Twisters can appear in the ocean as well as in the atmosphere. Atmospheric twisters have short lifetime; they move at enormous speeds and are often very destructive. Underwater twisters are calmer, they can be detected only by means of special devices, but they slowly mix ocean waters and influence climate at a global scale.
The scientists from Pacific Oceanology Institute (Vladivostok) observe underwater twisters for more than ten years. These underwater twisters appear upon the confluence of two largest currents in the West of Pacific – Kuroshio Current and Oyashio Current. The twisters form in the east of Japan and, absorbing water masses from the very bottom to the surface, move northward along the Kurile-Kamchatka deep trench. They are moving slowly, at a rate of 1cm/s, and live for several months. The core of a twister is located at the depth of 400-600 meters – it consists of waters, captured during twister formation and transferred to great distances.
The scientists have paid attention to cyclic cataclysms occurring in the Far East in the last quarter of 20th century. In 1976, for example, a severe drought has occurred in the Primorski Krai, after which more and more rains have been detected reaching their maximum in 1992; another drought in 1997, then precipitation increase and powerful floods in 2000. The same year precipitation total in Korea and Japan has reached its maximum for the whole observation period since 19th century. Thus, for two summer days more than 80 cm of precipitation have come down. Nearly the same amount of precipitation is detected in Vladivostok for the whole year. Another record had been set up late fall of 2000, when a very deep cyclone with the pressure of 950 mbar in its centre has formed to the northwest of the Pacific. It caused the wreck of the “Ryasan” ship in the Bering Sea on November 6, 2000. May be we should blame the global warming for such catastrophes.
And what happens to the ocean at this time? The ocean gets warmer in its Arctic zones, the fact confirmed by measurement results. Not only currents are to blame for this, but also underwater twisters, which transfer warm and salty ocean waters from the south to the north and directly affect region precipitation. Unique observations of twisters from Russian, Canadian and Japanese ships allowed the scientists to state – for recent ten years twisters transfer larger amounts of warm and salty water from southern parts of the ocean, and their size and velocity has grown significantly. One of the twisters was a long-liver; since 1886 it has been moving to the northeast along the Kurile-Kamchatka deep trench for five years. Its energy source still remains a mystery.