Eddies Warm Up The Ocean

Eddies appear in the ocean like in the atmosphere. Atmospheric eddies are short-lived, extremely speedy, and often very hazardous. Oceanic eddies are slower and can be observed only with the use of special equipment, but these eddies gently mixing ocean waters affect the climate in general.

For more than ten years specialists from the Pacific Institute of Oceanology in Vladivostok have observed the oceanic eddies formed at the confluence of two largest undercurrents in the west of the Pacific Ocean, Kuroshio and Oyashio. These eddies are generated to the east of Japan and move to the north along the Kuril-Kamchatka Trench involving water masses from the bottom to the surface.

The velocity of eddies is not high, about 1 cm per second, and their lifetime is several months. At a depth of 400-600 meters, there is a `core` of the eddy, i.e., the water captured at the time of its birth and transported to a significant distance.

The scientists noticed that periodic cataclysms occurred in the Far East within the last quarter of the past century. For instance, there was a severe drought in the Primorsky Territory in 1976, then the amount of precipitation increased year by year and reached a maximum in 1992. The next drought occurred in 1997 and it was followed by an increase in precipitation and strong floods of 2000. That year was marked by the greatest sum of precipitation for the whole period of observations in Japan and Korea since the 19th century. More than 80 cm of precipitation fell within a period of two days in summer. Approximately the same amount of precipitation falls in Vladivostok annually.

Another record was established in the late autumn of 2000, when a very deep cyclone with a pressure of 950 millibar in the center appeared in the northwest of the Pacific Ocean. It caused the wreck of the Vladivostok motor ship “Ryazan” in the Bering Sea on November 6, 2000. Apparently, such accidents on the earth are connected with the global warming.

And what happens to the ocean at the present time? It becomes warmer in its Arctic regions, as is proved by the results of measurements. And not only currents are responsible for that, but also eddies carrying heat and salt of deep layers of the ocean from the south to the north, as the humidity of an area directly depends on these characteristics. On the basis of unique observations on eddies from Russian, Canadian, and Japanese ships, the scientists established that the eddies brought the increasing amounts of warm salty water from the southern parts of the ocean, and their dimensions and velocities grew considerably within the last decade. One of the eddies was an old-timer, it was moving along the Kuril-Kamchatka Trench to the northeast for a period of 5 years since 1986. What served as its energy source still remains a mystery.