Comparison of continental Portugal and Azores Islands aerosol during a Sahara dust storm

Airborne particulate matter plays an important role in the Earth's energy balance. One of the main reasons is that the real size of a significant number of the particles, mainly those of anthropogenic origin, is similar to the wavelength of visible light. Knowledge of the composition of such particles, as well as their dynamics and trajectories in the atmosphere is therefore very important. In the period from 23 February to 22 March 2000, a movement of airborne particulate matter going over Europe and towards Azores was identified based on satellite observation. This work presents a preliminary study based on PIXE and nuclear micro-probe analysis of samples collected during that period both in Portugal mainland and in Terceira Island in the Azores. Time-shifted correlation of sample composition and individual particle composition are presented and discussed. Results point to the possibility of inferring long-range transport of aerosol particles from the samples multi-element analysis, and to the existence of fractions of the North Atlantic aerosol identical at both Portugal mainland and Terceira Island