Simulations of the collection of mesospheric dust particles with rocket instrument
Abstract. We investigate the collection of dust from the mesosphere with the MESS instrument that is designed to fly on a sounding rocket. The instrument consists of a collection device with an opening and closure mechanism and an attached conic funnel. Attaching the funnel increases the sampling area in comparison to the collection area. The instrument will collect primary particles that directly hit the collection area and secondary particles that form from mesospheric dust hitting the funnel. We simulate the entry and impact of dust onto the detector considering their trajectories in the airflow and the fragmentation at the funnel. We estimate the collection efficiency of the instrument and the impact energy of particles at the collecting area. The design considered has a sampling area of 5 cm diameter and a collection area of 1.8 cm diameter.
We use the results of the calculations to estimate the amount of dust that MESS (MEteoric Smoke Sampler) can collect during a rocket flight. We consider meteoric smoke particles (MSP) based on a model of the MSP distribution. In addition we assume that water ice particles that form close to the mesopause contain a fraction of smaller MSP. The water ice sublimates during the collection or later during rocket flight so that only refactory material remains. Assuming the collected particles contain 3 % volume fraction of MSP, we find that the instrument would collect of the order of 1014 to 1015 amu of refractory MSP particles. The estimate basis on the assumption that the ice components are melting and the flow conditions in the instruments are for typical atmospheric pressures at 85 km. Aside from the instrument conditions that we investigate in this paper, our estimate of the mass that we expect to collect with MESS applies the results from a particle transport model for the meteoric smoke particles and from the description of noctilucent cloud particles based on published model and observational results.
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