INSPYRE

INSPYRE is a multi-year field investigation that will use the NASA ER-2 and the NASA GV to constrain the role of pyroCbs in Earth's atmosphere and their relationship with intense wildfires. INSPYRE will be based in Great Falls, MT (ER-2), and Boulder, CO (GV), both which offer ideal locations for sampling pyroCbs in the stratosphere. Both aircrafts, along with a ground team, will carry an extensive suite of instruments to measure trace gases and aerosol properties and can operate at altitudes as high as 70,000 feet. Commercial airliners, by comparison, typically fly at around 35,000 feet.

Large and intense wildfires can generate powerful clouds called pyroCbs, which can carry massive amounts of smoke high into the atmosphere and, in some cases, directly into the stratosphere. INSPYRE studies how extreme wildfire behavior leads to pyroCb formation and how these clouds transport smoke into the upper troposphere and lower stratosphere. By combining aircraft, ground-based, satellite, and modeling observations, scientists hope to better understand how wildfire smoke affects atmospheric composition, radiation, and climate, while improving predictions of pyroCb development and extreme fire behavior.

The extreme heat from a wildfire causes hot air, smoke, and moisture to rapidly rise, forming a large thunderstorm that can transport smoke and pollutants high into the atmosphere. PyroCbs can also produce strong winds, turbulence, and lightning. Lightning generated by these storms can travel beyond the original fire and ignite new fires, creating a cycle in which one wildfire can contribute to the development of additional fires. The combination of intense heat, strong updrafts, lightning, and shifting winds can make pyroCb events especially difficult to predict and control, while also allowing large amounts of wildfire smoke and other emissions to be transported throughout the atmosphere.

The Harvard Team at INSPYRE flew the DCOTSS Portable Optical Particle Spectrometer paired with the Mini-MOUDI Cascade Impactor (DPOPS) on the NASA ER-2 to make size distribution measurements and collect particles for offline analysis. The POPS provides real-time, in-situ particle size distributions from roughly 0.14 to 3 μm in diameter at high time resolution, while the Mini-MOUDI collects size-resolved samples on impaction substrates for electron microscopy and compositional analysis. DPOPS, alongside additional ER-2 and GV measurements, can help narrow down questions about the impact of pyroCbs in the stratosphere and their relationship with wildfires.