Izvorni znanstveni članak
PM10 TRANSPORT AND DIFFUSION IN NORTHERN ITALY
A. Balanzino
; Dipartimento di Scienze e Tecnologie Avanzate (DISTA), Universita’ del Piemonte Orientale “A.Avogadro”, Alessandria, Italy
G. Pirovano
; CESI RICERCA, Milano, Italy
M.G. Riva
; CESI RICERCA, Milano, Italy
E. Ferrero
; Dipartimento di Scienze e Tecnologie Avanzate (DISTA), Universita’ del Piemonte Orientale “A.Avogadro”, Alessandria, Italy
M. Causa
; Dipartimento di Chimica, Universita' di Napoli “Federico II”, Napoli, Italy
Sažetak
A secondary pollution modelling system for simulating airborne dispersion and chemical reactions is tested over a
regional scale domain located in the North-West of Italy, covering areas characterized by different emission levels and where urban
and industrial areas are present. This region is often affected by severe pollution episodes, which are driven by anthropogenic
emissions and meteorological conditions. The domain is centred over a main plain area, surrounded by elevated Alpine mountains
and the sea. This valley is characterized by unfavourable meteorological conditions, such as weak circulation, frequent low wind
and stagnant conditions. Moreover the complexity of the orographic site affects both reconstruction of a proper emission picture and
meteorology, in particular at the domain borders where the Alpine mountains are located. The model resolution was 5 km and
simulations have been run for the whole year 1999. Emissions are derived from different inventories based on different territorial
units. The meteorological input was provided by the meteorological model RAMS, whereas the dispersion and chemical reactions
were computed by CAMx photochemical model. The results of the simulations are compared together with measured sulphur
dioxide, nitrogen dioxide and particulate matter data. Two winter periods were considered because of the PM accumulation
processes that take place during the cold season. The simulated PM concentrations are also compared with the results of the same
modelling system, applied over a larger scale and at lower (25 km) resolution. CAMx provided quite satisfactorily performances in
reproducing the seasonal evolution of PM10, particularly at 5 km resolution. Afterwards, model performances have been compared
against SO2 and NO2, two of the most important particulate matter precursors. As expected, the comparison shows a worsening in
the model performance moving from gas species to PM10, confirming that some processes related to particulate matter are still
missing in chemical transport models. Moreover, PM10 performances proved to be related more to NO2 than SO2. In fact, while the
former gives rise mainly to local scale production, sulfate formation is generally related to large-scale processes, hence less linked to
the precursor concentration at the receptor point.
Ključne riječi
atmospheric dispersion; secondary pollution; numerical modelling
Hrčak ID:
64293
URI
Datum izdavanja:
12.12.2008.
Posjeta: 1.014 *