by Staff Writers
Thursday, March 22, 2012
Pollution Dispersion Pattern Prediction Advanced
If it does not predict the dispersion of the pollutants it will certainly point to break points that will naturally retro adjust the modeling to improve its predictive powers. One still has to map flow patterns and we are some ways away from having that information.
Yet with this technique in hand we now have the justification to develop measuring devices that capture that information which would have otherwise been meaningless. Thus flow patterns are predictable and like the weather which is also about flow patterns, there is a clear economic incentive to gather the data. In fact the weather department needs to be able to also spot pollutants as they are the guys with tools and boots on the ground.
We are needing resolution that the weather boys only dream about but the fact remains that they need the resolution also and technology is today able to deliver that resolution.
The shape of things to come
by Staff Writers
Using Lagrangian Coherent Structures scientists at the Univeristy of Miami and McGill University were able to study the internal movements of oil in the Gulf of Mexico, and can use this same methodology in the study of volcanic ash, according to a study published in Proceedings from the National Academy of Sciences. Credit: UM/RSMAS.
When oil started gushing into the
Gulf of Mexico
in late April 2010, friends asked George Haller whether he was tracking its
movement. That's because the McGill engineering professor has been working for
years on ways to better understand patterns in the seemingly chaotic motion of
oceans and air. Meanwhile, colleagues of Josefina Olascoaga in were asking the geophysicist a similar
question. Fortunately, she was. Miami
For those involved in managing the fallout from environmental disasters like the Deepwater Horizon oil spill, it is essential to have tools that predict how the oil will move, so that they make the best possible use of resources to control the spill.
Thanks to work done by Haller and Olascoaga, such tools now appear to be within reach. Olascoaga's computational techniques and Haller's theory for predicting the movement of oil in water are equally applicable to the spread of ash in the air, following a volcanic explosion.
"In complex systems such as oceans and the atmosphere, there are a lot of features that we can't understand offhand," Haller explains. "People used to attribute these to randomness or chaos. But it turns out, when you look at data sets, you can find hidden patterns in the way that the air and water move."
Over the past decade, the team has developed mathematical methods to describe these hidden structures that are now broadly called Lagrangian Coherent Structures (LCSs), after the French mathematician Joseph-Louis Lagrange.
"Everyone knows about the Gulf Stream, and about the winds that blow from the West to the East in
," says Haller,
"but within these larger movements of air or water, there are intriguing
local patterns that guide individual particle motion." Olascoaga adds,
"Though invisible, if you can imagine standing in a lake or ocean with one
foot in warm water and the other in the colder water right beside it, then you
have experienced an LCS running somewhere between your feet." Canada
"Ocean flow is like a busy city with a network of roads," Haller says, "except that roads in the ocean are invisible, in motion, and transient." The method Haller and Olascoaga have developed allows them to detect the cores of LCSs. In the complex network of ocean flows, these are the equivalent of "traffic intersections" and they are crucial to understanding how the oil in a spill will move.
These intersections unite incoming flow from opposite directions and eject the resulting mass of water. When such an LCS core emerges and builds momentum inside the spill, we know that oil is bound to seep out within the next four to six days. This means that the researchers are now able to forecast dramatic changes in pollution patterns that have previously been considered unpredictable.
So, although Haller wasn't tracking the spread of oil during the Deepwater Horizon disaster, he and Olascoaga were able to join forces to develop a method that does not simply track: it actually forecasts major changes in the way that oil spills will move. The two researchers are confident that this new mathematical method will help those engaged in trying to control pollution make well-informed decisions about what to do.
The research was funded by: the U.S. National Science Foundation (NSF), NIH/National Institute of Environmental Health Sciences, NASA, BP/The Gulf of Mexico Research Initiative, and Natural Sciences and Engineering Research Council of Canada (NSERC). The
University of Miami is the largest private research institution in
the southeastern . The University's mission is to
provide quality education, attract and retain outstanding students, support the
faculty and their research, and build an endowment for University initiatives. United