Duster - in the Upper Stratosphere Tracking Experiment and Return: a Balloon Flight in Arctic Region
Palumbo, Pasquale ; Della Corte, Vincenzo ; Ciucci, Alessandra ; ...Ibba, Roberto
Jan - 2010

journal : 38th COSPAR Scientific Assembly. Held 18-15 July 2010, in Bremen, Germany
type: Article Journal

This self-contained instrument was designed to collect nanometer to micrometer scale solid and condensed-liquid aerosol particles in the upper stratosphere at about 40 km that operates in a stand-alone autonomous mode when carried aloft during long-duration stratospheric balloon flights. During its maiden flight as part of an Italian Space Agency campaign, DUSTER [0.4x0.4x0.3 m3 and weighing 30 kg] was launched from Longyearbyen (Svalbard, Norway) on June 2008. The autonomous instrument was in the stratosphere for 3.5 days, and collected aerosol particles at an average 37 ± 1 km altitude during a 55-hour period. With this first flight we have demonstrated that 1. The self-contained design of the instrument survives transportation and recovery, 2. The instrument performed within the design parameters of environmental specifications (-80° C; 3-10 mbar) and continuous autonomous operation in the sampling mode, 3. Inertial impact collection of aerosols ˜500nm to 150 microns on holey-carbon thin films mounted on Au mesh grids was achieved by continuous air flow through the chamber, 4. The dual-module design of an active collector exposed to the air flux was and a collector to monitor the pre-flight and flight environments within of the collector using an identical sample holder provided a `blank internal dust environment sample, 5. Save storage of collected samples, and subsequent retrieval in the laboratory, was achieved with no measurable contamination, 6. Reduced sample manipulation allowed the chemical and structural characterization of col-lected dust particles by Field-emission scanning electron microscopy and energy dispersive X-Ray analyses, and infrared and Raman micro-spectroscopy. The main and most ambitious goal is the collection and characterization of solid aerosol par-ticles less then 2 microns of solar system debris, or from the interstellar medium, that are currently not sampled on a routine basis. DUSTER will provide a time-stamped record of the amount of condensed and solid aerosols, their size, shapes and chemical properties in the upper stratosphere to be used assessing their role in atmospheric chemistry and radiation budget. The preliminary results show that ˜30\% of aerosols is in size range that is still poorly studied (0.5 -2 micron). The largest of small grains are a Na,Ca-rich silica shard and a F-bearing Ca-carbonate grain. The smallest grains are mostly carbonates and Al-rich with associated carbonaceous matter. The largest grains are Na and Ca (Na/Ca = 0.85/0.15 atomic) containing silica spheres that could be coal fly ash spheres or have a volcanic origin. DUSTERs maiden flight appears to have sampled terrestrial (natural and anthropogenic) dust. Most importantly it has shown the ability to collect dust for laboratory analyses.

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