How many people know where Tokelau is? I didn't before I became involved in an international oceanographic experiment to study an amazing and important natural wonder 5 kilometers below the surface of the ocean just east of Tokelau. Here almost all of the coldest, densest water that forms at the surface far away in the North Atlantic and off the coast of Antarctica flows north through a narrow gap in an otherwise blocking ridge system that spans the Pacific. This gap is called the Samoan Passage. When oceanographers typically think of deep or abyssal flows, the words sluggish and laminar come to mind---meaning no turbulence and no mixing. Though we expected some acceleration of the flow here, what we found when were were sampling this flow for 40 days this past July and August was that it was like a raging river---but with flow about 40 times the peak flow of the Amazon. About 6 million metric tons per second. We observed phenomenon here that are usually only seen in vigorous tidal flows in coastal regions---things such as "hydraulic jumps" and extremely elevated turbulence levels. Why do we care? Well, climate models can't resolve places like the Samoan Passage and so have to use much simpler approximations to account for these places. What we learn will hopefully improve these models and our understanding of how the Earth's climate system works. Another goal is to detect any long-term changes in deep water properties---and this spot is ideal for this because it is essentially collecting water from the entire South Pacific. That is, instead of measuring water properties at 100 different locations, we can just measure it in several in the Samoan Passage and essentially get the same information about long-term trends in temperature, salinity and other water properties. For more info about this cool place go to wavechasers.uw.edu.
Janus - låter denna plats fantastiskt! Har du några videoklipp eller foton du kan dela med oss? Också - 40 dagar på en båt?? Det är en lång tid! Grattis :-)
Sure do. Photo of the ship is in Apia, Western Samoa as is one of rowers.