RAPID: PAEROS ChArMEx Mountain Experiment (PACMEx)

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

The Mediterranean Region has been identified as a hot-spot in future climate change projections, as expected changes in the hydrological cycle will affect the water resources for millions of people by the turn of the century. Model simulations suggest a significant decrease in the summer precipitation along with a rise in ambient temperature; in addition, a greater variability in precipitation will likely increase the intensity of flash floods, droughts, and heat waves. Until now, however, most models have not accounted for the impacts of aerosol in the Mediterranean Basin, whose major sources include Saharan dust, biomass burning and anthropogenic emissions. Recent airborne studies led by the PI indicate that aerosol sources from Europe and Africa are transported throughout the lower troposphere up to 6 km. Because of their complex vertical distribution, it is a challenge to capture the variability and quantify the contribution of these sources to the radiative budget (both direct and indirect effects). Under this RAPID award, a miniaturized aerosol package (PAEROS; Portable AERosol Observing System) will be deployed at a mountain site in Corsica for six weeks in June/July 2013 to complement other ground-based and airborne activities and measure aerosol physical and optical properties, Cloud Condensation Nuclei (CCN) spectra, radiative fluxes and meteorological parameters. Specifically, this project addresses the following science objectives:(i) Investigate the sources and sinks of aerosol over the Mediterranean Basin to identify the contribution of European emissions, Saharan dust and biomass burning above the boundary layer where much of the transport occurs; (ii) Enhance an observational network of airborne and other ground-based measurements (in the boundary layer) to characterize aerosol-cloud interactions and mixing between the free troposphere and boundary layer; (iii) Use hygroscopicity to study the evolution of aerosol during transport and quantify the characteristic time of the transformation; and (iv) Demonstrate the technical capability of PAEROS by operating the observing system at a remote mountain site with a solar panel array and wind power for an extended period. Improved understanding of the hydrological cycle has tremendous societal impacts. This project also fosters international collaboration between French and American research institutions through direct involvement of PhD students and post-docs.