Though it’s hundreds of miles from the Gulf of Mexico, Texas Tech University has produced one of the leading teams in hurricane wind research.
Lubbock is familiar with weather events that incur strong winds, like tornadoes and haboobs. It gets 100-plus-degree heat, ice storms, floods and everything in between. One weather phenomenon the Hub City doesn't experience, though, is the hurricane. Yet, despite being more than 500 miles from the Gulf of Mexico, Lubbock is home to one of the premier research groups gathering hurricane wind and thermodynamic measurements – Texas Tech University's Hurricane Research Team (TTUHRT).
“I've been with the TTUHRT since its inception in 1998,” said team founder John Schroeder, a professor of atmospheric science in Texas Tech's Department of Geosciences and the senior director of the National Wind Institute (NWI). “It started with my doctoral dissertation. Back in those days, there was almost no data from a landfalling hurricane. I mean, you had flight-level data and things like that offshore, but once it made landfall, the power grid would go down. There would basically be no records on shore.
“So, there was just a general, basic need to take measurements that would help engineers in the early stages to decide whether the wind in a hurricane was structured like the wind in West Texas or if they were completely different. If they were completely different, then that wasn't reflected in building design standards.”
The TTUHRT's mission
The lack of information of the wind field produced during a hurricane troubled Schroeder. So, the mission of the TTUHRT is to take measurements of the wind field to better understand the core risk associated with hurricanes.
“If you start with a blank slate and you really don't know what happened in these storms, then it's very difficult to understand the damage patterns and make improvements in engineering design or draw conclusions from any other research agenda that depends on assessed storm strength,” Schroeder said. “If you have no concept, or a very limited concept of what the actual wind field looked like, you're just guessing.
“It's like the foundational building block of information that impacts every other research avenue that comes afterward. What happened in this storm? How strong was the wind? How much did it vary from one location to another? It may only be 10 miles away, but how much gradient in the wind was there? If you don't have that basic information, then you really can't go to the next step with any certainty. You can estimate, but now we're introducing uncertainty right at the start.”
Schroeder says what the TTUHRT does is fundamental to everything that comes after a hurricane because the group helps nail down what actually took place during the storm. He said that's imperative to know because it then advances the research.
“There are all sorts of unique research threads that come out of that for us, that we can pick on and move forward,” he said. “But, fundamentally, knowing what the heck happened during the storm is really important to moving any sort of research forward after the fact. Because if you don't have it, you're in the dark right from the start.”
Back in the late 1990s
When Schroeder developed his plans to build a wind-measuring platform to support his dissertation, he recruited civil engineering students for the project.
“The platform was built by me and several civil engineering undergraduates,” he said. “We got the tower from mechanical engineering. They were going to throw it out. And that was the start of it. But the entire thing was all built and integrated by students.
“We started building it in 1997 and finished in 1998 during the early part of the hurricane season, and then we deployed.”
Schroeder put his newly built tower to the test later that year at the Texas coastline for tropical storm Charley. Shortly after the team returned to Lubbock, they found themselves packing up for another storm.
“Immediately after tropical storm Charley, Hurricane Bonnie made landfall in North Carolina near Wilmington,” Schroeder said. “That was the first hurricane we deployed to.”
Hurricane Bonnie making landfall in Pender County, North Carolina in 1998.
(Courtesy: NOAA)
The now-retired platform created from scrap parts and with sweat equity worked like a charm. The 30-foot-tall tower took complex measurements – even more complex than the TTUHRT's current StickNet platforms.
“We used multiple levels of instrumentation on the tower, so we had more than one measurement height and could assess the vertical profile of the wind,” Schroeder said.
New chapter, new member
The original tower built by Schroeder and the civil engineering undergraduate students was retired in 2005, a year after Brian Hirth, a research professor at the NWI and the current leader of the TTUHRT, joined the team.
“I made the decision to attend graduate school at Texas Tech in part because I had a professor as an undergraduate who had completed her master's here, and she told me, ‘They do a lot of wind-related field work there and have a hurricane research program. You should go check it out,'” Hirth said. “I had a general interest in going into the field and making scientifically meaningful measurements, getting out of the office and getting my hands dirty. That was the reason I came here.”
Though he was interested, there was no guarantee Hirth could even be part of the TTUHRT.
“Within the first couple weeks of being at Texas Tech, I introduced myself to John,” Hirth said. “The team had already deployed to storms that summer, so there were some new students who were already ingrained into the team. John knew I wanted to be part of the team, so he said, ‘Well, just help us out doing things around here, testing instruments, preparing the systems for deployment and we'll see if we can get you involved,' and so I did. It didn't take long before my first opportunity to deploy came in 2004 for Hurricane Frances in Florida. After that hurricane season, John became my graduate adviser and I've been working with him ever since.”
With the original tower retired and Hirth on board, it was time to innovate the team's approach to taking wind measurements in the field. In 2005, the TTUHRT began using smaller, 7-foot-tall StickNet platforms. The StickNet project began in the summer of 2005 with the design of two prototype systems. The original design was developed entirely by graduate students during a summer field laboratory. The two completed prototypes were tested in the spring of 2006 and modifications were made to the original platform.
Construction was completed on the first 10 probes and the first transport trailer in time for the 2006 Atlantic hurricane season. The project was designed and implemented entirely by students from wind engineering and the atmospheric science group.
Now, the team has 48 StickNet platforms at their disposal, as well as two Ka-band Mobile Doppler Radar trucks.
“The StickNet fleet provides a rapidly deployable adaptable array of sensors, so we can move them around and place them wherever we want to and organize them however we want to,” Schroeder said. “With 48 StickNets, you have 48 places that you're taking measurements from. Wind and pressure are the two biggest things we measure, but wind trumps everything.”
Hirth says the StickNets basically form a scatter plot with a wind record at each point, spaced out across the hurricane landfall region. The Ka-band Mobile Doppler Radar trucks, however, provide a different perspective.
“With a radar, we're able to paint a spatially continuous picture of the wind,” he said. “From that, you can start to map the size and translation of things. Our interest is more in the turbulence features, the gusts and the lulls in the wind, how those are moving and evolving through an area. From an engineering perspective, you can have multiple points and records of the wind from a traditional wind sensor, but to be able to see the wind structure in multiple dimensions spatially and see the gust move and evolve and morph is really important and kind of next-generation for hurricane research and wind research in general.
“People have used anemometers or point measurements to measure the wind for decades. But now, using radar provides new ways to look at the wind and try to map these turbulence features and characterize them in a different way. The radars are located on the ground but they're scanning upward above the ground. So, you can acquire a map of the wind above the ground and then simultaneously you have these StickNet point measurements on the ground. Our active research is asking the question, how can you connect the dots between these two measurement techniques? If we can paint the wind but the measurements are from above where all of the built structures are, what can that tell us about what's occurring down below where the built structures are?”
Deploying to a storm
While people may evacuate an area about to be hit by a tropical storm or hurricane, the TTUHRT goes directly into the chaos. Every day during hurricane season, the group looks at global forecast models and assesses which storms show potential for deployment. A storm must meet certain conditions before the team decides to leave Lubbock.
“We're nowhere near the coast, so we have criteria as to what we consider deploying to,” Hirth said. “If there's going to be a hurricane in Texas that we can get to in time, we'll be there no matter what. For the rest of the Gulf Coast region, we typically will go if the storm is forecast to be a Category 2 hurricane. We consider deploying to the East Coast if it's a Category 3 or greater hurricane since that would be a two- to three-day drive just to get to the coast and the full deployment is a significant time commitment for the team. Within five days or so of landfall, we'll start assembling a team, get them notified and ready. Typically, we try to arrive at the landfall region between one to two days before landfall. If we go to the East Coast, we may leave three or four days before the storm is supposed to make landfall because it takes so long to get there.”
Once the team decides to deploy to a storm and arrives at its desired location, it begins to look at sites to set up the 48 StickNet platforms.
“We mostly use Google Earth and our database of locations we've deployed in the past to find deployment sites,” Hirth said. “When we're looking for sites, we're really looking for areas that are open, without a lot of obstructions. Our platforms are about 7 feet tall, so we don't want to deploy them right next to a tree or a house. We want to put them in open areas where we can properly characterize the wind conditions. We're looking for open farmland, or if we can get right up to the coast and stay out of the storm surge that's forecast for that storm, we'll go right on the beach on sand dunes that are tall enough, or try to find elevated areas.
“So, during our drive to the coast, we're looking for potential sites, and once we get there, we meet as a team and divide the landfall region into four deployment zones, assign each team their deployment zone, and they take the database of the sites that were scouted as we were making the trip and start to pick out which ones they want to use in their area.”
A typical deployment team consists of 8-10 people. It takes four trailers to carry all 48 StickNet platforms, and two to three people are assigned to each trailer. Once the StickNets are deployed, the team goes to a nearby hotel to wait out the storm. Afterward, it's time to collect their things and go home.
“Ideally, we want to get in and get out,” Hirth said. “We're there to take wind measurements and leave. Our team is not usually charged with surveying the detailed damage afterward. As soon as the strongest winds are gone, we'll head back out from the hotel to begin picking everything up – which takes about a day – and head back to Lubbock.”
Current Texas Tech graduate students Jacob Nadolsky, Natalie Trout and Matthew Asel are all pursuing their master's degrees in atmospheric science. This past season was Nadolsky's and Trout's first deployment when the team went to assess Category 4 Hurricane Ida.
“It's cool because you get to be in a hurricane, but it's also cool because you get to hang out with people who you normally just see in an office setting,” Nadolsky said. “It's very different. Obviously, field work is a different environment, a different space that you get to see people in, so there are trials and tribulations, for sure. But, at the end of the day, you get back to the hotel late and you think, ‘I did really good work today, and I'm proud of what we did.' So, it's a lot of fun.”
Trout said learning outside the classroom was a beneficial experience.
“You can sit at a computer for hours and look at data, but it's a whole other world when you actually get to put out all of the instrumentation, look back at a later time and say, ‘I deployed a StickNet that got a hit,'” she said.
Hurricane Ida was Asel's third deployment, but he echoed Nadolsky's and Trout's sentiments.
“You can learn so much more by going out into the field versus just reading books,” Asel said. “The trips are a bunch of fun. I enjoy going out into the hurricane winds to deploy StickNets out in the middle of nowhere. Most people think that's strange, but I actually get a rush out of it.”
Hurricane Katrina and the power of storm surge
When Schroeder and Hirth were asked which storm was the most intense the team has deployed to, the answer was immediate: Hurricane Katrina. While the damage in New Orleans has become synonymous with Hurricane Katrina, coastal Mississippi was ground zero for the storm surge.
“Storm surge is where the storm drags or pushes water from the ocean onshore with it,” Schroeder said. “You had the levee breaches in New Orleans that led to a catastrophe. In Mississippi, it was a storm surge-driven catastrophe. The storm surge brought water all the way to the parking lot of the hotel we were staying in. Houses on the other side of the highway across from our hotel had water up to the roofline. People had to be in their attics because there was no other place to go.
Courtesy: Library of Congress
“It wasn't the wind that drove the shock and awe; it was the storm surge. To see water come that far inland and to come that high up, and to see the impact of that across the street on a family, that's what drove home the severity of it.”
For reference, the hotel the TTUHRT was staying at in Gautier, Mississippi, had an elevation of roughly 18 feet and was about a mile inland from the Gulf of Mexico. The houses across the street from the hotel sat at an elevation of seven feet.
The night before Hurricane Katrina made landfall in Mississippi, the coastal areas of Mississippi were still bustling. The next day, only destruction remained – and that has stuck with Hirth ever since.
“We stocked up with some supplies at a Walmart down on the beach in Bay St. Louis, Mississippi, and there were people everywhere on their porches, hanging out,” Hirth said. “This was one of the first few storms I had ever deployed to, so I didn't have an appreciation for storm surge. I had never seen meaningful surge before, but the forecasts were pretty significant. We were wondering what all these people were still doing here. Then, the next day, when the storm finally made landfall, I'm sitting in the hotel thinking, ‘Where are all those people now? What happened to them?' And, in a lot of locations right on the coast, the answer wasn't good.
“I have so much more appreciation for storm surge now. I think it's far more dangerous than wind in a hurricane because of the magnitude of water and how quickly it comes. To see water where it shouldn't be is really crazy.”
The storm surge was so severe that the Walmart, houses and other establishments along the coastline were wiped clean, which is a testament to the power of storm surges, Schroeder said.
“Picture 50-60 miles of coastline, you go in 5-10 blocks and it's all gone,” Hirth said. “It was wiped off the map. It's just concrete slabs, and there's nothing left.”
A lasting impact
The TTUHRT has been going strong for more than two decades, which speaks to how valuable the team is to the atmospheric science community.
“I've been doing this for 23 years, and we've been funded for 23 years,” Schroeder said. “I think that speaks to the evolution of the program and our ability to always take steps forward. But, it also speaks to the quality of work we do; I don't think anyone else does it to the level we do. Even though we're from Lubbock and nowhere near the coastline, when it comes to hurricanes that make landfall, I think we do it better than anybody else.
“It doesn't show any signs of slowing down, either. In fact, it's accelerating. So, I don't think it's going to go away. People may change and evolve, and students will come in and students will graduate and go out there, but I think back to how many students have been out on these trips, how many have experienced these sorts of deployments and the logistics and seeing the destruction and so forth by being a part of the team and how that's impacted our science community. I think it's a pretty significant impact.”
One big takeaway from all the research the team has conducted is the behavior of the wind inside a hurricane.
“We've realized that in most situations within the hurricane vortex, the wind is pretty well behaved relative to what the previous expectations were from an engineering perspective,” Schroeder said. “There may be some small transient events that really change things. Those are really hard to capture because they're not very large, they move through the storm circulation, and they quickly evolve. They're there and then they're gone. Those are still hard to capture, even with our data sets.
“But, in general, I think the wind is relatively well behaved, at least compared to expectations, and that's especially true in the higher wind speed areas within the storm. So, weird things can happen, but statistically they're unlikely. And so, I think from that perspective, we've been able to show that the wind is relatively well behaved over and over again through an archive of data that's developed over the years.”
The future of TTUHRT
After founding and leading the TTUHRT for more than 20 years, Schroeder has stepped back a bit while Hirth takes on more responsibility.
“I'm just a team member at this point,” Schroeder said. “Brian's taking on a bigger role. I'm much busier than I used to be, but I still like to go out in the field. It's fun.”
While the TTUHRT could expand its fleet of StickNet platforms, Hirth said the team must figure out the cost and benefit.
“There's been outside interest, but for every new truck and trailer, it's two more people in the field, more time to maintain and fix things,” he said. “Forty-eight platforms have proven to be enough to adequately cover the landfall region. How much value does it add to have more? I think we're at a crossroads.”
Schroeder said the future is in radar.
“Even though they cost a whole lot more – $1.5 million compared to $10,000 for a StickNet – I think radar is really where the investment needs to be,” he said. “Whether that's taking our existing systems to the field at times, working with others who have radar or expanding our own radar capabilities with time, I think that's where we see the future – painting that picture and then relating it to the ground, as Brian said.
“That's where most of our research is driving toward now because, someday, radar could basically replace StickNets. Because if you can paint a picture and reliably tie it to the ground, now we don't need as many StickNets. That's kind of the future we predict.”
Reflecting
Even if the StickNets become obsolete and are replaced with radar in the next 5-10 years, the platforms are still responsible for helping build a renowned research team and collecting important data.
“I think back to 1998 when we had the tower and we were trying to provide one data point, and trying to get a better understanding of the wind field from an engineering perspective,” Schroeder said. “Now, we deploy 48 StickNets. The amount of knowledge that comes from that, to be able to define what happened with the wind, is orders of magnitude different than where we started. So, have we impacted things? Yeah, because now we have an archive of information that feeds into research efforts across the board. Without it, we're still looking at 1998. We're all in the dark.”
