SEZIONE DI FIRENZE
ABSTRACT: This seminar focuses on the transatlantic transport of aerosols across the North Atlantic free troposphere, based on the long term records of aerosol chemical composition at Izaña Observatory, Tenerife, 2400 masl. Two air streams linked to the general circulation have been studied: the westerlies –typical of the mid latitudes- and the Saharan Air Layer –the conveyor belt exporting dust from North Africa to the Americas-. The record in the Saharan Air Layer allows studying: (i) the large scale meteorology that have influenced the inter-annual variability of dust during the last 3 decades (ending 1980 to mid 2010s), (ii) the origin of the pollutants mixed with dust and (iii) the sources contributing to organic aerosols. The record in the westerlies shows that there is an almost permanent corridor –North America to Europe- of (i) dust emitted in the Texas to Great Plains, (ii) organic aerosols in SE – US, (iii) sulphate from NE – US, and (iv) elemental carbon - soot in the large cities of NE – US and SE – Canada, whose export to the Atlantic is modulated by the seasonal variability of the general circulation. The overall results show that emissions standards and land use influence on the aerosol composition in the remote free troposphere, where impacts are modulated by meteorology and atmospheric processes. (Dr. Sergio Rodriguez)

DATA: 11-10-2018