Search for Extraterrestrial Origin of Atmospheric Trace Molecules — Radio Sub-MM Observations during the Leonids

To identify the effect of meteor showers on the molecular content of the upper atmosphere of the Earth, we have carried out ground-based observations of atmospheric HCN. HCN radio observations at CSO (Hawaii) on Nov 18/19, 1999, the night after the second Leonid shower maximum, show unusually low HCN abundances above 45 km altitude, which are only recovered after sunrise. We also investigated UARS/HALOE satellite data on H2_O and O_3. No correlation appears of year round H_2O and O_3 around 55 km with annual meteor showers, nor with meteor activity at the time of the 1998 Leonid shower