Electrical structure of PMSE and NLC regions during the DROPPS program

The electrical structure of NLC/PMSE regions was investigated by different rocket-borne in situ probe techniques as part of the DROPPS program. Gerdie n condenser measurements of very small mobility values suggest concentratio ns of positively charged aerosols/dust comparable to the density of more mo bile positive ions at PMSE/NLC altitudes. Relative electron density values and associated large- and small-scale vertical structure measured by DC Lan gmuir probes revealed very deep (by a factor of 50) biteouts in PMSE/NLC re gions. These biteouts were seen during strong and weak NLC conditions when PMSEs were either present or absent.