More accurate tropical cyclone prediction model developed

ScienceDaily (Nov. 18, 2011) — Researchers at the Naval Research Laboratory Marine Meteorology Division (MMD), Monterey, Calif., have developed the Coupled Ocean/Atmosphere Mesoscale Prediction System Tropical Cyclone (COAMPS-TC™) model, achieving a significant research milestone in predictions of tropical cyclone intensity and structure.

While the predictions of the paths or tracks of hurricanes, more generally referred to as tropical cyclones (TC), have steadily improved over the last few decades, improvements in the predictions of storm intensity have proven much more difficult.

"Over the past two years, the COAMPS-TC model has shown to be the most accurate emerging research model for predicting tropical cyclone intensity," said Dr. Jim Doyle, research meteorologist, NRL Monterey. "There is no better example of these difficult challenges than the intensity predictions for Hurricane Irene this past August."

Producing very accurate intensity predictions during a real-time experimental demonstration of Hurricane Irene, COAMPS-TC intensity errors were six knots on average for a series of three-day forecasts, a clear improvement over the official National Hurricane Center (NHC) forecast and other operational models that ranged from 20-30 knots.

The successful predictions have demonstrated that Numerical Weather Prediction (NWP) models can outperform operational statistical-dynamic models that are based on climatology and previous behavior. It is further believed that NWP models, which explicitly predict the location, dynamics and intensity of a storm, will eventually provide the most promising approach to achieve accurate TC intensity and structure prediction.

Advancing further methodologies used for vortex initialization, data assimilation and representation of physical processes, COAMPS-TC is expected to become fully-operational in 2013 at the Navy's Fleet Numerical Meteorology and Oceanography Center (FNMOC) in Monterey. Considerable advancements have been made to several components of the modeling system including the data assimilation of conventional and special TC synthetic observations, vortex initialization, and representation of key TC physical processes such as air-sea fluxes, clouds and convection.

The COAMPS-TC project will potentially signal a paradigm shift in TC forecasting and is already making a strong impression on the forecasting community. Focusing on the development and transition of a fully coupled air-ocean-wave prediction system, the COAMPS-TC model includes nonhydrostatic atmospheric dynamics, multiple nested moving grids that follow the center of the storm and improved boundary layer and cloud physical parameterizations.

COAMPS-TC was first tested in real-time in support of two field campaigns sponsored by the Office of Naval Research (ONR). The Tropical Cyclone Structure-08 (TCS-08) conducted as part of The Observing System Research and Predictability Experiment (THORPEX) Pacific Asian Regional Campaign (T-PARC) in 2008 and the Impact of Typhoons on the Ocean in the Pacific (ITOP) in 2010, both of which took place in the Western Pacific. Additionally, COAMPS-TC advancements and real-time demonstrations in the Eastern Pacific and Western Atlantic have taken place through collaboration with the National Oceanic and Atmospheric Administration (NOAA) as part of the Hurricane Forecast Improvement Project (HFIP) -- a community-wide effort focused on improving operational hurricane prediction.

In June 2011, COAMPS-TC was one of nine worldwide winners of the inaugural High Performance Computing (HPC) Excellence Award presented at the ISC-11 International Supercomputing Conference in Hamburg, Germany -- an award presented annually to recognize noteworthy achievements by users of HPC technologies. As a result, COAMPS-TC was recognized for achieving 'a significantly improved model for tropical cyclone forecasting.' COAMPS-TC development benefited significantly from the Department of Defense HPC Modernization Program Office (HPCMO) computational assets at the Navy Defense Supercomputing Resource Center (DSRC) at Mississippi's Stennis Space Center.

Increasingly-sophisticated developmental versions of COAMPS-TC will continue to be demonstrated in real-time and in support of the Joint Typhoon Warning Center and the National Hurricane Center. A key additional enhancement will be a fully coupled ocean-atmosphere version in which the NRL Costal Ocean Model (NCOM) and the Wave Watch III (WWIII) will provide the ocean circulation and wave components, respectively.

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Fast high precision eye-surgery robot developed

ScienceDaily (Oct. 27, 2011) — Researcher Thijs Meenink at Eindhoven University of Technology (TU/e) has developed a smart eye-surgery robot that allows eye surgeons to operate with increased ease and greater precision on the retina and the vitreous humor of the eye. The system also extends the effective period during which ophthalmologists can carry out these intricate procedures.

Meenink will defend his PhD thesis on Oct. 31 for his work on the robot, and intends later to commercialize his system.

Filters-out tremors

Eye operations such as retina repairs or treating a detached retina demands high precision. In most cases surgeons can only carry out these operations for a limited part of their career. "When ophthalmologists start operating they are usually already at an advanced stage in their careers," says Thijs Meenink. "But at a later age it becomes increasingly difficult to perform these intricate procedures." The new system can simply filter-out hand tremors, which significantly increases the effective working period of the ophthalmologist.

Same location every time

The robot consists of a 'master' and a 'slave'. The ophthalmologist remains fully in control, and operates from the master using two joysticks. This master was developed in an earlier PhD project at TU/e by dr.ir. Ron Hendrix. Two robot arms (the 'slave' developed by Meenink) copy the movements of the master and carry out the actual operation. The tiny needle-like instruments on the robot arms have a diameter of only 0.5 millimeter, and include forceps, surgical scissors and drains. The robot is designed such that the point at which the needle enters the eye is always at the same location, to prevent damage to the delicate eye structures.

Quick instrument change

Meenink has also designed a unique 'instrument changer' for the slave allowing the robot arms to change instruments, for example from forceps to scissors, within only a few seconds. This is an important factor in reducing the time taken by the procedure. Some eye operations can require as many as 40 instrument changes, which are normally a time consuming part of the overall procedure.

High precision movements

The surgeon's movements are scaled-down, for example so that each centimeter of motion on the joystick is translated into a movement of only one millimeter at the tip of the instrument. "This greatly increases the precision of the movements," says Meenink.

Haptic feedback

The master also provides haptic feedback. Ophthalmologists currently work entirely by sight -- the forces used in the operation are usually too small to be felt. However Meenink's robot can 'measure' these tiny forces, which are then amplified and transmitted to the joysticks. This allows surgeons to feel the effects of their actions, which also contributes to the precision of the procedure.

Comfort

The system developed by Meenink and Hendrix also offers ergonomic benefits. While surgeons currently are bent statically over the patient, they will soon be able to operate the robot from a comfortable seated position. In addition, the slave is so compact and lightweight that operating room staff can easily carry it and attach it to the operating table.

New procedures

Ophthalmologist prof.dr. Marc de Smet (AMC Amsterdam), one of Meenink's PhD supervisors, is enthusiastic about the system -- not only because of the time savings it offers, but also because in his view the limits of manual procedures have now been reached. "Robotic eye surgery is the next step in the evolution of microsurgery in ophthalmology, and will lead to the development of new and more precise procedures," de Smet explains.

Market opportunities

Both slave and master are ready for use, and Meenink intends to optimize them in the near future. The first surgery on humans is expected within five years. He also plans to investigate the market opportunities for the robot system. Robotic eye surgery is a new development; eye surgery robots are not yet available on the market.

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The above story is reprinted from materials provided by Eindhoven University of Technology.

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