| 翻訳と辞書 |
| Cold core ring ： ウィキペディア英語版 |
Cold core ring
Cold-core rings are a type of oceanic eddy, which are characterized as unstable, time-dependent swirling ‘cells’ that separate from their respective ocean current and move into water bodies with different physical, chemical, and biological characteristics.〔Lochte, K. and O. Pfannkuche. 1987. Cyclonic cold-core eddy in the eastern North Atlantic. II. Nutrients, phytoplankton and bacterioplankton. Marine Ecology Process Series, Vol. 39; 153-164.〕 Their size can range from 1 mm to over 10,000 km in diameter with depths over 5 km.〔Steele, J., K. Turkian, and S. Thorpe. (ed.). 2001. Mesoscale Eddies. Encyclopedia of Ocean Sciences, Academic Press. Print. Vol. 3; 1717-1730.〕 Cold-core rings are the product of warm water currents wrapping around a colder water mass as it breaks away from its respective current. The direction an eddy swirls can be categorized as either cyclonic or anticyclonic depending on the hemisphere. A counterclockwise movement of water in the Northern hemispheres is cyclonic, but the same counterclockwise movement is anticyclonic in the Southern hemisphere (Yasuda, 2000). Although eddies have large amounts of kinetic energy, their rotation is relatively quick to diminish in relation to the amount of viscous friction in water. They typically last for a few weeks to a year.〔 The nature of eddies are such that the center of the eddy, the outer swirling ring, and the surrounding waters are well stratified and all maintain their distinct properties throughout the eddy’s short time-scale.〔The Ring Group. 1981. Gulf Stream cold-core rings: their physics, chemistry and biology. Science, Vol. 212;1091-1100.〕
== Formation ==
The governing forces of an eddy are very dependent on its size. Small eddies are largely governed by viscosity and direction of a water body.〔 However larger eddies are formed from a balance between the horizontal pressure gradient force, arising from differences in densities of the meeting water masses, and the Coriolis force.〔Mittelstaedt, E. 1987. Cyclonic cold-core eddy in the eastern North Atlantic. I. Physical description. Marine Ecology Process Series, Vol. 39; 145-152.〕 Due to the turbulent nature of the earth’s oceans, eddies can be found almost everywhere. Mesoscale eddies are usually seen in areas of intense, winding currents such as the Gulf Stream and the Antarctic Circumpolar Current that feeds into the South Pacific and Indian oceans, but in general can be caused by a combination of factors such as cooling of sea surface temperature, convection, direct generation from wind, or water flow past an irregular coastline.〔 Cycolic cold-core eddies are frequently formed at the polar front by the Gulf Stream and Labrador Current.〔 The cold, nutrient-rich waters from the Labrador Sea flow south and get caught in the eastward meandering of the Gulf Stream, traveling east across the Atlantic Ocean.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Cold core ring」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|