This article was updated on the 3rd September 2019.
Shutterstock.com / KAE CH
Drones are being used increasingly to gauge weather in real-time and in places not monitored in the past. This goes way past storm watching and can help in predicting severe weather and changes in the atmosphere in areas that ground-based equipment cannot reach.
While the U.S. National Weather Service sends many weather balloons each day into the sky to assess temperature and other aspects of weather, drones are useful for providing more real-time information in parts of the sky or in parts of the country (as in rural versus urban areas) that are not as well-monitored by other means.
These flights are not easy to carry out. Just under two decades ago, attempts made by scientists in Taiwan at its Central Weather Bureau tried to use aerial drones to track typhoons, but the system crashed.
Recently, NASA put probes called TAMDAR on commercial airlines to monitor weather. In 2017, a miniaturized, lightweight version of the probe was being used more routinely on NASA’s “Ikhana” remotely-piloted aircraft, and on the Iridium communications satellite network to provide real-time weather data.
Such data includes:
- Temperature, including humidity, moisture, and icing;
- Winds and turbulence;
- Altitude; and
- Pressure relative to GPS coordinates to pilots.
This information allows for the confirming, troubleshooting, and refining of weather forecasting models and for the improvement of flight safety.
Oregon State University environmental engineer Chad W. Higgins and colleagues have been looking at areas of the sky where weather is not often studied.
They have attached fiber-optic cables to drones to better monitor temperature closer to where people live, rather than where weather balloons monitor.
Through Raman spectroscopy, a spectroscopic technique that uses monochromatic light from a laser, the group achieved data resolution that is 10,000 times denser than has appeared before. Thus, air temperature recordings, occurring once every second, had a resolution of roughly 10 cm and 0.01 °C.
As the Oregon University team is focusing on temperature, the TAMDAR team is focusing on moisture, which is a measurement area that can often signal storms but is not always well-assessed by standard weather systems in aircraft. It is refining the TAMDAR probe to act as a heat detector for quantitative ice measurements, into classifications such as trace icing, moderate icing, or severe icing.
In 2010, the National Aeronautics and Space Administration (NASA) bought two Northrop Grumman Global Hawks from the U.S. Air Force, after which it oversaw flying the first high-altitude drone into a cyclone. In this situation, drones monitor the progression of storms, such as a tropical storm developing into a hurricane.
NASA is using data found through the probe and feeding it into another project that will help storm watching. The idea is that the TAMDAR-carrying Global Hawk would also carry re-usable gliders that are essentially radiosondes (an instrument that is carried to different atmospheric levels to transmit data via radio signals) that can be flown into storms.
There, they can assess storm features such as intensity and expanse to improve warning signals to aid better evacuation plans, and limit damage to properties, infrastructure, and reduce risk to life. Evacuations can also carry costs of $1 million for each mile of coastline, proving that drone use for storm analysis is an important intervention.