英语语法分析

Siberian clod downwelling is from surface dive to near CMB;

西伯利亚下降流，规模大，从地表下降到下地幔下部；

In spring, weak upwelling exists in the river mouth, whereas in summer downwelling occurs in steep area north and south of the mouth.

春季在长江口近岸存在弱上升流，夏季长江口外的陡坡区出现下降流，而长江口以北和以南的陡坡区出现上升流。

Reasonable results have been obtained from these experiments: both upwelling and downwelling light show exponential attenuation with increasing depth;

大部分数据显示， 水下上行光和下行光对深度有良好的指数衰减；