This changes the way heat, nutrients, and carbon are transported in parts of the ocean. Most eddies drift to the west at or around a particular speed that depends on latitude, faster near the equator, and slower near the poles (about 1–2 km/d at midlatitudes). However, it has long been theoretically predicted that eddies can sometimes pair up in a way that allows them, like smoke rings, to travel much faster, to the east as well as west, staying together for a long time. For the first time, using satellite measurements of sea level, we have seen these eddy pairs, called modons, traveling over long distances in the oceans. Eight pairs are seen around Australia and one in the South Atlantic. They travel at about 10 times the typical eddy speed, over distances of 1,000 km or more, stirring up the surface temperatures as they pass and lasting for about 6 months before splitting up,” Huges writes it off.

Using satellite data and satellite imagery in his study Huges was able to identify a total of nine modons which he described as the clearest ones. The study used data that ranged from 1993 to 2016.

“Eddies are beneficial to the oceans because of how they churn nutrients in the deeper parts of the oceans. Phytoplankton feed on those nutrients, which is crucial as they're the starting point of the food chain,” Glenn Flierl, professor of oceanography science at Massachusetts Institute of Technology who was not involved in the research, told Newsweek.

“My thinking is that these linked, fast-moving eddies could ‘suck-up’ small marine creatures and carry them at high speed and for long distances across the ocean…You would get particular blobs of water where the biology and the conditions are totally different from the surrounding area. It’s quite possible there are shoals of particular types of fish following these eddies for their special conditions. Fish would actually actively follow the eddies by choice because of what’s in them.” Hughes kick it in Popular Science.