Nucleation and growth of new particles in Po Valley, Italy

Abstract

Abstract. Aerosol number distribution measurements are reported at San Pietro Capofiume (SPC) station (44°39' N, 11°37' E) for the time period 2002–2005. The station is located in Po Valley, the largest industrial, trading and agricultural area in Italy with a high population density. New particle formation was studied based on observations of the particle size distribution, meteorological and gas phase parameters. The nucleation events were classified according to the event clarity based on the particle number concentrations, and the particle formation and growth rates. Out of a total of 769 operational days from 2002 to 2005 clear events were detected on 36% of the days whilst 33% are clearly non-event days. The event frequency was high during spring and summer months with maximum values in May and July, whereas lower frequency was observed in winter and autumn months. The average particle formation and growth rates were estimated as ~6 cm−3 s−1 and ~7 nm h−1, respectively. Such high growth and formation rates are typical for polluted areas. Temperature, wind speed, solar radiation, SO2 and O3 concentrations were on average higher on nucleation days than on non-event days, whereas relative and absolute humidity and NO2 concentration were lower; however, seasonal differences were observed. Backtrajectory analysis suggests that during majority of nucleation event days, the air masses originate from northern to eastern directions. We also study previously developed nucleation event correlations with environmental variables and show that they predict Po Valley nucleation events with variable success.

Basic characteristics of atmospheric particles, trace gases and meteorology in a relatively clean Southern African Savannah environment

“…If we compare the observations with measurements carried out in other sites (see Kulmala et al, 2004, and references therein) as well as recent study from Po-valley, Italy (Hameed et al, 2007) we notice that the frequency of the new-particles formation events, as also the particle formation and growth rates, are among the highest observed in continental areas. Other important difference is the any lack of seasonal variability -clearly, we have enough nucleating and condensing vapors as well as solar radiation for nucleation to take place throughout the year.…”

Seasonal trends and spatial variations of PM10-bounded polycyclic aromatic hydrocarbons in Veneto Region, Northeast Italy

“…In this area, the high anthropogenic pressure combined with peculiar weather conditions favor pollutant accumulation and nucleation events (e.g. Hamed et al, 2007;Squizzato et al, 2013), which are mainly responsible for the highest levels observed for many atmospheric pollutants (EEA, 2013).…”

A procedure to assess local and long-range transport contributions to PM2.5 and secondary inorganic aerosol

“…The concentrations and formation mechanisms of PM 2.5 and SIA were already studied in some sites of Po Valley such as San Pietro Capofiume (Boulogne), Milan, Venice Lagoon (see e.g., Hamed et al, 2007;Sogacheva et al, 2007;Lonati et al, 2008;Prodi et al, 2009), but relatively scarce data are available for the Eastern part of the Po plain. In particular only few studies reported on air quality in the Venice-Mestre area (Rampazzo et al, 2008a(Rampazzo et al, , 2008bStortini et al, 2009;Masiol et al, 2010) and mainly discussed element characterization, source identification and apportionment.…”