Spacecraft Reentry: A Novel Source of Aerosol to the Stratosphere

DANIEL MURPHY, NOAA CSL

     Abstract Number: 475
     Working Group: Aerosol Processes and Properties in Changing Environments in the Anthropocene

Abstract
Measurements of aerosol particles in the stratosphere show that metals that were vaporized during the reentry of rocket boosters and satellites accumulate in the stratosphere. These metals are incorporated into natural sulfuric acid particles in the stratosphere. Over 20 elements from reentry were detected and were present in ratios consistent with alloys used in spacecraft. The mass of lithium, aluminum, copper, and lead from the reentry of spacecraft exceeds the cosmic dust influx of those metals. Remarkably, about 10% of stratospheric sulfuric acid particles larger than 120 nm in diameter contain aluminum and other elements from spacecraft reentry. With the rapidly increasing number of spacecraft reentry events, in the coming decades a majority of sulfuric acid particles in the stratosphere could contain novel metals from spacecraft in addition to the meteoric metals that are already present.

These metal-containing particles are found in the same air that contains the ozone layer. The addition of materials from spacecraft might affect heterogeneous chemistry in the ozone layer or change ice nucleation in polar stratospheric clouds.