Arctic Research Soars to New Heights
Radiance Calmer holds the wide wings of a drone in place on its launcher, scanning the blue Boulder sky for potential obstacles. Behind her, Jonathan Hamilton stands with a controller in hand. Calmer counts down, “Three...two...one...zero!” and releases. The drone flies off the launcher, hovers just a few feet above the ground for a precarious moment, and then zooms into the clouds at 35 mph.
That February 2020 practice run was just one of two years’ worth of flight tests preparing for an Arctic mission that is pushing the limits in atmospheric research.
Calmer, a postdoctoral researcher with CIRES, and Hamilton, an aerospace engineering graduate student at the University of Colorado Boulder, leave in May for the MOSAiC expedition where they will pilot drones to collect atmospheric data over the frozen Arctic Ocean. The National Science Foundation-funded project, spanning several months, involves 20 drones outfitted for atmospheric science and marks the first time drones have been used to gather near-surface atmospheric readings so far north.
Gina Jozef, a Ph.D. candidate in CIRES and CU Boulder’s Atmospheric and Oceanic Sciences department, has been blogging her experience aboard the RV Polarstern. “Throughout the week, we did seven successful flights (and two unsuccessful flights), which is a record!” Jozef wrote in early April.
The drone project is largely the brainchild of Gijs de Boer, a CIRES scientist affiliated with NOAA's Physical Sciences Laboratory. De Boer’s journey to MOSAiC began in 2012, when he wrote a review paper on the importance of Arctic clouds in atmospheric processes. “I realized that we [didn’t] necessarily have the right observational tools to fully measure all the things that come together to support the lifecycle of these clouds,” de Boer said.
Together with CU Boulder’s Integrated Remote and In-Situ Sensing (IRISS) program, he began experimenting with unmanned aircraft as a way to collect missing pieces of atmospheric data not only in the Arctic but across the globe*. Drones could help close some knowledge gaps: for example, the lower atmosphere in remote Arctic regions where low-altitude flights on manned research aircraft are dangerous. Drones also allow for flexibility; a pilot can quickly direct an unmanned aircraft system (UAS) to interesting features in the landscape like cracks in the ice.
The drones on the German icebreaker RV Polarstern carry instruments to measure things like temperature, wind, humidity and solar intensity. Together, these measurements provide a profile de Boer hopes will help scientists and MOSAiC funders, including NSF and the Department of Energy's Atmospheric Radiation Measurement (ARM) user facility program, better understand how much energy is transported between ocean and atmosphere in the Arctic.
Calmer and Hamilton will be on MOSAiC’s “new leg 4,” with an adjusted timeline caused by the COVID-19 pandemic. From May to late August, the team will watch part of the Arctic atmosphere transition from spring to summer, as sea ice melts. Shifts in the Arctic melt season are a major climate change indicator, with temperatures rapidly rising over the north polar region and implications for warming around the rest of the planet.
Hamilton estimates that he’s spent at least 41 hours flying UAS, in Boulder and in Svalbard, Norway, where he and de Boer traveled in spring 2019 to put their systems through the paces in an environment that’s more similar to what they will face on MOSAiC.
Despite meticulous planning and testing, uncertainties remain. A lack of satellite imagery makes planning launching points difficult and ice ridges can complicate equipment placement. Jozef already found that batteries drain faster than expected, leading to some premature landings in risky locations on the ice.
Those uncertainties are part of pressing the boundaries on atmospheric research. “If we come back with all 20 drones I’m going to be a bit disappointed,” de Boer said. “It likely means we weren’t pushing our limits far enough or that outside factors prevented us from [more flights].”
*De Boer has also conducted drone research in slightly warmer places, like Barbados.