Mesospheric charged dust layer: Implications for neutral chemistry

Abstract

The presence of a dust layer in the Earth's mesosphere is generally accepted on theoretical grounds (Hunten et al., 1980), but its experimental verification has been difficult and its influence on mesospheric dynamics and chemistry is not yet understood. Four sounding rockets carrying detectors designed to measure nanometer‐sized charged dust particles were flown from Poker Flat in March 2002. Ground‐based lidars were used to measure neutral sodium and iron densities during the launches in an effort to determine whether dust has an influence on mesospheric chemistry, specifically, as related to atomic Na and Fe. In situ measurements of charged dust and plasma densities were compared with the ground‐based lidar data. Strong correlations between the charged dust profile and the neutral Fe profile were observed on all four flights. This finding suggests that dust serves as a reservoir for atomic iron in the mesosphere.