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Researchers at the University of Nebraska-Lincoln are trying to better understand severe weather. They have teamed up with several universities around the country, including Texas Tech University and the University of Colorado, to study storms by flying fixed-wing aircraft drones into supercell thunderstorms and tornadoes over the Great Plains. Brandon McDermott of NET News sat down with the lead researcher at UNL, Dr. Adam Houston, to discuss what has happened thus far and what researchers are looking for going forward.
Brandon McDermott, NET News: With your research, how did the focus turn to severe spring and summer weather over the Great Plains?
The research team ready for an oncoming storm. (Photo courtesy Adam Houston, UNL)
Dr. Adam Houston, University of Nebraska-Lincoln researcher: The great plains tend to be the place in the world where severe weather is most common. It's a great laboratory, but our intent here is to use this laboratory to better understand severe weather and use the technology we have at our disposal and that we've developed to do so.
McDermott: You called the Great Plains a "laboratory,” can you explain why this is such a great place to study severe storms and why you used this for your research?
Houston: We know that it's a hotbed for severe weather, but that's not an accident. It has geographically and meteorologically the confluence of several features that make for severe weather. Number one, we have the Gulf of Mexico, which is a long ways away from Nebraska sure, but that air travels long distances. It is a very warm body of water and the air that sits over the body of water acquires the moisture and warmth of that water.
The air gets drawn up into Nebraska. It has a lot of energy and it can fuel the thunderstorms. The other thing that happens, because of the Rockies and because the way they're oriented north-to-south, they tend to support the rapid development of these large-scale systems, not the thunderstorms, but the parent systems that within which the thunderstorms develop.
Adam Houston wrote the following after returning from a two-week long research excursion across the Great Plains in June with the team:
During the first two weeks of June, our group, composed of UNL, the University of Colorado Boulder, and Texas Tech University, operated a fleet of research instruments throughout the Great Plains region of the United States.
Our operations extended as far south as the Oklahoma Panhandle and as far north as North Dakota, covering a distance of more than 4,000 miles in the process. Instrument platforms included drones, mobile mesonets, and mobile radars. Highlights of the operations period include coordinated data collection (data collection involving all assets) near the base of the mesocyclone of a strong supercell near Norris, South Dakota and data collection involving mobile radars and mobile mesonets on a Mesoscale Airmass with High Theta-E (MAHTE) and it's possible interaction with a super-cell in the Oklahoma Panhandle.
We also had the chance to engage in a number of extemporaneous conversations with curious “passer-bys” along the way. It was good to describe what we were doing and share our enthusiasm for our work. One such encounter in North Dakota led to a free meal (grilled burgers and brats!) for the entire crew (all 36 of us!) provided by a generous local farmer (thanks again, “North Dakota Dave”!).
Overall, the lack of severe weather during our operations period (a time period selected months before based on climatology) made for a challenging field season. Nevertheless, the data collected over the last two field seasons can hopefully be used to better assess the viability of operational targeted surveillance of severe storms.
The rapid development means that you get explosive development of thunderstorms provided that this energy is available.
McDermott: How about the drones that you're using in this research, talk a little bit about that as well as some of the goals of the study.
Houston: For this particular project the type of unmanned aircraft they were using as a fixed-wing aircraft, in contrast to what most people are probably familiar with which is the multi-rotor -- it has three, four, five or six rotors on it – it goes up and down and may be able to move laterally. The aircraft they were using are more like a regular aircraft, of course much smaller and without a person on board.
The reason we do that is because you can get much longer flight times with a fixed-wing aircraft than with a rotary-wing aircraft. It's a challenge to get anything more than about 30 or 40 minutes of flight time with a rotary-wing aircraft. With a fixed-wing aircraft that we use we can get upwards of three, four, five or six hours. So, that gives us a lot of flexibility and in the kind of work that we do it's almost a prerequisite. With the fixed-wing aircraft we can fly across features in the atmosphere that we're trying to sample, we can fly into areas that are not accessible, because we have this long flight time we can launch in a safe location and move towards hazardous locations.
So in terms of the goals for this particular study, the aim is to move the bar forward or up towards a point where we're using fixed-wing unmanned aircraft for targeted surveillance of severe storms – to go towards storms not just to understand them, but actually to improve predictability.
The team gets ready to release the drone into the sky. (Photo courtesy Adam Houston, UNL)
McDermott: You've been working on this study for several years. What have you found thus far?
Houston: One of the sub objectives of this work is to determine where in a supercell thunderstorm – these are the thunderstorms that typically produce most of the strongest tornadoes – where you would sample a supercell thunderstorm to improve predictability. We can get an aircraft into the storm, but is it in the right place? Is the data that are being collected valuable?
This is actually kind of maybe paradoxically something that you don't even have to fly an aircraft to determine. What we do is we fly a synthetic aircraft and model data so we take a very sophisticated numerical model that has all the equations to predict the movement and the evolution of the atmosphere. We “fly” an aircraft through this model and determine where if we collected data in the model we could actually improve predictability.
McDermott: How does your understanding of severe storms change during this process?
Houston: The problem of determining where you fly in a storm – even in a model world – has been much more difficult than I expected. I think we're moving forward and I'm excited about the future, I know we have some big things planned for the future. I hope we can get the funding to execute them and hopefully this isn't the last time we have this conversation.