Synopsis: How Ice Bridges Form

New theoretical work predicts the conditions under which sea ice will clog a narrow channel to create a natural bridge across it.
Synopsis figure
NASA Worldview

In the straits and channels of the Canadian Arctic Archipelago, chunks of sea ice jam and form frozen bridges nearly every winter. These natural walkways may help polar bears and other animals reach previously inaccessible areas. And they may affect local as well as global climate by preventing ice flow into warmer oceans. Yet there isn’t much knowledge about how ice bridges form. Bhargav Rallabandi and Howard Stone from Princeton University, New Jersey, and colleagues have now developed a theoretical model that details some of the conditions necessary for ice-bridge formation. What’s more, the authors say that the model might also be applicable to the jamming of dense granular flows in confined geometries.

The team modeled the motion of a layer of sea ice along a narrow Arctic-like channel with a length much larger than its width. The flow of the layer is driven by an external wind that acts on its top surface, but it’s also hindered by water drag on the bottom surface and by internal stresses. The researchers assumed that these internal stresses, which depend on the channel width and the thickness and compactness of the ice field, dominate the water drag for jammed ice. Under this assumption, the model predicts that, for a given wind stress and minimum and maximum widths of the channel, an ice bridge will only form beyond some critical thickness and compactness of the layer. These critical thresholds may prove useful in predicting ice-bridge formation and breakup in a warmer world with thinner ice and slower winds.

This research is published in Physical Review Letters.

–Ana Lopes

Ana Lopes is a Senior Editor of Physics.


Features

More Features »

Announcements

More Announcements »

Subject Areas

GeophysicsFluid DynamicsSoft Matter

Previous Synopsis

Semiconductor Physics

Straining After Quantum Dots

Read More »

Next Synopsis

Quantum Information

Traveling with a Quantum Salesman

Read More »

Related Articles

Focus: Why Sediments Are So Uniform
Fluid Dynamics

Focus: Why Sediments Are So Uniform

A new theory suggests that sedimenting particles of irregular shape will drift horizontally as they fall, a result that may resolve a long-standing puzzle. Read More »

Focus: Making Rogue Waves with Wind and Water
Fluid Dynamics

Focus: Making Rogue Waves with Wind and Water

Wind-generated waves in a ring-shaped water tank can spontaneously grow into single behemoth waves, mimicking a poorly understood ocean phenomenon.   Read More »

Synopsis: Small Particles Untangle Polymer Chains
Soft Matter

Synopsis: Small Particles Untangle Polymer Chains

Adding nanoparticles to molten polymer disentangles its constituent molecular chains, allowing them to flow more easily. Read More »

More Articles