Between severe drought in California and unprecedented flash flooding in New York, 2021 has been a year for alarming weather patterns. And in Arizona, monsoon season was especially wet — and it’s set to only get worse in terms of impact to the environment and people in the coming years.
And while preventing flooding is a gargantuan task, predicting monsoons and preparing for their impacts is completely doable, thanks to drones. We’re in the midst of monsoon season right now, which typically runs from September to February.
Scientists at Embry-Riddle Aeronautical University are leveraging drone technology used in tandem with sonic anemometers to improve predictions of the North American monsoons. Despite how we know now versus even a few short decades ago, scientists still don’t know what triggers that very localized precipitation of what’s ultimately considered a monsoon. Research involving drones could change that.
A peek inside monsoon research using drones
As part of the research, drones are outfitted with meteorological instruments called anemometers that can detect and measure humidity, temperature, pressure, and wind speed as thunderstorms form. That helps research more effectively monitor the timing and location of convective cells which further helps scientists forecast flash floods and severe thunderstorm events that impact the region.
“This was a very complex operation involving four multi-rotor unmanned aircraft systems (UAS), a fixed-wing UAS, manned aircraft, along with multiple weather balloon launches and a sophisticated distributed ground sensor network,” said Dr. Kevin Adkins, Associate Professor in the College of Aviation, at Embry-Riddle Aeronautical University’s Daytona Beach Campus, who is one of the lead investigators conducting field campaigns in Arizona and New Mexico this year. “The unmanned aircraft allowed us to investigate the unique weather phenomenon present during the monsoon season at a finer spatial and temporal scale than had ever been done before.”
“We set up in areas of known hot spots for monsoon-associated convection and analyzed the role topography plays in that process,” Dr. Adkins said. “Specifically, what we were looking at is convective initiation with respect to the monsoon set up and how the topography of the area contributed to that. So, things such as flow channeling and how that may enhance and promote, or do the opposite for this type of convection.”
The project used all types of drones — and weather balloons too. Multi-rotor drones and weather balloons were used to deliver essential vertical wind and weather profiles. The drones were made with a VLOS airframe which held a TriSonica Mini Wind and Weather Sensor from Anemoment. The TriSonica Mini is an ultrasonic anemometer that captures the three-dimensions of the wind, along with temperature, pressure, humidity, and time. It’s much more compact and lightweight than most other low velocity anemometers (it weighs less than 50 grams and has a measurement path of just 35 mm), making it ideal for drones.
Meanwhile, fixed-wing unmanned aircraft (specifically, a Sentaero VLOS by Censys Technologies) was used to sample the lower portion of the boundary layer, a task that cannot be done safely with manned aircraft.
An improvement over past methods of monsoon research
Using drones for monsoon research is a potentially huge improvement over traditional monsoon forecast models. Drones can vapture detailed meteorological data from the lower atmosphere, an area that plays a critical role in the initiation of convective storms. Most computer models do not account very well for the complexities within the lower-atmosphere.
Additionally, researchers typically relied on fixed local weather stations. The challenge with immovable stations is that they might fail to capture the meteorological interactions that occur over complex terrain. But with drones, measurements can be captured horizontally and vertically. With denser and more frequent measurements, forecasts are more accurate.
All that together could have a helpful impact on what’s set to be a major climate challenge in the coming years. The 2021 North American monsoon through July was among the wettest on record for parts of Arizona, with some regions receiving more than 200% of the average rainfall, according to the National Oceanic and Atmospheric Administration. Tucson recorded its wettest month ever this July.
As far as next steps, the Embry-Riddle team will analyze, logging and validate their data, which they intend to present at the AGU Fall Meeting in New Orleans in December 2021.
“It’s very compelling research,” Adkins said. “Everyone wants to be a part of it.”