Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How Earth's rotation affects vortices in nature

16.10.2013
French researchers develop sophisticated mathematical model to study the behavior of earthly vortices, like hurricanes and ocean currents

What do smoke rings, tornadoes and the Great Red Spot of Jupiter have in common?


This is a view from above of the growing and spiraling wave field emitted by a geophysical vortex due to the radiative instability. The black circle represents a boundary of the vortex core.

Credit: J. Park/Ecole Polytechnique-CNRS

They are all examples of vortices, regions within a fluid (liquid, gas or plasma) where the flow spins around an imaginary straight or curved axis. Understanding how geophysical (natural world) vortices behave can be critical for tasks such as weather forecasting and environmental pollution monitoring.

In a new paper in the journal Physics of Fluids, researchers Junho Park and Paul Billant of the CNRS Laboratoire d'Hydrodynamique in France describe their study of one such geophysical vortex behavior, radiative instability, and how it is affected by two factors, density stratification and background rotation.

Radiative instability is a phenomenon that alters the behavior of fluid flows and can deform a vortex. The "radiative" tag refers to the fact that it is an instability caused by the radiation of waves outward from a vortex.

"These waves can exist as soon as there is a density stratification -- a variation of densities -- throughout the vertical column of the vortex," Park said. "In this study, we have considered how background rotation -- in this case, the rotation of the Earth -- impacts them."

Examples of density stratification in nature, Park explained, include the decrease in air density as one moves higher in the atmosphere or the increase in water density due to salinity and temperature with increasing ocean depth. "So, the waves in our mathematical model are somewhat analogous to waves on the ocean surface," he said. "Likewise, the impact from background rotation on our modeled waves serves as an equal for the impact of the Coriolis force caused by the Earth's rotation."

"What we learned from our models is that strong background rotation suppresses the radiative instability, a characteristic that had been expected but whose dynamics had never been studied precisely," Park said. "We've now developed a sophisticated mathematical means to explain this phenomenon, and that's important to being better able to study and understand the behavior of geophysical vortices such as hurricanes and ocean currents."

Park said that he and Billant next plan to study instability behaviors in vortices with non-columnar shapes. "For example," he said, "there are pancake-shaped flows called Mediterranean eddies, or meddies, that would be worth studying since we know they affect the mixing of the components that make up the ocean ecosystem."

The article, "Instabilities and waves on a columnar vortex in a strongly-stratified and rotating fluid" by Junho Park and Paul Billant appears in the journal Physics of Fluids. See: http://dx.doi.org/10.1063/1.4816512

ABOUT THE JOURNAL

Physics of Fluids is devoted to the publication of original theoretical, computational, and experimental contributions to the dynamics of gases, liquids, and complex or multiphase fluids. See: http://pof.aip.org

Jason Socrates Bardi | EurekAlert!
Further information:
http://www.aip.org

More articles from Physics and Astronomy:

nachricht Two dimensional circuit with magnetic quasi-particles
22.01.2018 | Technische Universität Kaiserslautern

nachricht Meteoritic stardust unlocks timing of supernova dust formation
19.01.2018 | Carnegie Institution for Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Thanks for the memory: NIST takes a deep look at memristors

22.01.2018 | Materials Sciences

Radioactivity from oil and gas wastewater persists in Pennsylvania stream sediments

22.01.2018 | Earth Sciences

Saarland University bioinformaticians compute gene sequences inherited from each parent

22.01.2018 | Life Sciences

VideoLinks Wissenschaft & Forschung
Overview of more VideoLinks >>>