Wednesday, November 30, 2016

The Southern Ocean: The Last Great Mystery

Hi there! My name is Greta Shum and I'm asking, "What's going on in the Southern Ocean?"

That's the question that's bugging scientists all over the world--and not just oceanographers. Climate scientists have realized that the Southern Ocean, the little-known ocean surrounding Antarctica, is a major part of the story of climate change. And the Southern Ocean Carbon and Climate Observations and Modeling Project (or SOCCOM) has set out to study it!

It's very possible that you haven't heard of the Southern Ocean. If that's the case, here's a map:



And that trail of markers is where I'll be going this winter--but not alone! I'll be on a boat with a team of scientists, who will be using new technology to observe this amazing place... but I'll get to that later.

First let's talk about the Southern Ocean! What's important about this particular ocean is how unique and powerful it is. Because of its location, the Southern Ocean is one of the only places in the world where deep, cold, nutrient-rich water, flowing south from other oceans, finally rises to the surface and interacts with the atmosphere.

Then at the surface, that ancient water in the Southern Ocean can absorb excess carbon dioxide and heat from the atmosphere. (I say it's "ancient" because sometimes this deep water hasn't seen the sun for centuries!)

At certain times, though, the Southern Ocean will also expel carbon dioxide from the water into the air, increasing the amount of greenhouse gases in the atmosphere, and contributing to overall global warming. Read more about that here.

So as you can see, the Southern Ocean is a bit unpredictable. It can act both as a carbon sink and a carbon ... faucet (so to speak). From what scientists have observed so far, the Southern Ocean can actually absorb up to 50% of all the carbon dioxide that the global oceans take up and 75% of all the heat absorbed by the oceans. That's a big portion!

What scientists would like to do is understand exactly which mechanisms will be dominant in the future--will we see more absorption of carbon dioxide in the future or will we see an overall switch? Is there a limit on how much carbon dioxide it can absorb? Will it start to slow down its absorption? In order to find out, we need to develop a clearer picture of how the Southern Ocean works.

Ideally scientists would like to have enough data to build reliable models of the ocean.

But, there are some hiccups. Of all the places in the world to do science, the Southern Ocean is probably one of the worst! In the past scientists have taken water samples from aboard enormous research vessels, which can only sample once at any one location and, because of the rough seas and powerful winds, only go to the Southern Ocean during the austral (or southern hemisphere) summer. Scientists have had so much trouble taking measurements in the Southern Ocean that this place, despite its critical importance to climate change, remains very much a mystery.

In fact, one way to think about the Southern Ocean is to see it as Mordor from the Lord of the Rings by J. R. R. Tolkien.

For those of you who don't know-- Mordor is the the area occupied by (the evil) Sauron in Tolkien's fantasy series. It's protected on three sides by mountain ranges which makes it difficult to access. The rub is that inside Mordor is a very critical player--Mount Doom, which is the only place where Frodo (our hero) can destory the ring.


That's of course where we come in! Much like the fellowship in the Lord of the Rings, a band of scientists and videographers are making the journey from the southern tip of Chile across the Southern Ocean toward the largest American station in Antarctica, McMurdo Station.

The mission?

To deploy a new technology that will allow scientists to observe the Southern Ocean remotely and over time.

Here's what that technology looks like:

Photo Credit to Isa Rosso

This float is about as tall as a person, and is designed to ...float... in the Southern Ocean. Over the course of our time in the Southern Ocean, the team of scientists I'm accompanying will deploy 12 of these floats, each of them equipped with sensors that measure the "vital signs" of the Southern Ocean.

How much carbon dioxide, oxygen, nitrate, biological matter, etc. is in the water?

So far, the scientists have deployed 51 floats in the Southern Ocean, and if you'd like to see what they're seeing, you can look at the data here!

We set sail from Punta Arenas, Chile on December 24.

Right now, I'm packing my warmest clothing and planning my trip to Punta Arenas. When I arrive there, I'll check in with you again.

As we deploy these 12 floats, I'll be keeping you updated right here! I'll also tweet and post on Instagram with any updates. It's going to be an adventure, and even though you're not with me, I'll be your eyes and ears. And if you'd ever like to ask me a question while I'm out here, just post a comment, and I'll do my best to find an answer.

See you in Chile!

Greta

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