Even though 2013 was a quiet hurricane season, the Global Hawks did manage to obtain important data that will help researchers better understand rapid storm intensification, according to NASA.
The over-storm Global Hawk flew over Hurricane Ingrid on Sept. 15, 2013 according to NASA. The storm moved through the extreme southwestern Gulf of Mexico, traveling west-northwestward along Mexico's east coast. The plane's Hurricane Imaging Radiometer, HIRAD, measured energy coming from the rough ocean surface caused by rain and strong winds, enabling it to identify an area of heavy rain and likely strong winds on the storm's eastern side.
The environmental payload Global Hawk flew over the remnants of Tropical Storm Erin to capture data on the SAL in the Eastern Atlantic Ocean, obtained data from Tropical Storm Humberto, studied a storm that had a 70 percent chance to develop but never did, and analyzed the environment of Tropical Depression 7, which would become Tropical Storm Gabrielle.
The HS3 mission isn't the first time NASA used NovAtel's SPAN technology to obtain accurate navigation measurements. NASA first used SPAN during 2010 in an experiment known as GRIP-the Genesis and Rapid Intensification Processes. This six-week mission was conducted to help better understand how tropical storms form and develop into major hurricanes, according to NASA.
During this experiment, a Global Hawk gathered data from Hurricane Karl, a Category 3 hurricane that made landfall in Mexico, leaving nearly half a million people without power and 20,000 damaged or flooded homes. It also studied Hurricanes Earl and Matthew.
The HIRAD instrument on board the Global Hawk was able to measure strong ocean winds through heavy rain during Karl, providing both rain rate and wind speed. “We've learned that we've been able to derive winds within a storm,” Heymsfield says.
“We had 12 different passes over Hurricane Karl and we were able to put together an evolution and time sequence of pictures of the storm intensifying.”
Studying hurricanes and why they evolve is challenging. While researchers have made progress on accurately predicting the path of a storm, determining how intense the storm will be once it lands has proven more difficult.
The two Global Hawks that are part of the HS3 mission make it possible to study the processes that lead to intense, devastating hurricanes. These high-altitude Unmanned Aircraft Systems carry the equipment needed to study these storms and have the endurance necessary to travel to storms in the Atlantic, storms researchers couldn't study close up before.
When the HS3 team collects the last field measurements for the mission in 2014, that data, along with what they've already collected, will lead to a better understanding of what causes storms to grow stronger and how to forecast intense, potentially devastating hurricanes well before they make landfall. The high-altitude, long endurance Global Hawks give researchers the opportunity to gather a wealth of data that will help them better understand and predict how these storms evolve.
As a leader in precision GNSS technology to the unmanned industry, NovAtel's SPAN is well suited for a mission like HS3, providing researchers with the accurate navigational data they need to account for the plane's attitude and position.
“It's very important we have good navigation data measured close to our radar,” Heymsfield says. “We could do it other ways, but I think it [SPAN-SE] has been very good for us. It's been useful. It makes it easier to process the data and we understand the data better.”
And that data will help those in a hurricane's path better prepare for what's coming their way.