This award is for post-doctoral research on sporadic micrometeor mass influx into the upper atmosphere. The study makes use of data from the Arecibo Radar in Puerto Rico and the European Incoherent Scatter (EISCAT) radar in Norway. The micrometeor velocities will be deduced from Doppler measurements made by the radars. The comparison between the Arecibo and EISCAT results will reveal summer and winter differences at the two locations. The differential in flux may play a major role in the formation of noctilucent clouds and related summer upper atmosphere phenomena that may be harbingers of global change. Meteoroid destruction mechanisms and deposition of meteoric mass will also be investigated. This is critical to elucidating the origins of metal layers above the meteor zone and the observed low atmospheric abundance of calcium relative to that expected from meteorite composition.
