To better understand both the causes of an electrical
storm’s fury and its effects on our home planet, NASA and
university research scientists will use a tool no
atmospheric scientist has ever used to study lightning — an
uninhabited aerial vehicle.

The research is part of the Altus Cumulus Electrification
Study (ACES), a collaboration among NASA’s Marshall Space
Flight Center, Huntsville, Ala.; the University of Alabama
at Huntsville; NASA’s Goddard Space Flight Center,
Greenbelt, Md.; Penn State University, University Park; and
General Atomics Aeronautical Systems, Inc., San Diego.

Based at the Naval Air Station Key West in Florida,
researchers in August will chase down thunderstorms using an
uninhabited aerial vehicle, or “UAV” — allowing them to
achieve dual goals of gathering weather data safely and
testing new aircraft technology. This is expected to mark
the first time a UAV is used to conduct lightning research.

“What we learn has the potential to help forecasters improve
weather prediction, especially for storms that may produce
severe weather,” said the study’s principal investigator,
Dr. Richard Blakeslee, a NASA atmospheric scientist at the
Global Hydrology and Climate Center in Huntsville. “Also, by
learning more about these individual storms, we hope to
better understand weather on a global scale.

“Using the aerial vehicle, we will make electric, magnetic
and optical measurements of the thunderstorms, gauging
elements such as lightning activity and the electrical
environment in and around the storms,” explained Blakeslee.
“At the same time, ground-based radar and satellite
observations will provide detailed information on the cloud
properties and storm severity.”

This ground- and satellite-based data will include details
on lightning flash rate, amount of precipitation and speed
of updraft — providing a comprehensive view of the storm
from the ground, as well as from the sky.

By learning more about individual storms, scientists hope to
better understand the global water and energy cycle as well
as climate variability. The study also will provide federal,
state and local governments with new disaster-management
information for use during severe storms, floods and
wildfires.

In the process, researchers will learn more about UAV
aircraft and how they can be used for future research
missions. “The UAV is an exciting new technology,” said
Blakeslee. “By getting this close to storms, we’re
demonstrating the promise of using uninhabited aerial
vehicles for meteorological applications.”

“The mission will utilize the Altus UAV — built by General
Atomics Aeronautical Systems — chosen for its slow flight
speed of 70 to 100 knots (80 to 115 mph), long endurance,
and high-altitude flight (up to 55,000 feet),” said ACES
project manager Tony Kim of Marshall Space Flight Center.
“The Altus boasts a wing span of 55 feet.” These qualities
give the Altus aircraft the ability to fly near
thunderstorms for long periods of time, allowing
investigations to be conducted over the entire life cycle of
storms.

The Altus overcomes the limitations of conventional aircraft
that, because of their greater speed, provide only brief
snapshots of storm activity sandwiched between long periods
of no observations.

As part of NASA’s Uninhabited Aerial Vehicle-based, science
demonstration program, these flights also will demonstrate
this aircraft’s ability to carry Earth-viewing scientific
payloads into environments where pilots would be exposed to
potentially life-threatening hazards.

“In the summer, Florida is the best location in the United
States to study thunderstorms because the large number of
storms that occur there should provide frequent
opportunities to observe them,” said Blakeslee.

The mission is part of NASA’s Earth Science Enterprise, a
long-term research effort designed to help us better
understand and protect our home planet, while inspiring the
next generation of explorers.