HEMERA campaign concluded
Precise measurements of the atmosphere are indispensable for predictions of climate change and its consequences. A group of researchers from the Helmholtz Association in Jülich and Karlsruhe has therefore been carrying out unique experiments in August in Kiruna in northern Sweden. Two large balloon gondolas were prepared and launched as part of the EU Horizon 2020 HEMERA research infrastructure (https://www.hemera-h2020.eu/).
The first gondola contained instruments from Forschungszentrum Jülich as well as the Universities of Frankfurt, Groningen, and Reims. The Jülich instrument was a so-called “MegaAirCore”, through which 51 stratospheric air samples were successfully collected. These samples will travel back to Jülich to be analysed for a large suite of ozone-depleting substances and greenhouse gases with an ultra-sensitive mass spectrometer system.
The second gondola carried, alongside instruments by scientific partners, the GLORIA remote sensing instrument. GLORIA is the abbreviation for “Gimballed Limb Observer for Radiance Imaging of the Atmosphere.” It is an infrared camera, which can resolve the measured radiation into individual spectral colors. GLORIA registers numerous climate-relevant trace gases at an altitude of six to 36 kilometers: for example, carbon dioxide, methane, ozone and water vapor, as well as many nitrogen and chlorine compounds. During the flight, unique measurements were taken to better understand the bromine diurnal cycle, which is important for ozone destruction in the stratosphere. A second important objective was to examine the impact of emissions caused by raging wildfires in the northern hemisphere during summer. Once such plumes enter the stratosphere, they may have long-lasting impact on stratospheric chemistry and dynamics. A final objective was to better gain insight into some of the performance characteristics of GLORIA as part of a pre-study for the European Space Agency Earth Explore 11 candidate mission CAIRT. By measuring radiation emitted by the same airmass, which was sampled by a second balloon flying a smaller Air-core sampler, the capability to determine stratospheric transport times (i.e. the “age” of the air) with CAIRT was explored.
Both balloon gondolas were successfully started from the European Space and Sounding Rocket Range in Northern Sweden, which is operated by the Swedish Space Cooperation. After reaching an altitude of up to 36km, the first balloon was vented and separeted and the gondola floated back down again on a giant parachute. The second balloon stayed afloat for half a day before being dropped by parachute and recovered by helicopter from the Arctic tundra.
