Multiple sounding rocket observations of charged dust in the polar winter mesosphere

Abstract

[1] We present data from a winter 2002 sounding rocket campaign for multiple observations of mesospheric charged dust. The campaign consisted of four identically instrumented payloads carrying detectors for charged mesospheric dust particles. The payloads reached an altitude of 100 km in the nighttime mesosphere and were flown from Poker Flat Research Range, Alaska, in conjunction with observations by the UAF sodium and iron resonance lidar system. Three of the four flights flew in sequence during the course of one night to study the temporal evolution of dust layers. Observations show good correlations between structure seen in the charged dust altitude profile, structure seen in the neutral metal layers observed by the lidars, and structure in the plasma density seen by the onboard Langmuir probes. The dust detector is sensitive to positively and negatively charged dust particles with ram energies of 1 to 11 eV for negatively and 3-11 eV for positively charged dust; that is, particles of approximately 5000 amu. The charged dust densities seen (estimated to be approximately 5 to 10 percent of the total dust density) are approximately 100 particles per cc, and the dust is negatively charged. Variations in the dust density of about 10% are seen in conjunction with structure in the plasma density and with the neutral metal layers. In this paper we present the details of the dust data and instrumentation; a companion paper explores the implications of the correlations seen between the dust and other mesospheric layers.

Distribution of meteoric smoke – sensitivity to microphysical properties and atmospheric conditions

“…As mentioned earlier the smallest particles do not ablate and the biggest impacts are very rare and the involved meteoroids do not fully ablate. Within the remaining size range of meteoroids the mass distribution peaks around 10 −5 g (Flynn, 2002) and as much as 80% of the incoming mass originates from meteoroids of sizes between 10 −7 g and 10 −3 g (von Zahn, 2005). Hence, for atmospheric studies, it is enough to consider this mass range.…”

“…The real temperature varies with season and latitude and reaches its extreme values at the poles with a summer-winter difference of nearly 100 K at the mesopause (e.g. Lübken and von Zahn, 1991). To study the effects of the background atmosphere we therefore used summer temperatures and densities taken from the CHEM2D model (Summers et al, 1997).…”

“…This lack of knowledge is mainly due to the complications involved in measurements at these altitudes where in situ studies only can be carried out using sounding rockets. Because of the difficulties in detecting neutral particles, measurements of nanometre-sized particles in the mesosphere are so far only 4416 L. Megner et al: Meteoric smoke particle distribution available for the charged fraction of the total particle population (Schulte and Arnold, 1992;Gelinas et al, 1998;Croskey et al, 2001;Lynch et al, 2005;Rapp et al, 2005).…”

Meteor smoke particle properties derived from Arecibo incoherent scatter radar observations

“…However, due to the above mentioned tiny dimensions, measurements of MSPs have been very difficult to obtain. Hence, until now only a few sounding rocket experiments have succeeded detecting heavy (i.e., much heavier than ordinary molecular and cluster ions) charged constituents in the D-region which were interpreted as charged MSPs [Gelinas et al, 1998;Kelley et al, 1998;Lynch et al, 2005;Rapp et al, 2005].…”

Technical Note: A novel rocket-based in situ collection technique for mesospheric and stratospheric aerosol particles

“…On the other hand, the microphysical properties of meteoric-smoke particles are still poorly understood. This lack of knowledge is due to the complications involved with in situ measurements at mesospheric altitudes that can only be reached by sounding rockets (Farlow et al, 1970;Havnes et al, 1996;Goldberg et al, 2001;Smiley et al, 2002;Rapp et al, 2005;Lynch et al, 2005;Hedin et al, 2007b). Furthermore, the detection of nanometre-sized particles is constrained by the shock wave in front of the rocket, which may prevent small particles from reaching the detector (Hedin et al, 2007a) and by contamination from the rocket itself.…”