This density difference is an index of ocean stratification.

这种水密度差就是海洋分层的标志。

The most important reason, though, for thinking that global warming will not produce an Arctic feeding frenzy is that it may increase ocean stratification.

但是，认为全球变暖不会使北极成为巨大“经济资源”最重要的原因是，它可能会加剧海洋的分层化。

So changes in ocean stratification in the North Pacific like in the Bering Sea and the Northern North Atlantic Greenland Sea area can change the boundary between the polar ocean and the mid-latitude oceans.

因此，北太平洋如白令海和北大西洋格陵兰海域的海洋分层变化可以改变极地海洋和中纬度海洋之间的边界。