Il 10 marzo 2016, ore 14:30, Aula Magna del Dipartimento di Fisica dell’Università di Genova si terrà un micro-workshop con due seminari consecutivi tenuti dai Prof. J. Chow e J. Watson del Desert Research Institute di Reno, Nevada.
I due oratori sono punto di riferimento della ricerca mondiale sugli aerosol atmosferici, i loro effetti su salute e clima, le tecniche per individuarne le sorgenti.
La loro presenza a Genova è un’occasione unica di conoscenza di un tema così complesso e controverso.

La partecipazione è gratuita ma è richiesta l’iscrizione scrivendo a prati@ge.infn.it
 

Light Absorbing Carbon from Combustion Sources and Its Effect on Health and Climate

Judith C. Chow (Judith.chow@dri.edu) and John G. Watson

Desert Research Institute, Nevada System of Higher Education, Reno, Nevada, USA

Most of the light absorbing material is the result of soot from incomplete combustion, often termed black carbon or soot.  Minerals in fugitive dust also have light absorbing properties, as do certain organic compounds formed from oxidation of directly emitted organic gases.  The smoldering phase of biomass burning produces smoke with a variety of colors, including browns, yellows, and chartreuses that are distinctive from the black carbon associated with the biomass flaming phase and engine exhaust. The absorbance spectra, ranging from the near-UV to the near-IR (λ= ~300 to ~1000 nm) of suspended particulate matter (PM) is indicative of the sources, chemical composition, and radiative balance influence of the aerosol.  Several instruments are now available to quantify absorption spectra at continuous and discrete wavelengths.  Multiwavelength measurements are being added to U.S. speciation monitoring networks owing to their value in identifying potential sources and determining adverse effects.

Receptor Model Source Apportionment for Air Quality Management

John G. Watson (john.watson@dri.edu) and Judith C. Chow Desert Research Institute, Nevada System of Higher Education, Reno, Nevada, USA

Receptor-oriented source apportionment models intend to identify and quantify contributions from different source types to pollutant concentrations measured at receptors.  Air quality managers should use receptor model results as part of a broader “weight of evidence” approach that challenges their accuracy in light of other information, such as that derived from applying multiple solution methods, evaluating performance measures, obtaining  more source-specific PM measurements, conducting detailed case studies, and reconciling with emission inventories and source-oriented models.  Modern air quality management also requires more specific source identification than “mobile sources,” “biomass burning,” “industry,”  “fugitive dust,” “sea salt,” and “secondary sulfates and nitrates,” which are often the categories indicated by a receptor model study.  As primary emissions decrease, the importance of secondary organic aerosol (SOA) increases. Refining source contributions is seldom possible when using only the mass, elements, water-soluble inorganic ions, and carbon fractions available from widely-used speciation networks More information can, and should, be obtained from existing compliance and speciation network samples that can address these challenges.