It might not be a mystery you ponder everyday, but it's puzzled scientists for ages: how do deep and mid-depth waters mix in our world's oceans? The answer: giant underwater mountains.
Scientists studying the wild waters around Antarctica discovered that deep and mid-depth waters mix when currents go through the underwater mountains in the Drake Passage, the channel of water that lies between the southern tip of the South American continent and Antarctica.
"A thorough understanding of the process of ocean mixing is crucial to our understanding of the overall climate system," said Andrew Watson, a professor at the University of Exeter.
"Our study indicates that virtually all the mixing in the Southern Ocean occurs in Drake Passage and at a few other undersea mountain locations. Our study will provide climate scientists with the detailed information about the oceans that they currently lack."
The mixing of waters is incredibly important to the environment, as it not only plays a huge role in oceanic currents, but in the trapping of carbon dioxide as well. The mixing of deep and mid-depth seawater helps store carbon dioxide in the oceans, and contributes greatly to lowering carbon dioxide levels in our atmosphere. Carbon dioxide has been identified as one of the leading contributors to rising global temperatures.
The team of researchers arrived at their conclusion by releasing amounts of a tracer chemical in the southeast Pacific and following its path. They found almost no vertical churning in the Pacific Ocean, and the currents mixed only when they flowed through the undersea mountains in the Drake Passage.
You can read the full published study detailing the findings in the journal Nature.