Faculty, students to chase tornadoes again this spring

By Staff

University of Colorado at Boulder faculty and students will join a storm-chasing science team for the second year in a row across the nation's infamous "Tornado Alley" this spring in an effort to understand how and why tornadoes form and evolve in order to improve warning forecasts of the violent events.

The second Verification of the Origins of Rotation in Tornadoes Experiment, or VORTEX2, began May 1 and will continue through June 15. Now in its second and final season, VORTEX2 is the largest tornado field project in history and will involve more than 100 scientists and 40 support vehicles. The plan is to surround severe storms — including tornadoes — with the latest technology to learn more about their birth, duration and wind speeds and to assess death, injury and damage potential.

One of the CU-Boulder VORTEX2 projects involves placing laser instruments known as disdrometers in the paths of severe "supercell" storms capable of producing damaging winds, large hail and tornadoes in order to measure the size, velocity and reflectivity of individual precipitation particles. A second CU effort involves flying an unmanned aerial vehicle along the fringes of such storms to measure air pressure, temperature, humidity and wind velocities.

Led by CU-Boulder Assistant Professor Katja Friedrich of the atmospheric and oceanic sciences department, the disdrometer team will use three vehicles to travel from state to state in pursuit of severe storms. Based on weather forecasts, research vehicles will be dispatched every day to areas of forming severe storms in Colorado, Wyoming, Kansas, Nebraska, South Dakota, Oklahoma, the Texas Panhandle and western Iowa, Friedrich said.

Disdrometers, which are essentially high-tech rain gauges, consist of two mailbox-sized parts — a transmitter and a receiver — that are mounted about a foot apart and connected by a beam of laser light. Precipitation droplets that pass through the beam are measured and classified by size and velocity, Friedrich said. CU-Boulder disdrometers have been used in many experiments, including the 2009 VORTEX2 campaign and in an experiment measuring Hurricane Ike that made landfall in Galveston, Texas, in September 2008.

"The idea is to space these instruments in a line along the ground in the paths of oncoming storms," Friedrich said. "Our hope is to use the data to help better predict the duration, size, location and severity of storms, including tornadoes. Ultimately we would like to use data from VORTEX2 to improve tornado forecasting, reduce false warnings and decrease fatalities and property damage from severe weather events."

Friedrich and her team, which drove roughly 12,000 miles during the five-week 2009 VORTEX2 season, said the effort provides students with valuable, real-world experience. "This project gives them a chance to see how large science campaigns like these are planned and organized, including deploying and maintaining instruments," she said. "They see how challenging it can be to keep the instruments running in adverse conditions in order to make accurate and meaningful measurements."

While last year's CU-Boulder team had only two disdrometers, Friedrich's group will have eight this year, thanks to a $500,000 grant from the National Science Foundation. The NSF and the National Oceanic and Atmospheric Administration are spearheading the VORTEX2 campaign.

The eight students on Friedrich's team include CU-Boulder doctoral students Stephanie Higgins, Danielle Nuding, Evan Kalina and James Rudolph. Others include University of Florida doctoral student Carlos Lopez and undergraduate George Fernandez, National Center for Atmospheric Research scientist Scott Landolt, who will enter CU's atmospheric and oceanic sciences department as a doctoral student in the fall, and Metropolitan State University undergraduate Cameron Redwine.

CU-Boulder's Research and Engineering Center for Unmanned Vehicles also will participate in VORTEX2, flying an Unmanned Aircraft System, or UAS, during the campaign. According to team leader and aerospace engineering sciences Professor Brian Argrow. The propeller-driven aircraft — which weighs 12 pounds and has a 10-foot wingspan — has received approval from the Federal Aviation Administration to be deployed onto the edges of severe, supercell storms during the 2010 VORTEX2 season.

The UAS has FAA clearance to altitudes up to 1,000 feet and are projected for launch in eastern Colorado, Nebraska and Kansas. "The objective of the team is to develop and demonstrate an inexpensive, small UAS that combines meteorological radar data with the UAS command, communications and tracking data to safely navigate the unmanned aircraft below the clouds of developing supercell storms to collect meteorological data," Argrow said.

"While the engineering systems development is the primary focus of the current program, a secondary objective is to collect useful meteorological data that might address scientific questions and aid in the development of a more capable UAS," he said.

Argrow's team also includes CU-Boulder assistant professor Eric Frew, research assistant Thomas Aune and doctoral students Jack Elston, Maciej Stachura, Jason Roadman, Jason Durrie and Tony Carfang. The effort also includes collaborators from the University of Nebraska at Lincoln, the University of Oklahoma and Rasmussen Systems of Grand Junction.

Both CU-Boulder efforts are funded by NSF's Atmospheric Sciences Division. VORTEX2 is a $12 million program funded by the National Oceanic and Atmospheric Administration, NSF and a number of universities and nonprofit organizations.

CU-Boulder students participating in the disdrometer experiment will be posting daily blogs on the research effort at To learn more about CU-Boulder's UAS project, including a map of the operations area, visit

To learn more about the experiment visit the VORTEX2 site at and the official project website at