Internal waves happen because the ocean is layered. Deep water is cold, dense, and salty, while shallower water is warmer, lighter, and fresher.
出现内波是因为海洋是分层的，深层水更凉，密度高而且含盐量高，浅层水更暖和，密度小而且更淡。
2
She was in the habit of going out on the balcony at the end of the day. She would take a chair and lean her mouth against the cold and salty iron of the railing.
她习惯每天晚上到外面的阳台上去，搬把椅子坐下，把嘴巴靠在冰冷咸涩的铁栏杆上。
3
However the sites are too warm for frozen carbon dioxide, and in some regions too cold for pure, non-salty water.