Presence and potential impacts of meteoritic aerosol material in the stratosphere
Abstract:
Ralf Weigel, Stephan Borrmann, Johannes Schneider, Martin Schnaiter, Robert Wagner, John M. C. Plane, Alexander James, Konrad Kandler, Martin Ebert, Antonios Dragoneas, Sergej Molleker, Oliver Appel, Andreas Hünig.
The amount of cosmic dust particles that globally enters the Earth`s upper atmosphere is still highly uncertain. Estimates concerning the cosmic input vary by two orders of magnitude from about 3 to 300 tons/day [Plane, 2012]. Reasons for this uncertainty as well as the current knowledge concerning the occurrence, the chemical composition and the physical habit of Meteoric Smoke Particles (MSPs) is summarized in Kremser et al. 2016.
Most recent chemical analyses of airborne sampled aerosol particles in the arctic winter vortex stratosphere (Ebert et al. ACP 2016) and further airborne measurements in the lowermost stratosphere over Central Europe and over the Indian Subcontinent strongly indicate that MSPs are ubiquitously present within the stratosphere. These new findings by means of online laser ablation aerosol mass spectrometry were performed during three independent aircraft missions, over Central Europe at altitudes of up to 14 km and 20 km, respectively, and the measurements over the Indian Subcontinent reached up to 20 km.
Due to their ubiquitous presence the MSPs very likely play a significant role in the high altitude cloud formation (e.g. sub-visible cirrus) and heterogeneous chemistry by providing surfaces for condensation and chemical reactions. However, the abundance of MSPs within the winter vortex stratosphere over polar regions may particularly impact the formation of Polar Stratospheric Clouds (PSC) and, thus, the denitrification of the polar stratosphere.
We present most recent findings from airborne measurements in the stratosphere and will introduce envisaged laboratory studies to get further insights into the potential role of MSPs in the PSC formation.