Measurements of Stratospheric Aerosol to Altitudes above 35 km in Austral Autumn

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

Particles in the atmosphere play key roles in controlling the Earth's hydrologic, chemical, and radiation balances. In the troposphere aerosols provide surfaces for cloud formation, for the absorption of trace gas pollutants, and they either warm or cool the Earth depending on their optical properties. In the stratosphere they provide surfaces for the conversion of chlorine from a passive to an active state which will catalytically destroy ozone, crucial as a filter against damaging UV radiation. Stratospheric aerosols also contribute to increasing the solar albedo, and to the absorption of terrestrial infrared radiation. Particles are self-limiting through the formation of new particles, growth through diffusion, coagulation, condensation of trace gases, and ultimately sedimentation and deposition or capture by clouds. Recent developments extend the observational possibilities. These are i) year round (aircraft) access to McMurdo during austral autumn (April-June) and ii) development of smaller, lighter, inexpensive condensation nuclei counters (CNC) allowing (balloon borne) profiles to higher altitude(>35km). This new instrumentation can now be deployed in the fall, when chances of recovery are limited, and flown to altitudes above 35 km, necessary to measure meteoritic smoke particles. Providing additional quantification of the contribution of meteoritic smoke particles to stratospheric aerosol will improve the understanding of the stratospheric aerosol budget. There will be training opportunities in polar measurements for a post-doctoral scholar This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.