Layers of salty ocean water mix with layers of fresher water, creating a salty staircase or layering driven by small-scale convection known as salt fingers. Although scientists have known about salt fingers since 1960, when they were discovered at the Woods Hole Oceanographic Institution, they have not understood their role in ocean mixing and the ability of the ocean to absorb heat, carbon dioxide and pollutants from the atmosphere. Results of a new experiment, sponsored by the National Science Foundation and reported in todays issue of Science, indicate that salt fingers are vertically mixing ocean waters more than previously thought. The finding will improve understanding of how water masses in the ocean mix, leading to better climate prediction models.
Researchers from the Woods Hole Oceanographic Institution (WHOI) studied salt fingers by injecting a dye or tracer into the ocean, much like dyes are used in medical tests to trace bodily fluids. The tracer was released from an injection sled towed at a depth of approximately 400 meters (about 1,200 feet) from a ship in the tropical Atlantic near Barbados. Returning to the area nine months later, they found a significant vertical spread of the tracer indicating an enhanced mixing process, with salt and the tracer mixing twice as much as heat.
In this region, warm, high salinity subtropical water lies over cooler, fresher water flowing northward from Antarctica, creating a unique stratification with distinct layers of water. As many as ten to fifteen layers, each 10 to 30 meters thick (roughly 30 to 90 feet) with uniform temperature and salinity, are separated by interfaces with rapidly changing temperature and salinity, half a meter to 5 meters (about 2 feet to 10 feet) thick, to form a "thermohaline staircase" of sorts. The process known as salt fingers occurs at the interfaces and keeps the mixed layers uniform.
Shelley Dawicki | EurekAlert!
Arctic melt ponds form when meltwater clogs ice pores
24.01.2017 | University of Utah
New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg
A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
24.01.2017 | Physics and Astronomy
24.01.2017 | Life Sciences
24.01.2017 | Health and Medicine