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Leigh G. Orf

University of Wisconsin-Madison

Atmospheric Sciences


Lawrence R. Frank, Vitaly L. Galinsky, Leigh Orf, and Joshua Wurman (2018): Dynamic Multiscale Modes of Severe Storm Structure Detected in Mobile Doppler Radar Data by Entropy Field Decomposition, Journal of the Atmospheric Sciences, American Meteorological Society, Vol 75, Num 3, pp709-730


Leigh Orf, Robert Wilhelmson, Bruce Lee, Cathy Finley, and Adam Houston (2017): Evolution of a Long-Track Violent Tornado Within a Simulated Supercell, Bulletin of the American Meteorological Society, American Meteorological Society, Vol 98, Num 1, pp45


Matthieu Dorier, Gabriel Antoniu, Franck Cappello, Marc Snir, Robert Sisneros, Orcun Yildiz, Shadi Ibrahim, Tom Peterka, and Leigh Orf (2016): Damaris: Addressing Performance Variability in Data Management for Post-Petascale Simulations, ACM Transactions on Parallel Computing, Association for Computing Machinery (ACM), Vol 3, Num 3, pp15:1--15:43
Matthieu Dorier, Robert Sisneros, Leonardo Bautista Gomez, Tom Peterka, Leigh Orf, Lokman Rahmani, Gabriel Antoniu, and Luc Bouge (2016): Adaptive Performance-Constrained in Situ Visualization of Atmospheric Simulations, IEEE, 2016 IEEE International Conference on Cluster Computing (CLUSTER), pp269-278, Taipei, Taiwan
Leigh Orf, Robert Wilhelmson, and Louis Wicker (2016): Visualization of a Simulated Long-Track EF5 Tornado Embedded Within a Supercell Thunderstorm, Parallel Computing, Elsevier BV, Vol 55, pp28--34


Leigh G. Orf (2017): Simulating The Most Devastating Tornadoes Embedded within Supercell Thunderstorms, 2017 Blue Waters Annual Report, pp82-83

2015 Blue Waters Symposium highlights successes, looks to the future of supercomputing

May 29, 2015

The 2015 Blue Waters Symposium, held May 10-13 at Oregon's beautiful Sunriver Resort, brought together leaders in petascale computational science and engineering to share successes and methods. Around 130 attendees, many of whom were Blue Waters users and the NCSA staff who support their work, enjoyed presentations on computational advances in a range of research areas—including sub-atomic physics, weather, biology, astronomy, and many others—as well as keynotes from innovative thinkers and leaders in high-performance computing. Over the three days of the symposium, 58 science teams from across the country presented on their work on Blue Waters.


Takeaways from the Milwaukee HPC User Forum

Sep 19, 2017

Milwaukee’s elegant Pfister Hotel hosted approximately 100 attendees for the 66th HPC User Forum (September 5-7, 2017). In the original home city of Pabst Blue Ribbon and Harley Davidson motorcycles the agenda addressed artificial intelligence, self-driving vehicles and drug repositioning. Innovation Award Winners Paul Morin (The Polar Geospatial Center University of Minnesota) and Leigh Orf (University of Wisconsin at Madison). Dr. Morin caught my attention when he claimed he could use all possible cycles in the world to analyze geospatial mapping of the poles. ... His plan is to process 80 trillion pictures of the entire arctic at a resolution of two meters. Then repeat – effectively providing time-dependent photography that can track changes in elevation. He uses Blue Waters as a capacity machine today but its scheduler had to be rewritten to handle thousands of job launches.


Into the Vortex: Megacomputers and the Quest to Understand Superstorms

Nov 1, 2017

At the edge of emerald fields of corn and soybeans sits the National Peta­scale Computing Facility, the crown jewel of the University of Illinois at Urbana–Champaign. The 88,000-square-foot glass-­covered facility looks like a fancy convention center, and it’s surrounded by a black steel fence strong enough to stop a speeding Mack truck. Past a retina scanner and through a heavy-gauge steel door resides a computer named Blue Waters. It’s big—spanning 10,000 square feet—and it’s made up of 288 matte-black rack towers that house the 27,000 nodes that are the key to its power. Each node holds two microprocessors, not unlike a stripped-down PC but faster than anything you’ll find at Best Buy. Since powering up in 2013, Blue Waters has been one of the few computers in the world capable of processing the biggest of big data sets, encompassing everything from the evolution of the universe to the global spread of flu pandemics. It’s also one of the only machines in the world that can model the staggering complexities of a supertornado, which is exactly what an atmospheric scientist named Leigh Orf spent the better part of 2013 failing to do.


YT Project Awarded NSF Grant to Expand to Multiple New Science Domain

Aug 11, 2017

The yt Project, an open science environment created to address astrophysical questions through analysis and visualization, has been awarded a $1.6 million dollar grant from the National Science Foundation(NSF) to continue developing their software project. This grant will enable yt to expand and begin to support other domains beyond astrophysics, including weather, geophysics and seismology, molecular dynamics and observational astronomy. It will also support the development of curricula for Data Carpentry, to ease the onramp for scientists new to data from these domains.


How scientists modeled a deadly tornado with an insanely powerful computer

Jun 27, 2017

Supercell thunderstorms are giant tempests with powerful rotating updrafts at their cores—and one out of every four or five spawn tornadoes. Most of these twisters are little, but some can grow fierce. To predict the rare killers, and thus give more targeted warnings, meteorologists need to better understand how tornadoes form. But simulating a supercell thunderstorm and the tornado it produces involves hundreds of terabytes of data—an amount so vast that Leigh Orf, an atmospheric scientist at the University of Wisconsin at Madison, had to use a supercomputer to make it happen.


To save lives, supercomputers dive into the hearts of nature’s worst tornadoes

Apr 14, 2017

Leigh Orf chases tornadoes across America’s central plains, but not from inside a pickup truck. His preferred vehicle is a computer. Orf, a University of Wisconsin-Madison meteorologist, creates computer simulations of supercell thunderstorms — and the twisters they spawn — from the safety of his lab. Even when they don’t yield twisters, supercells are some of the most powerful and deadly forms of severe weather, and like many in his field, Orf wants to understand their inner mechanics. He and his team use Blue Waters — one of the most powerful supercomputers in the world — to run many of their models.


Beautifully Recreated Digital Disaster

Apr 5, 2017

A tornado can give you goose bumps that you just cannot stop. It has the world at its feet, literally! Tornado is found in most part of world today due to the changing climatic conditions. The U.S. is one of the most commonly tornado struck regions. The constant tornados in the regions have encouraged the scientist Leigh Orf from the Cooperative Institute for Meteorological Satellite Studies of the University of Wisconsin to look into the concerning matter. To get detailed and intense information regarding this dark tunnel of destruction is something next to impossible. But, the current advancement in the field of technology and science has helped build tools such as the supercomputers in order to get the things next to impossible right.


Researcher and Supercomputer Re-Create Historic Tornado

Mar 28, 2017

With tornado season fast approaching or already underway in vulnerable states throughout the U.S., new supercomputer simulations are giving meteorologists unprecedented insight into the structure of monstrous thunderstorms and tornadoes. One such recent simulation recreates a tornado-producing supercell thunderstorm that left a path of destruction over the central Great Plains in 2011. The person behind that simulation is Leigh Orf, a scientist with the Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin–Madison. He leads a group of researchers who use computer models to unveil the moving parts inside tornadoes and the supercells that produce them.


Researchers create mesmerizing tornado simulation algorithm

Mar 21, 2017

The world of meteorological forecasts has changed dramatically over the years. There’s a lot more statistics and mathematical modelling than most people realize. Basically, by taking the observations from weather stations at ground level over land and from weather buoys at sea and applying the equations of fluid dynamics and thermodynamics, numerical models are created — and those numerical models are the core of weather forecasting. Numerical models have become a core aspect of many fields of research, but rarely have they been as prevalent as in weather and climate science. It’s not just forecasts, they allow us to understand complex phenomena — such as tornadoes. ... Leigh Orf, an atmospheric scientist at the University of Wisconsin-Madison, wants to unravel the secrets of a tornado, and for that he needs much more than a laptop — he needs a supercomputer.


Check Out the Most Detailed Tornado Simulation So Far

Mar 16, 2017

George Dvorsky at Gizmodo reports that the team led by University of Wisconsin-Madison atmospheric scientist Leigh Orf, created a model of the category 5 “El Reno” tornado that cut a 63-mile swath through Oklahoma in May 24, 2011, staying on the ground for two hours and killing nine people. Using the Blue Waters Supercomputer at the University of Illinois at Urbana-Champaign, Orf and his team loaded observed data into the machine, including temperature, wind speed, air pressure, moisture, wind shear and other factors. The simulation shows how these conditions combined to create a super cell, which eventually spawned El Reno, a process called “tornadogenesis” or the creation of a twister.


Supercomputer re-creates the perfect storm

Mar 18, 2017

One of the precedents of a tornado is a natural phenomenon known as a supercell, which is a deep, rotating updraft in the atmosphere. It is a condition that can spawn one or more high-intensity tornadoes that can often achieve wind speeds in excess of 200 Km/h. The force of these super storms is immense enough to upturn cars and rip out houses from their foundations, leaving a trail of devastation in their wake. To attain a clearer picture of what goes on inside these tornadoes, scientists at the University of Wisconsin-Madison recently simulated one of the most powerful storms to hit the United states in recent history: a storm that hit Oklahoma on 24 May 2011.


Come watch a supercomputer simulation of a devastating tornado

Mar 16, 2017

When Leigh Orf, an atmospheric scientist at the University of Wisconsin-Madison, strives to unravel the mysteries of tornado formation, he needs something way bigger than a laptop. Phenomena like the huge, supercell thunderstorms he studies involve such vast amounts of data, only a supercomputer will do. Orf wants to answer what he said is a key question in meteorology: “Why do some of these storms produce these devastating tornadoes?" To get at the answer, he turned to simulation.


Stunning new tornado simulation may help meteorologists unlock their secrets

Feb 22, 2017

Weather experts are calling it the most realistic computer simulation of a tornado ever created. Dr. Cathy Finely at Saint Louis University played a big role in making it happen. She is part of a team of meteorologists from around the country that are working together to bring this simulated tornado to life. “What we are trying to do is model supercell thunderstorms, which are the rotating thunderstorms that produce tornadoes and tornadoes at a very high resolution,” says Finley.


“Making Of..” Behind the Scenes Mini-Documentaries

Nov 11, 2016

Dr. Leigh Orf, a scientist from the University of Wisconsin, tells us how he designed the most detailed supercomputer models of a tornadic thunderstorm ever produced. Robert Stein, Michigan State University describes how he got interested in stars and used computing to uncover the secrets of our sun.


Super Tornado

Jan 7, 2016

May 22nd, 2011. A powerful tornado cut a mile-wide swath through Joplin, Missouri. It was the costliest tornado disaster in history, with insured losses close to two billion dollars. It was also one of the deadliest, with 161 lives lost… and one thousand injured. What did scientists learn when they peered into the realm of this SuperTornado? Dr. Leigh Orf, a scientist from the University of Wisconsin, tells us how he designed the most detailed supercomputer models of a tornadic thunderstorm ever produced.


Supercomputer storm blurs the lines between sim and reality

Aug 15, 2015

There's movie special effects and then there's this: a new supercomputer visualization that's so real, it actually blurs the line between simulation and reality. ... There's movie special effects and then there's this: a new supercomputer visualization that's so real, it actually blurs the line between simulation and reality.


CMU meteorologist shares expertise at National Center for Supercomputing Applications

Apr 13, 2015

Central Michigan University meteorologist Leigh Orf was one of four researchers nationwide, selected from among 200 teams, invited to speak at the National Center for Supercomputing Applications conference celebrating the second birthday of its Blue Waters supercomputer. ​ Blue Waters is one of the most powerful supercomputers in the world. Orf and his research team used Blue Waters to create a first-of-its-kind, spectacular 3-D simulation of a long-track EF5 tornado and the supercell thunderstorm that spawned it. ​


Celebrating Blue Waters

Apr 7, 2015

On April 6, U.S. Sen. Mark Kirk (R-IL) convened a celebration in honor of the second birthday of NCSA’s Blue Waters supercomputer, which is used by scientists and engineers across the country to tackle challenging research for the benefit of science and society. In kicking off the event, Kirk highlighted the importance of Blue Waters—and of continuing investment in high-performance computing. ... A panel of Blue Waters users—four from among the 200 teams across the country that have used the system—then briefly described how the supercomputer accelerates their research:


Modeling Mother Nature

Jul 9, 2013

What occurs within a thunderstorm that leads to the formation of destructive weather events such as tornadoes and downbursts? Leigh Orf of Central Michigan University, NCSA’s Robert Wilhelmson, and Eric Savory of the University of Western Ontario are utilizing an idealized cloud model designed specifically for massively parallel architectures (CM1) to model storms and hoping that advances in supercomputing power will bring them closer to answers.


When tornadoes attack

Apr 6, 2010

In many ways, tornadoes remain a mystery. While their powerful winds can leave broad swaths of devastation—damaged and destroyed homes and businesses, injuries and fatalities—twisters are a challenge for atmospheric scientists to study. It's difficult (not to mention hazardous) to be in the exact right place at the precisely the right time to see one in action, and models that capture all of the critical small-scale details within a dynamic storm system are computationally demanding. That's where the sustained-petaflop Blue Waters supercomputer comes into the picture. The University of Illinois' Bob Wilhelmson is the principal investigator for a Petascale Computing Resource Allocation project.


Breakthrough simulation: A supercell producing a long-track EF5 tornado

Jun 18, 2014

Long-track EF5 tornadoes, like the one that touched down in 2011 in Joplin, Missouri, US, are the longest-lived and most destructive of their kind. Most have wind speeds that reach more than 200 miles (322 kilometers) per hour and create major devastation. These tornadoes are also the most rare, which makes studying them all the more difficult. Using Blue Waters at the National Center for Supercomputing Applications (NCSA) at the University of Illinois, US, scientists have created the first simulation of a long-track EF5 tornado — including the supercell thunderstorm that spawned the tornado.